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Animal Science Journal (2014) ••, ••–••
doi: 10.1111/asj.12219
ORIGINAL ARTICLE Evaluation of vaginal discharge with the Metricheck device and the relationship to reproductive performance in postpartum dairy cows Christian LAMBERTZ,1 Denise VÖLKER,1 Ulrich JANOWITZ2 and Matthias GAULY1 1
Department of Animal Sciences, Georg-August-University, Göttingen and 2Rinder Union West eG, Münster, Germany
ABSTRACT Vaginal mucus during estrus was examined with the Metricheck device and the relationship to the reproduction of high-yielding dairy cows was studied. The study was conducted in 99 dairy herds located in Western Germany and 1348 Holstein-Friesian heifers and cows showing spontaneous estrus were examined. Independent of the Metricheck result, the animals were inspected by professional insemination technicians and those suitable for insemination (n = 989) were bred by artificial insemination (AI). Reproductive performance was characterized by non-return rate at 90 days (NRR90). The discharge of the animals predominantly had a clear appearance (70%) and a stringy consistency (80%). Animals with clear vaginal discharge had higher NRR90 (56%; n = 697) than animals with abnormal (turbid, mucopurulent, purulent, sanguineous) vaginal secretion (48%, n = 292; P < 0.05). NRR90 was lower in animals with short calving to AI interval (< 70 days; 39%) than with medium (70–130 days; 54%) or long (> 130 days; 62%) intervals (P < 0.05). NRR90 decreased by 12% from the lowest (< 15 kg) to the highest (> 45 kg) milk yield class. In conclusion, the use of the Metricheck device integrated into the insemination procedure is recommended to identify dairy cows suffering severely from uterine disease.
Key words: dairy cattle, endometritis, Metricheck device, reproductive performance, vaginal discharge.
INTRODUCTION A healthy uterine environment is the key factor for optimal fertility in dairy herds expressed as a high reproductive efficiency. However, under practical conditions declining fertility is one of the major problems observed in high-yielding dairy cows (Dobson et al. 2007). Among fertility-related diseases, endometritis belongs to the most important veterinary-treated cases. Evaluating more than 5500 veterinary-treated cases from eight Holstein-Frisian dairy herds raised in loose housing systems in Germany, fertility-related cases comprised 21.6% of all cases. Besides ovarial cysts and abnormal estrus (10.5%), endometritis (7.8%) was diagnosed most commonly within the fertility complex (Sanker et al. 2013). Endometritis impairs reproductive efficiency and thereby causes tremendous economic losses (LeBlanc et al. 2002a; Gilbert et al. 2005). In the first 2 weeks postpartum (pp) the uterus of almost every dairy cow is contaminated with multiple bacterial species (Sheldon et al. 2002). Although these bacterial infections are normally eliminated within a few weeks after calving, persisting infections are © 2014 Japanese Society of Animal Science
common and may result in metritis and endometritis. Generally, 10-20% of the dairy cows develop a metritis and approximately 15% a clinical endometritis, which is defined as an abnormally enlarged cervical diameter (> 7.5 cm) and a purulent vaginal mucus later than 3 weeks pp (LeBlanc et al. 2002b; Sheldon et al. 2006). Another 15% are found with symptoms of subclinical endometritis (LeBlanc et al. 2011). Decreased reproductive performance due to increased days to first service, decreased conception and pregnancy rates, reduced milk yield, and increased feed intake and culling rate are all factors associated with an endometritis causing economic losses (LeBlanc et al. 2002a; Gilbert et al. 2005). Under practical conditions cost- and time-effective methods of diagnosing endometritis are required. Evaluating the character and odor of the vaginal
Correspondence: Christian Lambertz, Department of Animal Sciences, Georg-August-University, Albrecht-Thaer-Weg 3, 37075 Göttingen, Germany. (Email: [email protected]) Received 9 September 2013; accepted for publication 6 February 2014.
