Search

The present study aimed to quantify calves'(Bos taurus) preference for long versus chopped hay and straw, and hay versus straw, using cross point analysis of double demand functions, in a context where energy intake was not a limiting factor. Nine calves, fed milk replacer and concentrate, were trained to work for roughage rewards from two simultaneously available panels. The cost (number of muzzle presses) required on the panels varied in each session (left panel/right panel): 7/35, 14/28, 21/21, 28/14, 35/7. Demand functions were estimated from the proportion of rewards achieved on one panel relative to the total number of rewards achieved in one session. Cross points (cp) were calculated as the cost at which an equal number of rewards was achieved from both panels. The deviation of the cp from the midpoint (here 21) indicates the strength of the preference. Calves showed a preference for long versus chopped hay (cp = 14.5; P = 0.004), and for hay versus straw (cp = 38.9; P = 0.004), both of which improve rumen function. Long hay may stimulate chewing more than chopped hay, and the preference for hay versus straw could be related to hedonic characteristics. No preference was found for chopped versus long straw (cp = 20.8; P = 0.910). These results could be used to improve the welfare of calves in production systems; for example, in systems where calves are fed hay along with high energy concentrate, providing long hay instead of chopped could promote roughage intake, rumen development, and rumination.

This study investigated firstly if confined calves perform more locomotor behaviour when open-field tested in pairs than when tested individually, and secondly if length of confinement affects the build-up of motivation to perform locomotor behaviour. In the first experiment,14 calves were open-field tested on two successive days either individually or as a pair. Calves walked more and performed more locomotor play when tested in pairs, suggesting that it may be appropriate to avoid isolation when aiming to measure the effects of confinement on locomotor behaviour. In the second experiment, in each of three successive weeks, 24 calves had access to an exercise arena for 45 min daily on three successive days either: (i) the first 3 days, (ii) the third, fourth and fifth day, or (iii) the fourth, fifth and sixth day. On the seventh day the calves were released into the arena for 10 min (open-field test). All calves received all three treatments in a Latin square design. Calves performed more locomotor play, and they trotted more after 3 days without access to the arena than after 1 or 0 days, suggesting that in calves the motivation to perform locomotor play and trotting increases with length of confinement.

An open-field test and a preference test were used to investigate the motivation of calves and heifers to perform locomotor behaviour. Thirty-six calves and 48 heifers were housed in large pens for a pre-period of 2 weeks. During the last week of the pre-period, all calves were subjected to a 10-min open-field test where locomotor behaviours (walking, trotting, galloping and bucking) were recorded. The spatial preferences of 28 of the calves were also measured in a maze where they could choose between a large (21 m2) and a small (2.4 m2) goal room in six successive tests (runs). During the experimental period, calves and heifers were confined and thus deprived of the opportunity to perform locomotor behaviours for either 4 weeks, 2 weeks or 1 week immediately before being tested, or they stayed in the large pens for the whole period (control). All calves and heifers were subjected to the 10-min open-field test and 28 of the calves were subjected to the spatial preference test two days later. Finally, a third test was conducted in which 21 of the calves could choose between the large room and the small room containing a small amount of food. During the open-field test after the experimental period, confined calves galloped and bucked more than control calves (19.4, 17.1, 11.4 and 4.4 s for treatments 4wk, 2wk, 1wk and control; P

To investigate the effect of social contact during early development on open-field responses and social responses, 80 female dairy calves were housed either in open single pens (SOpen), closed single pens (SClosed), calf-groups (GCalf), or groups of calves and cows (GCow) until 3 months of age. During the first 3 months, the calves were open-field tested at 2 and 10 weeks of age. Calves isolated in closed single pens (SClosed) performed more exploration during the open-field tests at 2 and 10 weeks of age than did calves housed in open single pens (SOpen). During the open-field test after the experimental period at 6 months of age, previously isolated calves (SClosed) had a longer latency to enter an open-field arena, and during a social test at this stage group-reared calves (GCalf and GCow) sniffed and mounted other calves more than calves housed in single pens (SOpen and SClosed). The results suggest that isolation increases the motivation to explore a novel environment, and that housing in groups faci...

