Abstract
The present study aimed at investigating the role of a synbiotic fermented milk synergistic with some active ingredients of the extraction of antioxidative compounds from Citrus aurantium, Withania somniferum, Trigonella foenum-graecum, Chicorium intybus and Lupinus termis and honey on the enhancement of the pregnancy rate, litter size, litter birth weight and progesterone (P4) profile of oestrous-synchronized Najdi ewes. A synbiotic syrup was prepared by mixing fermented cow's milk containing Streptococcus thermophilus, Lactobacillus acidophilus and Bifidobacterium bifidum with natural antioxidants isolated from functional foods and herbal extract. Twenty seven adult Najdi ewes were utilized in the experiment and randomly allotted into three groups. Nine ewes served as control (given no synbiotic formula, C group), 9 ewes were designed to be orally given 30 ml of the mixture twice per week for 12 consecutive weeks (Low dose, LD group) and 9 females were orally given 60 ml of the mixture (High dose, HD group) by the same regime. All ewes were synchronized for oestrus by inserting a controlled intravaginal drug release (CIDR) for 12 days just after the commencement of the syrup administration. Blood samples were collected from three ewes within a treatment once a week via jugular venipuncture in non-heparinized tubes. Sera were harvested and P4 was determined. Forty eight hours after CIDR removal fertile Najdi rams were introduced to mate oestrus ewes. Pregnancy rate, litter size, birth litter weight and mean lamb birth weight were determined. Pregnancy rate increased in LD (78%) and HD (78%) as compared to control ewes (56%). Mean litter size was 1.40, 1.30 and 1.00 for C, LD and HD, respectively. On the contrary, mean lamb birth weight significantly (P<0.01) increased in treated compared to control ewes (3030, 3500 and 4921.4 g for C, LD and HD, respectively). The increase in lamb birth weight approached +16% (LD) and +62% (HD) more than that found in control ewes. Progesterone pattern was typical in case of CIDR existence and absence, giving rise to high levels during CIDR, declined to a low level at its removal and at oestrus and increased thereafter in pregnant ewes. Throughout the course of pregnancy, there were significant (p<0.01) increases in mean P4 concentrations due to treatment. In conclusion, administration of a synbiotic formula to oestrous-synchronized Najdi ewes resulted in increased lamb birth weight and elevated the progesterone pattern throughout the pregnancy.