7238

6744

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1391

هشت، 57ص.: مصور، جدول

ص.ع. به فارسي و انگليسي

غلامرضا قرباني، محمد خوروش

سعيد انصاري، مسعود عليخاني

16/8/91

احمد رياسي، جمشيد رزمجو

1396/09/21

كتابنامه

كشاورزي

مهندسي كشاورزي

ID6744

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

61Evaluation the effects of Alfalfa Particles Size in Acidogenic Ratios on Mid LactationHolstein Dairy Cows Performance and Health Ali kahyani Ali kahiani@yahoo com Date of Submission June 11 2012 Department of Animal Science Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor M Khorvash and G R Ghorbani ghorbani@cc iut ac irAbstract This experiment was conducted to investigate mid lactating Holstein cows performance and behaviorinresponse to alfalfa hay particle size in acidogenic based diets Nine multiparous mid lactation Holstein dairycows 653 53BW 45 4 milk yield 88 15 DIM mean SD fed total mixed rations 40 60 forage toconcentrate ratio containing 3 sizes of alfalfa hay with geometric mean 2 fine 3 5 medium and 5 mm long were used in a replicated 3 3 Latin square designwith 21 d periodsincluding 14 d of adaptationand 7 d of data collection Cows within a square were assigned randomly to dietary treatments Cows wereblocked into 3 squares of 3 cows each based upon milk production body condition score and DIM andwithin blocks were assigned to 1 of the 3 experimental diets Treatment diets were randomly assigned afterblocking to minimize carry over effects Cows were housed individually in box stalls 4 m x 4 m that wereequipped with concrete feed bunk and waterers Clean wood shavings and sawdust were used for beddingand refreshed once a day Cowswere fed ad libitum once a day permitting 10 refusals with free access towater A second cut alfalfa hay at 50 flowering provided by Lavark farm waschopped by a harvestingmachine with screen size regulator The geometric means of rations were 3 00 3 54 and 3 87 mm in fine medium and long alfalfa hay treatments respectively Reduction of alfalfa hay particle size linearlydecreased rations geometric mean physically effectiveness factor of 2 pef 8 and 3 pef 1 18 sieves physically effective NDF of 2 peNDF 8 and 3 peNDF 1 18 sieves Intake of DM OM EE peNDF 1 18 andyield of raw and 4 fat corrected milk and also ruminating time changed quadratically to be higher inmedium sized alfalfa hay Furthermore intake of peNDF 8 milk fat percentage and fat to protein ratio eating time and eating time when expressed as kg of DMI and sorting of particles retained on pan linearlydecreased with decreasing alfalfa hay particle size However reduction of alfalfa hay particle size linearlyincreased intake of CP eating rate and chewing time when expressed as kg of peNDF 8intake Also intake ofneutral detergent fiber milk total solid yield total chewing time and rumen fluid pH 4 h post feeding changed quadratic ally however DMI 6 h post feeding milk fat yield eating time when expressed as kg ofNDF intake eating length min meal and sorting of particles retained on 19 mm sieve tended P 0 15 todecrease linearly with decreasing particle size of alfalfa hay Total tract nutrient digestibility and rumenfluid pH 2 h post feeding were not affected by treatment Results indicate that change of alfalfa hay particlesize in an acidogenic based diet can be an effective way to manipulate DMI and chewing activity whereasfurther study is warranted to determine whether alfalfa hay particle size and acidogenic diet haveinteraction In conclusion cows fed an acidogenic diet positively responded to medium size alfalfa hay undercurrent feeding conditions Keywords Alfalfa hay particle size physically effective fiber acidogenic ration sorting behavior

غلامرضا قرباني، محمد خوروش

سعيد انصاري، مسعود عليخاني

احمد رياسي، جمشيد رزمجو