Revista Brasileira de Zootecnia
Print version ISSN 1516-3598
OSMARI, Elisa Köhler et al. Roughage intake, milk yield and physicochemical composition from F1 Boer × Saanen goats. R. Bras. Zootec. [online]. 2009, vol.38, n.12, pp. 2473-2481. ISSN 1516-3598. http://dx.doi.org/10.1590/S1516-35982009001200025.
The effects were assessed of supplying supplementary roughage on intake, milk yield and milk physical and chemical composition in F1 (Boer ×Saanen) goats. Eighteen females were placed in three stalls, and received as ad libitum supplement sorghum silage, corn silage and mulberry hay (MHT), with daily control of dry matter intake. The average daily production per week was calculated by gathering the milk data in three post-parturition periods: 1 (34-40 days/7 days); 2 [(64-70 days/7 days) + (91-97 days)/7 days)]/2 and 3 (125-131 days/7 days). Daily spot-average of each period (DSAP) was calculated from the reference dates of average daily production per week, that was correlated with the composition of fat, protein, lactose, total solids composition and the somatic cell count. The weekly data for acidity and density were grouped in 37, 81±13, 128 and 151±10 days post-parturition. Using mixed models, the animal was computed as random and the fixed effects were three supplements and three periods (composition, average daily production per week and per period) or four (acidity and density). Mulberry hay intake (0.657 kg) was greater than corn silage (0.604 kg) that was greater than sorghum silage (0.305 kg). In period 2, the ether extract composition was smaller because of the decrease in fat and lactose. In period 3, protein and acidity increased and density was great in periods 1 (1.0270) and 3 (1.0277). Mastitis increased SCC in period 2. The type of supplement was not significant for protein, but there was post partum period ×supplement effect. The other variables were not influenced by the type of supplement, only by the post-partum period. Mulberry hay increased the supplement intake by the goats compared to corn and sorghum silage, but it did not improve milk yield = means and composition. Grazing Boer ×Saanen goats with supplementation have good milk production potential.
Keywords : composition; goat; milk; mulberry; roughage; supplement.