5308

4978

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1388

نه،61ص.:مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

غلامرضا قرباني، محمد خوروش

اسدا... تيموري ياسري،ابوالفضل زالي

7/4/89

مسعود عليخاني، امير حسين گلي

1395/08/23

مهندسي كشاورزي

ID4978

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

62 Responding of Mid lactating Dairy Cows to Different Alfalfa Hay Particle Size with Varied Ruminal Starch Degradability Sayyed Mahmoud Nasrollahi sm nasrollahi@ag iut ac ir Date of Submission 2009 11 23 Department of Animal Science Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor G R Ghorbani ghorbani@cc iut ac irAbstractThis experiment carried out to investigate the effects of and interactions betweenmarginal change in alfalfa hay particle size and barley or mixed corn and barley in diet onperformance of dairy cows Eight cows 175 days in milk were assigned to fourtreatments including fine alfalfa FA and long alfalfa LA that were combined withconcentrates based on either only ground barley GB FAGB and LAGB or 50 groundbarley 50 ground corn GBC FAGBC and LAGBC in a double 4 4 Latin squarethat arranged in a 2 2 factorial design Diets were fed ad libitum as total mixed rationwith a concentrate to forage ratio of 60 40 Averaged NEL predicted FNDF CP and NFCwere same for all diets and average NDF and ADF were 36 8 and 16 8 for GB and 36 5and 16 1 for GBC respectively Geometric mean particle size for FA and LA were 3 43and 4 33 mm and also for FAGB LAGB FAGBC and LAGBC were 3 6 3 8 3 4 and3 7 mm respectively Dry matter intake as other nutrient was greater in GBC than GB 1 34 kg d that was not affected by forage particle size Fiber digestibility was higher forGBC than GB Barley based diet had more non fiber carbohydrate NFC digestibilitythan GBC and with increased alfalfa particle size NFC digestibility was increased anddecrease respectively for GB and GBC The rumen pH at 3 h post feeding and totalchewing activity increased as hay particle size increased instead ruminal pH at 6 h postfeeding and total eating activity for GBC was higher than barley Acetate to propionateacid ratio was tended to decrease with increased hay particle size Total mean retentiontime was decrease and passage rate was increased with decreased hay particle size butrumen mean retention time was unaffected from hay particle size Fractional passage rateand VFA production was not affected from source of grain Milk production wasunaffected but milk fat to milk protein ratio was increased as alfalfa hay particle sizeincreased Hay particle size could not affect feces particle size and fermentability however GBC had higher feces particle size and fermentability Body weight tended to behigh for GBC but total efficiency of energy was 0 52 vs 0 58 for GBC and GBrespectively Increased of hay particle size or changed in grain source could not affectparticle sorting This study show that increase about 1 mm with the initial 3 mm alfalfahay particle size may improve animal health and performance and prevent from mildacidosis particular when barley is dominant grain fed Keywords physical fiber hay particle size barley corn feed efficiency

غلامرضا قرباني، محمد خوروش

اسدا... تيموري ياسري،ابوالفضل زالي

مسعود عليخاني، امير حسين گلي