Competition for water at feeding time The effect of. increasing number of individuals per water dispenser

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1 Competition for water at feeding time The effect of increasing number of individuals per water dispenser Applied Animal Behaviour Science 1, - 1

2 Competition for water at feeding time The effect of increasing number of individuals per water dispenser REBECCA EHRLENBRUCH, TRUDE POLLEN, INGER LISE ANDERSEN AND KNUT EGIL BØE Norwegian University of Life Sciences, Department of Animal- and Aquacultural Sciences, P.O. Box 00, 1 Ås, Norway 1 Corresponding author: Rebecca Ehrlenbruch, (rebecca.ehrlenbruch@umb.no, Norwegian University of Life Sciences, Department of Animal- and Aquacultural Sciences, P.O. Box 00, 1 Ås, Norway, telephone + 0; fax: + 1) 1 1 Abstract The aim of this study was to study the competition for water at feeding time by increasing number of individuals per nipple drinker (., 1 or 0 goats per nipple) with regard on physical displacements from the nipple drinker, queuing, drinking time, drinking frequency and time per drinking bout. A group of 0 dry and pregnant dairy goats were exposed to three treatments; treatment 1:. individuals/nipple ( days), treatment : 1 individuals/nipple ( days) and treatment : 0 individuals/nipple ( days). All goats were video recorded on the last day of each treatment period to observe physical displacement from the nipple drinker, time spent in queue, drinking time and drinking frequency. The goats behaviour was significantly affected by the number of individuals per nipple drinker. Number of physical

3 1 1 1 displacements from the nipple drinker was significantly higher with 0 goats/nipple compared to. and 1 goats/nipple (P<0.01), and queuing only occurred in the treatment with 0 goats/nipple (P<0.0001). Increasing the number of individuals per nipple over. goats/nipple decreased total drinking time (P<0.0001) and drinking frequency (P<0.001).The goats drank significantly faster per drinking bout with 1 and 0 goats/nipple than. goats/nipple (P<0.0). Age had a significant effect on the goats behaviour; where the oldest goats were displacing others more often from the water dispenser (P<0.0) and spent less time in queue (P<0.0). The oldest goats had lower total drinking time (P<0.0) and time per drinking bout (P<0.0) compared to younger goats. Age had no effect on the goats drinking frequency. In conclusion, increasing the number of individuals over 1 goats per nipple drinker increased the competition for water at feeding time. Queuing only occurred with one nipple per 0 goats and this treatment also had the highest number of physical displacements whereas total drinking time, drinking frequency and time per drinking bout decreased when having more than. goats per nipple drinker. 1 1 (Key words: goat; nipple drinker; restricted resource) Introduction Drinking occurs mainly during feeding for both pigs (Bigelow and Houpt, 1) and goats (Rossi and Scharrer, 1) and is generally socially facilitated (Forkman, 1) and synchronized (e. g. Rook and Penning, ). Reduced possibility to simultaneous feeding and drinking can lead to decreased feeding/drinking time and hence lower the feed/water intake. Especially the low ranking individuals may suffer from this (e.g. Millinski and Parker, ). In a study on dairy goats, Jørgensen et al. (00) found that feeding time was reduced

4 when increasing number of individuals per feeding place and that the difference between low ranking and high ranking increased. Studies on both cattle (e. g. Corkum et al., 1; DeVries et al., 00) and pigs (e. g. Hansen et al., 1; Andersen et al., 1; Rasmussen et al., 00), show that eating time is reduced and aggression is increased when increasing the number of animals per feeding place over a certain level. 1 Data on the effect of increasing the number of animals per water dispenser is not so well documented. Turner et al. (1) found that when increasing the number of pigs per drinker from to 0, number of displacements at the water dispenser and queuing increased, whereas water usage was unchanged. In sheep, an increased number of ewes per nipple drinker gave an increase in total drinking time and number of displacement, but there was no effect on queuing (Bøe, 1). To our knowledge, no such documentation exists in goats The aim of this experiment was to study the competition for water at feeding time by increasing the number of individuals per nipple drinker (., 1 or 0 goats per nipple) in dairy goats Materials and methods Experimental design 1 A group of 0 dairy goats were exposed to three different treatments where each treatment lasted for five days. At the start of the experiment the goats had access to four nipple drinkers (treatment 1:. individuals/nipple), then two nipple drinkers (treatment :1

