animal
Animal (2016), 10:5, pp 868–877 © The Animal Consortium 2016 doi:10.1017/S1751731116000124
Questionnaire identifying management practices surrounding calving on spring-calving dairy farms and their associations with herd size and herd expansion C. Cummins1,2, D. P. Berry1, R. Sayers1, I. Lorenz2 and E. Kennedy1† 1 Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland; 2School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland
(Received 31 August 2015; Accepted 13 December 2015; First published online 9 February 2016)
Healthy calves are fundamental to any profitable dairy enterprise. Research to-date, has focused on year-round calving systems which experience many different challenges compared to spring-calving systems. The objective of the present study was to determine the on-farm dry cow, calving, and colostrum management practices of spring-calving dairy production systems, and quantify their associations with herd size and herd expansion status (i.e. expanding or not expanding). Information on these management practices was available from a survey of 262 Irish spring-calving dairy farmers, representative of the Irish national population. Herd expansion in the 2 years before, and the year that the survey was conducted was not associated with any of the management practices investigated. Fifty-three percent of respondents had an average calving season length of 10 to14 weeks with 35% of herds having a longer calving season. Previous research in cattle has documented that both colostrum source and feeding management are associated with the transmission of infectious disease from cow to calf. In the present study 60% of respondents fed calves colostrum from their own dam; however, 66% of those respondents allowed the calf to suckle the dam, 23% of survey respondents fed calves pooled colostrum. Larger herds were more likely ( P < 0.01) to use pooled colostrum supplies, while smaller herds were more likely ( P < 0.05) to allow the calf to suckle the dam. The majority (86%) of respondents had stored supplies of colostrum; average-sized herds had the greatest likelihood of storing colostrum ( P < 0.05), compared to other herd sizes; larger sized herds had a lesser likelihood ( P < 0.05) of storing colostrum in a freezer, compared to other herd sizes. Although freezing colostrum was the most common method used to store colostrum (54% of respondents), 17% of respondents stored colostrum at room temperature, 29% of which stored it at room temperature for greater than 4 days. The results from the present study indicate that a particular focus needs to be placed on calving and colostrum management because this study has highlighted a number of areas which are below international standards, and may have repercussions for calf health. Furthermore, management practices on larger farms could be improved and, as these represent the future of dairy farming, a focus needs to be placed on them. Expanding herds are not a particular concern as herd expansion, independent of herd size, does not seem to be associated with calving and colostrum management practices on Irish spring-calving dairy herds. Keywords: dry period, calving, colostrum, calves, dairy
Implications The results from the present study provide information on dry-cow, calving and colostrum management practices used in spring-calving systems. It highlights the management areas that are similar to and the areas that are different from yearround calving systems. Practices such as grouped calving pens and short term colostrum storage are more common in springcalving systems due to a large number of cows calving in a †
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short space of time. Results also show that calving management practices such as hygiene in the maternity pen and colostrum management practices, such as colostrum storage are suboptimal according to international standards. The results also provide direction for future research to focus on the specific challenges facing farmers in spring-calving systems. Introduction Calves are born agammaglobulinemic and thus are extremely susceptible to infectious diseases, particularly in the first
Calving management on spring-calving dairy farms hours of life (McGuirk and Collins, 2004). Consequently, it is essential to minimize the risk of disease to the newborn calf while maximizing development of immunity (Godden, 2008). Care of the calf begins before birth. Appropriate feeding of the dry cow (Mulligan and Doherty, 2008), calving facilities and calving management are all essential to optimizing the health of newborn calves (Gulliksen et al., 2009a). Over or underfeeding the dry cow influences her body condition score (BCS), changes in which may lead to a greater incidence of dystocia (Berry et al., 2007) thus appropriate nutrition of the dry cow is crucial. In addition to dry cow nutrition, monitoring of the cow around calving is important for successful healthy calf births (Lombard et al., 2007). Furthermore, management of hygiene in the calving area is attributable to the exposure of calves to pathogens and the associated impact on infection in the calf (Gulliksen et al., 2009a). To develop immunity against disease, calves must receive adequate volumes of good quality colostrum within the first 4 h of birth (Weaver et al., 2000; Godden, 2008). Colostrum is the first milk secreted after parturition and provides neonates with essential elements including immunoglobulins (Ig) and other nutrients (McGuirk and Collins, 2004). Colostrum quality is influenced by the cow directly, as well as on-farm management during collection, storage and feeding. Cows that produce greater milk volumes, as well as younger parity cows, tend to produce colostrum of reduced quality (Conneely et al., 2013). In terms of management, a delay in collection of colostrum from the cow, pooling of colostrum, general poor hygiene, as well as warm storage conditions can result in poorer quality colostrum (Stewart et al., 2005; Godden, 2008; Conneely et al., 2013). Additionally, colostrum feeding management protocols such as inadequate volume of colostrum fed to the neonate and delayed timing of the calf’s first feed can adversely affect calf immunity (Weaver et al., 2000; Beam et al., 2009; Conneely et al., 2014). In countries such as Ireland and New Zealand, where compact calving pasture-based systems of dairy production prevail, there is a knowledge gap as to current prevailing dry cow, calving and colostrum management practices. Moreover, herd size is expected to increase in Ireland over the coming years (O’Donnell et al., 2011) which will inevitably place increased strain on existing resources, increasing any calf health risks currently facing dairy farmers (Gulliksen et al., 2009a). The aim of the present study therefore was to determine the dry cow, calving and colostrum management practices on commercial spring-calving dairy farms, and quantify their associations with both herd size and recent herd expansion status. Identifying these management practices provide a focus for future research with the ultimate aim to improve dairy calf health. Material and methods
Sample selection Herds were selected from HerdPlus®, the Irish breeding information decision support tool for farmers (n = 7800) coordinated by the Irish Cattle Breeding Federation (ICBF).
From a national total of ~18 000 dairy herds, and an expected response rate of 50% to 60%, 320 herds were invited to participate in the present study. This was deemed necessary (CL, 95%; CI, 5.0%) to ensure sufficient observations to cover the estimation of the coefficients for each response. Herd selection was random, stratified by herd size (small ⩽ 65 cows, average ⩾ 65 and ⩽ 100 cows, large ⩾ 100 and ⩽ 150 cows, extra-large ⩾ 150 cows) and geographical location. Strata were chosen to provide data representative of the Irish national average.
Survey development A total of 104 questions relating to calf health and husbandry, were devised across three different management areas: 1. Cow management: pre-calving nutritional management; 2. Calving management: calving facilities and peri-parturient period management; 3. Colostrum management: colostrum collection, storage and feeding. Questions were designed based on a full review of peerreviewed international publications and on the knowledge of researchers based at Teagasc Moorepark Animal and Grassland Research and Innovation Centre, Co. Cork, Ireland. Questions were predominantly close-ended, to obtain concise information. Questions were structured to prevent ambiguity, while making it easy for the farmer to understand and complete. A copy of the original questions is available in Supplementary material S1. BCS was defined according to a 5-point scale where 1 = emaciated and 5 = extremely 5 (Edmonson et al., 1989).
