Effect of Dietary Supplementation with Probiotic and Prebiotic on Physiological Performance and Rumen Ecology of Growing Lambs

Abstract

The objectives of this study were to evaluate the effects of dietary supplementation with probiotic (BIOGEN B) and prebiotic (Biolex®MB40) on growth performance, physiological responses, rumen ecology and histometric measurements of the small intestine in lambs under three different feeding regimes. Sixty three male desert lambs (Hamari ecotype, 5 month) were obtained from the local livestock market. The animals were allowed to adapt for 2 weeks. Lambs were kept in naturally ventilated, open-sided animal house. Oxytetracycline L.A 20%, Ivermectin and Albendazole were administered during the adaptation period. The study was performed at the Department of Physiology, Faculty of Veterinary Medicine, University of Khartoum (during February 2020 to March 2021). The study was conducted in three separate experiments. The experiment was performed in a CRD. In each experiment, 21 lambs were assigned to 3 equal groups (A, B and C). In experiment I, lambs were fed roughages Rhodes grass (Chloris gayana) ad libitum and concentrates (0.4 kg /animal/ day), in experiment II, roughages alfalfa (Medicago sativa) ad libitum and in experiment III, roughages alfalfa (Medicago sativa) 50% feed restricted. Group A served as a control, Whereas group B supplemented with probiotic (0.5 g /animal/ day) and Group C supplemented with prebiotic (3 g/ animal/ day). The duration of each experiment was 8 weeks. The BW and BWG were recorded every two weeks, blood samples were collected weekly. Haematological parameters assessed were PCV, Hb, TEC and TLC. plasma glucose (Gl), and serum concentrations of total protein (TP), albumin (Alb), globulins (Glo), cholesterol (Chol), urea (Ur), creatinine (Cr), ALT, AST, Na+ , K+ , Clˉ, Ca+2 and Mg+2, and thyroid hormones (T3 and T4) were determined. Rumen liquor samples were collected every two weeks for monitoring pH, TVFA and NH3. Samples from duodenum, jejunum and ileum were collected at the end of each experiment for histometric measurement. SPSS V.23 was used for data analysis using one way ANOVA test. Means were separated by LSD test, P-value ≤ 0.05 was considered significant. In experiment I, the probiotic and prebiotic groups showed (P ≤ 0.05) increases in BWG, PCV, Hb and TEC compared to the control. However, TLC was (P ≤ 0.05) higher in prebiotic group compared to both probiotic and control groups. Serum TP (P ≤ 0.05) and Alb (P≤ 0.001) were higher in probiotic group compared to the control. Probiotic group showed (P ≤ 0.001) increase in serum Alb compared to the prebiotic group. Serum Glo (P ≤ 0.05) and Ur (P≤ 0.001) were higher in prebiotic group compared to both probiotic and control groups, respectively.Serum ALT increased (P≤0.05) in probiotic group compared to the control. Meanwhile, serum AST was (P≤ 0.001) lower in probiotic and prebiotic groups compared to the control. Serum Na+ was (P≤0.01) decreased in prebiotic group compared to probiotic and control groups. Serum Clˉ was (P≤0.05) higher in probiotic group compared to control and prebiotic groups. Ruminal TVFA was (P≤0.05) higher in probiotic group compared to the control. The jejunum villus height, jejunum, and ileum crypt depth were (P≤0.001) increased in probiotic group compared to prebiotic and control groups. In experiment II, probiotic group showed (P ≤ 0.05) increase in Hb, PCV and TLC and (P ≤ 0.001) increase in TEC compared to control. Both probiotic and prebiotic groups showed (P ≤ 0.001) increase in serum TP and Glo compared to the control. Compared to the control group, probiotic group showed increase in serum Alb (P ≤ 0.05), Chol (P ≤ 0.01), AST (P≤0.001) and (P≤ 0.05) decrease in serum Ur. Probiotic group showed (P ≤ 0.05) increase in serum ALT compared to control only at week 5. Probiotic group had (P≤0.05) higher serum Na+ at weeks 3, 5 and 6 compared to the control, meanwhile, the prebiotic group showed (P≤0.05) increase compared to control only at week 4. Both probiotic and prebiotic groups showed (P≤0.05) decrease in serum K+ compared to the control. Serum Clˉ was (P≤0.05) higher in probiotic and prebiotic groups than the control at week 7. Only at week 3, the probiotic group showed (P≤0.05) increase in ruminal TVFA compared to control, which was associated with (P≤0.05) decrease in ruminal pH and NH3. The crypt depth of duodenum and jejunum increased in probiotic (P≤0.05) and prebiotic (P≤0.001) groups compared to control. The jejunum villus height increased (P≤0.05) in prebiotic group compared to the control. In experiment III, the BWG increased (P≤0.01) in probiotic group at week 6 compared to the control. meanwhile, the BW was (P≤0.05) higher in prebiotic group compared to the control. Both probiotic and prebiotic groups showed (P≤0.001) increase in Hb, PCV, TEC. TP and (P≤0.05) increase in serum Chol compared to control. Serum Alb increased in probiotic (P≤0.001) and prebiotic (P≤0.01) groups compared to the control. Serum Ur was (P≤0.05) lower in prebiotic group compared to the control. Probiotic group showed (P≤0.05) decrease in ALT and AST compared to the control, meanwhile, serum ALT was only (P≤0.001) lower in prebiotic group compared to the control. Serum K+ was (P≤0.001) lower in both probiotic and prebiotic group compared to the control. However, serum Ca+2 was (P≤0.001) decreased in prebiotic group compared to both probiotic and control groups. The Mg+2 was (P≤0.05) higher in probiotic group compared to the prebiotic and the control groups. The ruminal TVFA increased (P≤0.001) in probiotic group compared to both prebiotic and control groups. The prebiotic one showed (P≤0.05) increase in TVFA at day 7, which was associated with (P≤0.05) decrease in ruminal NH3 compared to the control. Both probiotic and prebiotic groups showed (P≤0.001) increase in the jejunum villus height compared to the control. The study concluded that supplementation of probiotic and prebiotic to lambs diet induced positive effects on growth performance, significant increase in Hb, PCV, TEC, TLC, TP, Alb, Glo, Chol, Na+ and Clˉ and significant decrease in ALT, AST, Ur and K+ . There was significant increase in ruminal TVFA and positive effects on villus height and crypt depth of small intestine. The findings indicate interaction between probiotic and prebiotic supplementation and different types of feeding regime. Therefore, the study recommends that probiotic and prebiotic supplementation could be used to promote growth performance and immunity in lambs during different feeding regimes.