Studies On Effect Of Different Plants Oil On The Rumen Fermentation And The Content Of Conjugated Linoleic Acids Of Milk Fat In Dairy Cows

The high content of energy and low consumption in supplying energy fat added was used as an effective method of increasing diet energy concentration. Especially during the period of prelactation, the certain amount of fat added can relieve the negative balance of energy and improve milk output and CLA content in milk fat. Studies have shown that fat content in ruminant diets shouldn't exceed 7%, because excessive fat adding can influence the activity of rumen microbes and result in disorder of rumen function and decrease of animal performance. In this paper we studied the effect of plant oil supplement on rumen fermentation, digestion, metabolism, CLA content of milk fat and dairy product performance in cows. The results are as follows:1. According to adding different plant oil (rapeseed, sunflower seed and benne seed), three groups were generated, and the level of the fat in diets was 6.5%. The results of experiment in vitro suggest that there were no significant differences between the three groups (rapeseed, Sunflower seed, benne seed) in pH value, protozoa counts (average value of different incubation times), concentration of NH3-N, BCP, TVFA, and degradation of DM and NDF (P>0.05). But protozoa counts, concentration of BCP and TVFA and degradation of DM and NDF were highest for group of 6.5% (diet fat level), at the same time, NH3-N concentration was lowest for group of 6.5%.2. Study in vivo showed that no significant differences were found between groups of adding three different plant oil in pH value, protozoa counts, concentration of NH3-N and BCP (P>0.05). TVFA concentration and the ratio of acetate to propionate were not significantly different between groups. Passage rate of liquid (L/h) was 13.34, 11.89 and 12.68 for rapeseed group, sunflower seed group and benne seed group respectively, but the difference between groups was not significant (P>0.05).3. Study in vivo also suggested that there were no significant differences between three groups in dry matter intake, metabolism of energy and nitrogen, the apparent digestibility of OM, CP, NDF and EE in cows (P>0.05).4. The results also indicated that no significant differences were found between three groups in milk output and composition (P>0.05). milk output (Kg) was 22.63,21.59 and 22.40 in sunflower seed group, benne seed group and rapeseed group respectively,...