Survey administration To determine feasibility and comprehensiveness of the survey, the questionnaire was piloted using 30 farmers. Appropriate alterations were made before sending survey packs to the remaining famers. Survey packs contained the questionnaire, a cover letter, a return-addressed envelope, and were mailed to each participating farmer between 11 July and 15 August 2013. A reminder SMS message was issued 4 weeks post-mailing, followed by a reminder telephone call 2 weeks later, to which ~25% (n = 70) of all respondents replied to. The cover letter outlined the purpose of the research, details of collaborating organizations, the time frame in which surveys were to be returned, and assurance that all surveys would be kept strictly confidential. Participation by farmers was completely voluntary and was not incentivized. Ancillary information In addition to the self-declared information collected from the questionnaire, data on a further 10 additional factors were obtained from the ICBF database for the years 2011, 2012 and 2013. These factors were considered for inclusion in the model of analysis as confounding variables. These included the total number of dairy cows on the farm for each of the 3 years, mean herd parity and average herd age 869
Cummins, Berry, Sayers, Lorenz and Kennedy Table 1 Summary of responses to each dry cow management survey question Variable Average length of dry period (N) 4 to 8 weeks 8 to 12 weeks 12 to 16 weeks Diet of dry cows (N) Grass silage only Grass silage + concentrate TMR Is straw fed to dry cows (B) No Yes Length of time cows receive pre-calving minerals (N) ⩽5 weeks pre-calving 6 to 8 weeks pre-calving >8 weeks pre-calving Type of pre-calving minerals (B) Powder Other Target BCS for cows at calving (N) 3.5
Total respondents (n)
Frequency (n)
Percent (%)
41 205 14
16 79 5
130 97 22
52 39 9
218 41
84 16
74 147 35
29 57 14
176 76
70 30
38 158 14
18 75 7
260
249
259
256
252
210
N = nominal response; B = binary; BCS = body condition score.
(recorded for each cow at calving), percentage of heifers in the lactating herd, length of calving season, mean annual herd milk production (calculated from individual cow milk recordings; liters), milk fat and protein (kg), herd somatic cell count (SCC), herd economic breeding index values (EBI), and the predominant breed of cow in the herd. Calving season length refers to duration (weeks) for which ⩾85% cows are calving between January and June (O’Doherty et al., 2013). The EBI value is a single figure profit index used to identify the most profitable bulls and cows for breeding dairy herd replacements (Berry et al., 2014). Nine herds were eliminated from the analyses as cow numbers and calving information were missing for either 1 or more years. Respondents did not answer every question in the survey and so the numbers of respondents with each variable differ.
Statistical determination of herd characteristics Linear robust regression was fit to annual herd size over 3 years (2011, 2012, 2013) using PROC ROBUSTREG (SAS, 2011), as described by Jago and Berry (2011). The resulting intercept and linear regression coefficient was used to stratify herds on size and whether or not they were expanding. Herds were classified into one of four groups based on number of cows estimated from the regression for the year 2012 as, small (⩽65 cows; n = 37), average (65 to 100 cows; n = 81), large (101 to 150 cows; n = 73), and extra-large (>150 cows; n = 71). If the linear regression coefficient was not different (P > 0.05) from zero, the herd was classified as not expanding (Jago and Berry, 2011). 870
Herds with a regression coefficient greater (P < 0.05) than zero were classified as expanding (Jago and Berry, 2011).
Statistical analysis Dependent variables of interest were classified as binary, ordinal or nominal (data in the Tables 1, 3, 4 and 6). If 150 cows (‘extra-large’ herds). Of all respondents, 20% were deemed as expanding, and this was not associated with any cow, calving or colostrum management practices investigated in the current study.
Dry cow management The majority of respondents (79%) imposed a dry period of 8 to 10 weeks and more than half of all respondents (i.e. 52%) fed only grass silage during this time (Table 1). Of respondents that fed minerals to cows during the dry period (>95% of respondents), 57% fed them for 6 to 8 weeks pre-calving. Powdered minerals were the most common form of minerals used (70% of respondents; Table 1). Compared to average-sized herds, small herds were almost twice as likely (P < 0.05) to feed minerals in bolus/lick form rather than powdered form (Table 2). Eighty percent of respondents in the present study reported setting a target herd average BCS for calving (Table 1); of these, 75% set a target calving BCS of between 3.0 and 3.5 (5-point scale: 1 = emaciated and 5 = extremely fat). Large herds were five times more likely (P < 0.05) to set a target BCS than average-sized herds. In contrast, the likelihood that extra-large and small herds set a target BCS for calving, compared to average-sized herds, was not different (Table 2). Calving management The majority of respondents (53%) had a 10 to 14 week calving season, while 35% had a longer season (Table 3). Shared pens were used for calving cows by 49% of respondents, while 14% used a combination of both shared and individual maternity pens; 37% of respondents used only
individual maternity pens (Table 3). Of all respondents, 41% transferred cows to a maternity pen >24 h pre-calving (i.e. before the appearance of the amniotic sac), while 46% moved cows into maternity pens ⩽ 24 h pre-calving. The remaining 14% of respondents moved cows either during calving, or when they had calved. The most common bedding (93% of respondents) used in calving pens was straw (Table 3). Of the 92% of respondents that cleaned calving pens, 56% cleaned calving pens at least once every 2 weeks, while 22% of respondents cleaned calving pens no more than once per month, or between seasons only (Table 3). Calving pens were cleaned out (i.e. bedding completely removed), washed and disinfected during each cleaning event by 37% of respondents, while 46% removed bedding and either washed or disinfected pens (Table 2). Thirty-three percent of respondents inspected cows for calving events at least once every 6 h during the day or night, while 24% of respondents inspected cows for calving events during the day only (Table 3). Small herds, were less likely (P < 0.05) to use video surveillance than average-sized herds, while large sized herds had a greater likelihood (P < 0.01) of using a video surveillance than average-sized herds (Table 2). Of the sample population in the present study, 39% of respondents waited no more than 2 h from the time a calving event commenced (Table 3). Of respondents that stated when a veterinary surgeon is called to a calving (n = 213), 40% wait until their own attempts at rectifying the difficult calving have failed (Table 3).
Colostrum selection, collection and storage Of respondents that collected colostrum from freshly calved cows (98%), 51% collected colostrum within 2 h of calving, and 49% collected colostrum between 5 h post-calving and the next milking (Table 4). No respondent in the present study had a standard colostrum collection time of 2 to 5 h post-calving. In the present study, 54% of all respondents used any colostrum to feed calves (i.e. did not screen
Table 2 Herd size odds ratios (95% confidence interval) with dry cow and calving management practices Survey question and variable contrast What type of pre-calving minerals are fed Other v. powder Other v. powder Other v. Powder Is a target BCS used for cows at calving Yes v. No Yes v. No Yes v. No Is video surveillance used for calving cows Yes v. No Yes v. No Yes v. No
Class contrast (herd size)
Odds ratio (95% CI)
Model1 P value
Small v. Avg Large v. Avg Extra-large v. Avg
1.89 (1.37, 2.48) 0.42 (0.11, 0.97) 0.86 (0.34, 1.30)
Herd size Expansion **
Small v. Avg Large v. Avg Extra-large v. Avg
0.51 (0.20, 1.28) 4.65 (1.54, 14.10) 0.56 (0.21, 1.40)
Herd size Expansion *
Small v. Avg Large v. Avg Extra-large v. Avg
0.32 (0.16, 0.99) 5.80 (1.92, 17.79) 0.38 (0.12, 1.13)
Herd size Expansion **
CI = confidence interval; Avg = average-sized herds (reference herd size); BCS = body condition score. 1 Independent variable(s) included in the final logistic regression model. *P < 0.05, **P < 0.01.