5 individuals/nipple) and at the end the goats had only access to one nipple drinker (treatment : 0 individuals/nipple)... Experimental pen 1 1 The experiment was performed in an insulated, mechanically ventilated building where the ambient air temperature was kept at -1 C. The goats were kept in a pen with expanded metal flooring and had a total area of 1. m, giving 0. m /goat. This is a low space allocation per animal and does not meet the space requirement for organic goat farming in Norway (which is 1. m /goat), but is representative for the indoor space allocation used for dairy goats in commercial production in Norway. Four nipple drinkers (mod. Suevia Haiges, flow rate of approximately.0 l/min) were localized in the middle of the pen, two on each side of a centre water supply pipe Animals and feeding Thirty dry and pregnant (approximately 0 days) goats of the standard Norwegian dairy goat breed were used, and were on average. years old (range - years) with a body weight of. ±.0 kg (mean ± SD). The goats were fed twice a day (0.0 h and 1.00 h) where hay was offered ad libitum and 0. kg of standard concentrate (1.0 MJ NE 1 /kg DM) was given each goat per feeding time. The group was kept stable in the same pen for at least four months before the experiment... Behavioural observations and water usage

6 1 The goats were individually marked on their back and video recorded the last day of each treatment for two hours (from 0.0 to 0.0 h and from 1.00 to 1.00 h) right after new roughage was offered at the feeding table. One camera (Panasonic NV-GS0) was suspended above the nipple drinkers with a wide-angle lens (DS-WA-, Schneider Optics). The number of physical displacements from the nipple drinker (one goat has a nipple in its mouth and another goat is taking over, forcing it away by butting or pushing) was scored continuously for the individual that displaced. In addition, the time per drinking bout (started when the goat had its lips around the nipple and terminated when it took its lips away from the nipple) time spent drinking (total time a goat had a nipple in its mouth) and time spent queuing (head oriented towards the nipple, with the head less than 0. m from the occupied nipple, Turner et al., 1) was scored. From these observations the drinking frequency, drinking time and time spent queuing were calculated Water usage was recorded at morning feeding every day for each treatment ( days) by reading the water meter (Altaїr N C0 A), which was connected to the water supply pipeline. The water meters were carefully calibrated (accuracy ± 0.1 litres) before the start of the experiment. The flow rate from the nipple drinkers was measured to be.0 l/min. Water wastage was not recorded Statistical analysis 1 A Kruskal-Wallis Test (Hatcher and Stephanski, 1) was used to analyze the effect of increasing number of individuals per nipple drinker (., 1, 0) on the goats behaviour with respect to physical displacements from the nipple drinker, queuing, drinking frequency, drinking time and time per drinking bout. Differences between means were analysed by using

7 the Student-Newman Keul Test. Pearson correlation was used to test the relationship between age, displacements, drinking time, drinking frequency, time per drinking bout and time spent in queue.. Results Number of displacements was generally quite low, but significantly higher in treatment than in treatment 1 and (Table 1). Older goats were displacing other goats from the nipple drinker more often than younger goats (P<0.0, R=0.) Queuing was only found in treatment where each goat spent on average. s queuing (Table 1), but individual differences were prominent. Ten goats were never observed queuing whereas five goats were standing in queue in more than one minute in the total time observed. Older goats spent less time queuing than younger goats (P<0.0, R=-0.). The goats that were spending more time queuing were also the goats with the highest drinking frequency (P<0.001, R=0.) Total drinking time was minutes and seconds per goat in the treatment with. goats/nipple (treatment 1) and was reduced by. % and 0. % respectively when increasing the number of individuals per drinker to 1 (treatment ) and 0 (treatment ) (Table 1). The individual variation in total drinking time increased with increasing number of goats per nipple drinker (CV = %, 0 % and 0% for., 1 and 0 individuals/nipple respectively). In treatment, seven of the 0 goats had their total drinking time reduced by more than 0% compared to the total drinking time they had in treatment 1, whereas in