Dairy cows are typically gregarious, but isolate themselves in the hours before calving when kept on pasture. Self-isolation is also a common behavior of ill animals. The objectives of this study were to determine if dairy cows would (1) isolate to calve when housed indoors in an individual maternity pen and (2) continue to isolate when ill after calving. We selected individuals from a pool of 79 multiparous Holstein dairy cows based on inclusion criteria created to address each objective. Cows were moved from a group pen to 1 of 10 adjacent maternity pens. Half of these individual pens were partially covered with plywood, creating a secluded corner as well as a window that provided visual access to the group pen. The other individual pens were uncovered on all sides. For our first objective, we selected 39 cows that were moved into the maternity pens >8h before calving (partially covered: n=19; uncovered: n=20). For our second objective, we selected 18 cows housed in the partially covered pens: 9 cows with high rectal temperature after calving and signs of an infectious disease (mastitis, metritis, pneumonia, or some combination), and 9 healthy cows paired with ill cows based on the amount of time they spent in the maternity pen before calving. Ten-minute scan sampling was used to record the location and lying time from 6h before to 72h after calving. Individual feed intake was measured after calving. Binomial tests were used to determine if cows in both pen types were more likely to calve in the corner or window side of the pen. Repeated-measures ANOVA were used to determine if cows used the corner more as calving approached and if ill cows spent more time lying or more time in the corner compared with healthy cows in the 72h after calving. Cows in the uncovered pens were equally likely to calve on both sides of the pen (10 vs. 10), but 79% of cows in the partially covered pens calved on the corner side of the pen (15 vs. 4). Cows in the partially covered pens used the corner side of the pen more in the 1h before and after calving compared with those housed in the uncovered pens. Ill cows housed in the partially covered pens ate less, tended to spend more time lying down, and spent more time in the corner of the pen compared with healthy cows. These results indicate that periparturient dairy cows seek seclusion to calve and when ill, which suggests that adding a secluded area to maternity and hospital pens may be beneficial.

The aim of this study was to investigate behavioural changes before and after calving in dairy cows in order to describe behavioural signs of imminent calving and of cows’ recovery after calving. Thirty-two multiparous Danish Holstein Frisian cows with an unassisted calving were studied from 96 h before until 96 h after calving while housed in individual calving pens. Data on behaviour were obtained via video recordings and accelerometers attached to the cows’ legs. Cows spent less time lying, had more lying bouts and were more active the day before calving as compared to 2–4 days before calving. The number of lying bouts and the level of activity increased throughout the 6 h prior to calving. During the last 2 h prior to calving the duration of contractions and the number of times the cow turned her head towards the abdomen were increased, while the duration of feeding and drinking was decreased. Within minutes after calving cows stood up and licked their calves; second parity cows had a longer latency to stand than later parity cows. Sniffing and licking the calf peaked during the first hour after calving and decreased during the five successive hours, while calves’ sniffing the cow peaked during the second hour after birth. The high level of cows’ sniffing and licking their calves coincided with low levels of lying and feeding during the first hours after calving. Compared to the first 6-h period after calving, cows spent more time lying and feeding during the following two 6-h periods, while the duration of sniffing and licking calf and the number of lying bouts decreased throughout the 24 h after calving. Calves spent the most time sniffing the cow and suckling during the first 6-h period after birth, while the time spent lying increased and the number of lying bouts decreased throughout the 24 h following birth. Cows spent more time lying on the second day after calving than on the first day after calving. The results show marked behavioural changes during the last 6 h prior to calving and suggest that behavioural changes may be useful indicators of imminent calving. Furthermore, the results show that the first hours after calving contain most cow–calf interaction. These behaviours were at the expense of the cows’ resting and feeding, which showed a rebound during the subsequent hours and the following day. This suggests that ample opportunity to rest and feed during the first days after calving may be beneficial for cow welfare.