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Cummins, Berry, Sayers, Lorenz and Kennedy Table 3 Summary of responses to each calving management practice survey question Variable Average length of calving season (O) Up to 10 weeks 10 to 14 weeks 14 to 18 weeks >18 weeks Type of calving pens used (N) Shared Individual Both Length of time cows spend in calving pens pre-calving (O) >24 h pre-calving ⩽24 h pre-calving When calving/calved How are calving pens cleaned (N) Clean out only Clean out and wash or disinfect Clean out wash and disinfect Frequency of cleaning calving pens (O) Once every 2 weeks or more frequently Once a month or less frequently Between seasons only Frequency cows in calving pens are checked (O) Every 0 to 6 h during the day only Every 0 to 6 h during the day and late at night Every 0 to 6 h day and night Is video surveillance used for cows at calving (B) No Yes Length of time before assisting cows at calving (O) 4 h When is a vet called to a cow at calving (N) When assistance is tried and failed Mal presented/large calf/twisted womb Decide after assessment Severe cases/emergency/almost never
Total respondents (n)
Frequency (n)
Percent (%)
30 138 68 23
12 53 26 9
125 96 36
49 37 14
105 118 35
41 46 14
40 112 89
17 46 37
134 53 54
56 22 22
47 85 64
24 43 33
108 154
41 59
102 135 23
39 52 9
85 39 44 45
40 18 21 21
259
257
258
241
241
196
262
260
213
N = nominal response; O = ordinal; B = binary.
according to any criteria such as parity or disease status). The primary source of colostrum used by the majority of respondents (60%) was the calf’s own dam, while 23% pooled colostrum for feeding (Table 4). Compared to average-sized herds, small herds were more likely (P < 0.05) to use the calf’s own dam, rather than a single cow or pooled colostrum, while large and extra-large herds were less likely (P < 0.05) to use the calf’s own dam than average-sized herds. When choosing a cows’ colostrum to use other than the calf’s own dam, 54% of respondents used any cow (i.e. no selection criteria; Table 4). The number of respondents that answered the question regarding a substitute colostrum source included any respondents that used the calf’s own dam a single cow or pooled colostrum as their primary source, hence the number of responses to this question (n = 248) was greater than the number of respondents that used a source other than the 872
calf’s own dam (n = 195). When a substitute supply of colostrum was needed, 14% of respondents offered newborn calves transition milk, while 13% offered a neighboring farm’s supply or colostrum replacer (Table 4). The majority of respondents (73%) stored frozen colostrum to use as a substitute to the primary colostrum source (Table 5). Of these, extra-large herds were least likely (P < 0.01) to use frozen colostrum, compared to all other herds (Table 5). Additionally, of respondents that stored colostrum 17% stored it at room temperature and 4% used a refrigerator, rather than freezing it (Table 4). More than half of respondents stored colostrum in a refrigerator for >48 h, while 29% stored colostrum at room temperature for up to 1 week (Table 4). Sixty-five percent of respondents reported that paratuberculosis disease was tested for in milk, feces, blood, or a combination of methods. Of the respondents who tested for this disease, large and extra-large herds were more likely
Calving management on spring-calving dairy farms Table 4 Summary of responses to colostrum collection & storage practice questions Variable Time after calving when colostrum is collected (O) Within 2 h 5 h to next milking At next milking Source of first feed colostrum (N) Calf’s own dam Colostrum from single cow Pooled colostrum Source used if dam is not used/available (B) Any cow Other (mature/healthy cows) Other colostrum source (N) Own frozen supply Transition milk Other Has paratuberculosis been diagnosed (B) No Yes How soon is colostrum stored after collection (B) Within 2 h ⩾5 h How is colostrum stored Refrigerator Freezer only Room temperature Combination of methods How long is colostrum stored in the refrigerator (B) 48 h How long is colostrum stored in the freezer (O) ⩽6 months 12 months Any length How long is colostrum stored at room temp (O) ⩽24 h 48 to 72 h 4 to 7 days How is colostrum defrosted (B) Immerse in warm water Other
Total respondents (n)
Frequency (n)
Percent (%)
130 28 96
51 22 39
156 43 61
60 17 23
106 89
54 46
180 35 33
73 14 13
72 90
44 56
31 192
14 86
4 123 39 62
2 54 17 27
12 14
46 54
75 63 22
47 39 14
27 30 23
34 38 29
141 79
64 36
254
260
195
248
162
223
228
26
160
80
220
N = nominal response; O = ordinal; B = binary.
(P = 0.05) to have a positive diagnosis, compared to average-sized herds (Table 5). Additionally, compared to respondents that cleaned calving pens, respondents that did not clean calving pens were 16 times more likely (P < 0.01) to diagnose paratuberculosis. Moreover, paratuberculosis was more likely to be diagnosed in herds with longer calving seasons (P < 0.05; Table 5).
Colostrum feeding The majority of respondents (i.e. 84%) ensured calves were fed colostrum (artificially or suckling the dam) within 3 h of birth (Table 6). Colostrum was fed via bottle or bucket and teat by 49% of respondents, while 40% allowed the calf to suckle the dam (Table 6). Compared to average-sized herds,
large herds were more likely (P < 0.05) to use an artificial feeding method (i.e. bottle or stomach tube) rather than allowing the calf suckle the dam (Table 5). Of respondents that artificially fed calves (n = 152), 5% fed 3 l Length of time fed transition milk (B) 1 to 3 days >3 days
Frequency (n)
Percent (%)
93 127 30 12
36 48 11 5
105 127 28
40 49 11
105 122 30
41 47 12
164 86
66 34
262
260
257
250
N = nominal response; O = ordinal; B = binary.
