Conception rate, which is an important parameter to evaluate female fertility, has been gradually decreasing in Japanese Black cattle during the past decades. In this study, we found a non-synonymous variant of the MLH3 gene that has been reported to be involved in meiotic recombination rate is also significantly associated with conception rate. This novel variant is suggested to use as a potential marker for selecting the Japanese Black cattle for improving fertility.

This article belongs to the Collection Sustainable Animal Agriculture for Developing Countries 2023.

In the feedlot, during the latter phase of finishing, animals show lower efficiency because weight gain is more directed to fat than protein. Several strategies are used to change the gain composition during this phase, such as beta-agonist zilpaterol (ZH), but the effectiveness of ZH can be affected by several factors. This is the first study that has provided information that the effectiveness of ZH in fattening lambs is independent of the energy concentration in the finishing diets.

Cold stress during the first week of rearing negatively impacted broiler chicks from 29-week-old breeders compared with 42-week-old breeders, leading to higher corticosterone levels, and reduced yolk sac absorption and crop filling. Chicks from 42-week-old breeders showed better overall performance, with higher body weight and feed intake regardless of environmental temperature. The study highlights the importance of maintaining thermal comfort for optimal chick development, particularly that from younger breeder flocks, to mitigate stress, and improve viability and growth performance.