2 C. LAMBERTZ et al.
mucus reflects the number of bacteria in the uterus (Williams et al. 2005) and is the key for an effective diagnosis of endometritis. Different diagnostic tools were developed and evaluated (Runciman et al. 2009; Senosy et al. 2012). Visual vaginoscopy and transrectal palpation are less time-consuming and costly but less sensitive and/or specific than the histological examination of the endometrium, transrectal ultrasonography or endometrial cytology. Despite its usefulness and accuracy for detecting dairy cows with a reduced reproductive performance (Runciman et al. 2009; Leutert et al. 2012), vaginoscopy is not used as the standard diagnostic tool by clinical practitioners (LeBlanc et al. 2002a). As an alternative approach which is rapid, simple and requires less equipment than vaginoscopy, the Metricheck device was developed in New Zealand. With this device consisting of a silicon cup attached to a stainless steel rod, vaginal mucus can be collected from the anterior vagina for visual examination (McDougall et al. 2007). This diagnostic tool was postulated to be more convenient under practical conditions and found more sensitive but less specific than vaginoscopy (McDougall et al. 2007). Comparing different evaluation methods of the uterine condition in pp dairy cows, including Metricheck, vaginoscopy, endometrial cytology and ultrasonography in clinically normal dairy cows, Senosy et al. (2012) confirmed the usefulness of the Metricheck device for predicting the reproductive performance of dairy cows. However, the effect of different Metricheck results examined during estrus on reproductive performance in dairy cows is not clear yet. Therefore, the aim of the present study was to examine vaginal mucus during estrus with a Metricheck device and to study the relationship to reproductive performance in high-yielding dairy cows.
MATERIALS AND METHODS Animals and herds The study was conducted in 99 dairy herds with an average herd size of 83 animals (range 10–362) and an average milk yield of 8855 kg (range 5678–12013 kg) per cow with 4.07% fat (range 3.33–4.73%) and 3.38% protein (range 3.19– 3.58%). Farms were located in Western Germany. A total of 1348 Holstein-Friesian heifers and cows showing spontaneous estrus were examined, whereas nine of the animals were Holstein-Friesian × Fleckvieh crossbreds. Except for 15 herds with tie-stalls, loose-housing systems were predominant. The study period lasted for 4 months.
Vaginal mucus collection and evaluation Vaginal mucus of all animals was collected with the Metricheck device (Simcro Tech Ltd, Hamilton, New Zealand) as previously described by McDougall et al. (2007). The appearance and consistency of the discharge within the concave surface of the device were scored according to a modified version of Williams et al. (2005) and McDougall © 2014 Japanese Society of Animal Science
et al. (2007). The following scores were used for appearance: 1 = clear; 2 = turbid; 3 = mucopurulent; 4 = purulent; 5 = sanguineous; and consistency: 1 = stringy; 2 = sticky; 3 = viscous. Multiple Metricheck devices were used in each herd in order to rinse the equipment with warm water and disinfect with alcohol solution (70%) between examinations of the cows. Once per day, the devices were disinfected for 30 min in alcohol solution. After all the cows showing spontaneous estrus were examined by the same person with the Metricheck device, the animals were inspected independent of the Metricheck result by professional insemination technicians. This included an inspection for vulval discharge around the perineum and tail and a rectal palpation of the uterus and ovaries. Hereby, it was ensured that the decision whether or not to inseminate the animals was not influenced by the Metricheck result. Two technicians of one breeding organization operating in bordering districts were chosen to increase the number of animals studied. The technicians’ efficiency was measured by the non-return rate at 90 days (NRR90) during the last 3 years, which was defined as the percentage of inseminated cows that did not return to estrus within 90 days. NRR90 differed between the two persons by 5% in each year and ranged between 60% and 70%. Each day, each technician was accompanied by the person doing the Metricheck analysis for half the day. Herds were visited once per day. After the examination by the technicians, animals which were evaluated positively were inseminated by artificial insemination (AI) using frozen semen. Reproductive performance was characterized by NRR90 as described above. This parameter was calculated based on the insemination records. Accordingly, inseminated animals could be identified whether they were inseminated within 90 days or not. Furthermore, records of animal identification, number of inseminations and identification of the bull were collected. Test-day records were used to identify birth date, calving date (last- and second-to-last calving), lactation number, milk yield and days between calvings.