8 treatment no goats experienced such a large reduction. Age clearly influenced total drinking time, as older goats had lower drinking time compared to young ones (P<0.0, R=-0.). The goats drank more frequently in treatment 1 compared to treatment and, where the drinking frequency decreased down to.1 in the h observation period (Table 1). However, the goats drank significantly faster per drinking bout in treatment and compared to treatment 1 (Table 1). Age of the goats also influenced this parameter as older goats tended to have shorter drinking bouts (P<0.0, R=-0.). (Table 1 here) Water usage was. ± 0.1,. ± 0.1 and. ± 0. litres/goat (mean ± SE) for treatment 1 (. individuals/nipple), treatment (1 individuals/nipple) and treatment (0 individuals/nipple), respectively. Water usage did not differ between treatments and there was a small variation between days within treatments Discussion The main result from this experiment was that the competition for water at feeding time increased when having more than 1 goats per nipple drinker. Queuing only occurred with one nipple per 0 goats and this treatment also had the highest number of physical displacements, whereas total drinking time, drinking frequency and time per drinking bout decreased when having more than. goats per nipple drinker.

9 Restricting the access to important resources will generally lead to increased aggression level (e. g. Hansen et al., 1; Bøe et al., 00). Increasing number of animals per nipple drinker have resulted in more physical displacements both in ewes (Bøe, 1) and pigs (Turner et al., 1), but the water usage was unchanged in these studies. When increasing the competition for water like in the present study, the oldest individuals got better access to the dispenser than the youngest ones by displacing others from the dispenser more frequently and standing less time in queue. This is not surprising since the social rank in goats is reported to be strongly correlated with age and body size (Barroso et al., 000). 1 1 Queuing did only occur when 0 goats had to share one nipple drinker and this corresponds to Turner et al. (1) who found more queuing with a poorer drinker allocation (0 vs. individuals/nipple), whereas Bøe (1) found no effect of number of ewes per nipple drinker (. vs. 1 vs. 0 individuals/nipple) on queuing The reduction in time spent drinking when increasing the number of animals per nipple drinker is in accordance with comparable results in pigs (Turner et al., 1). Further on, several studies show a clear reduction in time spent eating when increasing the number of animals per feeding place (goats: Jørgensen et al., 00; cattle: e.g. DeVries et al., 00; pigs: Rasmussen et al., 00). Also the time per drinking bout decreased when having more than. goats per nipple drinker. However, a reduced time spent drinking does not necessarily imply that the actual intake of water decreased as the goats may have increased their consumption rate and/or alternatively may have postponed their water intake to after the observation period. The likelihood that the goats have postponed their water intake is small, since they prefer to drink at feeding (e.g. Rossi and Scharrer, 1) and their behaviour is often synchronized (e.g. Rook and Penning, ). Jørgensen et al. (00) found that

10 reducing the feeding space for dairy goats resulted in a reduced time spent feeding and the goats did not utilize the strategy of consuming feed at different times of the day, consequently outside the rush hours. In pigs, Turner et al. (1) found that even if the time spent drinking decreased, the water usage was maintained at the same level and so was the average daily gain. Similar, there was no change in water usage between treatments in this experiment. Correspondingly, Jørgensen et al. (00) found that the intake of hay in goats was maintained even if the time spent eating decreased when increasing the number of goats per feeding place The large reduction in drinking time is a major concern for some of the individuals. For example in the treatment with 1 individuals per nipple, one goat had a total drinking time of only sec. Also Jørgensen et al. (00) found that some goats hardly had access to the feed when number of individuals per feeding place increased. However, we do not know if the goats with a low total drinking time have postponed their water intake after our observation period where there was lower competition than during feeding time. A change in feeding strategy with increased competition has been reported in both pigs and cattle (Nielsen et al., 1; Olofsson, 1) In addition to animal/dispenser ratio, the number of water dispensers functioning in the group is of great importance, giving the animals the opportunity to drink simultaneously which they normally prefer (Forkman, 1). The experimental results show that the competition for water at feeding time increased when having more than 1 goats per nipple drinker, but it is hard to say at which level between 1 and 0 individuals per nipple drinker this increase occurred.

11 In conclusion, increased number of individuals to 0 goats per nipple drinker enhanced the competition level substantially. Queuing only occurred with one nipple per 0 goats and this treatment also had the highest number of physical displacements whereas total drinking time, drinking frequency and time per drinking bout decreased when having more than. goats per nipple drinker. Acknowledgements 1 1 The authors would like to thank Magnhild Nymo and her colleagues at Senja Agricultural School for taking good care of the goats during the experiment. The experiment was financially supported by grants from the Norwegian Research Council, Agricultural Agreement Research Fund and Foundation for Research Levy on Agricultural Products.

