Differential voluntary feed intake and whole transcriptome profiling in the hypothalamus of young sheep offered crude protein and phosphorus deficient diets

摘要: A reduction in voluntary feed intake is observed in ruminants consuming nutrient deficient diets, such as those with a low CP or P content, and has been attributed to active metabolic regulation, rather than a physical constraint. The hypothalamus is the key integrator of feed intake regulation in mammals. The objectives of this experiment were to 1) establish a model of metabolic feed intake regulation in ruminants consuming diets of variable CP and P content, and 2) determine key biochemical pathways and influential points of regulation within the hypothalamus. Merino wethers [n = 40; 23.7 ± 1.4 kg liveweight (mean ± SD)] were fed one of five dietary treatments (n = 8/treatment) for 63 days in individual pens. The treatments included targeted combinations of high (H) and low (L) CP (110 and 55 g/kg DM) and high and low P (2.5 and 0.7 g/kg DM) with 9 MJ metabolisable energy (ME) per kg DM which were fed ad …