Statistical analysis Data were analyzed using the software package SAS (SAS Institute Inc., Cary, NC, USA) with a logit link function. NRR90 results were analyzed using the maximum likelihood approach within the GLIMMIX procedure. The scales for the appearance (1 = clear mucus; 2 = turbid, mucopurulent, purulent, sanguineous) and consistency (1 = stringy; 2 = sticky, viscous) were transformed into binary variables and treated as fixed effects. For both parameters score 1 was defined as normal or Metricheck-negative and score 2 as abnormal or Metricheck-positive appearance and consistency of the vaginal discharge. Furthermore, the statistical model contained the insemination technician (1, 2), the interval from calving to Metricheck examination and AI (1 ≤ 70 days; 2 = 70–130 days; 3 ≥ 130 days), the lactation number (1 = 1st lactation; 2 = 2nd lactation; 3 = ≥ 3 lactations), the insemination number (1 = 1st insemination; 2 = 2nd insemination; 3 = ≥ 3 inseminations) as fixed effects and the herd and bull as random effects. In the following, the interval from calving to Metricheck examination and AI will be shortened to calving to AI interval. Furthermore, regression coefficients to the polynomial of the third degree of the covariate test-day milk yield were included, whereas the milk yield was divided into classes (1 ≤ 15 kg; 2 = ≥ 15– 130 days) calving to AI interval. This finding of improved reproductive performance with increasing period from calving to AI is consistent with the study by Cutullic et al. (2012), who compared dairy cows at different levels of feeding and milk yield. In the study by Yusuf et al. (2011) the first AI conception rate increased linearly up to 100 days in milk. Larsson and Berglund (2000) compared a herd which was managed for 12or 15-month calving intervals with a herd managed for 12- or 18-month intervals. An improved fertility was found in cows managed for longer calving intervals as revealed from higher conception rates at first AI, a lower number of inseminations per conception and reduced first AI to conception intervals. The observed adverse effects of increasing milk yield on the reproductive performance are also commonly found (Dobson et al. 2007; Sakaguchi 2011). Comparing high-fed and low-fed Holstein cows, Cutullic et al. (2012) found a negative relationship between milk yield and reproductive performance expressed in depressed estrus behavior and increased rates of embryo mortality. However, as proposed by Cutullic et al. (2012), the effects of milk yield on the reproduction may vary at different stages of the reproductive process. Nevertheless, our results support the finding Animal Science Journal (2014) ••, ••–••
METRICHECK RESULTS ON REPRODUCTION
that increasing milk yields are associated with decreasing reproductive efficiency. However, further studies are needed to verify the effects of milk yield on vaginal discharge. The finding that neither the lactation and insemination number nor the insemination technician influenced the reproductive performance contradicts some previous studies. Rocha et al. (2001) found NRR90 to be 6% higher in heifers than in cows and in pluriparous cows higher than in primiparous ones. As well, contrary to our results, the overall NRR90 at the first AI of 71.7 ± 6.5% differed significantly between insemination technicians (Rocha et al. 2001). In conclusion, the Metricheck device is a useful and practical tool to assess mucus of the cranial vagina as an indicator for endometritis. Its use at the time of estrus is meaningful whether or not the cow should be inseminated, because animals with abnormal discharge are associated with reduced reproductive performance. Therefore, the use of the Metricheck device integrated in the insemination procedure is recommended to identify dairy cows suffering severely from uterine disease. However, high hygienic standards have to be met in order to reduce the risk of contamination.
ACKNOWLEDGMENTS The authors acknowledge the breeding organization Rinder Union West eG and Innovationsteam Hessen for their support.
