Performance and serum cortisol concentration in Santa Inês lambs under different suckling schemes

Abstract

-The objective of this study was to examine the effects of suckling schemes (continued, controlled, and total separation) and the type of pregnancy on performance and serum cortisol concentration in lambs. A total of 29 Santa Inês ewes and 40 lambs were used, and the randomized block design was applied in a split-plot scheme with a 3 × 2 factorial arrangement in the plot and time in the subplot. For controlled suckling, the diet was supplied twice daily during one hour, starting on their 10th day of life. Total and average daily intakes of concentrate dry matter of lambs that underwent total separation was higher than those of lambs under continued suckling. Lambs subjected to total separation demonstrated higher concentrate dry matter intake/weight gain ratio, lower total weight gain, lower average daily weight gain, and lower weaning weight than those subjected to continued and controlled suckling. Lambs from single pregnancy demonstrated higher weight gain and obtained higher weight at weaning. Lambs subjected to total separation have a developmental delay. However, the lower performance of lambs subject to total separation cannot be attributed to stress because there is a decrease in the serum cortisol concentration over time.

The impact of melatonin administration on the fertility performance and several relating parameters during the breeding season in the Arabi ewes

“…In addition, there was an increase in the concentration of cortisol in first and second months of gestation in comparison with other months. As known, cortisol is a glucocorticoid hormone and considered as an anti-stress hormone, which normally increases when animals are under stress condition such as pregnancy and take some time to return to normal range (36). According to Firat et al (37), the level of cortisol increases during 100 days of gestation and then decline during late gestation in Sakiz ewes.…”

Sexual performance and semen quality of pubertal lambs treated with different weaning methods

“…The stress caused to the lamb at weaning can be increased if the lamb is in poor body condition (Chai et al, 2015), exposed to parasite infestation (Campbell et al, 2017), or with health problems (Destrez et al, 2017). While these changes in lamb body development have been shown to occur in the first-week post-weaning, many stressors can occur, including social, environmental, physical, and nutritional factors (Alves et al, 2016), which affect performance post-weaning (Henrique et al, 2018). However, one of the objectives of our study was to evaluate the effect of weaning method on the sexual behavior and semen quality of the 3-month-old rams.…”