A.M. de Passillé

Invited review: The welfare of dairy cattle--key concepts and the role of science.

Concerns about the welfare of animals typically include 3 questions: is the animal functioning well (e.g., good health, productivity, etc.), is the animal feeling well (e.g., absence of pain, etc.), and is the animal able to live according to its nature (e.g., perform natural behaviors that are thought to be important to it, such as grazing)? We review examples, primarily from our own research, showing how all 3 questions can be addressed using science. For example, we review work showing 1) how common diseases such as lameness can be better identified and prevented through improvements in the ways cows are housed and managed, 2) how pain caused by dehorning of dairy calves can be reduced, and 3) how environmental conditions affect cow preferences for indoor housing versus pasture. Disagreements about animal welfare can occur when different measures are used. For example, management systems that favor production may restrict natural behavior or can even lead to higher rates of disease. The best approaches are those that address all 3 types of concerns, for example, feeding systems for calves that allow expression of key behaviors (i.e., sucking on a teat), that avoid negative affect (i.e., hunger), and that allow for improved functioning (i.e., higher rates of body weight gain, and ultimately higher milk production).

Assessing cow comfort: effects of two floor types and two tie stall designs on the behaviour of lactating dairy cows

Our objective was to test the effects of two types of stall flooring and two tie stall designs on the behaviour of dairy cows. Using two cross-over designs, 16 lactating Holstein cows were housed for 3-week periods in each of four tie stalls to compare the effects of concrete versus mattress flooring, and a narrow versus a wide stall front opening. When cows were housed on a mattress flooring they increased their total lying time by 1.8h per day (51.0 versus 43.4% time per day). The duration of individual lying bouts was longer on concrete flooring (78 versus 62min) and the same was true for the duration of individual bouts of standing (80 versus 48min). On mattress flooring cows stood up and lay down more often than on concrete (28 versus 20 per day, respectively). On concrete cows spent more time standing without eating (35.2 versus 28.1% of sampling observations). Cows consistently made use of the additional space provided with the wide stall front opening, placing their head in the manger area during 70.6% of lying observations compared to only 43.4% of observations in the narrow stall front. However, measures of general activity were not significantly different for the two stall designs. Cows spent similar amounts of time eating and consumed similar quantities of feed in all four tie stalls. Our results suggest a lack of comfort may be apparent in reduced time spent lying and a subsequent increase in time spent standing without eating. A lower frequency of standing and lying and an increase in the bout duration of lying suggests that cows on concrete flooring have difficulty standing up and lying down.

A survey of dairy calf management practices in Canada that affect animal welfare

There is growing interest among the public in farm animal welfare and a need for methods to assess animal welfare on farm. A survey on calf rearing practices that might affect dairy calf welfare was performed via a 1-h interview on 115 dairy farms (mean +/- SD: herd size=52.5+/-20.9 cows; milk production=8,697+/-1,153L) distributed throughout the province of Quebec. Despite frequent recommendations, many dairy producers continue to use management practices that increase the health risks of milk-fed calves. Major risk factors for poor calf welfare identified were 1) no use of calving pen in 51.3% of herds and low level of surveillance of calvings, especially at nighttime (once every 12h), 2) no disinfection of newborns navel in 36.8% of herds, and delayed identification and, hence, calf monitoring (3 d), 3) 15.6% of farms relied on the dam to provide colostrum and none checked colostrum quality or passive transfer of immunity, 4) dehorning and removal of extra teats proceeded at late ages (6.4 wk and 6.7 mo, respectively) and without adequate pain control, 5) use of traditional restrictive milk feeding and waste milk distributed to unweaned calves without precaution in 48.2% of herds, 6) abrupt weaning performed in 16.5% of herds, and 7) calves housed individually in 87.9% of herds, and most inappropriate housing systems (crate=27.0%, tie-stall=13.9%, attached against a wall=5.7%) remained. This risk factor assessment was the first step in an intervention strategy to improve calf welfare on dairy farms.

Using gait score, walking speed, and lying behavior to detect hoof lesions in dairy cows

