Effect Of The Mulberry Leaves And Isovaleric Acid On Rumen Fermentation And Nutrient Digestion And Utilization In Jinnan Cattle

In order to study the effect of mulberry leaf and isovaleric acid effect on rumen fermentation and nutrient digestibility and utilization of Jinnan cattle, through in vitro and in vivo digestion trial to discuss. In experiment 1, here used mulberry leaves and maize straw to prepare different concentrate to forage ratio(40:60,50:50, and 60:40) of diet, which were determined fermentation characteristic. In the test, with the proportion of concentrate increase, the pH and the concentration of ammonia nitrogen in fermented liquid significant decrease(P<0.05); the concentration of total volatile fatty acid and A/P in 60:40 and 50: 50 group was significantly higher than that of 40:60 group (P<0.05); in 60:40 and 50:50 group, here higher digestibility of organic matter and crude protein, and lower digestibility of dry matter and neutral detergent fiber compared with concentrate to forage ratio 40:60(P<0.05). The results show that, the best concentrate to forage ratio is 50:50. In experiment 2, here used mulberry leaves to prepare concentrate to forage ratio 50:50 of diet add 0,15,30,45,60,90?L isovaleric acid, which were determined fermentation characteristic.In the test,30 and 45?L group, here had lower concentration of ammonia nitrogen, and higher concentration of total volatile fatty acid and A/P in fermented liquid compared with control group(P<0.05); the nutrient digestibility in 30 and 45?L group significantly higher than control group (P<0.05). The results show that, the optimum adding amount of isovaleric acid is 30?L. In experiment 3, three head cattle (310.5±21.8 kg) equipped with permanent rumen fistula were chosen, silage and mixed concentrate diet (concentrate to forage ratio was 50:50) as basic diet, used 3×3 Latin square design, the control feeding based diet, the ML group replace 50% of silage with mulberry leaves on the basis diet, the MLIV(compound to add mulberry leaf isovaleric acid groups) group added 25 ml/d isovaleric acid in ML group. The results show that, the pH and concentration of ammonia nitrogen in rumen fluid in MLIV group significantly lower than that of ML group and control (P<0.05); the concentration of total volatile fatty acid and A/P in MLIV group significantly higher than that of ML group and control (P<0.05); the molar ratio of acetic acid, valeric acid, isovaleric acid and butyric acid in MLIV and ML group significantly higher than that of control (P<0.05), but MLIV group and ML group were no significant difference. The enzyme activity of filter paper, carboxymethyl cellulase, xylanase, pectinase and protease in MLIV group significantly higher than that of control (P<0.05). The soluble fiber butyrate vibrio, white of rumen bacteria and succinic acid production filamentous bacteria in MLIV group and ML group significantly higher than that of control (P<0.05), MLIV group and ML group were no significant difference; the yellow rumen bacteria in MLIV group significantly higher than that of ML group and control (P<0.05). The effective degradation rate, diet nutrient digestibility and the amount of rumen microbial protein synthesis and deposition of nitrogen/digestible nitrogen in rumen of mulberry leaf and mixed concentrate in MLIV group significantly higher than that of control (P<0.05). The serum glucose and total cholesterol levels in MLIV group and ML group significantly lower than that of control (P<0.05); the activity of lactate dehydrogenase and alkaline phosphatase in MLIV group and ML group significantly higher than that of control (P<0.05), but MLIV group and ML group no significant difference; the levels of triglycerides, glutamic oxalacetic transaminase and somatotropic axis hormone in MLIV group significantly higher than that of control (P<0.05). In conclusion, mulberry leaf replaced 50% silage contribution with isovaleric added could improve rumen fermentation and nutrient digestion utilization of Jinnan cattle.