ABSTRACT
This experiment designed to study the effect of two levels of Biogen–Zinc (BZ) as a probiotic or a Direct Fed Microbes (DFM) containing Bacillus subtilis and Zinc methionine that work as a feed additive for dairy Damascus goats. The study aimed to recognize the effect of BZ on nutrients digestibility, some rumen parameters, some blood parameters, milk yield and composition, daily gain of kids and economic efficiency. Thirty-six Damascus does (1-2parities), with 48.2 kg average BW and 1.5- 2 years old (within the last 45 days of pregnancy and 90 days post kidding) chosen and divided into three similar groups (12 does each) according to their body weight and fed according to NRC (1981). The control group was fed basal ration composed of 60% concentrate feed mixture (CFM), 20% berseem hay (BH) and 20% rice straw (RS), without additives. The tested groups (BZ1and BZ2) fed the control ration supplemented with Biogen–Zinc (BZ1) at levels 0.5 g BZ/h/d (25 mg Zn) and 1.0 g BZ/h/d (50 mg Zn), respectively.
The obtained results could summarized as follows
1- Supplementing dairy Damascus goats' rations with the two levels of BZ improved the digestibility of all nutrients within late pregnancy and lactation periods.
2- Biogen–Zinc treatments led to a significant increase in both birth and weaning weights of kids. The best weights occurred with BZ2.
3- Milk yield and composition increased by addition of BZ to diets.
4- Biogen–Zinc improved the biochemical parameters of blood total protein, globulin, glucose, total cholesterol, triglycerides, total lipids and concentrations of zinc, iron, calcium and phosphorus in blood plasma within late pregnancy and lactation period.
5- Feed and economic efficiencies were better for animals fed supplemented BZ2 than other groups.Accordingly, it could concluded that Biogen–Zinc, as a probiotic, supplementation for ration of dairy Damascus goats could improve nutrients digestibility, nutritive value, increase kids born and weaning weights, milk yield and composition, beside better-feed conversion efficiency and economic efficiency.