School of Animal and Range Sciences, College of Agriculture and Environmental Sciences, Haramaya University, P.O. Box 138, Dire Dawa, Ethiopia
Mekasha, Y., School of Animal and Range Sciences, College of Agriculture and Environmental Sciences, Haramaya University, P.O. Box 138, Dire Dawa, Ethiopia; Urge, M., School of Animal and Range Sciences, College of Agriculture and Environmental Sciences, Haramaya University, P.O. Box 138, Dire Dawa, Ethiopia
The effect of substitution of poultry litter (PL) by groundnut cake in a dairy ration was evaluated using 20 crossbred (Holstein Frisian x Zebu) dairy cows at Haramaya University dairy farm, Ethiopia. The mean (±SD) initial body weight of the animals was 437.2±54.6 kg. Experimental animals were randomly assigned to one of the four dietary treatments, which included supplementation of concentrate mix containing PL and groundnut cake (GNC) varying at different proportion. Animals were fed a basal diet of chopped maize stover ad libitum. Treatments were: PL45= 45% PL and 0% GNC; PL35=35% PL and 10% GNC; PL22= 22%PL and 17% GNC; PL0=0% PL and 29% GNC. Dairy cows fed PL22 diet had the highest (P<0.05) basal and total Dry Matter Intake (DMI) followed by PL35, while cows in PL0 had the highest (P<0.05) supplement DMI followed by PL22. Inclusion of PL at 22% (PL22) and 35% (PL35) of the concentrate mix improved (P<0.05) basal DMI by 13% and 9%, respectively. However, supplement and total CPI was the highest (P<0.001) for cows in PL0 followed by PL22. Dairy cows fed PL0 diet produced the highest (P<0.05) daily and 305-days milk yield followed by PL22. Including PL at 35% (PL35) and 22% (PL22) of the concentrate mix significantly extended lactation length. Dairy cows in PL35 produced milk more efficiently (P<0.05) per unit DMI. But no difference (P>0.05) noted between cows in PL22 and PL0. Efficiency of protein utilization for milk production was also the highest for cows in PL35 followed by PL22, but least for cows in PL0. In general, inclusion of PL beyond 22% resulted in loss of milk yield, body weight change, and reproductive wastage. The economic efficiency of dairy cows for milk production was highest for PL45 followed by PL22 but lower for other treatments. It is, therefore, concluded that PL could substitute GNC up to 22% of the concentrate mix for dairy cows fed a basal diet of maize stover, and this could be considered as an alternative feeding strategy to improve the performance of high-grade dairy cows.