The present study investigated the effects of source and level of dietary fiber (DF) and feeding frequency (once vs. twice daily) on feeding motivation and plasma metabolites at 4 different time points post feeding. Sixty pregnant sows (Sus scrofa, 4 blocks of 15 sows) were allocated to 1 of 5 diets within blocks. Four diets were restricted (approximately 35 MJ ME/d): a barley and wheat control diet (171 g DF/kg DM; 12 g DF/MJ ME), and 3 fiber diets formulated to contain 35% DF by including pectin residue (323 g DF/kg DM; 25 g DF/MJ ME), potato pulp (404 g DF/kg DM; 29 g DF/MJ ME), or sugar beet pulp (367 g DF/kg DM; 25 g DF/MJ ME). The fifth diet was a mixture including an equal amount of the 3 fiber diets offered semi ad libitum (ad libitum access to feed during 6 periods of 1 h starting at 0300, 0600, 1100, 1500, 1800, and 2300; 354 g DF/kg DM; 25 g DF/MJ ME). The experimental period included 2 periods of 4 wk each. Restricted-fed sows were fed once daily (0800 h) during the first period and twice daily (0800 and 1500 h) during the second period, or vice versa. Semi ad libitum fed sows had access to feed 6 times a day in both periods. In each period, the feeding motivation was assessed in an operant conditioning test, and samples of peripheral blood were taken in a balanced design, at 0900, 1200, 1900, and 0700 h, corresponding to 1, 4, 11, and 23 h after feeding for restricted sows fed once daily. No differences in the feeding motivation were found between the 4 restricted diets at any of the time points post feeding, but semi ad libitum fed sows had a decreased feeding motivation (P < 0.001). Among the restricted-fed sows, feeding twice daily resulted in decreased feeding motivation at 1900 h (P < 0.001) and at 0700h (P < 0.05) compared with feeding once daily, but not at 0900 and 1200 h, indicating that feeding twice daily reduced feeding motivation during the night compared with feeding once daily. Among restricted-fed sows, plasma concentrations of short-chain fatty acids (SCFA) were greater in sows fed high-fiber diets compared with the control (P = 0.02). Nonesterified fatty acid was least in sows on the control diet and greatest in sows on the potato diet, whereas sows on the pectin and sugar beet diets were intermediate (P < 0.001). Less diurnal variation in glucose (P < 0.001) was seen in sows on high-fiber diets. In spite of the found effects on plasma metabolites, the applied level of fiber in the diet of restrictedly fed sows did not reduce their feeding motivation irrespective of fiber source.

The aim was to investigate the early behaviour in dairy cows and their calves. Thirty-eight multiparous Danish Holstein Frisian cows and their calves were housed in individual calving pens during the first twelve days post-partum and their behaviour was observed during 24 h on days 3, 7 and 11. Cows gradually reduced the time spent sniffing and licking their calves from 59 to 49 min over the days studied (P < 0.05). On the other hand, they increased the time spent sniffing and licking the neighbouring cow from less than half a minute on days 3 and 7 to 1 min on day 11 (P < 0.05). Calves increased the time spent sniffing and licking their dams’ head from 2 to 8 min over the days studied (P < 0.001). Furthermore, they increased the time spent performing locomotor play behaviour from 7 to 10 min (P < 0.05) and the time spent performing social play behaviour from 1.4 to 4 min over the days studied (P < 0.01). To test the effect of day after calving on cows’ behavioural priorities, the cows were tested on either day 4, 8 or 12 after calving by removing them from their pens during 3 h and subsequently reintroducing them. Behavioural observations during 3 h after reintroduction showed that cows tested on day 4 spent more time sniffing and licking their calves than cows tested on days 8 and 12. The decrease in maternal grooming, and the concurrent increase in social behaviour of the calf towards the dam, may illustrate the beginning of a gradual shift from the dam being the initiator of cow–calf contact to the calf being the initiator, while the increase in social behaviour of the cows towards the neighbouring cow on day 11 suggests an increased motivation to associate more with other cows at this stage after calving.