The objective was to determine whether changes in the different components of gait, walking speed, and lying behavior were associated with hoof pathologies in lactating Holstein cows. In experiment 1, 53 cows had their gait scored, their walking speed estimated, and their lying behavior monitored before clinical assessment of the hooves. Multiparous cows with ulcers scored higher than cows without ulcers for overall gait score [numerical rating score (NRS); 3.3 +/- 0.2 vs. 2.8 +/- 0.2], back arch, joint flexion, asymmetric steps, and reluctance to bear weight. Although cows with ulcers did not walk more slowly than cows without ulcers (1.4 m/s), they spent more time lying down (827.8 +/- 29.1 vs. 738.2 +/- 15.5 min/d) because of longer lying bouts (93.3 +/- 5.9 vs. 79.7 +/- 3.4 min). In experiment 2, 47 cows were monitored for hoof health and changes in gait score from 4 wk before to 24 wk after calving. Differences were found after calving between cows that developed an ulcer and cows that did not for NRS (3.1 +/- 0.1 vs. 2.35 +/- 0.1), back arch, joint flexion, asymmetric steps, and reluctance to bear weight. Numerical rating score, back arch, and asymmetric steps were able to discriminate cows with ulcers at least 4 wk before the diagnosis. Cows that developed a sole ulcer had a faster decline in lying time during the periparturient period and a faster increase beginning in wk 2 after calving. The NRS was a more consistent predictor of sole ulcers than lying behavior or speed. The NRS was able to discriminate cows with ulcers across studies at a high intraobserver accuracy and reasonable specificity and was able to predict the presence of ulcers at least 4 wk before diagnosis. Abduction/adduction of the rear legs, head bob, and tracking-up did not consistently discriminate cows with ulcers, and we suggest that these measures are less useful for on farm gait assessment. Compared with the other gait attributes, back arch, joint flexion, asymmetric steps, and reluctance to bear weight best predicted the presence of sole ulcers.

Duration of weaning, starter intake, and weight gain of dairy calves fed large amounts of milk

When calves are weaned abruptly off large amounts of milk, weight gain is reduced as a result of low intake of starter. We compared gradual and abrupt weaning of 40 calves allowed to drink up to 12kg of milk/d by automated feeders, housed in groups of 4, and weaned at 41 d abruptly or over 3 gradual weaning periods (4, 10, or 22 d), with one calf within each group randomly allocated to each treatment, balancing for sex and birth weight. During the milk-feeding period, the calves weaned over 22 d drank the least milk and ate the most starter, but these calves had the lowest total digestible energy intake and weight gains. The abruptly weaned calves had the highest digestible energy intakes and weight gains during the period before weaning. During the 9 d following weaning, the calves weaned over 22 and 10 d ate more starter and had better weight gains than abruptly weaned calves and those weaned over 4 d. Abruptly weaned calves lost weight during this period. In summary, gradual weaning improved starter intake, but because of reduced milk availability, this resulted in reduced total digestible energy intake before weaning. Weaning over 10 d resulted in the best overall weight gains over the study.

Automated methods for detecting lameness and measuring analgesia in dairy cattle.

The objective was to assess gait, automated measures of weight distribution among the legs, and daily activity as methods for detecting lameness in dairy cows and measuring pain mitigation by nonsteroidal antiinflammatory drugs. Fifty-seven lactating cows (28 of which were lame) were injected twice with ketoprofen (3.0 mg/kg i.m.) or isotonic saline solution. Gait scores (numerical rating system, NRS), time spent lying down, frequency of steps, and weight distribution among legs when standing before, during, and after injections were measured to assess whether automated measures of activity can detect lameness and the effect of analgesic drugs in cows. Lame cows (NRS >3) shifted weight between contralateral legs more often (SD of the weight applied: 31.1+/-2.1 vs. 24.5+/-1.9kg), had a greater asymmetry in the weight applied to the rear legs (leg weight ratio=0.78+/-0.02 vs. 0.87+/-0.02), had longer lying bouts (94.0+/-4.9 vs. 78.2+/-5.8min), and walked slower (1.28+/-0.3 vs. 1.42+/-0.3 m/s) than nonlame cows. Variability over time (SD) of the weight applied to the rear legs was the most accurate predictor of whether a cow was lame or not (area under the curve=0.71). The SD of the weight applied to the rear legs decreased on the days when ketoprofen was given compared with the day before and after (18 and 12% decrease for lame and nonlame cows, respectively). Ketoprofen did not affect any other measure. Measures of weight shifting between legs while cows are standing have potential as an automated method of detecting lameness and analgesia.

Preparturient variation in progesterone, prolactin, oxytocin and somatostatin in relation to nest building in sows

Abstract Progesterone, prolactin, oxytocin and somatostatin concentrations in the plasma of ten multiparous Swedish Landrace sows were measured during the last 72 h prepartum and related to nest-building behaviour. The beginning of nest building was determined when the sow started to take straw from the rack and to deposit it. Rooting, pawing and arranging straw, and taking and carrying straw were recorded as separate behaviour components. Nest building started within 24 h and peaked 6–12 h before parturition. Only prolactin concentrations 2 days before parturition were independently correlated with the nest-building onset. Prolactin levels started to increase before the nest-building onset and only reached maximum values after it, suggesting that it is the preparturient rise in prolactin concentration that initiates nest building. The duration of carrying and depositing straw correlated positively with progesterone concentrations and negatively with somatostatin concentrations 2 days before parturition. Nest building ceased within 4 h before parturition. Oxytocin concentration 8 h before parturition was related to the end of nest building. The results suggest that nest building in sows is under multiple hormonal control and that the beginning and end, and the different behaviour types are related to different parturient endocrine changes.