REFERENCES Cutullic E, Delaby L, Gallard Y, Disenhaus C. 2012. Towards a better understanding of the respective effects of milk yield and body condition dynamics on reproduction in Holstein dairy cows. Animal 6, 476–487. Dobson H, Smith R, Royal M, Knight C, Sheldon I. 2007. The high-producing dairy cow and its reproductive performance. Reproduction in Domestic Animals 42 (Suppl 2), 17–23. Dubuc J, Duffield TF, Leslie KE, Walton JS, LeBlanc SJ. 2010. Definitions and diagnosis of postpartum endometritis in dairy cows. Journal of Dairy Science 93, 5225–5233. Gilbert RO, Shin ST, Guard CL, Erb HN, Frajblat M. 2005. Prevalence of endometritis and its effects on reproductive performance of dairy cows. Theriogenology 64, 1879–1888. Giuliodori MJ, Magnasco RP, Becu-Villalobos D, Lacau-Mengido IM, Risco CA, De la Sota RL. 2012. Clinical endometritis in an Argentinean herd of dairy cows: risk factors and reproductive efficiency. Journal of Dairy Science 96, 210–218. Larsson B, Berglund B. 2000. Reproductive performance in cows with extended calving interval. Reproduction in Domestic Animals 35, 277–279. LeBlanc SJ, Duffield TF, Leslie KE, Bateman KG, Keefe GP, Walton JS, Johnson WH. 2002a. The effect of treatment of
Animal Science Journal (2014) ••, ••–••
5
clinical endometritis on reproductive performance in dairy cows. Journal of Dairy Science 85, 2237–2249. LeBlanc SJ, Duffield TF, Leslie KE, Bateman KG, Keefe GP, Walton JS, Johnson WH. 2002b. Defining and diagnosing postpartum clinical endometritis and its impact on reproductive performance in dairy cows. Journal of Dairy Science 85, 2223–2236. LeBlanc SJ, Osawa T, Dubuc J. 2011. Reproductive tract defense and disease in postpartum dairy cows. Theriogenology 76, 1610–1618. Leutert C, Von Krueger X, Plöntzke J, Heuwieser W. 2012. Evaluation of vaginoscopy for the diagnosis of clinical endometritis in dairy cows. Journal of Dairy Science 95, 206–212. McDougall S, Macaulay R, Compton C. 2007. Association between endometritis diagnosis using a novel intravaginal device and reproductive performance in dairy cattle. Animal Reproduction Science 99, 9–23. Pleticha S, Drillich M, Heuwieser W. 2009. Evaluation of the Metricheck device and the gloved hand for the diagnosis of clinical endometritis in dairy cows. Journal of Dairy Science 92, 5429–5435. Rocha A, Rocha S, Carvalheira J. 2001. Reproductive parameters and efficiency of inseminators in dairy farms in Portugal. Reproduction in Domestic Animals 36, 319–324. Runciman DJ, Anderson GA, Malmo J. 2009. Comparison of two methods of detecting purulent vaginal discharge in postpartum dairy cows and effect of intrauterine cephapirin on reproductive performance. Australian Veterinary Journal 87, 369–378. Sakaguchi M. 2011. Practical aspects of the fertility of dairy cattle. Journal of Reproduction and Development 57, 17–33. Salasel B, Mokhtari A, Taktaz T. 2010. Prevalence, risk factors for and impact of subclinical endometritis in repeat breeder dairy cows. Theriogenology 74, 1271–1278. Sanker C, Lambertz C, Gauly M. 2013. Climatic effects in Central Europe on the frequency of medical treatments of dairy cows. Animal 7, 316–321. Senosy W, Uchiza M, Tameoka N, Izaike Y, Osawa T. 2012. Evaluation of reproductive tract infection during early post-partum period and its relationship with subsequent reproductive performance in high milk producing dairy cows. Reproduction in Domestic Animals 47, 203–207. Sheldon IM, Lewis GS, LeBlanc S, Gilbert RO. 2006. Defining postpartum uterine disease in cattle. Theriogenology 65, 1516–1530. Sheldon IM, Noakes DE, Rycroft AN, Pfeiffer DU, Dobson H. 2002. Influence of uterine bacterial contamination after parturition on ovarian dominant follicle selection and follicle growth and function in cattle. Reproduction 123, 837–845. Williams EJ, Fischer DP, Pfeiffer DU, England GCW, Noakes DE, Dobson H, Sheldon IM. 2005. Clinical evaluation of postpartum vaginal mucus reflects uterine bacterial infection and the immune response in cattle. Theriogenology 63, 102–117. Yusuf M, Nakao T, Yoshida C, Long ST, Gautam G, Ranasinghe RMSBK, et al. 2011. Days in milk at first AI in dairy cows; its effect on subsequent reproductive performance and some factors influencing it. Journal of Reproduction and Development 57, 643–649.
