No abstract

The objective of the study was to evaluate the maternal protective behavior of zebu-type cattle (Bos indicus) and its association with temperament. A total of 40 cow-calf pairs raised under extensive conditions were randomly assigned to 1 of 4 groups (n = 10), which were evaluated at 30, 60, 90, and 120 d postpartum (dpp), respectively. Measures obtained were defense responses of cows protecting their calves assessed by categorizing the behavioral response of the dams during handling of their calves and chute exit score and facial hair whorl (HW) position as indirect measures associated with temperament. No association was found between protective behavior and exit score or HW measures (rs < 0.22 and 0.13, respectively; P > 0.05). At 30 dpp, 90% of the cows responded to the stimulus of calves being handled, 40% reacted exclusively to alien calves, and 50% responded to their own or alien calves. Sixty days later, the proportion of cows responding to alien calves decreased (P < 0.05) to 10%, and at 120 dpp, cows responding to any calf decreased (P < 0.05) to 20%, while the nonresponding cows increased (P < 0.05) to 60%. Similarly, as dpp increased, the intensity of the reaction of the cows to the manipulation of their calves declined. The intensity of the response was exacerbated (P < 0.05) when a human being was less than 1 m distance from the calf, also when the calf was its own or when the calf vocalized. Furthermore, independent of the sex of their own calf, cows reacted more to male than female calves (P < 0.05). It was concluded that zebu cows may display maternal protective behavior to their own or alien calves, which weakens about 120 dpp and is not influenced by individual temperament.

No abstract

No abstract

The aim of this study was to establish if pre-synchronization would enhance the number of animals cycling prior to conventional breeding at 45 days irrespective of the length of calf separation. Multiparous Bos indicus cows were allotted in four groups (n = 10). Control group (C) dams remained with their calves; groups G24, G48 and G72, which were partially weaned for 24, 48 and 72 h, respectively, were estrus synchronized using a controlled internal drug. These procedures were performed at 25 days and again at 45 days postpartum. The number of follicles, presence of a corpus luteum and back fat thickness (BFT) were determined by ultrasound. The proportion of cows with estrus and ovulation at day 25 postpartum was statistically different between the control and treated groups, with the values being 20, 60, 50 and 70 for the control, G24, G48 and G72 groups respectively (P < 0.05). At days 45 postpartum, the proportion of cows with estrus and ovulation was different in group G48 compared with the other groups (P <0.05). The average BFT and body condition score for the four experimental groups in the two periods were similar (P >0.05). Animals with a higher proportion of follicles from 17 to 21 mm, BFT values above 3.5 mm and a regular body condition were significantly different regardless of whether the dams remained with their calves or were separated, regardless of the length of this event. It can be concluded that (1) a pre-synchronization program at day 25 could trigger the onset of ovarian activity and facilitate a breeding program at day 50 and (2) temporary weaning enhances the effect of a pre-synchronization program.