Improving the nutritive value of wheat straw with urea and yeast culture for dry season feeding of dairy cows

The study evaluated the effects of feeding urea treated/supplemented wheat straw-based diets with addition of yeast culture (YC) as a dry season feed for dairy cows. Wheat straw diets with 3.6 % urea and 5.8 % molasses were formulated to upgrade nonprotein nitrogen levels and fibre degradation in the rumen. Yeast culture was included at 0 and 10 g/cow/day in mixer with commercial dairy meal to improve on fibre degradation and milk yield. Two experiments were conducted. Firstly, an in sacco dry matter degradability (DMD) trial with three steers in a completely randomized design (CRD) with a 3?×?2 factorial arrangement to determine the effects on intake and rumen degradation parameters. Secondly, feeding trial with 18 lactating cows in a 3?×?2 factorial arrangement at two levels of yeast culture (0 and 10 g/cow/day) and three types of urea interventions: No intervention (WS); addition of urea to straw at the time of feeding (USWS); and 7 days incubation of straw with urea (UTWS). Yeast cultures addition had no effect on rumen pH and NH₃-N, but urea intervention showed an effect on rumen pH with USWS being lowest (p?<?0.05). Both urea interventions and yeast culture addition had no effect (p?>?0.05) on dry matter intake, milk yield, and milk composition but they increased (p?<?0.05) propionate yields.     

Nutrient intake,digestibility and rumen fermentation characteristics of sheep fed on selected forage sweet potato cultivars

Selected forage sweet potato cultivars (Ipomoea batatas Lam) have superior forage characteristics, have high rates of regeneration after harvest, are able to smother weeds and can tolerate diseases and moisture stress. However, little information is documented on their feeding value. The study objective was to determine nutrient intake, digestibility and rumen fermentation characteristics of sheep fed on four selected forage sweet potato cultivars (K158, Marooko, Mugande and Wagabolige). Cultivars did not influence intake of dry matter (DM) (93.8–98.1), organic matter (OM) (82.0–85.6), neutral detergent fibre (NDF) (37.6–38.8 g/kg W^0.75) and metabolizable energy (0.94–0.99 MJ/kg W^0.75); digestibility of DM (740.3–744.1) and OM (747.0–751.7 g/kg DM) and intake of digestible DM (69.8–72.6) and OM (61.3–64.4?g per kg W^0.75); rumen pH (6.80–6.86), molar percentages of acetate (68.34–69.59), propionate (21.35–22.58), butyrate (7.43–7.57) and acetate to propionate ratio (3.03–3.20). Cultivars influenced intake of crude protein (CP) (10.7–16.9) and acid detergent fibre (ADF) (25.9–28.5 g/kg W^0.75). Digestibility of CP (655.7–821.1), NDF (594.1–712.8) and ADF (477.0–483.7 g/kg DM); intake of digestible CP (7.0–13.9) and NDF (22.4–27.7?g per kg W^0.75) were also influenced by cultivar. CP and NDF digestibility differed among all four cultivars with Morooko and K158 having the highest CP and NDF digestibility, respectively. Sheep fed on K158 and Wagabolige ingested similar quantities of digestible CP (11.6–11.8?g per kg W^0.75), which was lower than in Marooko (13.9?g per kg W^0.75). The four cultivars provided superior feeds to sheep which classify them as high quality forages. Hence they have the potential to improve livestock production in Kenya.