© 2014 Japanese Society of Animal Science
Animal Science Journal (2014) ••, ••–••
doi: 10.1111/asj.12219
ORIGINAL ARTICLE Evaluation of vaginal discharge with the Metricheck device and the relationship to reproductive performance in postpartum dairy cows Christian LAMBERTZ,1 Denise VÖLKER,1 Ulrich JANOWITZ2 and Matthias GAULY1 1
Department of Animal Sciences, Georg-August-University, Göttingen and 2Rinder Union West eG, Münster, Germany
ABSTRACT Vaginal mucus during estrus was examined with the Metricheck device and the relationship to the reproduction of high-yielding dairy cows was studied. The study was conducted in 99 dairy herds located in Western Germany and 1348 Holstein-Friesian heifers and cows showing spontaneous estrus were examined. Independent of the Metricheck result, the animals were inspected by professional insemination technicians and those suitable for insemination (n = 989) were bred by artificial insemination (AI). Reproductive performance was characterized by non-return rate at 90 days (NRR90). The discharge of the animals predominantly had a clear appearance (70%) and a stringy consistency (80%). Animals with clear vaginal discharge had higher NRR90 (56%; n = 697) than animals with abnormal (turbid, mucopurulent, purulent, sanguineous) vaginal secretion (48%, n = 292; P < 0.05). NRR90 was lower in animals with short calving to AI interval (< 70 days; 39%) than with medium (70–130 days; 54%) or long (> 130 days; 62%) intervals (P < 0.05). NRR90 decreased by 12% from the lowest (< 15 kg) to the highest (> 45 kg) milk yield class. In conclusion, the use of the Metricheck device integrated into the insemination procedure is recommended to identify dairy cows suffering severely from uterine disease.
Key words: dairy cattle, endometritis, Metricheck device, reproductive performance, vaginal discharge.
INTRODUCTION A healthy uterine environment is the key factor for optimal fertility in dairy herds expressed as a high reproductive efficiency. However, under practical conditions declining fertility is one of the major problems observed in high-yielding dairy cows (Dobson et al. 2007). Among fertility-related diseases, endometritis belongs to the most important veterinary-treated cases. Evaluating more than 5500 veterinary-treated cases from eight Holstein-Frisian dairy herds raised in loose housing systems in Germany, fertility-related cases comprised 21.6% of all cases. Besides ovarial cysts and abnormal estrus (10.5%), endometritis (7.8%) was diagnosed most commonly within the fertility complex (Sanker et al. 2013). Endometritis impairs reproductive efficiency and thereby causes tremendous economic losses (LeBlanc et al. 2002a; Gilbert et al. 2005). In the first 2 weeks postpartum (pp) the uterus of almost every dairy cow is contaminated with multiple bacterial species (Sheldon et al. 2002). Although these bacterial infections are normally eliminated within a few weeks after calving, persisting infections are © 2014 Japanese Society of Animal Science
common and may result in metritis and endometritis. Generally, 10-20% of the dairy cows develop a metritis and approximately 15% a clinical endometritis, which is defined as an abnormally enlarged cervical diameter (> 7.5 cm) and a purulent vaginal mucus later than 3 weeks pp (LeBlanc et al. 2002b; Sheldon et al. 2006). Another 15% are found with symptoms of subclinical endometritis (LeBlanc et al. 2011). Decreased reproductive performance due to increased days to first service, decreased conception and pregnancy rates, reduced milk yield, and increased feed intake and culling rate are all factors associated with an endometritis causing economic losses (LeBlanc et al. 2002a; Gilbert et al. 2005). Under practical conditions cost- and time-effective methods of diagnosing endometritis are required. Evaluating the character and odor of the vaginal
Correspondence: Christian Lambertz, Department of Animal Sciences, Georg-August-University, Albrecht-Thaer-Weg 3, 37075 Göttingen, Germany. (Email: [email protected]) Received 9 September 2013; accepted for publication 6 February 2014.