Although horses are social animals they are often housed individually with limited social contact to other horses and this may compromise their welfare. The present study included eight young female horses and investigated the strength of motivation for access to full social contact, head contact and muzzle contact, respectively, to a familiar companion horse. Horses were housed individually next to their companion horse and separations between pens prevented physical contact. During daily test sessions horses were brought to a test area where they could access an arena allowing social contact. Arena access during 3 min was given after completion of a predetermined number of responses on a panel. Fixed ratios (FR) of 8, 16, 24, 32 and 40 responses per arena access were applied in a random order, one per daily test session, within each test week (Monday to Friday), and the number of rewards per daily test session was recorded. All horses could access all three types of social contact in a cross-over design, and an empty arena was used as control. Motivational strength was assessed using elasticity of demand functions, which were estimated based on the number of rewards earned and FR. Elasticities of demand for the three types of social contact were low (−0.20), and not significantly different, although increasing FR still resulted in a decrease in rewards obtained for all three types of social contact (P < 0.001). Across FRlevels horses earned more rewards for social contact than for an empty arena, as shown by much higher intercept values (2.51 vs. 0.99; P < 0.001). However, the elasticity of demand for infrequent access to an empty arena (−0.08) was lower than for social contact (P < 0.01) and not significantly different from zero (P = 0.07). Horses performed more social behaviour the lesser the restriction on social contact (full > head > muzzle). However, the finding that horses showed a similar and high motivation for all three types of social contact suggests that they are valued equally highly in a situation where the alternative is no social contact. Although horses are social animals they are often housed individually with limited social contact to other horses and this may compromise their welfare. The present study included eight young female horses and investigated the strength of motivation for access to full social contact, head contact and muzzle contact, respectively, to a familiar companion horse. Horses were housed individually next to their companion horse and separations between pens prevented physical contact. During daily test sessions horses were brought to a test area where they could access an arena allowing social contact. Arena access during 3 min was given after completion of a predetermined number of responses on a panel. Fixed ratios (FR) of 8, 16, 24, 32 and 40 responses per arena access were applied in a random order, one per daily test session, within each test week (Monday to Friday), and the number of rewards per daily test session was recorded. All horses could access all three types of social contact in a cross-over design, and an empty arena was used as control. Motivational strength was assessed using elasticity of demand functions, which were estimated based on the number of rewards earned and FR. Elasticities of demand for the three types of social contact were low (−0.20), and not significantly different, although increasing FR still resulted in a decrease in rewards obtained for all three types of social contact (P < 0.001). Across FRlevels horses earned more rewards for social contact than for an empty arena, as shown by much higher intercept values (2.51 vs. 0.99; P < 0.001). However, the elasticity of demand for infrequent access to an empty arena (−0.08) was lower than for social contact (P < 0.01) and not significantly different from zero (P = 0.07). Horses performed more social behaviour the lesser the restriction on social contact (full > head > muzzle). However, the finding that horses showed a similar and high motivation for all three types of social contact suggests that they are valued equally highly in a situation where the alternative is no social contact.

Udgivelsesdato: Maj 2010 Behavioral changes caused by variation in hunger have a great potential in health monitoring in dairy cattle. The present experiment used 48 Danish Holstein bull calves with a median age of 33 d. We examined the effect of different levels of hunger (reduced, in which calves were fed 1.5 L of milk via esophageal tube before feeding; increased, in which calves were fed half milk ration at the previous feeding, or control, in which calves were fed normal ration at the previous feeding) on feeding behavior of calves fed via different tube diameters (6.0, 3.0, or 1.5 mm). Behavior observed during a 40-min period after morning milk feeding on d 7, 9, and 11 of testing is reported. No significant interactions between tube diameter and hunger level on behavior were found. Reduced tube diameter led to increased latency to empty the teat bucket, increased duration of nutritive sucking, and decreased duration of nonnutritive sucking for calves fed via 1.5-mm tubes compared with calves in the 2 other treatments. The duration of nonnutritive sucking increased with increasing level of hunger. Furthermore, calves with reduced hunger showed a lower frequency of butting than calves at the 2 other hunger levels. The present results show that only a rather high reduction in tube diameter led to reduced drinking rate. Neither reduced nor increased hunger levels led to changes in drinking rate, but calves showed reduced nonnutritive sucking and butting when they were less hungry and increased nonnutritive sucking and butting when hunger was increased. The results suggest that nonnutritive sucking is a more sensitive indicator than drinking rate of changes in feeding motivation. Consequently, reduction in nonnutritive sucking might be a new candidate in the search for behavioral indicators of disease in dairy calves.

