Nutritional and environmental effects on reproduction in small ruminants.

摘要: Animals live in environments that are both complex and continually changing, so they have to respond short- long-term variations a wide range of factors, such as photoperiod, nutrition sociosexual signals. Before were domesticated, animals developed reproductive strategies coped with these changes often took advantage them. The physiological processes implement been modified some extent during several millennia controlled breeding, but most persist. Thus, many genotypes still exhibit profound responses external inputs, the induction ovulation by signals doubling litter size change nutrition. complexity is now becoming clearer. For example, signals, we need consider stimulatory effects males on females, females females. Similarly, impact has extended beyond control puberty production gametes include phenomena 'fetal programming', its potentially life-long performance animals. Fortunately, our capacity research greatly enhanced technical improvements hormone assays, molecular cellular biology, real-time ultrasound. This brought us better understanding environmental influences reproduction, including: within ovarian follicles mediate effect rate; neuroendocrine pathways through which nutritional inputs affect brain centres appetite reproduction; intracerebral (olfactory non-olfactory) stimulate axis. Importantly, beginning realise that, well considering interactions between genotype, take into account factors themselves, just do. We long way go for complete understanding, nevertheless position where can begin use this information develop new management systems improve their productivity.