Furthermore, as calf health diseases were recently deemed as an animal health priority (More et al., 2010) it may have provided farmers with an additional incentive to participate in the survey. Alternatively, it may simply be due to the number of reminders the respondents received to complete the survey. There are no documented reasons for farmers 874
opting out of responding to the survey and thus the response may be a random occurrence. The average size of herds in the present study (131 cows) was larger than the Irish national average, reported as 66 cows in 2013 (Teagasc, 2013). As expansion was not associated with management practices in the present study, it is deemed that the process
Calving management on spring-calving dairy farms
Dry cow management Accumulation of IgG in colostrum begins 5 weeks before parturition (Godden, 2008). Thus the 16% of respondents that provide a short non-lactating period may have compromised colostrum quality (Rastani et al., 2005), and less time to increase cow BCS reserves. Extra-large farms were less likely to use a target BCS, possibly due to the increased time resources required to individually assess each cow. The greater likelihood of larger herds offering dry cows powdered minerals may be due to the convenience of incorporation into the dry cow diet compared to bolus minerals, which require individual cow administration.
can be exposed to a greater bacterial load compared to pens that are cleaned out and washed or disinfected (46% of respondents), or cleaned out, washed and disinfected (34% of respondents). In the present study, respondents may be exposing themselves to increased risk of stillbirths and deaths in the 1st week of life (Wells et al., 1996; Gulliksen et al., 2009a) as 24% of respondents only inspected cows for calving events during the day. The use of video surveillance (59% of respondents), is an additional support that allows the farmer to view the cows without visiting the maternity house. Extra-large herds are likely to have more cows calving in a short space of time and thus rather than installing a video surveillance system, the farmer may have continuously observed the cows. Furthermore, as these larger farms have many more cows than small farms, more staff may be involved in monitoring cows when calving, but unfortunately this data was not attained in the present survey.
Calving management The use of shared maternity pens by 63% of respondents in the present study, is a management strategy which was previously been reported to increase the risk of the spread of infectious disease to the calf, compared to individual maternity pens (37% of respondents; Sweeney et al., 2012). According to previous research, respondents that provided individual pens for cows at calving, are not only more likely to have a reduced risk of spreading infection (Sweeney et al., 2012), but are also minimizing the risk of stress to the cow (Vasseur et al., 2010), which has been reportedly associated with a reduced risk of prolonged parturition and weaker calves at birth (Gulliksen et al., 2009a). The timing of transferring cows to a calving pen pre-calving is a component of stress management for the periparturient cow; according to previous research the 87% of respondents that transfer cows >24 h before calving are minimizing stress on the cow (Bao and Giller, 1991). The opposite can be said for the 14% of respondents that transferred cows to a calving pen once calving had commenced. This is particularly true for nervous cows and heifers (Mee, 2008). Moving cows when they had already calved has been reported to increase the risk that the calf will contract infection (Gulliksen et al., 2009a; Sweeney et al., 2012) as stress can increase the shedding of diseases that may be present such as Infectious Bovine Rhinotracheitis. The most common bedding type, that is straw, used in the present study is a good insulator, but if not cleaned regularly it can quickly become damp and dirty, thus having unfavorable consequences for animal health (Tuyttens, 2005). Frequent cleaning of maternity pens reduces pathogen buildup and calf exposure to infectious disease (Gulliksen et al., 2009b); but 22% of respondents in the present study cleaned maternity pens no more than once per month, or only between seasons. The method of cleaning may also affect calf health. If maternity pens are not washed or disinfected during cleaning (17% of respondents did not), the pathogenic load can accumulate and persist and the neonate
Colostrum selection, collection and storage A key factor to ensure calves absorb maximum IgG levels from colostrum in the first hours after birth, is the source of colostrum (e.g. calf’s own dam) (McGuirk and Collins, 2004). When selecting colostrum from a single cow, that is not the calf’s own dam, 22% of respondents selected a cow deemed to be healthy (i.e. free from paratuberculosis, mastitis or any clinical illness present at calving) which is important to minimize transmission of disease to the calf (McGuirk and Collins, 2004). Feeding pooled colostrum (more likely on larger farms in the present study) is convenient, particularly in spring-calving systems when collecting colostrum from many different cows at the same time, but increases the risk of spreading diseases such as paratuberculosis throughout the herd (McGuirk and Collins, 2004). As larger herds are less likely to feed colostrum from the calf’s own dam, the risk of spreading disease throughout the herd is greater. Calves and young stock are most susceptible to paratuberculosis (Sweeney et al., 2012). More than 20% of Irish herds have diagnosed at least one positive paratuberculosis animal in their herd (Good et al., 2009); however 35% of respondents in the present study had never tested for the disease. The greater likelihood of the disease being diagnosed in larger herds agrees with previous research (Kennedy et al., 2014). It is evident in the present study that good hygiene is essential to minimize accumulation and spreading throughout the herd as failure to clean out maternity pens was associated with a positive diagnosis of the disease (Gulliksen et al., 2009a). Some substitute colostrum sources identified in the present study should never be used on a dairy farm; these include transition milk (used by 14% of respondents) as it does not contain adequate IgG to ensure adequate passive transfer of immunoglobulins, and a neighboring farms supply as this is a biosecurity hazard (McGuirk and Collins, 2004), Although colostrum replacer (13% of all respondents), is a more favorable alternative than those previously mentioned, it is lower in quality than maternal colostrum and will not
of herd expansion is not expected to result in compromised herd management. This is similar to the findings of Jago and Berry (2011), who investigated the association between dairy herd expansion and reproduction, and calving performance (i.e. age at first calving, calving interval, dystocia).
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Cummins, Berry, Sayers, Lorenz and Kennedy contain any specific immune factors cows develop from the environment (Godden, 2008). Keeping stored supplies is a good alternative; early storage of colostrum post-collection (86% of respondents) minimizes bacterial growth, which is thought to affect the rate of passive transfer in the calf (James et al., 1981; Godden, 2008). For the same reason, the duration of colostrum storage is also important when storing colostrum above 0°C, particularly at room temperature (17% of respondents), or in a refrigerator (4% of respondents) as longer storage durations result in significantly altered bacteria and pH levels (Stewart et al., 2005).
majority of respondents fed calves within 3 h of birth, feeding practices that influence neonatal calf immunity such as the quality and volume of colostrum fed should be improved; most herds did not test colostrum for quality and 41% did not know the volume of colostrum consumed. Additional management practices identified in the current study such as storing colostrum at room temperature for >48 h may contribute to the failure of passive transfer occurring in Irish dairy calves due to bacterial growth, but further studies should be conducted to identify best colostrum storage practices.
