Effects Of Supplementation PEG On Intake, Digestibility And Rumen Fermentation Parameters Of Caragana Diet In Sheep

The digestibility of different caragana pellets in sheep,effects of supplementation PEG on rumen fermentation and digestibility of caragana in sheep were studied in the thesis.The objectives of this thesis were to determine the supplemental doses of PEG and exploiting the Caragana into the feed of ruminant.The study comprised three parts.Part 1. Comparative Study on the digestibility of different caragana diet in sheepNine Mongolian and Han crossbreed wether sheep,aged about 1.5 years and weighting 35 kg were used to study on the intake, apparent digestibility and nitrogen metabolic of different caragana diet in sheep. The results showed that The increase of caragana concent(tanning concent increase else) resulted in a linear decrease of the nutrients intake and apparent digestibility. There was a negative relationship between nitrogen intake, digestible nitrogen, nitrogen retention and caragana concent. However, Nitregen excretion in faeces was associated with caragana concent(tannin concent). there was no significantly different in urinary N between different foliages. Besides, the results also indicated feeding sheep on caragana foliage continuously made them anorectic and apathetic, and their faeces was sticky.Part 2.Effects of PEG on rumen fermentationThe objectives of this experiment were to study on the effect of polyethylene glycol(PEG) supplementation on rumen fermentation and further to determine the supplemental doses of PEG by in vitro technique. The substrate for fermentation was caragana pellets. There were five treatments based on different supplemental doses of PEG(0, 1.85, 3.69, 7.38, 11.07mg),each treatment had three duplications. The results indicated that Addition of PEG increased In vitro gas production, NH₃-N, BCP and VFA concentrations,as well as DM and CP digestibility. Whereas, there were no significantly effects on pH and the ratio acetate to propionate between the five treatments. The optimum doses of PEG which can mitigate adverse effects of tannins was 7.38 and 11.07mg.Part 3. Effects of PEG on intake and digestibility of caragana diet in sheepSix Mongolian and Han crossbreed wether sheep, aged about 1.5 years and weighting 35 kg were used to comparatively study on intake and apparent digestibility of Caragana pellets in sheep. The results indicated that sheep fed PEG–supplemented diet consumed more DM, OM , CP, NDF, ADF and had higher apparent digestibility than those fed no PEG foliage. Nitrogen intake, digestible nitrogen and nitrogen retention increased significantly in sheep fed PEG–supplemented diet compared to control group. Faecal N loss was lower in experiment group than in control group. In contrast, urinary N loss increased with fed foliage addition of PEG, but no significantly difference.