Composition and Yield of Goat Milk as Affected by Nutritional Manipulation

This report deals with the influence of quantity and nature of roughages and concentrates on milk yield and composition by goats producing 500 to 900 kg milk per year, particularly the influence of crude fiber and crude protein.Forages with most voluntary intakes and milk yielding capabilities were legumes (alfalfa, red clover) and Italian ryegrass.Milk production was highest with green forages and hay pellets.Corn silage feeding reduced milk yields by 5 to 14% and hay of medium quality by 15 to 25%.Supplementary concentrates during midlactation increased intakes of dry matter and energy and milk production.Milk protein percentage was increased, but milk fat contents were lower.Increased intakes of energy raised percentages of palmitic acid and decreased carbon-18 acids.Low lipid contents (<1% of dry matter) in the total ration reduced milk production, fat percentages, and carbon-18 fatty acids in milk fat.Formaldehyde-treated oil-meals improved milk production.Concentrates at 400 g/kg milk instead of 200 g improved milk production by 20 to 25% in early lactation and by 7.5% in midlactation.Because of persistency, the feeding plan giving most economic returns during the whole cycle of reproduction seems to be a medium 200 to 400 g concentrates per day in late pregnancy and a high 300 to 400 g/kg milk during lactation.