2 C. LAMBERTZ et al.
mucus reflects the number of bacteria in the uterus (Williams et al. 2005) and is the key for an effective diagnosis of endometritis. Different diagnostic tools were developed and evaluated (Runciman et al. 2009; Senosy et al. 2012). Visual vaginoscopy and transrectal palpation are less time-consuming and costly but less sensitive and/or specific than the histological examination of the endometrium, transrectal ultrasonography or endometrial cytology. Despite its usefulness and accuracy for detecting dairy cows with a reduced reproductive performance (Runciman et al. 2009; Leutert et al. 2012), vaginoscopy is not used as the standard diagnostic tool by clinical practitioners (LeBlanc et al. 2002a). As an alternative approach which is rapid, simple and requires less equipment than vaginoscopy, the Metricheck device was developed in New Zealand. With this device consisting of a silicon cup attached to a stainless steel rod, vaginal mucus can be collected from the anterior vagina for visual examination (McDougall et al. 2007). This diagnostic tool was postulated to be more convenient under practical conditions and found more sensitive but less specific than vaginoscopy (McDougall et al. 2007). Comparing different evaluation methods of the uterine condition in pp dairy cows, including Metricheck, vaginoscopy, endometrial cytology and ultrasonography in clinically normal dairy cows, Senosy et al. (2012) confirmed the usefulness of the Metricheck device for predicting the reproductive performance of dairy cows. However, the effect of different Metricheck results examined during estrus on reproductive performance in dairy cows is not clear yet. Therefore, the aim of the present study was to examine vaginal mucus during estrus with a Metricheck device and to study the relationship to reproductive performance in high-yielding dairy cows.
MATERIALS AND METHODS Animals and herds The study was conducted in 99 dairy herds with an average herd size of 83 animals (range 10–362) and an average milk yield of 8855 kg (range 5678–12013 kg) per cow with 4.07% fat (range 3.33–4.73%) and 3.38% protein (range 3.19– 3.58%). Farms were located in Western Germany. A total of 1348 Holstein-Friesian heifers and cows showing spontaneous estrus were examined, whereas nine of the animals were Holstein-Friesian × Fleckvieh crossbreds. Except for 15 herds with tie-stalls, loose-housing systems were predominant. The study period lasted for 4 months.
Vaginal mucus collection and evaluation Vaginal mucus of all animals was collected with the Metricheck device (Simcro Tech Ltd, Hamilton, New Zealand) as previously described by McDougall et al. (2007). The appearance and consistency of the discharge within the concave surface of the device were scored according to a modified version of Williams et al. (2005) and McDougall © 2014 Japanese Society of Animal Science
et al. (2007). The following scores were used for appearance: 1 = clear; 2 = turbid; 3 = mucopurulent; 4 = purulent; 5 = sanguineous; and consistency: 1 = stringy; 2 = sticky; 3 = viscous. Multiple Metricheck devices were used in each herd in order to rinse the equipment with warm water and disinfect with alcohol solution (70%) between examinations of the cows. Once per day, the devices were disinfected for 30 min in alcohol solution. After all the cows showing spontaneous estrus were examined by the same person with the Metricheck device, the animals were inspected independent of the Metricheck result by professional insemination technicians. This included an inspection for vulval discharge around the perineum and tail and a rectal palpation of the uterus and ovaries. Hereby, it was ensured that the decision whether or not to inseminate the animals was not influenced by the Metricheck result. Two technicians of one breeding organization operating in bordering districts were chosen to increase the number of animals studied. The technicians’ efficiency was measured by the non-return rate at 90 days (NRR90) during the last 3 years, which was defined as the percentage of inseminated cows that did not return to estrus within 90 days. NRR90 differed between the two persons by 5% in each year and ranged between 60% and 70%. Each day, each technician was accompanied by the person doing the Metricheck analysis for half the day. Herds were visited once per day. After the examination by the technicians, animals which were evaluated positively were inseminated by artificial insemination (AI) using frozen semen. Reproductive performance was characterized by NRR90 as described above. This parameter was calculated based on the insemination records. Accordingly, inseminated animals could be identified whether they were inseminated within 90 days or not. Furthermore, records of animal identification, number of inseminations and identification of the bull were collected. Test-day records were used to identify birth date, calving date (last- and second-to-last calving), lactation number, milk yield and days between calvings.
