Effect of Diets Contaning Green Bean (Phaseolus vulgaris) Vines Hay on Milk Yield, its Composition and Yoghurt Quality for Dairy Goats.

This study was conducted to investigate the effect of inclusion green bean vines hay (GBVH) in replacing with clover hay (CH) in diets of Damascus goat does on nutrients digestibility, milk yield, milk composition, some blood parameters and yoghurt quality. Twenty-five lactating Damascus goat does with an average live body weight of 42.8±1.5kg at the 3 and 4 parities were divided randomly into five similar groups (5 each) where each group received one of 5 experimental rations. The first group was received concentration feed mixture (CFM) and (CH)(50:50%) as control ration (R0). Meanwhile, the tested rations R1 , R2 , R3 and R4 were received rations containing 25, 50, 75 and 100% GBVH in replacing CH in control ration, respectively. Results revealed that the chemical composition of both CH and GBVH is nearly similar respecting, CP and CF%. No significant differences between control ration (R0) and tested rations (R1, R2 and R3) in digestion coefficients of (DM, OM, CP, CF, EE, NFE%) as well as the feeding values (TDN and DCP). Inversely the tested rations of the highest level of GBVH (R4) almost had the lowest values of nutrients digestibility and TDN. While DCP values did not significant affected by the dietary treatments being the highest value was recognized with R3. Actual milk and 4%FCM yields were significant higher with the 75% GBVH ration (R3) and insignificant higher with the tested rations R1and R2, than those of control ration (R0). But the highest level of 100% GBVH ration (R4) had produced the lowest amount of milk among the four tested rations. Concerning milk composition, most of tested rations significant increased fat percentage compared with control one, while inverse trend was observed with milk protein percentage among treatments. Slightly improvement respecting milk TS was observed with the most tested rations compared with control ration with significant differences among some tested rations (R2 and R4) with control (R0). No significant differences among experimental rations regarding all offspring performance measurements, with highest values of weight at birth, weight at 1 month, weight at 2 month, daily gain from birth to 1 month and daily gain from birth to 2 month which recorded (4.5kg, 10.6kg, 14.2kg 203.13g and 161.56g) at R2, respectively. At the end of the experimental period, plasma total protein was unaffected significantly (P<0.05) by the experimental rations with the highest value (9.43g/dl) was occurred with R2 and the lowest one (6.50g/dl) was with R3. Fat and TS contents were somewhat improved with tested rations in comparison with control ration regarding the produced yoghurt. Also, R1 and R3 have good organoleptic properties of fresh yoghurt made from goat milk. Results indicated that the GBVH replacement in (R1 up to R4) reflected superiority over the control ration. Yoghurt prepare from milk produced from R1 and R3 groups had higher curd tension and lower cured syneresis than those of the other treatments. Feed conversion and economic efficiency were considerably seemed to be the best ones with R2 and R3 rations. Therefore, the replacement of clover hay with green bean veins hay in dairy goat rations is highly recommended in the practical feeding of goats.