5871

5486

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1389

نه،150ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

حميدرضا رحماني، محمد خوروش

محمد علي ادريس، مسيح ا... فروزمند

14/2/90

احمد رياسي، جواد كرامت

1395/08/23

مهندسي كشاورزي

ID5486

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

The Effects of Using Protected Fat During Transition Period on Reproductive Performance of Holstein Dairy Cows Mohamad Hossein Mostafavi Sahar8009@yahoo com Department of Animal Science Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc H R Rahmani hrahmani@iut ac ir M Khorvash khorvashm@yahoo com Abstract The proportion of lactating dairy cows on commercial farms that become pregnant at the first insemination has decreased over the last 30 years The objective of the experiment was to determine the effects of fat supplementation on progesterone concentration follicular development and conception rate Dietary fat supplements in early lactation may affect reproductive outcome by improving energy intake and reducing the extent of negative energy balance as well as by increasing size of the ovulatory follicle and lifespan of the coupus luteum In this experiment 24 multiparous Holstein cows were used in a completely randomized design test to evaluate the impact of protected fat supplements derived from soybean oil in transition period on reproductive performance of lactating cows Protected fat calcium salt of soybean oil containing 49 6 Linoleic acid of the total unsaturated fatty acids was used Fat supplementation at two levels of 0 and 2 5 of dietary DM was applied during transition period before and after calving Diets were formulated to contain differing fatty acid concentrations and to be isocaloric and isonitrogenous Before calving cows were allocated in to two groups 12 cows per each and after calving each group was divided to two subgroups 6 cows per each subgroup Treatment fed protected fat before and after calving treatment FF fed protected fat only before calving treatment FC fed protected fat only after calving treatment CF and control treatment treatmant CC Multiparous cows were randomly assigned to one of the two treatments consisting of calcium salt of soybean oil from 21 days prepartum to end of experiment Blood samples were taken before and after calving Blood samples were taken on days 14 10 9 8 7 6 5 4 3 2 1 before calving Blood samples after calving were taken on days 0 1 3 5 7 14 21 and each week up to end of the experiment One month after calving ovary was evaluated by ultrasonography Measurement of follicle size was performed by using a 7 5 MHz ultrasonographic probe and a imaging ultrasonograph Progesterone cholesterol TG VLDL HDL and LDL levels were also evaluated Progesterone was determined by Radio Immuno Assay in plasma samples Performance and hormonal response were analyzed using the GLM procedure of SAS 9 1 Means of treatment compared with LSMEANS in SAS 9 1 software The use of these supplements increased progesterone levels P 0 05 reducing the open days P 0 05 decreased an eight day calving interval to first estrous occurrence and reduction in the interval first oestrus to conception revealed P 0 05 and increasing follicle diameter P 0 05 Conception rate for first insemination in CC and FC treatments were 16 6 while FF treatment was 60 and CF treatment conception rate was 50 These results suggest that the best time to add this amount of protected fat is days before and after calving to increase energy balance and amount of steroid hormones as well Keywords oil protected fat progesterone energy balance

حميدرضا رحماني، محمد خوروش

محمد علي ادريس، مسيح ا... فروزمند

احمد رياسي، جواد كرامت