Effects of Different Stubble Heights on Nutrient Composition,Fermentation Quality,Rumen Degradation Rate and Dairy Cows,Performance of Whole-Plant Corn Silage
The aim of this experiment was to investigate the effects of different stubble heights on nutrient com-position,fermentation quality,rumen degradation rate and dairy cows,performance of whole-plant corn silage.The experimental corn variety was"Dongke 301",and a one-way experimental design was adopted,the whole-plant corn at the wax maturity stage was harvested at the same time and place,the stubble heights were set at 20,30 and 40 cm for three groups,respectively,and the sampling of stubble height was repeated for 3 times.The nutrient composition,fermentation quality and nutrient degradation rates and degradation parameters of whole-plant corn before and after silage were determined.Forty-five lactating dairy cows were selected and randomly divided into three groups(15 cows in each group)according to parity(3 parity),lactation days[(44.8±5.0)d],milk yield[(43.5±1.5)kg/d]and body condition score(3.5 score),and cows were fed total mixed rations which contained whole-plant corn silage with different stubble heights(20,30 and 40 cm),the pre-experimental period lasted for 10 days,and the experimental period lasted for 60 days.The results showed as follows:1)the contents of neutral detergent fiber and acid detergent fiber in whole-plant corn before and after silage of group 40 cm were significantly lower than those of group 20 cm(P＜0.05),and the con-tents of starch,water-soluble carbohydrates and non-fibrous carbohydrates and relative feeding value were sig-nificantly higher than those of group 20 cm(P＜0.05).2)The contents of acetic acid,propionic acid and total volatile fatty acids in whole-plant corn silage of group 30 cm and group 40 cm were significantly higher than those of group 20 cm(P＜0.05),and the butyric acid content was significantly lower than that of group 20 cm(P＜0.05).3)The 72 h degradation rates of dry matter,neutral detergent fiber and acid detergent fiber of whole-plant corn silage of group 40 cm were significantly higher than those of group 20 cm(P＜0.05),and the effective degradation rates of dry matter,neutral detergent fiber,acid detergent fiber and starch were signif-icantly higher than those of group 20 cm(P＜0.05).4)The milk yield,4％milk fat corrected milk,energy corrected milk,feed conversion rate and milk fat and milk protein contents of group 40 cm were significantly higher than those of group 20 cm(P＜0.05).In conclusion,increasing the stubble height of whole-plant corn not only enhances the nutritional value,silage quality and digestible substance contents of whole-plant corn si-lage,but also helps to improve the milk yield and feed conversion rate of dairy cows after feeding,as well as increases the contents of milk fat and milk protein,and improves the milk quality.Under the conditions of this experiment,the appropriate stubble height of whole-plant corn is 40 cm.[Chinese Journal of Animal Nutri-tion,2024,36(9):5722-5735]
万方数据
维普
