Suchergebnisse

The aim of this study was to evaluate the incidence of diseases as well as metabolic and zootechnical parameters in Holstein calves maintained in individual or collective housing systems in the extreme south of Brazil. One hundred calves were included immediately after birth and monitored for 90 days. Animals were randomly divided into two groups: individual stalls group (ISG; n=50) and collective stalls group (CSG; n=50). ISG calves were individually housed in 1.2m² wood pens and received 6 L of milk/day and concentrate food and water ad libitum for 90 days. Calves in the CSG were housed in groups of up to 25 animals, in a total of two stalls containing one animal per 3 m2. CSG calves received up to 8 L of milk/day at 0-15 days, milk ad libitum at 15-40 days, 7.2 L of milk. /day at 40-60 days, and gradual weaning at 60-90 days with concentrate food and water ad libitum, using an automatic feeder. In both groups, Zootechnical parameters (weight, thoracic perimeter, height at the withers, and rump width) were measured weekly during the first 28 days and once every 15 days until weaning. Blood samples were retrieved weekly during the first 28 days. Metabolic parameters evaluated in this study were total calcium, beta-hydroxybutyrate (BHBA), free fatty acids (FFA), and glucose. The animals were monitored daily for clinical signs of diseases diarrhea and respiratory symptoms. General morbidity was higher in CSG 92% compared to ISG 74% (p<0.05). We observed increased diarrhea-related morbidity and a higher rate of recurrence in the ISG (50% and 60%, respectively; p<0.05) compared to those in the CSG (both 20%, p<0.05 between groups). The morbidity due to bronchopneumonia was higher in the CSG (92%) than in the ISG (74%, p<0.05). Recurrence of bronchopneumonia and mortality were similar between groups (p>0.05). Glucose, FFA, and BHBA concentrations were higher in the ISG (p<0.05) and total calcium higher in CSG (p<0.05). Finally, the weight and thoracic perimeter were higher in the CSG than those in the ISG, whereas the height and, rump width, at the withers was higher in the ISG than that in the CSG (p<0.05). In conclusion, animals raised in a collective system with automatic feeders exhibited less diarrhea and increased serum calcium as well as improved zootechnical development, although they had a higher incidence of bronchopneumonia.

This study evaluated the effect of two commercial forms of recombinant bovine somatotropin (rbST; Later® and Fast®; 500 mg) on feed variability, feeding behavior, zootechnical parameters, and milk production of Holstein cows after peak production. Eighteen cows were randomly divided into two groups and treated with injectable of rbST every 14 days for 70 days. Blood samples were collected on day 1, 4, and 7 of each cycle, to assess circulating levels of non-esterified fatty acids (NEFA). Weight and body condition score (BCS) assessments were performed. Milk yields were measured daily using the DelPro™ software (DeLaval®). Feed consumption and feeding behavior was obtained daily using automatic individual feeders (Intergado®). No difference was observed in dry matter intake (DMI) between groups (P=0.07), and no impact was noted on dietary variability (P=0.64). In addition, animals treated with rbST-Fast exhibited more frequent visits to feeders, longer time in consumption, and higher relative DMI (per percentage of live weight) (P<0.01). Animals in the rbST-Fast group produced more milk than those in the rbST-Later group (P=0.03). Furthermore, the weight of the cows was significantly different (P=0.05) between groups. The weight of the rbST-Fast animals was smaller and varied more than thot of the rbST-Later animals (P <0.01). Nonetheless, no difference was noted in BCS (P=0.30) between the groups. The animals in the rbST-Fast group had higher concentrations of NEFA than those in the rbST-Later group (P<0.01). In conclusion, behavioral and metabolic shifts that sustained greater milk production in the cows receiving rbST-Fast. Nonetheless, these shifts are likely linked to lipomobilization and not dietary variability or consumption, as evidenced by the increase in NEFA and greater weight loss in that group.