Colostrum feeding Failure of passive transfer is a prominent issue in calves, and was reported in almost 60% of serum samples from sick or dead calves that were submitted to Irish regional veterinary laboratories in 2013 (Anonymous, 2014). The 40% of respondents that allowed the calf to suckle the dam, were creating an environment that increased exposure of pathogens to the calf due to direct contact with the dam (Sweeney et al., 2012). Furthermore, the volume of colostrum consumed is immeasurable when the calf suckles the dam and dairy calves typically do not voluntarily consume sufficient volumes of colostrum to ensure adequate IgG absorption (Brignole and Stott, 1980; Besser et al., 1991). The likelihood that larger herds used an artificial colostrum feeding method, compared to average-sized herds, may be due to space limitations, which is of particular importance when the calving season is compact. Larger herds have more cows calving in a short space of time and may require the calving pens for other calving cows more quickly than smaller sized herds. To estimate the likelihood of sufficient absorption of IgG, it is essential to know the volume of colostrum ingested by the calf. The volume of colostrum fed to calves by 42% of respondents (
Animal (2016), 10:5, pp 868–877 © The Animal Consortium 2016 doi:10.1017/S1751731116000124
Questionnaire identifying management practices surrounding calving on spring-calving dairy farms and their associations with herd size and herd expansion C. Cummins1,2, D. P. Berry1, R. Sayers1, I. Lorenz2 and E. Kennedy1† 1 Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland; 2School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland
(Received 31 August 2015; Accepted 13 December 2015; First published online 9 February 2016)
Healthy calves are fundamental to any profitable dairy enterprise. Research to-date, has focused on year-round calving systems which experience many different challenges compared to spring-calving systems. The objective of the present study was to determine the on-farm dry cow, calving, and colostrum management practices of spring-calving dairy production systems, and quantify their associations with herd size and herd expansion status (i.e. expanding or not expanding). Information on these management practices was available from a survey of 262 Irish spring-calving dairy farmers, representative of the Irish national population. Herd expansion in the 2 years before, and the year that the survey was conducted was not associated with any of the management practices investigated. Fifty-three percent of respondents had an average calving season length of 10 to14 weeks with 35% of herds having a longer calving season. Previous research in cattle has documented that both colostrum source and feeding management are associated with the transmission of infectious disease from cow to calf. In the present study 60% of respondents fed calves colostrum from their own dam; however, 66% of those respondents allowed the calf to suckle the dam, 23% of survey respondents fed calves pooled colostrum. Larger herds were more likely ( P < 0.01) to use pooled colostrum supplies, while smaller herds were more likely ( P < 0.05) to allow the calf to suckle the dam. The majority (86%) of respondents had stored supplies of colostrum; average-sized herds had the greatest likelihood of storing colostrum ( P < 0.05), compared to other herd sizes; larger sized herds had a lesser likelihood ( P < 0.05) of storing colostrum in a freezer, compared to other herd sizes. Although freezing colostrum was the most common method used to store colostrum (54% of respondents), 17% of respondents stored colostrum at room temperature, 29% of which stored it at room temperature for greater than 4 days. The results from the present study indicate that a particular focus needs to be placed on calving and colostrum management because this study has highlighted a number of areas which are below international standards, and may have repercussions for calf health. Furthermore, management practices on larger farms could be improved and, as these represent the future of dairy farming, a focus needs to be placed on them. Expanding herds are not a particular concern as herd expansion, independent of herd size, does not seem to be associated with calving and colostrum management practices on Irish spring-calving dairy herds. Keywords: dry period, calving, colostrum, calves, dairy
Implications The results from the present study provide information on dry-cow, calving and colostrum management practices used in spring-calving systems. It highlights the management areas that are similar to and the areas that are different from yearround calving systems. Practices such as grouped calving pens and short term colostrum storage are more common in springcalving systems due to a large number of cows calving in a †
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short space of time. Results also show that calving management practices such as hygiene in the maternity pen and colostrum management practices, such as colostrum storage are suboptimal according to international standards. The results also provide direction for future research to focus on the specific challenges facing farmers in spring-calving systems. Introduction Calves are born agammaglobulinemic and thus are extremely susceptible to infectious diseases, particularly in the first
Calving management on spring-calving dairy farms hours of life (McGuirk and Collins, 2004). Consequently, it is essential to minimize the risk of disease to the newborn calf while maximizing development of immunity (Godden, 2008). Care of the calf begins before birth. Appropriate feeding of the dry cow (Mulligan and Doherty, 2008), calving facilities and calving management are all essential to optimizing the health of newborn calves (Gulliksen et al., 2009a). Over or underfeeding the dry cow influences her body condition score (BCS), changes in which may lead to a greater incidence of dystocia (Berry et al., 2007) thus appropriate nutrition of the dry cow is crucial. In addition to dry cow nutrition, monitoring of the cow around calving is important for successful healthy calf births (Lombard et al., 2007). Furthermore, management of hygiene in the calving area is attributable to the exposure of calves to pathogens and the associated impact on infection in the calf (Gulliksen et al., 2009a). To develop immunity against disease, calves must receive adequate volumes of good quality colostrum within the first 4 h of birth (Weaver et al., 2000; Godden, 2008). Colostrum is the first milk secreted after parturition and provides neonates with essential elements including immunoglobulins (Ig) and other nutrients (McGuirk and Collins, 2004). Colostrum quality is influenced by the cow directly, as well as on-farm management during collection, storage and feeding. Cows that produce greater milk volumes, as well as younger parity cows, tend to produce colostrum of reduced quality (Conneely et al., 2013). In terms of management, a delay in collection of colostrum from the cow, pooling of colostrum, general poor hygiene, as well as warm storage conditions can result in poorer quality colostrum (Stewart et al., 2005; Godden, 2008; Conneely et al., 2013). Additionally, colostrum feeding management protocols such as inadequate volume of colostrum fed to the neonate and delayed timing of the calf’s first feed can adversely affect calf immunity (Weaver et al., 2000; Beam et al., 2009; Conneely et al., 2014). In countries such as Ireland and New Zealand, where compact calving pasture-based systems of dairy production prevail, there is a knowledge gap as to current prevailing dry cow, calving and colostrum management practices. Moreover, herd size is expected to increase in Ireland over the coming years (O’Donnell et al., 2011) which will inevitably place increased strain on existing resources, increasing any calf health risks currently facing dairy farmers (Gulliksen et al., 2009a). The aim of the present study therefore was to determine the dry cow, calving and colostrum management practices on commercial spring-calving dairy farms, and quantify their associations with both herd size and recent herd expansion status. Identifying these management practices provide a focus for future research with the ultimate aim to improve dairy calf health. Material and methods
Sample selection Herds were selected from HerdPlus®, the Irish breeding information decision support tool for farmers (n = 7800) coordinated by the Irish Cattle Breeding Federation (ICBF).
From a national total of ~18 000 dairy herds, and an expected response rate of 50% to 60%, 320 herds were invited to participate in the present study. This was deemed necessary (CL, 95%; CI, 5.0%) to ensure sufficient observations to cover the estimation of the coefficients for each response. Herd selection was random, stratified by herd size (small ⩽ 65 cows, average ⩾ 65 and ⩽ 100 cows, large ⩾ 100 and ⩽ 150 cows, extra-large ⩾ 150 cows) and geographical location. Strata were chosen to provide data representative of the Irish national average.
Survey development A total of 104 questions relating to calf health and husbandry, were devised across three different management areas: 1. Cow management: pre-calving nutritional management; 2. Calving management: calving facilities and peri-parturient period management; 3. Colostrum management: colostrum collection, storage and feeding. Questions were designed based on a full review of peerreviewed international publications and on the knowledge of researchers based at Teagasc Moorepark Animal and Grassland Research and Innovation Centre, Co. Cork, Ireland. Questions were predominantly close-ended, to obtain concise information. Questions were structured to prevent ambiguity, while making it easy for the farmer to understand and complete. A copy of the original questions is available in Supplementary material S1. BCS was defined according to a 5-point scale where 1 = emaciated and 5 = extremely 5 (Edmonson et al., 1989).