12 References Andersen, I. L., Bøe, K. E., Kristiansen, A. L., 1. The influence of different feeding arrangements and food type on competition at feeding in pregnant sows. Appl. Anim. Behav. Sci., 1-. Barroso, F. G., Alados, C. L., Boza, J., 000. Social hierarchy in the domestic goat: effect on food habits and production. Appl. Anim. Behav. Sci., -. Bigelow, J. A., Houpt, R., 1. Feeding and drinking patterns in young pigs. Physiol. Behav., Bøe, K., 1. Drikkeadferd for drektige søyer, med fokus på antall dyr per drikkenippel (Drinking behaviour of pregnant ewes, with focus on number of animals per water nipple), ITF report no., Norges Landbrukshøgskole, Institutt for tekniske fag, Ås, pp Bøe, K. E., Berg, S., Andersen, I. L., 00. Resting behaviour and displacements in ewes effects of reduced lying space and pen shape. Appl. Anim. Behav. Sci.,

13 Corkum, M.J., Bate, L.A., Tennessen, T., Lirette, A., 1. Consequences of reduction of number of individual feeders on feeding behaviour and stress level of feedlot steers. Appl. Anim. Behav. Sci. 1, -. DeVries, T.J., von Keyserlingk, M.A.G., Weary, D.M., 00. Effect of feeding space on the inter-cow distance, aggression and feeding behavior of free-stall housed lactating dairy cows. J. Dairy Sci., 1-1. Forkman, B., 1. The social facilitation of drinking: What is facilitated, and who is affected? Ethol., Hansen, L.L., Hagelso, A.M., Madsen, A., 1. Behavioural results and performance of bacon pigs fed "ad libitum" from one or several self-feeders. Appl. Anim. Ethol., Hatcher, L., Stepanski, E. J., 1. A step-by-step approach to using the SAS System for univariate and multivariate statistics, Cary, NC: SAS Institute Inc, pp Jørgensen, G.H.M., Andersen, I.L., Bøe, K.E., 00. Feed intake and social interactions in dairy goats - The effects of feeding space and type of roughage. Appl. Anim. Behav. Sci., -1. 1

14 Milinski, M., Parker, G. A.,. Competition for resources, in: Krebs, J. R. Davies, N. B. (Eds.), Behavioural Ecology, Blackwell Scientific, Oxford, pp.1-1. Nielsen, B. L., Lawrence, A. B., Whittemore, C. T., 1. Effect of group size on feeding behavior, social behavior, and performance of growing pigs using single-space feeders. Livest. Prod. Sci., -. Olofsson, J., 1. Competition for total mixed diets fed for ad libitum intake using one or four cows per feeding station. J. Dairy Sci., Rasmussen, D.K., Weber, R., Wechsler, B., 00. Effects of animal/feeding-place ratio on the behaviour and performance of fattening pigs fed via sensor-controlled liquid feeding. Appl. Anim. Behav. Sci., Rook, A.J., Penning, P.D.,. Synchronization of eating, ruminating and idling activity by grazing sheep. Appl. Anim. Behav. Sci., Rossi, R., Scharrer, E., 1. Circadian patterns of drinking and eating in pygmy goats. Physiol. Behav. 1, -. 1

15 Turner, S.P., Edwards, S.A., Bland, V.C., 1. The influence of drinker allocation and group size on the drinking behaviour, welfare and production of growing pigs. Anim. Sci., 1-. 1

16 Table 1. Competition (mean ± SE) for water at feeding time (treatment 1:. goats/nipple, treatment : 1 goats/nipple, treatment : 0 goats /nipple). Number of individuals per nipple drinker. 1 0 F, P Number of physical displacements 0. ± 0. a 0. ± 0.1 a 1. ± 0. b. <0.01 from the nipple/goat Total time spent queuing (sec)/goat 0.0 ± 0.0 a 0.0 ± 0.0 a. ±. b. < Total drinking time (sec)/goat (range) 1. ±. a (-).0 ±. b (-1). ±. c (-1) 1.1 < Drinking frequency/goat (range).1 ± 0. a (-1).1 ± 1.0 b (-).1 ± 0. b (-). <0.001 Time per drinking bout (sec)/goat 1. ± 1. a 1. ± 1. b 1. ± 1. b. <0.0 Different superscripts show significant differences between means. 1