Effects of fibre and non-fibre carbohydrate and level of intake on microbial protein yield in Sarda sheep

Three studies using Sarda dairy sheep in dry, mid-lactation and late-lactation were carried out. Forty ewes for each physiological stage were fed 8 complete pelleted diets, which differed from each other in NDF and NFC content and source. Based on their main ingredient, diets were denominated: corn meal (CM), wheat middlings (WM), corn flakes (CF), barley meal (BM), corn cobs (CC), beet pulp (BP), alfalfa (AA), and soybean hulls (SH). In each study, rumen microbial protein (MCP) synthesis was estimated measuring urinary purine derivatives. In dry sheep, MCP synthesis was not affected by diet, while in mid- and late-lactation sheep dietary effects were observed. In mid-lactation, the highest MCP production was found for BM and BP (171 and 166 g/d, respectively), while the lowest was observed with AA (63 g/d). In late-lactation, the highest MCP yield (146 g/d) was observed in BP, while the lowest were for SH and CM. MCP synthesis, for each diet, was higher in mid-lactation than in latelactation, which in turn were higher than in the dry period. Dry matter intake (DMI) was positively associated to MCP. The MCP synthesis was best predicted by dietary energy (NEL) or digestible organic matter intake (dOMI)

FACTORS AFFECTING PRODUCTIVE AND REPRODUCTIVE PERFORMANCE OF FRIESIAN X BORANA CROSSBRED COWS UNDER SMALLHOLDER MANAGEMENT CONDITIONS IN ETHIOPIA

Factors contributing to milk yield, changes in body weight (BW) and body condition score (BC), and reproductive performances of 50 Friesian X Borana (F1) crossbred cows under smallholder farmers' management conditions were investigated. The F1 crossbred cows were distributed by International Livestock Research Institute (ILRI) in the study area with the objective of introducing multipurpose (dairy and draft) cow technology. Milk yield was found to be a function of wheat bran and hay intakes. Comparisons of mean change in initial and final BW and BC indicated that the animals lost their BW and BC during the study period and showed deficiency of 24% of metabolizable energy (ME). Change in BW was found to be a function of wheat bran and noug cake intakes. Mean (±SD) pasture time of dairy cows was 7:49±3:05. Based on their progesterone (P4) concentration, 60% of the dairy cows were acyclic (P4 < 1.63 ng/ml) throughout the study period, of which 50% (15/30) had P4 < 1 ng/ml. The acyclicity of dairy cows could be associated with 24% deficiency of ME, loss of BW and BC and long pasture time. Improvement of dry season feed supply would help reduce losses in BW, BC, production and reproductive performances. Key Words: Dairy cows, F1, Friesian x Borana, reproductive performance African Journal of Livestock Extension Vol.3 2004: 45-4