Hay provision affects 24-h performance of normal and abnormal oral behaviors in individually housed dairy calves.

Dairy calves often perform abnormal repetitive behaviors (ARBs) including tongue rolling and nonnutritive oral manipulation (NNOM) when opportunities to perform feeding behaviors are restricted. Many US dairy farms limit access to milk, a well-studied risk factor for ARBs. However, farms also commonly do not feed forage to young calves, and the motor patterns of oral ARBs resemble those necessary for acquiring and chewing solid feed. Our objective was to assess how access to hay from birth influenced time engaged in normal and abnormal oral behaviors across 24 h. Holstein heifer calves were housed individually on sand bedding and fed ad libitum water and grain (control, n = 11) or given additional access to hay (hay, n = 11) from birth. Calves were fed 5.7 to 8.4 L/d (step-up) of milk replacer via a teat. At the start of step-down weaning (50 ± 1 d), all calves were given access to a total mixed ration. Feed and water intake were measured daily. Oral behaviors (eating, ruminating, sucking milk, drinking water, panting, grooming, tongue flicking, tongue rolling, and NNOM) were recorded by direct observation at wk 2, 4, 6, and 8 using 1-0 sampling at 1-min intervals for 24 h. Grain, hay, and water intake increased over time in the preweaning period. One polydipsic calf regularly consumed >10 L of water/d. During weaning, hay calves tended to consume increasingly more total mixed ration, significantly more water, and less grain than control calves. Access to hay led to more observations spent eating solid feed (7% vs. 5%, mean percentage of intervals) and ruminating (24% vs. 16%) during the preweaning period compared with calves fed only grain, though control calves appeared to ruminate in absence of forage to re-chew. Rumination occurred, to a large extent, overnight. Hay calves also spent less time self-grooming (12% vs. 14%), tongue flicking (14% vs. 18%), and performing NNOM (17% vs. 21%) than control calves. Although NNOM peaked around milk feedings, all 3 behaviors were performed throughout the day. Tongue rolling was rare across treatments, as was panting, which occurred most frequently around 1400 h. There were no behavioral differences during weaning (wk 8). Overall, we found that hay provision affected most oral behaviors that calves perform; it promoted natural feeding behaviors and reduced abnormal ones, suggesting hay should be provided. We also found that calves performed other behaviors, including polydipsia, repetitive grooming, and apparent sham rumination, that may suggest a degree of abnormality in these behaviors that has not been previously identified. These results highlight the importance of considering all oral behaviors to better understand calf welfare.

Effects of feeding level, milking frequency, and single injection of cabergoline on feed intake, milk yield, milk leakage, and clinical udder characteristics during dry-off in dairy cows.

Abrupt and gradual dry-off strategies by reducing feeding level (normal vs. reduced energy density), reducing milking frequency (twice vs. once daily), and administration of a dopamine agonist after last milking (i.m. saline vs. cabergoline injection) were investigated (2 × 2 × 2 factorial arrangement) for their effects on feed intake, milk yield, energy balance, milk leakage, and clinical udder characteristics in 119 Holstein cows. In the last week before dry-off, cows were assigned to 1 of 4 combinations of feeding level and milking frequency. Within 3 h after last milking, cows were injected with either saline or a dopamine agonist (cabergoline; Velactis, Ceva Santé Animale; labeled for use only with abrupt dry-off, i.e., no preceding reduction in feeding level or milking frequency before last milking). After dry-off, all cows were fed the same diet for dry cows, and data collection continued for a week. Dry matter intake (DMI) was recorded in automated feed bins and milk yield in an automatic milking system where additional concentrate was fed. Clinical udder characteristics and milk leakage were scored 10 times during the week before and the week after dry-off. Before dry-off, total DMI decreased with reduced feeding level compared with normal feeding level, but did not differ between milking frequencies. The combined effect of reduced DMI and diet energy concentration resulted in a 47% lower net energy intake with reduced feeding level compared with normal feeding level during the week before dry-off. Milk yield was approximately 30% lower during the week before dry-off when either feeding level or milking frequency was reduced compared with no change in feeding level or milking frequency, whereas milk yield was 45% lower when both feeding level and milking frequency were reduced. The net energy balance during the week before dry-off was negative with reduced feeding level and more negative when combined with twice-daily milking. After dry-off, udder engorgement was reduced in the 3 gradual dry-off treatments compared with abrupt dry-off. Cabergoline injection after last milking resulted in least udder engorgement and signs of milk leakage for 48 h, but also resulted in abrupt reduction of DMI lasting approximately 24 h irrespective of treatment before dry-off. In conclusion, gradual cessation of lactation by reducing milking frequency to once daily without reducing the feeding level decreased milk yield before dry-off in high-yielding dairy cows and reduced udder engorgement after dry-off without inducing negative energy balance during the period of dry-off. In contrast, reduced feeding level induced negative energy balance, which may compromise welfare due to metabolic stress and hunger. No clear differences in risk of milk leakage after dry-off were observed between abrupt and gradual dry-off management strategies. Use of cabergoline led to fewer signs of milk leakage and reduced udder engorgement during the first days after dry-off, which may positively affect welfare at dry-off. However, the mechanism behind and the welfare consequences of the concomitant abrupt decrease in DMI lasting approximately 24 h needs further investigation to complete our understanding of dopamine agonist use for dry-off.

