Effect of low-forage rations on milk production of dairy goats: separate concentrate-forage versus mixed rations.

摘要

A 2-year study investigated two methods of feeding concentrated rations to intensively reared dairy goats: separate distribution of concentrate and forage in different feeders or concentrate and forage mixed rations. Both rations consisted, on dry matter basis, 15% ryegrass hay as roughage and 85% fibrous concentrate mixture (33% corn grain, 26.5% dehydrated alfalfa, 24% dehydrated beet pulp, 10% wheat bran and 6.5% soybean meal). The effect of each method of feeding on milk yield and composition of Canarian Majorera goats was studied during the first and second 41-week lactation. Forty-four Majorera goats were fed mixed rations and 46 goats were fed separate rations during their first lactation, and 37 and 38 goats, respectively, during their second lactation. The TMR system during the entire lactation (85/15) was similar than with the SR system at the beginning of lactation (86/14), but this ratio increased to 90/10 in the second half of lactation when SR was fed. Mixed rations increased the intake of concentrate (8-9% higher) and forage (42-44% higher) in both lactations. Total milk yield was about 10% greater with the mixed ration both on the first (414.9 l versus 371.5 l, P<0.001) and on the second (521.2 l versus 483.9 l, P<0.05) lactation. Feed efficiency (milk yield/DM intake) was similar between both feeding systems (0.65 in the first lactation and 0.72-0.75 in the second lactation). The percentage of milk fat and protein was about 5% higher (P<0.001), and daily yield of these milk components was about 15% higher (P<0.05), with the mixed ration. The results of this study showed that the use of mixed rations improves the production of goats in both lactations because they increased intake of concentrate and forage.Digital Object Identifier http://dx.doi.org/10.1016/j.smallrumres.2010.07.018