اثرات انرژي جيره غذايي در دوره انتظار تحت استرس گرمايي، بر عملكرد و متابوليت هاي خوني گاوهاي هلشتاين

چكيده انگليسي :

Effects of Dietary Energy in the Transition Period under Heat Stress on Performance and Blood Metabolites of Holstein Cows Hossein Akbarizadeh akbarizadehhossein@Yahoo com 22 December 2013 Department of Animal Science Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor G R Ghorbani ghorbani@cc iut ac irAbstractDry matter intake and energy restriction before parturition prevents high feed intake depending onrequirement and caused an improvement in health and better performance after parturition A decrease in dietenergy by using forage like chopped wheat straw causing a lightening of diet energy led to a prevention ofhigh energy intake during period before parturition The present study was carried out to evaluate the effectof different levels of feed intake before parturition on performance some reproductive performance andblood metabolites of transition Holstein cows subjected to heat stress Ninety multiparous Holstein cowswere randomly selected and assigned to 3 dietary treatments with 30 cows each in a repeated measurementdesign Total mixed diets according to NRC 2001 were used to feed cows Experimental diets consisted ofcontrol 12 05 straw a group with feed restriction and a diet with free feed intake The mean of maximumtemperature humidity index during this trial was 75 93 Colostrums sampling was done from the first milkingafter parturition and then blood samples were collected 10 days before parturition 1 and 10 d after parturitionand at the last of trial The results showed that milk production was significantly P 0 015 influenced bydietary treatments until 21 d after parturition and cows with limited feed had the lowest milk productioncompares to free feed intake and control groups 41 78 vs 43 07 43 74 Uncorrected milk production meanin total period and 3 5 corrected milk production in the first 21 d was unaffected by dietary treatments Furthermore milk total solid was the highest in control group compares to other groups P 0 005 Milk fatproduction and percentage protein percentage lactose production and percentage total solid production andcolostrums compositions were not affected by diets before parturition Before parturition diets had nosignificant effect on body weight and body condition score changes before parturition but significantdifference was observed between treatments on body weight P 0 057 and body condition score P 0 093 changes after parturition Glucose insulin and non esterified fatty acids concentrations were unaffected bydiets before parturition but there was a significant difference P 0 04 between treatments on beta hydroxylbutyrate acid concentration Dietary treatments had a significant effect on glucose P 0 03 and insulin P 0 005 concentrations after parturition No significant difference was observed between treatments ondays to first insemination open days and pregnancy percentage but the number of inseminations perpregnancy tended to be lower p 0 065 in cows receiving limited feed In general results of this studyindicated that feed intake restriction or consumption of copped wheat straw before parturition led to a betterresponses in performance reproductive parameters and blood metabolites in Holstein cows under heat stress Keywords feed restriction energy intake performance reproductive parameters heatstress Holstein cows

اكبري زاده، حسين

اثرات انرژي جيره غذايي در دوره انتظار تحت استرس گرمايي، بر عملكرد و متابوليت هاي خوني گاوهاي هلشتاين

محدوديت خوراك , انرژي مصرفي , عملكرد , صفات توليد مثلي