Author/Authors :
Darawish, Samir University of Jordan - Faculty of Agriculture - Department of Animal Production, Jordan , Harb, M. Y. University of Jordan - Faculty of Agriculture - Department of Animal Production, Jordan , Titi, H. H. University of Jordan - Faculty of Agriculture - Department of Animal Production, Jordan
Abstract :
Two experiments were conducted in the Agricultural Research Station in the Jordan Valley to study the effect of replacement of alfalfa hay by barley straw in Total Mixed Rations (TMR) for Awassi lambs upon nutrients digestibilities and fattening performance. In the first experiment, 16 lambs were allocated randomly to four isocaloric and isonitrogenous Total Mixed Ration (TMR) treatments containing different levels of alfalfa hay and barley straw. In the first treatment, alfalfa hay was the main source of roughage, while in the second and third treatments alfalfa hay was replaced partially by barley straw. In the fourth treatment, barley straw was the main source of roughage and alfalfa was not used. The digestibility experiment lasted 17 days to measure the digestibility coefficients of: dry matter, organic matter, crude protein, crude fiber, ether extract and nitrogen free extract. For the fattening experiment, 32 Awassi lambs (average initial live weight of 31.88 - 32.75 kg) were fattened for 56 days and allocated randomly to the same four TMR treatments mentioned above. In the first experiment, the dry matter digestibilities were 69.5, 70.9, 70.7 and 68.3% for T1, T2, T3 and T4, respectively, while the organic matter digestibilities were 71.7, 74.0, 73.9 and 69.9% for T1, T2, T3 and T4, respectively. Crude fiber digestibilities were 47.8, 49.4, 49.3 and 46.5% for T1, T2, T3 and T4, respectively and were significantly different (P 0.05) among treatments. The digestibilities of crude protein and nitrogen free extract were not significantly different. Results of the fattening experiment with lambs showed that the Voluntary Feed Intake (VFI) did not differ at partial replacement of alfalfa hay, while it was lowered when alfalfa hay was replaced completely. The average daily weight gain took a similar pattern with no differences between treatments. There were neither carcass nor loin characteristics changes between treatment
Keywords :
Lamb growth , Alfalfa hay , Straw , Digestibility , Carcass characteristics