The aim of the present study was to investigate the effects of teat-feeding method and weaning method on behavior, milk and concentrate intake, and weight gain of group-housed dairy calves. Forty-eight calves were housed in groups of 4 and offered 6 L of whole milk per calf in 2 daily feedings. In 6 of the 12 group pens, the calves were offered the milk in a teat bar with a separate milk compartment for each teat, whereas in the remaining 6 pens, the calves were offered the milk in a teat bar with all teats connecting to 1 shared milk compartment. Calves were gradually weaned off milk by reducing the volume of milk over a 10-d period, starting at an average age of 47 d. In 6 pens (3 pens with each of the 2 milk-feeding treatments), calves were weaned by volume reduction, whereas in the remaining pens, the calves were weaned by diluting the milk with water (WD) and maintaining the same total volume of liquid. Daily concentrate intake per pen was recorded during weaning and 1 wk after weaning. Behavior was recorded around milk feeding, by direct observation on 1 occasion before and on 1 occasion during weaning, and by video on 1 occasion before and 2 occasions during weaning. Furthermore, the behavior was recorded during the 15 h of light on 1 occasion during weaning. Individual milk intake was measured twice by weighing the calves immediately before and after milk feeding. The calves fed via a separate teat bar switched between teats more often than calves fed with a shared teat bar. There was greater variation in the duration of ingesting milk within groups fed via a separate teat bar, but no effect of teat bar design was found on the variation in milk intake within the groups. Calves fed via a separate teat bar took longer to start eating concentrate after milk feeding than calves fed with a shared teat bar. The WD calves had a lower concentrate intake during weaning than weaned by volume reduction calves. The WD calves were lying down less during the 30 min after milk feeding and during the 15 h of light, although they had a shorter latency to lie down after milk feeding. In conclusion, a separate teat bar increased teat switching, increased variation in duration of ingesting milk, and increased the latency to eat concentrates after milk feeding. There was no effect of the teat bar design on feed intake or weight gain. However, weaning the calves by gradually diluting the milk with water reduced lying during weaning and reduced the concentrate intake during and after weaning.

The effect of milk allowance and type of weaning on behaviour in dairy calves was investigated. A total of 72 calves divided into 6 blocks of 12 calves were used. The calves in each block were divided into two groups and housed in a separate section containing two straw-bedded pens, each with a computer controlled milk feeder. Within block, calves were assigned to either a low milk allowance (4.8 l/day for heavy breeds and 3.6 l/day for Jersey) or a high milk allowance (9.2 l/day for heavy breeds and 7.2 l/day for Jersey), while concentrate was feed ad libitum. One group in each block was assigned to gradual weaning from 6 to 8 weeks of age, while the other was assigned to abrupt weaning at 8 weeks of age. Recordings of cross-sucking were done on days before, during and after weaning, and use of milk and concentrate feeder was recorded throughout the experiment. Abruptly weaned calves performed more cross-sucking than gradually weaned calves immediately after weaning (P