Statistical analysis Data were analyzed using the software package SAS (SAS Institute Inc., Cary, NC, USA) with a logit link function. NRR90 results were analyzed using the maximum likelihood approach within the GLIMMIX procedure. The scales for the appearance (1 = clear mucus; 2 = turbid, mucopurulent, purulent, sanguineous) and consistency (1 = stringy; 2 = sticky, viscous) were transformed into binary variables and treated as fixed effects. For both parameters score 1 was defined as normal or Metricheck-negative and score 2 as abnormal or Metricheck-positive appearance and consistency of the vaginal discharge. Furthermore, the statistical model contained the insemination technician (1, 2), the interval from calving to Metricheck examination and AI (1 ≤ 70 days; 2 = 70–130 days; 3 ≥ 130 days), the lactation number (1 = 1st lactation; 2 = 2nd lactation; 3 = ≥ 3 lactations), the insemination number (1 = 1st insemination; 2 = 2nd insemination; 3 = ≥ 3 inseminations) as fixed effects and the herd and bull as random effects. In the following, the interval from calving to Metricheck examination and AI will be shortened to calving to AI interval. Furthermore, regression coefficients to the polynomial of the third degree of the covariate test-day milk yield were included, whereas the milk yield was divided into classes (1 ≤ 15 kg; 2 = ≥ 15– 130 days) calving to AI interval. This finding of improved reproductive performance with increasing period from calving to AI is consistent with the study by Cutullic et al. (2012), who compared dairy cows at different levels of feeding and milk yield. In the study by Yusuf et al. (2011) the first AI conception rate increased linearly up to 100 days in milk. Larsson and Berglund (2000) compared a herd which was managed for 12or 15-month calving intervals with a herd managed for 12- or 18-month intervals. An improved fertility was found in cows managed for longer calving intervals as revealed from higher conception rates at first AI, a lower number of inseminations per conception and reduced first AI to conception intervals. The observed adverse effects of increasing milk yield on the reproductive performance are also commonly found (Dobson et al. 2007; Sakaguchi 2011). Comparing high-fed and low-fed Holstein cows, Cutullic et al. (2012) found a negative relationship between milk yield and reproductive performance expressed in depressed estrus behavior and increased rates of embryo mortality. However, as proposed by Cutullic et al. (2012), the effects of milk yield on the reproduction may vary at different stages of the reproductive process. Nevertheless, our results support the finding Animal Science Journal (2014) ••, ••–••
METRICHECK RESULTS ON REPRODUCTION
that increasing milk yields are associated with decreasing reproductive efficiency. However, further studies are needed to verify the effects of milk yield on vaginal discharge. The finding that neither the lactation and insemination number nor the insemination technician influenced the reproductive performance contradicts some previous studies. Rocha et al. (2001) found NRR90 to be 6% higher in heifers than in cows and in pluriparous cows higher than in primiparous ones. As well, contrary to our results, the overall NRR90 at the first AI of 71.7 ± 6.5% differed significantly between insemination technicians (Rocha et al. 2001). In conclusion, the Metricheck device is a useful and practical tool to assess mucus of the cranial vagina as an indicator for endometritis. Its use at the time of estrus is meaningful whether or not the cow should be inseminated, because animals with abnormal discharge are associated with reduced reproductive performance. Therefore, the use of the Metricheck device integrated in the insemination procedure is recommended to identify dairy cows suffering severely from uterine disease. However, high hygienic standards have to be met in order to reduce the risk of contamination.
ACKNOWLEDGMENTS The authors acknowledge the breeding organization Rinder Union West eG and Innovationsteam Hessen for their support.
