EFFECT OF GRAZING TIME ON PRODUCTIVE PERFORMANCE OF GOAT IN HALAIB – SHALATEEN REGION

This study was carried out at Ras Hadraba Valley region (Shalateen Research Station, Desert Research Center). Thirty female local goats, 2-4 years were randomly distributed into three similar groups with 17.74 ± 0.57 Kg. the treatments included: 1st group (G1) without grazing and feed 1% concentrate feed mixture of total requirements as recommended by NRC (1981) plus berseem hay ad libitum. The 2nd (G2) and 3rd (G3) groups were fed 1% concentrate feed mixture and allowed daily to graze on Panicum turgidum as a basal range plant for 4,8 hours for G2 and G3, respectively. Nutrients digestibility, feeding values, does reproductive and productive performance and also economic feasibility were studied through this investigation. Dry matter intake (DMI) of P. turgidum during pregnancy period was increased by different level of grazing time between G3 and G2 while (DMI) were higher in G1 which fed berseem hay ad libitum as roughage. Moreover, expressing it as (g /kg BW/ hour) was different between all treatments. The greatest intake (g /kg BW/ hour) was recorded for goats in G2 followed by G1 and G3.From the results of chemical composition; found that (G1) obtained the highest amount of CP, CF and NDF followed by the G3 and G2. Total dry matter intake was affected among treatments, mainly owing to the difference in roughage intake. It was observed that (G1) showed the highest value of TDMI, CP, CF and NDF. The same trend was observed during lactation period Nutrients digestibility showed that, DM, OM, CP, and CF digestibility were affected significantly (P≤0.05) among treatments. It was observed that goat G3 showed the highest digestion coefficients of DM, OM, and CF.TDN and DCP of G3 showed the highest (P< 0.05) value of TDN% (71.78) comparing with G1 and G2. But grazing for 4hours (G2) resulted in a lowest value of TDN intake either as g/ kg BW (16.88). DCP expressed as percentage (g/kg BW) were not affected (P< 0.05) by time spent for grazing. It can be seen that, G1 showed the highest (P< 0.05) value of DCP % (12.08) comparing with G1 and G2. But grazing for 4hours (G2) resulted in a lowest value of DCP intake either as g/ kg BW (1.77). During early pregnancy (EP) body weight change was insignificant decreased as grazing time. The highest value of BWC as a percent of IBW in (EP) was recorded for G1 (11.15 %), followed by G3 (7.23 %) and G2 (6.13 %).Through pregnancy overall periods, BWC was significantly (P≤0.05) affected by grazing time, where the highest value was recorded for G3 followed by G2 and G1.Birth weight of kids varied insignificantly among groups. Birth weights of kids were 1.71, 1.52, and 1.44 kg for G3, G1and G2, respectively. During early lactation Does lost weight, while in late lactation there were no loses of does weight on G1 and G3 although that there were loses of does weight on G2 only. Daily (BWC) at late lactation were insignificantly among all treatments. Data of kidding live born were 9, 7 and 7 for G1, G2 and G3 respectively. while the much weaned kids were in G1 (6) than G2 (5) and G3 (2).The yields of kids born kg per 100 serviced does were 136.8, 121.1 and 100.8 for G1, G3 and G2, respectively, while Kids weaned kg per100 serviced does were higher in G1 (305.4) than G2 (277) and G3 (106). The relative milk yield of G2 and G3 at early lactation was 84.72 and 58.39 % compared to G1 (100%), respectively. In late lactation the relative milk yield was 76.94and 69.44% compared to G1 (100%). The total relative milk yield showed the same trend of early and late lactation which was 81.21 and 63.40 % for G2 and G3 compared to G1 (100%), respectively. Weaning weight showed a different trend of kids was 5.54, 5.30, and 5.09 kg for G2, G3and G1, respectively. However overall changes (0-16 wks.) were differed among all treatments. Average daily gain was between (0-16 wks.) was as follows 36.61, 32.06 and 31.88 (g/day) for G2, G3and G1 respectively. The economic evaluation was calculated for both pregnancy and milk lactation separately. From these results, we conclude that all groups were uneconomic; it led to economic inefficiency for female goats during pregnancy and births. Having in milk production G1 was economically feasible for milk return duo to increased milk production and payed back in term of money; however the G2 and G3 was more efficient in term of net milk revenue as a percent of feeding cost. And return (offspring + milk) was higher in G1 than G2 and G3 this is due to higher number of kids and milk production. Net revenue, EP / Doe was higher in G2 and the next G3 this is due to the decrease cost feeding values, while G1, whose cost was high. It could be concluded that G2 (4 hours grazing time) through production cycle period is feasible rather than G1 (zero hours grazing time) or G3 (8 hours grazing time). Also, using of supplementary feeding system for lactating goats wasn't economically feasible with such genetically marginal lactating goats.