The first objective was to test if pigs prefer a rooting material with food feedback to one without, and if they prefer to search for food while rooting compared to obtaining food without rooting. For measuring preferences we used cross-points between double demand curves. Demand curves describe the change in consumption with changing workload. Double demand curves are obtained by allowing animals to work concurrently for two resources. Their cross-point depends on the relative attractiveness of resources and therefore provides a measure of preference. The second objective was to test if results obtained when using a common scaling factor agrees with results obtained when using direct comparisons. The possibility of revealing lack of substitution by double demand curve slopes equal to zero was also addressed. Test resources used were sand, carrots, and sand with carrots. They varied according to whether the pigs could both root and eat (sand with carrots), only root (sand), or only eat (carrots). Peat was used as scaling factor. Ten ad libitum fed pigs were allowed to work concurrently, by pressing either of two panels, for two resources. Pigs were subjected to three scaling tests: peat versus sand, peat versus carrots, and peat versus sand with carrots, and three direct tests: carrots versus sand, sand with carrots versus carrots, and sand with carrots versus sand. The workload (FR, i.e. presses required per reward) alternated between FR8, FR16, FR24, FR32, and FR40 for one material, while it was kept constant for the other at FR24 (‘midpoint’). Double demand curves were constructed for all test conditions. For both the scaling tests and the direct tests, cross-points between the double demand curves showed that the pigs preferred both carrots and sand with carrots to sand, and that they did not prefer sand with carrots to carrots or vice versa. Preference quotients were calculated to measure the preference strength. Overall, results showed that a rooting material with food feedback was preferred to one without, and that non-hidden and hidden food was valued equally. Food feedback appears, thus, to be an important quality of a rooting material, even when pigs are fed ad libitum. Furthermore, results from the scaling tests overall agreed with results from the direct tests. The scaling approach therefore seems valid, at least for these particular resources. Yet, the possibility of revealing lack of substitution by slopes equal to zero is not clear.

To identify those behavioural patterns that represent ethological needs, the important questions are firstly how strongly motivated are behavioural patterns believed to represent ethological needs, and secondly how do we best provide an outlet for those behaviours. To establish motivational strength one approach is to impose an increasing cost of access to perform the particular behavioural pattern. The performance of the behaviour as a function of the cost imposed may be described by a so-called demand function. Measures derived from this function are the sensitivity to increasing cost (the price elasticity) and the maximum effort the animal will commit for access to perform a bout of the behaviour (the maximum price paid). It has been questioned whether a single price elasticity value may be assigned to the importance of each behavioural pattern, or if a value may only be assigned to a certain quantity of access. The prerequisites for price elasticity to be an indication of motivational strength of a behavioural pattern are outlined, and examples of systematic development of the price elasticity of demand as a measure of motivational strength are given. How do we identify those stimuli that best provide an outlet for the behaviours that represent behavioural needs? In addition to giving the animal a choice it is relevant to impose a cost on the choice. Measures of preference from analysis of cross-points between concurrent demand functions may be used to identify which resources best ensure the satisfaction of the ethological need.

We considered experiments where animals chose one of all possible simultaneously presented options. The animals might be observed at repeated occasions. In the ethological literature the analysis is often focused on testing the global hypothesis of no difference in preferences by non-parametric methods. This fails to address the estimation of a ranking. Often this approach cannot adequately reflect the experimental setting and the repeated measurement structure. Therefore, we propose to model the choice probabilities for the options with a multinomial logistic model. The correlation induced by repeated measurements is incorporated by animal specific random intercepts. The ranking of the options is taken as the order of the choice probabilities. Adopting a Bayesian approach samples from the posterior distribution of the choice probabilities provide directly samples from the posterior of the rankings. Based on this an estimate of the ranking and description of its variability can be derived. The computation was performed via Markov chain Monte Carlo sampling and was implemented using WinBUGS. We illustrate our approach with an experiment to determine the preference of pigs for three different rooting materials. The proposed method allowed deriving an overall ranking for different combinations of the materials and the spatial positioning.

Calves fed by computer-controlled milk feeders are often weaned gradually by reducing the size of the milk portions. However, reducing the number of milk portions instead may lower calves' occupation of the milk feeder and stimulate their concentrate intake, especially when they are offered a high milk allowance. Before weaning, but not during weaning, the calves on low milk allowance occupied the milk feeder more, consumed more concentrates, and had a lower daily gain. There was no interaction between milk allowance and weaning type. Weaning by reducing the number of milk portions resulted in more unrewarded visits to the milk feeder, but less time ingesting a similar amount of milk. The effect of milk allowance on milk feeder occupancy before weaning was not found when this allowance was halved during weaning.

Udgivelsesdato: 17. Maj

Udgivelsesdato: September