animal
Animal (2015), 9:6, pp 1038–1044 © The Animal Consortium 2015 doi:10.1017/S1751731115000063
Relationship between locomotor play of dairy calves and their weight gains and energy intakes around weaning G. G. Miguel-Pacheco1†a A. Vaughan1,2, A. M. de Passillé2 and J. Rushen2 1
Applied Animal Behaviour and Animal Welfare Programme, The University of Edinburgh, Easter Bush Veterinary Centre, Roslin EH25 9RG, UK; 2University of British Columbia, PO Box 1000, 6947 Highway 7, Agassiz, BC, Canada V0M 1A0
(Received 24 September 2013; Accepted 11 December 2014; First published online 12 February 2015)
Play behaviour has been proposed as a measure of good welfare in growing animals and locomotor play by calves is often reduced after weaning off milk. Adjusting weaning age according to individual calves’ abilities to eat solid feed maintains energy intake and weight gain during weaning. We investigated the effects of this method of weaning on locomotor play of calves and the relationship between locomotor play and energy intake and weight gains. We measured the running behaviour of 56 Holstein heifer calves before and after weaning. Calves were housed in groups of eight, fed milk, grain starter and hay from automated feeders. Weaning began when their voluntary intake of grain starter reached either 200 or 400 g/day, and weaning was completed when starter intake reached either 800 or 1600 g/day. Before weaning, older calves ran less than young ones; and the duration of running correlated with weight gains and digestible energy intake. Immediately after weaning, digestible energy intake and locomotor play decreased but no correlation was observed between these variables. One week after weaning, the duration of running was correlated with both energy intake and weight gain. Digestible energy intake increased but locomotor play continued to decrease. The amount of running a calf does after weaning partly reflects energy intake and weight gain, supporting suggestions that locomotor play is good indicator of welfare and fitness of growing animals. However, the decline in locomotor play following weaning is not solely due to decreased energy intake. Keywords: play, dairy calf, weaning, animal welfare
Implications Play behaviour is common in young calves and is linked to energy intake. Dairy calves fed milk ad libitum grow considerably faster and display more play than those fed 10–15% BW of milk per day. In current weaning procedures, calves reduce their play. Adjusting weaning age according to an individual’s ability to eat solid feed maintains energy intake and weight gain during weaning. This may have positive implications on the welfare of calves, and play behaviour may be useful as a welfare assessment tool for growing animals. Introduction Positive welfare indicators, such as play behaviour, highlight the presence of good welfare (Boissy et al., 2007; Yeates and Main, 2008). Locomotor play (consisting mainly of running, a
Present address: School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RG, UK. † E-mail:
[email protected] 1038
jumping and bucking) is common in young calves (Reinhardt, 1980; Jensen et al., 1998) and is susceptible to many welfare relevant factors such as food availability (Krachun et al., 2010), space allowance (Jensen and Kyhn, 2000; Mintline et al., 2012), social contact (Duve and Jensen, 2011) and pain (Rushen and de Passillé, 2012; Mintline et al., 2013). For young and growing animals, play behaviour has been proposed as an indicator of good management practices (Held and Špinka, 2011). For dairy calves, weaning off milk at the ages typical in dairy production can be stressful (Weary et al., 2008) and can result in reduced energy intake and poor growth (e.g. Sweeney et al., 2010; Rushen and de Passillé, 2012). Locomotor play is also reduced at weaning but the correlation between energy intake and locomotor play is variable (Krachun et al., 2010; Sweeney et al., 2010; Rushen and de Passillé, 2012) and the relationship with growth rate is unknown. Adjusting the weaning age of calves according to their individual intakes of solid feed can prevent the drop in energy intake and growth after weaning, but results in greater differences between calves in weight gains (WGs) during and immediately after weaning, and in the
Locomotor play of dairy calves around weaning age and duration of weaning (Roth et al., 2009; de Passillé and Rushen, 2012). However, it is not known how this method of weaning affects locomotor play. The aim of the study was to examine the effects on locomotor play of weaning calves off milk according to their intakes of solid feed. We examined whether locomotor play was maintained after weaning, and whether locomotor play was related to (a) digestible energy (DE) intake, (b) pre- and post- weaning growth and (c) age and duration of weaning.