Dairy cows with mild-moderate mastitis change lying behavior in hospital pens.

In dairy production, mastitis is a major problem affecting animal welfare, productivity, and economy. Hospital pens are typically not used for cows with mastitis, except for severe cases involving recumbency. This field trial included 47 cows from three Danish herds followed for 8 d, of which days 1-5 involved the experimental housing. After day 5, all cows were kept with the lactating group. We examined lying behavior in dairy cows with naturally occurring, mild-moderate mastitis in hospital pens [single or group (depending on conditions on the farm), all with deep straw bedding] vs. sick cows kept in the group of healthy herd mates. Within a herd, every other cow fulfilling the inclusion criteria regarding mastitis was allocated to each of the two experimental treatments. Clinical data from involved cases were collected. No significant differences between housing treatments were found in the clinical variables or the daily lying time. During the period of experimental housing, cows kept in hospital pens showed a higher frequency of lying bouts compared with control cows. This difference did not persist after reintroduction to the lactating herd mates. These results suggest that aspects of lying behavior of dairy cows with mastitis are sensitive to the environment as the frequency of lying bouts differed between cows kept in hospital pens and cows kept in control treatment. More controlled studies are needed to examine underlying motivations and evaluate consequences in terms of animal welfare. For such studies, the inclusion of healthy cows for comparison will be valuable.

The dose-response relationship between the amount of straw provided on the floor and gastric ulceration of pars oesophagea in growing pigs.

The aim of the present study was (1) to determine the dose-response relationship between the amount of straw provided on the floor and oesophageal ulceration in pigs kept under typical Danish production conditions (18 pigs/pen, 0.7m2/pig, partly slatted floor, ad libitum access to feed), (2) to reveal whether straw ingestion explains the effect of straw provision on the stomach health and (3) to elucidate the effect of straw ingestion on the stomach conditions. Data were collected at slaughter (approximately 100kg body weight) on pigs provided with straw amounts in the range 10g to 500g wheat straw/pig/day from 30kg body weight and fed a wheat-based pelleted feed added 15% non-heated and non-pelleted rolled barley. Aims (1) and (2) included 712 pigs kept in 42 pens, whereas (3) was studied on a subset of 37 pigs with either none or obvious amounts of straw in the stomach. The amount of straw provided affected stomach health in a curvilinear manner. Provision of up to approximately 300gstraw/pig/day progressively decreased the risk of oesophageal ulceration and scarring. At larger amounts of straw the ulceroprotective effect of straw was reduced which requires further investigation. Straw ingestion appeared to be an essential intermediary factor for the improvement of stomach health. The number of pigs without straw in the stomach decreased linearly with the logarithm of the amount of straw provided, which explained the effect of straw provision on stomach health. The structure of the stomach contents increased as revealed by the increased weight and dry matter content and decreased sedimentation of the digesta. Provision of approximately 300gstraw/pig/day on the floor may be a potential strategy to reduce, but not inevitably eliminate, oesophageal ulceration in pigs in commercial pig production.

Impact of the amount of straw provided to pigs kept in intensive production conditions on the occurrence and severity of gastric ulceration at slaughter.

This study examined effects of the amount of straw offered on occurrence and severity of gastric lesions in pigs kept in pens (18 pigs, 0.7 m(2)/pig) with partly slatted flooring and 10, 500 or 1000 g straw/pig/day from 30 kg live weight. The pigs had ad libitum access to dry feed. Forty-five pigs were used, three from each of 15 pens. After euthanization, the dimension of the non-glandular region of the stomach was measured. Lesions were characterized and scored. Irrespective of straw provided, 67% of the pigs showed signs of gastric pathology. Pigs provided with 500 or 1000 g straw were pooled as 'permanent access'. The proportion of pigs with ulcerations was reduced by permanent access to straw (7 vs. 33%; P<0.05), suggesting that permanent access to straw may improve animal health, and be considered as one possible strategy to limit gastric ulceration in pigs.