Survey administration To determine feasibility and comprehensiveness of the survey, the questionnaire was piloted using 30 farmers. Appropriate alterations were made before sending survey packs to the remaining famers. Survey packs contained the questionnaire, a cover letter, a return-addressed envelope, and were mailed to each participating farmer between 11 July and 15 August 2013. A reminder SMS message was issued 4 weeks post-mailing, followed by a reminder telephone call 2 weeks later, to which ~25% (n = 70) of all respondents replied to. The cover letter outlined the purpose of the research, details of collaborating organizations, the time frame in which surveys were to be returned, and assurance that all surveys would be kept strictly confidential. Participation by farmers was completely voluntary and was not incentivized. Ancillary information In addition to the self-declared information collected from the questionnaire, data on a further 10 additional factors were obtained from the ICBF database for the years 2011, 2012 and 2013. These factors were considered for inclusion in the model of analysis as confounding variables. These included the total number of dairy cows on the farm for each of the 3 years, mean herd parity and average herd age 869
Cummins, Berry, Sayers, Lorenz and Kennedy Table 1 Summary of responses to each dry cow management survey question Variable Average length of dry period (N) 4 to 8 weeks 8 to 12 weeks 12 to 16 weeks Diet of dry cows (N) Grass silage only Grass silage + concentrate TMR Is straw fed to dry cows (B) No Yes Length of time cows receive pre-calving minerals (N) ⩽5 weeks pre-calving 6 to 8 weeks pre-calving >8 weeks pre-calving Type of pre-calving minerals (B) Powder Other Target BCS for cows at calving (N) 3.5
Total respondents (n)
Frequency (n)
Percent (%)
41 205 14
16 79 5
130 97 22
52 39 9
218 41
84 16
74 147 35
29 57 14
176 76
70 30
38 158 14
18 75 7
260
249
259
256
252
210
N = nominal response; B = binary; BCS = body condition score.
(recorded for each cow at calving), percentage of heifers in the lactating herd, length of calving season, mean annual herd milk production (calculated from individual cow milk recordings; liters), milk fat and protein (kg), herd somatic cell count (SCC), herd economic breeding index values (EBI), and the predominant breed of cow in the herd. Calving season length refers to duration (weeks) for which ⩾85% cows are calving between January and June (O’Doherty et al., 2013). The EBI value is a single figure profit index used to identify the most profitable bulls and cows for breeding dairy herd replacements (Berry et al., 2014). Nine herds were eliminated from the analyses as cow numbers and calving information were missing for either 1 or more years. Respondents did not answer every question in the survey and so the numbers of respondents with each variable differ.
Statistical determination of herd characteristics Linear robust regression was fit to annual herd size over 3 years (2011, 2012, 2013) using PROC ROBUSTREG (SAS, 2011), as described by Jago and Berry (2011). The resulting intercept and linear regression coefficient was used to stratify herds on size and whether or not they were expanding. Herds were classified into one of four groups based on number of cows estimated from the regression for the year 2012 as, small (⩽65 cows; n = 37), average (65 to 100 cows; n = 81), large (101 to 150 cows; n = 73), and extra-large (>150 cows; n = 71). If the linear regression coefficient was not different (P > 0.05) from zero, the herd was classified as not expanding (Jago and Berry, 2011). 870
Herds with a regression coefficient greater (P < 0.05) than zero were classified as expanding (Jago and Berry, 2011).
Statistical analysis Dependent variables of interest were classified as binary, ordinal or nominal (data in the Tables 1, 3, 4 and 6). If 150 cows (‘extra-large’ herds). Of all respondents, 20% were deemed as expanding, and this was not associated with any cow, calving or colostrum management practices investigated in the current study.
Dry cow management The majority of respondents (79%) imposed a dry period of 8 to 10 weeks and more than half of all respondents (i.e. 52%) fed only grass silage during this time (Table 1). Of respondents that fed minerals to cows during the dry period (>95% of respondents), 57% fed them for 6 to 8 weeks pre-calving. Powdered minerals were the most common form of minerals used (70% of respondents; Table 1). Compared to average-sized herds, small herds were almost twice as likely (P < 0.05) to feed minerals in bolus/lick form rather than powdered form (Table 2). Eighty percent of respondents in the present study reported setting a target herd average BCS for calving (Table 1); of these, 75% set a target calving BCS of between 3.0 and 3.5 (5-point scale: 1 = emaciated and 5 = extremely fat). Large herds were five times more likely (P < 0.05) to set a target BCS than average-sized herds. In contrast, the likelihood that extra-large and small herds set a target BCS for calving, compared to average-sized herds, was not different (Table 2). Calving management The majority of respondents (53%) had a 10 to 14 week calving season, while 35% had a longer season (Table 3). Shared pens were used for calving cows by 49% of respondents, while 14% used a combination of both shared and individual maternity pens; 37% of respondents used only
individual maternity pens (Table 3). Of all respondents, 41% transferred cows to a maternity pen >24 h pre-calving (i.e. before the appearance of the amniotic sac), while 46% moved cows into maternity pens ⩽ 24 h pre-calving. The remaining 14% of respondents moved cows either during calving, or when they had calved. The most common bedding (93% of respondents) used in calving pens was straw (Table 3). Of the 92% of respondents that cleaned calving pens, 56% cleaned calving pens at least once every 2 weeks, while 22% of respondents cleaned calving pens no more than once per month, or between seasons only (Table 3). Calving pens were cleaned out (i.e. bedding completely removed), washed and disinfected during each cleaning event by 37% of respondents, while 46% removed bedding and either washed or disinfected pens (Table 2). Thirty-three percent of respondents inspected cows for calving events at least once every 6 h during the day or night, while 24% of respondents inspected cows for calving events during the day only (Table 3). Small herds, were less likely (P < 0.05) to use video surveillance than average-sized herds, while large sized herds had a greater likelihood (P < 0.01) of using a video surveillance than average-sized herds (Table 2). Of the sample population in the present study, 39% of respondents waited no more than 2 h from the time a calving event commenced (Table 3). Of respondents that stated when a veterinary surgeon is called to a calving (n = 213), 40% wait until their own attempts at rectifying the difficult calving have failed (Table 3).
Colostrum selection, collection and storage Of respondents that collected colostrum from freshly calved cows (98%), 51% collected colostrum within 2 h of calving, and 49% collected colostrum between 5 h post-calving and the next milking (Table 4). No respondent in the present study had a standard colostrum collection time of 2 to 5 h post-calving. In the present study, 54% of all respondents used any colostrum to feed calves (i.e. did not screen
Table 2 Herd size odds ratios (95% confidence interval) with dry cow and calving management practices Survey question and variable contrast What type of pre-calving minerals are fed Other v. powder Other v. powder Other v. Powder Is a target BCS used for cows at calving Yes v. No Yes v. No Yes v. No Is video surveillance used for calving cows Yes v. No Yes v. No Yes v. No
Class contrast (herd size)
Odds ratio (95% CI)
Model1 P value
Small v. Avg Large v. Avg Extra-large v. Avg
1.89 (1.37, 2.48) 0.42 (0.11, 0.97) 0.86 (0.34, 1.30)
Herd size Expansion **
Small v. Avg Large v. Avg Extra-large v. Avg
0.51 (0.20, 1.28) 4.65 (1.54, 14.10) 0.56 (0.21, 1.40)
Herd size Expansion *
Small v. Avg Large v. Avg Extra-large v. Avg
0.32 (0.16, 0.99) 5.80 (1.92, 17.79) 0.38 (0.12, 1.13)
Herd size Expansion **
CI = confidence interval; Avg = average-sized herds (reference herd size); BCS = body condition score. 1 Independent variable(s) included in the final logistic regression model. *P < 0.05, **P < 0.01.
