5676

5298

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1389

ده،89ص.: مصور، جدول

ص.ع.به فارسي و انگليسي

غلامرضا قرباني، محمد خوروش

عباس احمد رياسي، محمدرضا عبادي

11/12/89

احمد رياسي، خورشيد رزمجو

مهندسي كشاورزي

ID5298

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Comparison of chemical compositions fermentation and degradationparameters of sorghum green forage and silage varieties by corn and effect of replacing corn silage with sweet sorghum silage on performance dairy cows Ahmad Hedayati pour aa hedayati@ag iut ac ir Date of submission November 1 2010 Department of Animal Science Isfahan University of Technology Isfahan 84156 83111 Iran Degree M SC Language FarsiSupervisor G R Ghorbani@cc iut ac irAbstract The aim of this study was to compare the nutritive value fermentation characteristics and in situruminal degradation kinetics in green forage and silage of three varieties sorghum including Sweet Pegah and Speedfeed by corn green forage and silage As well as investigation the replacing cornsilage with Sweet sorghum silage on cows performance For in vitro experiment forages were plantedin same conditions and harvested in soft dough stage and ensilaged in four replicate in mini silos Inthis study buffering capacity of Sweet green forage was lower significantly p 0 05 than corn andSpeedfeed green forages Neutral detergent fiber content was significantly p 0 05 lower in greencorn forage as compared with the Pegah and Speedfeed and also acid detergent fiber and aciddetergent lignin content were higher p 0 05 and water soluble carbohydrate was lower significantly p 0 05 in Speedfeed green forage as compared with other varieties dry matter content wassignificantly p 0 05 lower in corn silage than other silages Neutral detergent fiber and aciddetergent lignin were lower significantly p 0 05 in corn silage than Sweet and Speedfeed sorghumsilages Also the corn silage had a significantly p 0 05 lower level of residual water solublecarbohydrate than other silages Lactate concentration was higher significantly p 0 05 in corn andPegah sorghum silages than Sweet and Speedfeed 3 61 2 19 3 43 and 2 02 percent for corn Sweet Pegah and Speedfeed and acetate percent was higher significantly p 0 05 in corn and Sweetsorghum silage For in situ evaluation duplicate samples of 8 treatment 4 green forage and 4 silage placed in nylon bags and were incubated in two rumen cannulated cow for 0 1 3 6 9 12 24 48 and72 h Results indicated that corn and Pegah green forage had greater significantly p 0 05 fractionaldegradation rate than other two green forage and this make were significantly p 0 05 highereffective degradability with a passage rate 0 08 h in this two forages but only Speedfeed green foragehad lower significantly p 0 05 potential degradability than others Slowly degraded fraction wasmore in corn silage than sorghum silages and this made a greater potential degradability 85 25 than others because of lower acid detergent lignin in corn silage In in vivo study eight multiparousHolstein cows 35 5 kg d milk on average were used in an repeated 4 4 latin square Sweet sorghumwas substituted for 0 33 3 66 6 and 100 of dry matter provided by corn silage Intake of dry matterand other nutrient were similar among treatments but digestibility of all treatment were reducedsignificantly p 0 05 when Sweet sorghum replaced corn silage However milk yield andcomposition were not different among treatments and not affected by digestibility Rumen Ph tended p 0 06 to increase by replacing 100 corn silage with Sweet sorghum In conclusion it seems thatSweet sorghum silage can be replaced by corn silage in condition like this experiment Keywords Sweet and Forage sorghum silage corn silage chemicals composition in situ degradationkinetics digestibility milk yield

غلامرضا قرباني، محمد خوروش

عباس احمد رياسي، محمدرضا عبادي

احمد رياسي، خورشيد رزمجو