Some effects of different rearing systems on health, cleanliness and injury in calves

The effect of pair housing on dairy calf health, performance, and behavior

Individual housing of dairy calves prevails in Europe and North America despite its negative effects on calf development. One of the main reasons is that farmers find individual housing of calves more practical than group housing. A compromise between practice and welfare could be housing calves in pairs. Therefore, we aimed to compare health, feed intake, growth, and behavior in a novel arena of 22 individually (INDI) and 44 pair-housed calves that were randomly assigned a treatment. Diarrhea and respiratory problems were recorded every day for the period of 49 d. Intake of calf starter and milk were measured every day for the period 48 and 49 d, respectively. Calf body weight gains were calculated as average daily gain. Calves were individually tested in a novel arena at 11 to 18 d, and their behavior was recorded according to an ethogram including 8 behavioral categories. Behavioral categories were first diminished by principal component (PC) analysis. We found that 2 PC explained 66% of the total variation in calf behavior. Movement-related behaviors (activity, play, and crossing the stair) loaded positively on PC1, and PC2 had positive loading on self-grooming and negative loading on exploration. There were no effects of housing on calf health, feed intake, or average daily gain. The INDI calves had higher PC1 scores than pair-housed calves, indicating a rebound effect of movement. Our results are consistent with other studies that found no negative effect of pair housing of calves on their health, feed intake, or growth compared with individually-housed calves. The rebound effect of movement-related behaviors of INDI calves in a novel arena implies that individual housing of calves causes activity deprivation by the second week of age.

Short communication: Design and validation of a hygiene score for calves

The objective of this study was the establishment and validation of a scoring system for calf dirtiness. Defined areas of the belly, side, and rear of the calves were scored according to the percentage of dirtiness: score 1 ranges from 0 to 10% of the area (no or little soiling), score 2 from over 10 to 30% (medium soiling), and score 3 applies to soiling of more than 30% of the area (heavy soiling). The scores of the individual regions were summed up to yield the calf hygiene score (CHS) ranging from 3 to 9. The validation of the CHS was performed by 5 veterinarians on 42 calves. It was validated for its inter- and intra-observer-reliability and against a standard method created by image processing of photographs of calves. The agreement between the observers and the standard method was weak to moderate with kappa values from 0.58 to 0.67. Inter- and intra-observer reliability resulted in a moderate to strong agreement with 29 of 36 kappa values between 0.60 and 0.89. The CHS was thus successfully validated as reliable and could be a useful tool for herd health management.

Invited review: Effects of group housing of dairy calves on behavior, cognition, performance, and health

Standard practice in the dairy industry is to separate the calf and dam immediately after birth and raise calves in individual pens during the milk-feeding period. In nature and in extensive beef systems, the young calf lives in a complex social environment. Social isolation during infancy has been associated with negative effects, including abnormal behavior and developmental problems, in a range of species. Here, we review empirical work on the social development of calves and the effects of social isolation in calves and other species; this evidence indicates that calves reared in isolation have deficient social skills, difficulties in coping with novel situations, as well as specific cognitive deficits. We also review the practices associated with group housing of dairy calves, and discuss problems and suggested solutions, especially related to cross-sucking, competition, aggression, and disease. The studies reviewed indicate that social housing improves solid feed intakes and calf weight gains before and after calves are weaned from milk to solid feed. Evidence regarding the effects of social housing on calf health is mixed, with some studies showing increased risk of disease and other studies showing no difference or even improved health outcomes for grouped calves. We conclude that there is strong and consistent evidence of behavioral and developmental harm associated with individual housing in dairy calves, that social housing improves intakes and weight gains, and that health risks associated with grouping can be mitigated with appropriate management.

Views on contentious practices in dairy farming: the case of early cow-calf separation

The public has become increasingly interested in the welfare of food animals, but the food animal industries possess few mechanisms for public engagement. Here we present results from a web-based forum designed to allow stakeholders to share views on controversial issues in dairying. In response to the question "Should dairy calves be separated from the cow within the first few hours after birth?" participants were able to indicate "yes," "no," or "neutral" and either write a reason in support of their view or select reasons provided by other participants. Four independent groups of participants were recruited (a total of 163 people); 31% said they had no involvement in the dairy industry; the remaining 69% (with some involvement in the industry) were students or teachers (33%), animal advocates (13%), producers (11%), veterinarians (9%) and other dairy industry professionals (3%). Overall, little consensus existed among participants across groups; 44% chose "yes," 48% "no," and 9% "neutral." Responses varied with demographics, with opposition to early separation higher among females, animal advocates, and those with no involvement with the dairy industry. A fifth group was recruited at a dairy industry conference (an additional 28 participants); 46% chose "yes," 32% "no," and 21% "neutral." Across all 5 groups, opponents and supporters often referenced similar issues in the reasons they provided. Opponents of early separation contended that it is emotionally stressful for the calf and cow, it compromises calf and cow health, it is unnatural, and the industry can and should accommodate cow-calf pairs. In contrast, supporters of early separation reasoned that emotional distress is minimized by separating before bonds develop, that it promotes calf and cow health, and that the industry is limited in its ability to accommodate cow-calf pairs. These results illustrate the potential of web-based forums to identify areas of agreement and conflict among stakeholders, providing a basis for the development of practices that address shared concerns.