Material and methods The study was carried out in compliance with the Canadian Council on Animal Care Guidelines and approved by the Institutional Animal Care Committee.
Animals, housing and diet We used 56 Holstein heifer calves (mean birth weight 42.7 kg; range 30.0 to 56.1 kg) that were separated from their dams within 6 h of birth. Each calf was housed in individual pens (1.22 × 2.44 m) on wood shaving. They were bottle-fed ad libitum with whole milk twice daily and had constant access to water in buckets. At 6 ± 1 days of age, the calves were moved to group pens (7.08 × 4.74 m) (Figure 1). Pens had slatted metallic floors (2.48 × 4.60 m) and a sawdust bedded area (4.6 × 4.74 m). Calves had access to automated feeders (CF 1000 CS Combi, DeLaval Inc., Tumba, Sweden) that provided whole milk (12 l/day at 40°C; herd averages of 3.97% fat, 4.10% protein and 3.30% lactose from bulk tank samples) and grain starter (ad libitum; CP = 17.9% on DM basis; main ingredients: 16% wheat, 14% barley, 13% canola meal, 13% oats, 10% soya, 105 corn and 4% molasses, Unifeed Ltd., Chilliwack, BC, Canada). They also had ad libitum access to hay (DM = 90.8%, CP = 15.1%, NDF = 51.1%
and ADF = 33.6%) and water troughs (Insentec, Marknesse, the Netherlands). Weigh scales (Smart1, Westernscale Inc., Port Coquitlam, BC, Canada) were located at the milk feeder and water trough. Automatic feeders were equipped with sensors that recognized each calf’s ear tag, allowing feeders to record individual’s intake and weight at each visit.
Treatments and experimental design Once calves were moved to group pens, animals were assigned to one of the four weaning treatments balancing birth weight and age across treatments (de Passillé and Rushen, 2012); resulting in seven experimental pens with eight calves in each (two calves per treatment per pen). Treatment groups were based on starter intake target at the beginning and end of weaning following a 2 × 2 design (Low-High, Low-Low, HighLow and High-High). For two groups, weaning started when average grain consumption over 3 consecutive days was equal to or greater than 200 g/day (Low start). The remaining two groups started weaning when average grain consumption reached 400 g/day over 3 consecutive days (High start). Milk was reduced accordingly to grain consumption. Weaning was completed when average grain consumption over 3 consecutive days was 800 g/day (low end) or 1600 g/day (High end). If calves had not begun weaning by 74 days of age due to insufficient grain consumption, the milk feeder automatically weaned them over a 7-day period. This new group was named computer weaned. Measurements Behavioural observations. Locomotor play was assessed using continuous observation between 0800 and 2300 h for a total duration of 15 h per day. No observations were made between 2300 and 0800 h as locomotor play rarely occurs during this period (Krachun et al., 2010). We recorded the start and end time of each bout of running, enabling measurement of total duration and frequency of running bouts. Calves were observed for 2 days from each of three periods related to weaning (as defined in Table 1), totaling 6 days of behavioural observations. Five of the 6 observed days were chosen randomly within each period, the remaining observed day (immediately post weaning period: 1st day of no milk) was fixed for all the calves. We defined locomotor play as running: that is a rapid forward movement that may include jumping, bucking and/or kicking with one or two legs (Jensen et al., 1998; Jensen and Kyhn, 2000), lasting a minimum of 3 s (Krachun et al., 2010). Table 1 Observation periods Period PreW
Description Before weaning
PW1 to 3 Immediately post weaning PW7 to 9 Later post weaning Figure 1 Layout of experimental group pen.
5 days before the beginning of weaning First 3 days of no milk (weaned) Between the 7th to 9th day after weaning complete
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Miguel-Pacheco, Vaughan, de Passillé and Rushen Bucking and jumping that occurred independently of running were not recorded, since the duration of these behaviours was very short. If a calf did two running bouts that were 0.10) 0.25 (0.08) 0.24 (0.09) 0.07 (0.63)
0.47 (