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Cummins, Berry, Sayers, Lorenz and Kennedy Table 3 Summary of responses to each calving management practice survey question Variable Average length of calving season (O) Up to 10 weeks 10 to 14 weeks 14 to 18 weeks >18 weeks Type of calving pens used (N) Shared Individual Both Length of time cows spend in calving pens pre-calving (O) >24 h pre-calving ⩽24 h pre-calving When calving/calved How are calving pens cleaned (N) Clean out only Clean out and wash or disinfect Clean out wash and disinfect Frequency of cleaning calving pens (O) Once every 2 weeks or more frequently Once a month or less frequently Between seasons only Frequency cows in calving pens are checked (O) Every 0 to 6 h during the day only Every 0 to 6 h during the day and late at night Every 0 to 6 h day and night Is video surveillance used for cows at calving (B) No Yes Length of time before assisting cows at calving (O) 4 h When is a vet called to a cow at calving (N) When assistance is tried and failed Mal presented/large calf/twisted womb Decide after assessment Severe cases/emergency/almost never
Total respondents (n)
Frequency (n)
Percent (%)
30 138 68 23
12 53 26 9
125 96 36
49 37 14
105 118 35
41 46 14
40 112 89
17 46 37
134 53 54
56 22 22
47 85 64
24 43 33
108 154
41 59
102 135 23
39 52 9
85 39 44 45
40 18 21 21
259
257
258
241
241
196
262
260
213
N = nominal response; O = ordinal; B = binary.
according to any criteria such as parity or disease status). The primary source of colostrum used by the majority of respondents (60%) was the calf’s own dam, while 23% pooled colostrum for feeding (Table 4). Compared to average-sized herds, small herds were more likely (P < 0.05) to use the calf’s own dam, rather than a single cow or pooled colostrum, while large and extra-large herds were less likely (P < 0.05) to use the calf’s own dam than average-sized herds. When choosing a cows’ colostrum to use other than the calf’s own dam, 54% of respondents used any cow (i.e. no selection criteria; Table 4). The number of respondents that answered the question regarding a substitute colostrum source included any respondents that used the calf’s own dam a single cow or pooled colostrum as their primary source, hence the number of responses to this question (n = 248) was greater than the number of respondents that used a source other than the 872
calf’s own dam (n = 195). When a substitute supply of colostrum was needed, 14% of respondents offered newborn calves transition milk, while 13% offered a neighboring farm’s supply or colostrum replacer (Table 4). The majority of respondents (73%) stored frozen colostrum to use as a substitute to the primary colostrum source (Table 5). Of these, extra-large herds were least likely (P < 0.01) to use frozen colostrum, compared to all other herds (Table 5). Additionally, of respondents that stored colostrum 17% stored it at room temperature and 4% used a refrigerator, rather than freezing it (Table 4). More than half of respondents stored colostrum in a refrigerator for >48 h, while 29% stored colostrum at room temperature for up to 1 week (Table 4). Sixty-five percent of respondents reported that paratuberculosis disease was tested for in milk, feces, blood, or a combination of methods. Of the respondents who tested for this disease, large and extra-large herds were more likely
Calving management on spring-calving dairy farms Table 4 Summary of responses to colostrum collection & storage practice questions Variable Time after calving when colostrum is collected (O) Within 2 h 5 h to next milking At next milking Source of first feed colostrum (N) Calf’s own dam Colostrum from single cow Pooled colostrum Source used if dam is not used/available (B) Any cow Other (mature/healthy cows) Other colostrum source (N) Own frozen supply Transition milk Other Has paratuberculosis been diagnosed (B) No Yes How soon is colostrum stored after collection (B) Within 2 h ⩾5 h How is colostrum stored Refrigerator Freezer only Room temperature Combination of methods How long is colostrum stored in the refrigerator (B) 48 h How long is colostrum stored in the freezer (O) ⩽6 months 12 months Any length How long is colostrum stored at room temp (O) ⩽24 h 48 to 72 h 4 to 7 days How is colostrum defrosted (B) Immerse in warm water Other
Total respondents (n)
Frequency (n)
Percent (%)
130 28 96
51 22 39
156 43 61
60 17 23
106 89
54 46
180 35 33
73 14 13
72 90
44 56
31 192
14 86
4 123 39 62
2 54 17 27
12 14
46 54
75 63 22
47 39 14
27 30 23
34 38 29
141 79
64 36
254
260
195
248
162
223
228
26
160
80
220
N = nominal response; O = ordinal; B = binary.
(P = 0.05) to have a positive diagnosis, compared to average-sized herds (Table 5). Additionally, compared to respondents that cleaned calving pens, respondents that did not clean calving pens were 16 times more likely (P < 0.01) to diagnose paratuberculosis. Moreover, paratuberculosis was more likely to be diagnosed in herds with longer calving seasons (P < 0.05; Table 5).
Colostrum feeding The majority of respondents (i.e. 84%) ensured calves were fed colostrum (artificially or suckling the dam) within 3 h of birth (Table 6). Colostrum was fed via bottle or bucket and teat by 49% of respondents, while 40% allowed the calf to suckle the dam (Table 6). Compared to average-sized herds,
large herds were more likely (P < 0.05) to use an artificial feeding method (i.e. bottle or stomach tube) rather than allowing the calf suckle the dam (Table 5). Of respondents that artificially fed calves (n = 152), 5% fed 3 l Length of time fed transition milk (B) 1 to 3 days >3 days
Frequency (n)
Percent (%)
93 127 30 12
36 48 11 5
105 127 28
40 49 11
105 122 30
41 47 12
164 86
66 34
262
260
257
250
N = nominal response; O = ordinal; B = binary.