Responses of young calves to low ambient temperatures at two levels of feeding

Seven groups of five or six Holstein-Friesian male calves were transported to an experimental farm at 2 to 3 days of age. At 6 days of age, heat production (HP) and metabolizable energy (ME) intake were measured for an 8-day period. During this period, calves were exposed to various ambient temperatures: 6, 9, 12 and 15°C. Ambient temperature was constant within days, but changed between days. Calves were fed below (four groups) or near (three groups) the maintenance requirements (290 or 460 kJ ME per kg M0·75 per day).

From 6 to 14 days of age the lower critical temperature (Tc) was 12·5°C and HP increased by 8·4 kJ/kg M0·75 per day per °Cfall in ambient temperature below Tc. Both Tc and increase in HP below Tc were not affected by feeding level. Rectal temperature was lower at low ambient temperatures. The decrease in rectal temperature with ambient temperature was greatest at the low feeding level.

During the experimental period, calves were not in a steady-state regarding energy metabolism. Heat production decreased with time. This decrease was affected by feeding level and ambient temperature. After arrival, the influence of both ambient temperature and feeding level on the energy metabolism of young calves increased with time.

Responses of young calves, on two levels of feeding, to transportation

The effect of transportation on energy metabolism in young calves was assessed at two feeding levels by indirect calorimetry during a 5·5-day experimental period. Twenty-six Holstein-Friesian male calves were assigned in a 2 × 2 factorial arrangement of treatments. Calves were fed below or near the maintenance requirements (270 or 420 k) metabolizable energy per kg M0·75 per day). At 5 days of age, 13 calves were transported. The applied transportation procedure was aimed to mimic common transport of young calves. The other 13 calves were controls. Metabolizability of dietary energy was low (0·808), but similar for control and transported calves. Despite the similar salivary cortisol concentrations after transportation, heat production was higher by 23 kJ/kg M0·75 per day in transported than in control calves. Calves were not in a steady-state regarding their energy metabolism. Heat production decreased with time. Both transportation and feeding level influenced the decline in heat production with time. Only during the first 3 days after transportation was heat production enhanced, suggesting a relatively short-term effect of transportation in young calves. The impact of transportation on heat production and time related alterations in heat production were not related to the calfs activity.

Investigation of calf health and welfare on dairy farms in south-west England

A questionnaire was designed to investigate calf health and welfare on dairy farms in the south west of England with regard to the degree of compliance with the Welfare of Farmed Animals (England) Regulations 2000. The level of veterinary involvement in calf rearing and management on dairy farms in the south west of England was also assessed. The questionnaire was sent to 32 large animal practices in the catchment area of the Veterinary Laboratories Agency--Langford. Compliance with the regulations was found to be variable. The requirements for the isolation of sick calves, provision of bovine colostrum within six hours of birth, the provision of fresh, clean water and restrictions concerning tethering were not well complied with. However, the requirements for twice-daily feeding and inspection, visual and tactile contact between calves, access to forage and the provision of clean, dry bedding were well complied with. The results also suggested that there was some lack of veterinary input into the health and welfare of calves on dairy farms visited by the practices routinely and non-routinely.

Cost-effective antimicrobial drug selection for the management and control of respiratory disease in European cattle

Respiratory disease in growing cattle has both animal welfare and economic implications, but the use of antimicrobial drugs to treat and control it is under public scrutiny owing to concerns that their use in food-producing animals may be detrimental to human health. This paper outlines criteria for the selection of appropriate and cost-effective drugs, based on good dinical practice and sound economic principles. It also suggests that these principles should be integrated into quality assurance schemes, and that the monitoring of antimicrobial resistance patterns among known bacterial respiratory pathogens should be improved.

