Endocrine/metabolic status and reproductive performances in Sarda dairy ewes given different nutritional plans

The first study investigate the carry-over effects of a background grazing during lactation on ewe’s reproductive performances evaluating if different time access to pasture during mid-lactation may exert a residual effect on ewe’s body weight and condition, milk yield at mating, and reproductive performance in ewes submitted to a flushing with lupin grains. These experiments demonstrated that ewes with severely restricted access to pasture during mid-lactation have detrimental effect on reproduction. The second study was designed to assess the effects on plasmatic and intrafollicular concentrations of metabolites and hormones in non-lactating Sarda ewes, and to evaluate its effects on metabolism, milk production and reproductive performances in lactating ewes. Treatment affect circulating concentration of metabolites and hormones in dry ewe and partially in follicular fluid. In lactating ewes, homeorhetic adaptation during lactation lead to a different response. The glycerol based mixture lead to increase in circulating glycerol concentration, affecting plasma osmolarity and total protein concentration, and likely blood volume. DMI decrease in ewe, maybe related by a lower fiber digestibility of glycerol-supplemented diet. Milk yield was significantly reduced in treated ewes. Milk protein content increased and milk fat was not affected. As for reproductive performances, the difference was not statistically significant.