THE EFFECT OF RELATIVE PROTEIN AND ENERGY CONTENT OF DAIRY RATIONS ON PRODUCTION AND COMPOSITION OF MILK

[摘要] Two trials, each with 12 Holstein cows in early lactation, were conducted to study the effect on yield and composition of milk when the relative protein and energy contents of dairy rations were altered. A change-over design of experiments was used and digestibility of representative rations was determined with steers. A significant increase in fat-corrected milk production was obtained when energy (T.D.N.) intake was raised 5 to 12 per cent above recommended feeding standards. The protein content of the milk was increased (P�?<�?0.05) when digestible crude protein was 20 to 30 per cent in excess of recommended allowances, but increases in milk production, in percentages of butterfat and solids-not-fat were not significant (P�?>�?0.05). When molasses comprised up to 18 per cent of dry matter of a ration, digestion co-efficients for protein and fibre were reduced.

[学科分类] 动物科学

[关键词] microRNA isolation;Clinical samples;Q-PCR;FFPE tissues