Characteristics of veal calves upon arrival, at 28 and 84 days, and at end of the production cycle

Holstein bull calves arriving at five special-fed veal farms (eight production groups) were scored for various physical condition traits and blood-sampled within 2 h after arrival and at 28 d, 84 d, and 1 wk prior to slaughter at 116 to 143 d. Of 1179 total calves in the production groups, 758 calves were scored and evaluated. Blood cell analyses (red and white blood cell counts, hemoglobin, and packed cell volume) were conducted at all four sampling times; total serum protein concentration was obtained at 0 and 28 d. The study was initiated in autumn and ended the following autumn. Mean initial and final body weights were 46.3+/-0.17 and 209.7+/-0.77 kg; mean mortality was 2.5%. Average daily gain of the eight groups ranged from 1.23 to 1.70 kg/d. Subjective scores of 5 = excellent to 1 = very poor condition were used to evaluate 16 different physical condition characteristics. With the exception of leg joint, hoof, and foot scores, most of the physical condition scores exhibited improvement during the first 28 d. Foot and leg impairments did not appear to hinder the ambulatory ability of the calves during the production period. Physical condition scores at d 0 and 28 were generally not related to numbers or types of medical treatments (enteric, respiratory, other, or total) or to average daily gain during the production period. Means for most erythrocytic and leukocytic traits upon arrival (d 0) were within normal ranges, although 27.4% of the calves were clinically or marginally anemic. Final mean hemoglobin and packed cell volume were 8.53 g/dl and 26.1%. Forty-three percent of the calves at d 0 were colostral deficient, assuming that total serum protein concentrations of <5.5 g/dl indicate colostral deficiency. No blood trait was consistently correlated with body weight gain when gain during the production period was divided into quartiles and the blood traits were averaged by gain quartile. Calves in the lowest serum total protein quartile (mean 4.58 g/dl) had more respiratory and total medical treatments than quartiles with higher total protein means. Dairy bull calves arriving at veal production units after transporting from the dairy farm to the auction market (or other collection facility) have several physical impairments. However, most of these physical impairments are improved early in the veal feeding period and are not generally related to subsequent growth rate or medical treatment.

Blood, growth, and other characteristics of special-fed veal calves in private cooperator herds

The objectives of this study were to determine the mean values for mortality, blood, and growth traits and the correlations among blood and growth traits on privately owned farms producing special-fed veal. Mortality percentages were available on 13 groups of special-fed veal calves (n = 1403) from four farms; growth and some blood traits were available on 9 groups from four farms (n = 975). Mean mortality percentages for periods 0 to 2, 2 to 7, and 7 to 16 wk, and over 16 wk were 1.0, 1.0, 1.0, and 3.1%, respectively. Means for average daily gain for 2 to 7 wk were 1.37 +/- .008 kg and for 7 to 16 wk were 1.52 +/- .001 kg. When calves arrived at the veal farm, total plasma protein averaged 6.2 +/- .05 g/dl. Examination of total plasma protein upon arrival of calves indicated that 81% of the calves had received colostrum. The base level indicating colostral deficiency was < 5.5 g/dl of total plasma protein; 51% of the calves had total plasma protein > 6.0 g/dl at arrival. Mean hemoglobin concentrations at arrival and at 2, 7, and 16 wk were 11.1 +/- .15, 10.6 +/- .18, 9.2 +/- .14, and 7.8 +/- .13 g/dl, respectively. Means for hemoglobin were generally higher than previously reported for special-fed veal calves reared in individual stalls. Hemoglobin and red blood cell counts were correlated positively with 16-wk average daily gain and body weight, and midtrial white blood cell counts were correlated negatively with average daily gain and body weight from 2 to 7 wk; there were no other significant relationships between blood traits and growth performance measures.

Dairy animal welfare: current and needed research

Of 25 milestones in dairy animal welfare, 10 were linked to laws and regulations, 9 to research, education, and development, 4 to books and publications, and 2 to human error (accidents). Animal rightists have attacked the dairy industry because of farm conditions, bovine somatotropin, overproduction of milk, dairy lobbies, and advertising of milk products. Evidence from Europe suggests that animal welfare has been largely promoted as a sociopolitical issue by nonagriculturalists. Codes, guidelines, and recommendations are well-established for northern Europe. The American Veterinary Medical Association Animal Welfare Committee has prepared the pamphlet on food animal welfare and addressed specific bovine welfare issues in its guide for veal calf care and production. From 1978 to 1986, only four US experiment station projects were concerned with dairy animal welfare. Needed research includes studying learned helplessness; analysis and economics of alternative husbandry systems for veal calves (and cows) freestall design and surfaces; and shade, cooling, and misting of mangers and holding pens prior to entering the parlor. Alert caretakers are encouraged to read behavior signals of cattle. Increased standing of cattle is often taken now as a sign of discomfort or discontent in studies of cow and calf confinement. Criteria that should be considered in assessing welfare or well-being are behavior, health, musculoskeletal soundness, productivity, physiological and biochemical characteristics, and reproduction.