بررسی تأثیر گیاه سوبابل (leucaena leucocephala) به جای یونجه بر هضم و تخمیر شکمبه ای، رفتار نشخوار و متابولیت های خونی بز نجدی

Abstract

Introduction: Subabul (leucaena leucocephala) is a tropical legume. Subabul leaf has high content of N (16 to 23 percent crude protein) and Ca, a low content of tannins and phenolic componds. This experiment was conducted to investigate the effect of subabul as a replacement for alfalfa on rumen fermentation and digestion, rumination and blood metabolites of Najdi goat. Materials and methods: The eight Najdi goats with average body weight average 35 kg that were fed with the control diet and diet containing subabul (50 percent of alfalfa) for 40 days. Animals were randomly treated with four replications. Forage to concentrate ratio was 50 to 50. The leave of subabul were collected from Mollasani and milled. Diets fed twice per day for 40 days. Daily feed intake, nutrient digestibility, rumen and blood parameters, rumination activity was recorded. Cumulative gas production data were fitted to the exponential equation Y=B (1−e−Ct). Partitioning factor, microbial biomass, actually degradable organic matter were calculated by Makkar. Digestibility of dry matter and NDF of the samples were determined using an in vitro procedure of tilly and terry method. Data were subjected to analysis as a completely randomized design using the General Linear Model (GLM) procedure of SAS. Results and Discussion: The result showed the dry matter intake in control treatment was more than treatment containing subabul (P 0.05). Time to eating, ruminating and chewing and each of those for DM and NDF was not different (P>0.05). But time of eating, ruminating and chewing for crude protein in diet containing subabul was more than control (P 0.05). Potential of gas production and microbial biomass production of wheat straw in control and subabul were not different (P>0.05) but partitioning factor and microbial biomass efficiency was significant (P 0.05) but digestibility of DM and NDF of soybean meal was significant between treatments (P<0.05). Legums because of high quantity of protein and carbohydrate and lower fiber can be used as a suitable substrate for rumen microbial growth. But some studies reported that regards to the presence of tannin caused to reduce gas production. Because tannins tend to make a complex with nutrients, therefore it keeps nutrients away from microorganisms and prevents their fermentation. Therefore, it should be Also, tannins make a complex with proteins and this complex in undigested residual cause lower estimate of true digested organic matter and error in PF quantity. Saponin and oxalate reduce fibrolytic enzyme activity and fiber degradability in rumen. Conclusion: Therefore, the replacing of the subabul plant by 50 percent alfalfa had no negative effect on digestibility and fermentation; it may be subabul can be used in the diet of Najdi goat.