پديد آورنده :
پزشكي، عادل
عنوان :
اثر دوره هاي خشكي كوتاه بر روي عملكرد توليد مثل و فراسنجه هاي متابوليك در گاوهاي شيري هلشتاين
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
﴿علوم دامي﴾
محل تحصيل :
اصفهان :دانشگاه صنعتي اصفهان، دانشكده كشاورزي
صفحه شمار :
يازده ، 133، [II]ص: جدول
يادداشت :
ص. ع. به فارسي و انگليسي
استاد راهنما :
غلامرضا قرباني، حميد رضا رحماني
استاد مشاور :
مسعود عليخاني ،مهدي محمد عليپور
توصيفگر ها :
آناليزهاي آماري , تزايد بافت پستان , رشد شبه انسولين , سوماتوتروپين , ليپوپروتئينهاي بسيار كم چگال
استاد داور :
عبدالحسين سميع، احمد خاتون آبادي
تاريخ ورود اطلاعات :
1396/02/12
چكيده فارسي :
به فارسي و انگليسي:قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Abstract Results from past retrospective analyses of observational data and some ofdesigned studies support a dry period DP of 40 60 d Recent designed studies havedemonstrated minimal effects of shortened dry periods on today s high producingcows The objective was to evaluate effects of different dry periods 56 42 35 day on milk yield and composition health status energy balance and reproductiveefficiency of multiparous and primiparous cows on a governmental dairy in Iran Onehundred and twenty two Holstein multiparous and primiparous cows were assigned toa completely randomized design with Traditional dry period Pimiparous TP Traditional dry period Mltiparous TM Intermediate dry period Primiparous IP Intermediate dry period Multiparous IM Short dry period Primiparous SP and Short dry period Multiparous SM in one herd Actual dry period lengths forrespective treatments was 56 5 1 42 2 1 35 2 7 A total of 14 cows wereremoved from all of the groups and only one hundred and eight cows were included instatistical analyses All cows were milked 3 times per day and milk yield wasrecorded at three consecutive milking daily throughout 210 DIM Body conditionscores were recorded at drying off day and thereafter at calving day and 15 wk oflactation Shortening the dry period 35 and 42 day induced to considerable milk lossin primiparous cows Additional milk production couldn t compensate milk loss ofcurrent lactation in primiparous cows In multiparous cows in addition to additionalmilk production 285 and 301 kg for 35 and 42 days dry groups respectively shortening the dry period hasn t affect milk yield of next lactation Adjusting milkproduction for 305d 305d ME 305d I Season approved that 42 days dry groupbecause of higher nutritional stress than other groups affect more Mean of milkprotein fat and lactose percentage didn t differ significantly between treatments however milk protein yield decreased in 35 days dry group compared with 56 daysdry There weren t any significant differences between groups for incidence ofmetabolic disorders Negative energy balance indexes BHBA NEFA and positiveenergy balance indexes VLDL TG and Glucose demonstrated that SP group was inbetter energy status than other groups Meanwhile SM TP IM and IP groups was inlesser energy status than others Insulin and IGF I serum levels were similar betweengroups Cows with shorter 35 dry period tended towards improved IGF I Nosignificant differences were detected in pregnancy rate first service conception rateand days to first service due to shortened dry periods but cows with 42 dry periodshad higher days open than others and SM group had higher services per conception incompared with other groups Shortening the dry period till 35 day didn t supplyenough time to replenishment the body reserves during the dry period but it inducedto survive BCS better than two other groups after parturition As a general conclusion it is beneficial to shorten the dry period length till 35 day in multiparous and fat cows
استاد راهنما :
غلامرضا قرباني، حميد رضا رحماني
استاد مشاور :
مسعود عليخاني ،مهدي محمد عليپور
استاد داور :
عبدالحسين سميع، احمد خاتون آبادي