REFERENCES Cutullic E, Delaby L, Gallard Y, Disenhaus C. 2012. Towards a better understanding of the respective effects of milk yield and body condition dynamics on reproduction in Holstein dairy cows. Animal 6, 476–487. Dobson H, Smith R, Royal M, Knight C, Sheldon I. 2007. The high-producing dairy cow and its reproductive performance. Reproduction in Domestic Animals 42 (Suppl 2), 17–23. Dubuc J, Duffield TF, Leslie KE, Walton JS, LeBlanc SJ. 2010. Definitions and diagnosis of postpartum endometritis in dairy cows. Journal of Dairy Science 93, 5225–5233. Gilbert RO, Shin ST, Guard CL, Erb HN, Frajblat M. 2005. Prevalence of endometritis and its effects on reproductive performance of dairy cows. Theriogenology 64, 1879–1888. Giuliodori MJ, Magnasco RP, Becu-Villalobos D, Lacau-Mengido IM, Risco CA, De la Sota RL. 2012. Clinical endometritis in an Argentinean herd of dairy cows: risk factors and reproductive efficiency. Journal of Dairy Science 96, 210–218. Larsson B, Berglund B. 2000. Reproductive performance in cows with extended calving interval. Reproduction in Domestic Animals 35, 277–279. LeBlanc SJ, Duffield TF, Leslie KE, Bateman KG, Keefe GP, Walton JS, Johnson WH. 2002a. The effect of treatment of
Animal Science Journal (2014) ••, ••–••
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clinical endometritis on reproductive performance in dairy cows. Journal of Dairy Science 85, 2237–2249. LeBlanc SJ, Duffield TF, Leslie KE, Bateman KG, Keefe GP, Walton JS, Johnson WH. 2002b. Defining and diagnosing postpartum clinical endometritis and its impact on reproductive performance in dairy cows. Journal of Dairy Science 85, 2223–2236. LeBlanc SJ, Osawa T, Dubuc J. 2011. Reproductive tract defense and disease in postpartum dairy cows. Theriogenology 76, 1610–1618. Leutert C, Von Krueger X, Plöntzke J, Heuwieser W. 2012. Evaluation of vaginoscopy for the diagnosis of clinical endometritis in dairy cows. Journal of Dairy Science 95, 206–212. McDougall S, Macaulay R, Compton C. 2007. Association between endometritis diagnosis using a novel intravaginal device and reproductive performance in dairy cattle. Animal Reproduction Science 99, 9–23. Pleticha S, Drillich M, Heuwieser W. 2009. Evaluation of the Metricheck device and the gloved hand for the diagnosis of clinical endometritis in dairy cows. Journal of Dairy Science 92, 5429–5435. Rocha A, Rocha S, Carvalheira J. 2001. Reproductive parameters and efficiency of inseminators in dairy farms in Portugal. Reproduction in Domestic Animals 36, 319–324. Runciman DJ, Anderson GA, Malmo J. 2009. Comparison of two methods of detecting purulent vaginal discharge in postpartum dairy cows and effect of intrauterine cephapirin on reproductive performance. Australian Veterinary Journal 87, 369–378. Sakaguchi M. 2011. Practical aspects of the fertility of dairy cattle. Journal of Reproduction and Development 57, 17–33. Salasel B, Mokhtari A, Taktaz T. 2010. Prevalence, risk factors for and impact of subclinical endometritis in repeat breeder dairy cows. Theriogenology 74, 1271–1278. Sanker C, Lambertz C, Gauly M. 2013. Climatic effects in Central Europe on the frequency of medical treatments of dairy cows. Animal 7, 316–321. Senosy W, Uchiza M, Tameoka N, Izaike Y, Osawa T. 2012. Evaluation of reproductive tract infection during early post-partum period and its relationship with subsequent reproductive performance in high milk producing dairy cows. Reproduction in Domestic Animals 47, 203–207. Sheldon IM, Lewis GS, LeBlanc S, Gilbert RO. 2006. Defining postpartum uterine disease in cattle. Theriogenology 65, 1516–1530. Sheldon IM, Noakes DE, Rycroft AN, Pfeiffer DU, Dobson H. 2002. Influence of uterine bacterial contamination after parturition on ovarian dominant follicle selection and follicle growth and function in cattle. Reproduction 123, 837–845. Williams EJ, Fischer DP, Pfeiffer DU, England GCW, Noakes DE, Dobson H, Sheldon IM. 2005. Clinical evaluation of postpartum vaginal mucus reflects uterine bacterial infection and the immune response in cattle. Theriogenology 63, 102–117. Yusuf M, Nakao T, Yoshida C, Long ST, Gautam G, Ranasinghe RMSBK, et al. 2011. Days in milk at first AI in dairy cows; its effect on subsequent reproductive performance and some factors influencing it. Journal of Reproduction and Development 57, 643–649.
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