Work

Diurnal and postprandial changes in key metabolic markers in high- and low-yielding early-lactation Saanen dairy goats

Year: 2026

Type: article

Abstract: Although diurnal variation in circulating hormones and metabolites is well-characterized in dairy cattle, limited information exists for dairy goats, despite its importance for accurate metabolic assessment in dairy species. This experiment investigated diurnal variation in key metabolites and hormones over a 48-h period in early-lactation Saanen dairy goats under controlled feeding conditions, comparing high- and low-yielding individuals. Twenty-nine multiparous goats (25 ± 4.7 DIM) were classified as high- (HP; n = 15) or low- (LP; n = 14) producers based on average milk yield over the previous 7 d, using fixed thresholds (<3 L/d for LP; >4 L/d for HP). Blood samples were collected every 2 h via jugular catheters and analyzed for nonesterified fatty acids (NEFA), glucose, BHB, insulin, creatinine, BUN, insulin-like growth factor-1, and growth hormone. Circulating NEFA, glucose, BHB, creatinine, and BUN displayed diurnal variation. The HP goats exhibited higher circulating concentrations of NEFA and BHB, but lower concentrations of glucose and insulin compared with the LP goats. These findings highlight the differences in energy metabolism and nutrient partitioning between production groups. Overall, sampling before morning feeding is recommended when assessing energy metabolism or basal nitrogen metabolism because there is less variability in metabolite concentration due to postprandial fluctuations, and metabolites are at their most extreme concentrations for assessing energy balance and metabolism. This experiment provides initial insights into the transient daily variation in blood metabolites during early lactation in dairy goats fed 1.4× maintenance requirements, which can assist in improved metabolic profiling in future experiments.

Source: Journal of Dairy Science

DOI: 10.3168/jds.2025-27030

Authors: J.L. Kirkham, F. Zamuner, A.W.N. Cameron, E.K. Carpenter, B.J. Leury, K. DiGiacomo

Institution: The University of Melbourne

Language: English

Topic: Ruminant Nutrition and Digestive Physiology

Subfield: Agronomy and Crop Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $3,500