Metabolic and hormonal control of energy utilization and partitioning from early to mid lactation in Sarda ewes and Saanen goats

In a recent study, we observed that starch-rich diets used in mid lactation induced lower milk production persistency and higher body fat accumulation dairy ewes compared with goats. Because these species differences could be linked to hormonal mechanisms drive energy partitioning, the same experiment, explored evolution of metabolic status during test this hypothesis. Twenty mature Sarda 20 Saanen goats [15–134 ± 11 d (DIM), mean SD] were simultaneously. early lactation, each was allocated one dietary treatment: high-starch diet [HS: 20.4% starch, on dry matter (DM) basis], whereas from 92 DIM, 1 2 treatments: HS (20.0% DM basis) low-starch (LS: 7.8% diets. Blood samples collected morning analyze glucose, nonesterified fatty acids (NEFA), growth hormone (GH), insulin, insulin-like factor I (IGF-I). Data analyzed using PROC MIXED procedure SAS repeated measurements (SAS Version 9.0). The LS applied did not affect animal within species; thus, only comparison between carried out. From plasma glucose concentration than (54.57 vs. 48.35 1.18 mg/dL), NEFA greater (0.31 0.25 0.03 mmol/L). Goats had GH insulin content (4.78 1.31 ng/mL 0.47; 0.11 0.26 ?g/L 0.02). Plasma IGF-I vary species. lactating goats, out by studying simultaneously stage experimental conditions, suggests explains why they partitioned more toward reserves mammary gland, especially lactation. This can justify negative effect mid-lactating ewes. Conversely, highest explain starch gland positive Together, different responses contribute specialized such as breed, have sheep breeds, Sarda.