Furthermore, as calf health diseases were recently deemed as an animal health priority (More et al., 2010) it may have provided farmers with an additional incentive to participate in the survey. Alternatively, it may simply be due to the number of reminders the respondents received to complete the survey. There are no documented reasons for farmers 874
opting out of responding to the survey and thus the response may be a random occurrence. The average size of herds in the present study (131 cows) was larger than the Irish national average, reported as 66 cows in 2013 (Teagasc, 2013). As expansion was not associated with management practices in the present study, it is deemed that the process
Calving management on spring-calving dairy farms
Dry cow management Accumulation of IgG in colostrum begins 5 weeks before parturition (Godden, 2008). Thus the 16% of respondents that provide a short non-lactating period may have compromised colostrum quality (Rastani et al., 2005), and less time to increase cow BCS reserves. Extra-large farms were less likely to use a target BCS, possibly due to the increased time resources required to individually assess each cow. The greater likelihood of larger herds offering dry cows powdered minerals may be due to the convenience of incorporation into the dry cow diet compared to bolus minerals, which require individual cow administration.
can be exposed to a greater bacterial load compared to pens that are cleaned out and washed or disinfected (46% of respondents), or cleaned out, washed and disinfected (34% of respondents). In the present study, respondents may be exposing themselves to increased risk of stillbirths and deaths in the 1st week of life (Wells et al., 1996; Gulliksen et al., 2009a) as 24% of respondents only inspected cows for calving events during the day. The use of video surveillance (59% of respondents), is an additional support that allows the farmer to view the cows without visiting the maternity house. Extra-large herds are likely to have more cows calving in a short space of time and thus rather than installing a video surveillance system, the farmer may have continuously observed the cows. Furthermore, as these larger farms have many more cows than small farms, more staff may be involved in monitoring cows when calving, but unfortunately this data was not attained in the present survey.
Calving management The use of shared maternity pens by 63% of respondents in the present study, is a management strategy which was previously been reported to increase the risk of the spread of infectious disease to the calf, compared to individual maternity pens (37% of respondents; Sweeney et al., 2012). According to previous research, respondents that provided individual pens for cows at calving, are not only more likely to have a reduced risk of spreading infection (Sweeney et al., 2012), but are also minimizing the risk of stress to the cow (Vasseur et al., 2010), which has been reportedly associated with a reduced risk of prolonged parturition and weaker calves at birth (Gulliksen et al., 2009a). The timing of transferring cows to a calving pen pre-calving is a component of stress management for the periparturient cow; according to previous research the 87% of respondents that transfer cows >24 h before calving are minimizing stress on the cow (Bao and Giller, 1991). The opposite can be said for the 14% of respondents that transferred cows to a calving pen once calving had commenced. This is particularly true for nervous cows and heifers (Mee, 2008). Moving cows when they had already calved has been reported to increase the risk that the calf will contract infection (Gulliksen et al., 2009a; Sweeney et al., 2012) as stress can increase the shedding of diseases that may be present such as Infectious Bovine Rhinotracheitis. The most common bedding type, that is straw, used in the present study is a good insulator, but if not cleaned regularly it can quickly become damp and dirty, thus having unfavorable consequences for animal health (Tuyttens, 2005). Frequent cleaning of maternity pens reduces pathogen buildup and calf exposure to infectious disease (Gulliksen et al., 2009b); but 22% of respondents in the present study cleaned maternity pens no more than once per month, or only between seasons. The method of cleaning may also affect calf health. If maternity pens are not washed or disinfected during cleaning (17% of respondents did not), the pathogenic load can accumulate and persist and the neonate
Colostrum selection, collection and storage A key factor to ensure calves absorb maximum IgG levels from colostrum in the first hours after birth, is the source of colostrum (e.g. calf’s own dam) (McGuirk and Collins, 2004). When selecting colostrum from a single cow, that is not the calf’s own dam, 22% of respondents selected a cow deemed to be healthy (i.e. free from paratuberculosis, mastitis or any clinical illness present at calving) which is important to minimize transmission of disease to the calf (McGuirk and Collins, 2004). Feeding pooled colostrum (more likely on larger farms in the present study) is convenient, particularly in spring-calving systems when collecting colostrum from many different cows at the same time, but increases the risk of spreading diseases such as paratuberculosis throughout the herd (McGuirk and Collins, 2004). As larger herds are less likely to feed colostrum from the calf’s own dam, the risk of spreading disease throughout the herd is greater. Calves and young stock are most susceptible to paratuberculosis (Sweeney et al., 2012). More than 20% of Irish herds have diagnosed at least one positive paratuberculosis animal in their herd (Good et al., 2009); however 35% of respondents in the present study had never tested for the disease. The greater likelihood of the disease being diagnosed in larger herds agrees with previous research (Kennedy et al., 2014). It is evident in the present study that good hygiene is essential to minimize accumulation and spreading throughout the herd as failure to clean out maternity pens was associated with a positive diagnosis of the disease (Gulliksen et al., 2009a). Some substitute colostrum sources identified in the present study should never be used on a dairy farm; these include transition milk (used by 14% of respondents) as it does not contain adequate IgG to ensure adequate passive transfer of immunoglobulins, and a neighboring farms supply as this is a biosecurity hazard (McGuirk and Collins, 2004), Although colostrum replacer (13% of all respondents), is a more favorable alternative than those previously mentioned, it is lower in quality than maternal colostrum and will not
of herd expansion is not expected to result in compromised herd management. This is similar to the findings of Jago and Berry (2011), who investigated the association between dairy herd expansion and reproduction, and calving performance (i.e. age at first calving, calving interval, dystocia).
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Cummins, Berry, Sayers, Lorenz and Kennedy contain any specific immune factors cows develop from the environment (Godden, 2008). Keeping stored supplies is a good alternative; early storage of colostrum post-collection (86% of respondents) minimizes bacterial growth, which is thought to affect the rate of passive transfer in the calf (James et al., 1981; Godden, 2008). For the same reason, the duration of colostrum storage is also important when storing colostrum above 0°C, particularly at room temperature (17% of respondents), or in a refrigerator (4% of respondents) as longer storage durations result in significantly altered bacteria and pH levels (Stewart et al., 2005).
majority of respondents fed calves within 3 h of birth, feeding practices that influence neonatal calf immunity such as the quality and volume of colostrum fed should be improved; most herds did not test colostrum for quality and 41% did not know the volume of colostrum consumed. Additional management practices identified in the current study such as storing colostrum at room temperature for >48 h may contribute to the failure of passive transfer occurring in Irish dairy calves due to bacterial growth, but further studies should be conducted to identify best colostrum storage practices.
Colostrum feeding Failure of passive transfer is a prominent issue in calves, and was reported in almost 60% of serum samples from sick or dead calves that were submitted to Irish regional veterinary laboratories in 2013 (Anonymous, 2014). The 40% of respondents that allowed the calf to suckle the dam, were creating an environment that increased exposure of pathogens to the calf due to direct contact with the dam (Sweeney et al., 2012). Furthermore, the volume of colostrum consumed is immeasurable when the calf suckles the dam and dairy calves typically do not voluntarily consume sufficient volumes of colostrum to ensure adequate IgG absorption (Brignole and Stott, 1980; Besser et al., 1991). The likelihood that larger herds used an artificial colostrum feeding method, compared to average-sized herds, may be due to space limitations, which is of particular importance when the calving season is compact. Larger herds have more cows calving in a short space of time and may require the calving pens for other calving cows more quickly than smaller sized herds. To estimate the likelihood of sufficient absorption of IgG, it is essential to know the volume of colostrum ingested by the calf. The volume of colostrum fed to calves by 42% of respondents (
