title: 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.
authors.affiliation: Department of Animal Sciences, Georg-August-University, Göttingen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Lambertz
authors.forename: Antje
authors.initials: A
authors.lastname: Farke-Röver
authors.forename: Matthias
authors.initials: M
authors.lastname: Gauly
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002417:Cattle / Q000254:growth & development / Q000502:physiology* / Q000523:psychology*; D005260:Female; D008297:Male; D012727:Sex Characteristics; D013315:Stress, Psychological / Q000503:physiopathology* / Q000523:psychology*; D014828:Vocalization, Animal / Q000502:physiology; D014886:Weaning; D015430:Weight Gain / Q000502:physiology*
keywords: age; beef calves; behavior; weaning; weight gain