Effects of sex and age on behavior and weight gain in beef calves after abrupt weaning

Abstract

The effects of weaning on beef calves of different ages were investigated. Forty male and 40 female calves were either weaned at 6 (W6, n = 40) or 8 (W8, n = 40) months of age. The vocalization activity and behaviors (feeding, lying and standing/walking) were observed during the first 3 days following weaning. Body weight was recorded at 6 and 8 months and 2 weeks following weaning. W6 animals vocalized more often than W8 calves and females more than males on day 1 (P < 0.05). The vocalization activity decreased at a higher rate in W8 than in W6 from days 1 to 3. On day 2, W6 calves spent less time lying and more standing/walking than W8 calves (P < 0.05). The behaviors did not differ between males and females. The average daily gain after weaning did not differ between weaning ages (P > 0.05), but W8 calves gained more from 6 to 8 months of age. In conclusion, weaning distress was more pronounced in W6 than in W8 calves. W8 calves also had a superior growth performance during 6 to 8 months of age. The effect of the calves' sex was less pronounced. Therefore, it is recommended to wean beef calves later than 6 months of age.

Effects of forage feeding on rumen fermentation, plasma metabolites, and hormones in Holstein calves during pre- and postweaning periods1

“…Weaning is a substantial stress for calves (Carroll et al, 2009;Lambertz et al, 2015), which can cause lower weight gains (Lambertz et al, 2015) and the occurrence of infectious diseases (Callan et al, 2002;Snowder, 2009). Generally, calf starters with high palatability and nutrition are fed excessively to promote the shift from liquid to solid feed and to avoid growth retardation.…”

Efecto del amamantamiento restringido y complementación alimenticia sobre el peso y cortisol en becerros Simbrah

“…El uso de complementos alimenticios (sustituto de leche, alimento balanceado y forraje verde o seco), y el amamantamiento restringido tiene como finalidad: 1) disminuir de manera gradual la dependencia de la cría a la leche materna y desarrollar la capacidad ruminal, lo más pronto posible, para ser destetada a corta edad. 2) mejorar el comportamiento reproductivo (anestro posparto) de la vaca al disminuir el estrés de la lactancia y el vínculo vaca-becerro que se genera por el amamantamiento (3,4,5).…”

“…Sin embargo, los becerros, al tener un mayor consumo de leche materna y bajo o nulo consumo de alimentos sólidos (alimento balanceado y/o forrajes), no tienen un desarrollo ruminal eficiente. Por lo tanto, al momento del destete, las crías sufren cambios bruscos a nivel físico, social y fisiológico (aumento de bramidos, agitación, caminar constantemente y reducción del consumo alimenticio) que pueden afectar su estatus quo generando estrés en los animales y en algunos casos la muerte (5,8,9). Bajo estas circunstancias, el uso de los métodos de amamantamiento restringido o destete precoz controlado son positivos para las vacas (2,10); pero negativos para los becerros, por la falta de bienestar animal, al causar estrés en ellos al separarlos de la madre (1).…”

“…Pocos estudios han determinado el efecto de la complementación alimenticia y nivel de estrés, causados por el destete, en el comportamiento posdestete en ganado de carne, especialmente en ganado Simbrah, en las regiones tropicales (5,10,11,13). El objetivo de este estudio fue determinar el efecto del amamantamiento restringido, destete precoz y la complementación alimenticia sobre la ganancia de peso y concentración sérica de cortisol en becerros Simbrah al destete y posdestete.…”

Effect of nursing or mentoring by adult cows on physical activity, performance and meat quality of fattening beef calves kept on alpine pastures

“…Yet, individual forage intake may be even more relevant than age per se . In suckling beef calves, the optimal weaning age to promote ADG was recently reported as at least 8 months . In addition, difficult grazing conditions may exacerbate the effect of an omission of milk on ADG of weaned calves, which have to browse more than nursed calves in order to cover their requirements by a higher herbage intake.…”