Aversion learning techniques to evaluate dairy cattle handling practices

Fear of humans is a source of stress for Holstein dairy cattle and can result when animals are handled aversively. We used aversion learning techniques to determine which handling practices cattle find most aversive. In an aversion race, the cows are repeatedly walked down a race and treatments applied when they reached the end; the time and force required for cows to walk down the race are measured. The animal learns to associate walking down the race with the treatment received; if the treatment is aversive, the animal will take more time and require more force to reach the end of the race than if the treatment is positive. In experiment 1, 54 cows were assigned to four treatments (hit/shout, brushing, control, and food). Treatments of 2-min duration were applied three times a day for 4 days. Cows on the hit/shout treatment took more time and required more force to walk through the race than cows on other treatments, while brushed cows took longer to move through the race than cows given food. In experiment 2, 60 cows were assigned to five treatments (electric prod, shouting, hitting, tail twist, and control). Treatments of 1-min duration were applied three times a day for 3 days. Cows on the shout and electric prod treatments took more time and required more force to walk down the race than cows on the control treatment. In experiment 3, thirty-six 1-1.5-year-old heifers were assigned to three treatments (hand feeding, gentling, or control) applied as in experiment 2. Treatments did not affect the time or force required to walk down the race. The aversion race successfully discriminated between handling treatments that differ greatly in aversiveness but lacked sensitivity to distinguish between treatments that were similar. Although many procedural factors must be considered, aversion learning techniques are an effective method to determine which handling practices cattle find aversive or rewarding.

Effects of Sand and Straw Bedding on the Lying Behavior, Cleanliness, and Hoof and Hock Injuries of Dairy Cows

This experiment compared the effects of sand and straw bedding in free stalls on resting time, cleanliness, hock injuries, and hoof health of dairy cows and tested whether cow preferences for a bedding material depended on the familiarity with the material. A total of 52 dairy cows were kept either on straw bedded concrete stalls or sand stalls for at least 21 wk. The lying behavior was observed, and hock lesions, hoof health, and cleanliness of the cows and stalls were measured. A 5-d preference test between sand and straw stalls was conducted at the end of the experiment. The total daily duration of lying was longer for cows on straw bedding than on sand bedding (straw 749 +/- 16 vs. sand 678 +/- 19 min). During the preference test, cows that had been kept on straw bedding preferred lying in straw stalls [straw 218.7 (133.4 to 239.7) vs. sand 9.0 min (2.8 to 44.8)]; however, cows that had been kept on sand showed no preference [straw 101.3 (51.7 to 205.9) vs. sand 94.3 min (54.1 to 156.1, median and interquartile range)]. Although there were no differences in the dirtiness of stalls, the cows using straw stalls were dirtier than cows using sand stalls [straw 6.04 (5.39 to 6.28) vs. sand 4.19 (3.62 to 5.16)]. At the end of experiment the severity of hock lesions was lower for cows on sand than for cows on straw [sand 0.5 (0.0 to 1.0) vs. straw 1.0 (1.0 to 2.0)]. The improvement in overall hoof health over the observation period was greater for cows kept on sand compared with cows kept on straw [sand -2.00 (-3.75 to -0.25) vs. straw 0.00 (-2.00 to 2.00)]. Straw bedding increased the time that cows spend lying, and cows preferred straw stalls to sand stalls. However, previous experience with sand reduces avoidance of sand stalls. Sand stalls were advantageous for cow cleanliness and health; hock lesions and claw diseases healed more quickly for cows using sand stalls compared with straw.

Does drinking milk stimulate sucking in young calves

To examine the motivation of non-nutritive sucking by calves, a series of tests was conducted on calves that were fed milk replacer by bucket and allowed to suck on a dry artificial teat. After the morning and afternoon meals, the calves sucked the teat for 4–6 min while they sucked it for less than 1 min when the teat was offered outside regular meal time (12:00 h). When milk replacer was offered outside regular meal time (12:00 h) calves sucked and butted the teat significantly more (P<0.001) than if no milk was offered. When the artificial teat was offered after a delay of 10, 30 or 60 min after the milk replacer meal, calves sucked and butted the teat significantly less than when the teat was offered immediately after the meal. The ingestion of water stimulated sucking (P<0.01) but not butting when it was offered at 12:00 h, while milk stimulated sucking and butting to a significantly higher level (P<0.01). We conclude that the ingestion of milk plays an important role in stimulating sucking in the calf. Nevertheless more research is needed to identify other factors that stimulate and/or control sucking and how these interact with the effect elicited by milk.