Comparison of Different Ideal Amino Acid Ratios in Male and Female Broiler Chickens of 21 to 42 Days of Age

An amino acid bioassay was carried out to compare responses of male and female broiler chicks to different ideal amino acid (AA) ratios from 21 to 42d of age. The ideal ratios were used to calculate AA requirements were IICP (Illinois Ideal Chick Protein), NRC (1994), RPAN (Rhone Poulenc Animal Nutrition) and feedstuff AA ratios which were compared with each other and with a positive control diet. Indispensable AAS were rationed to lysine according to requirement ratios in tested profiles, with digestible lysine set at 0.85 and 0.78 for male and female, respectively. Experimental period began at day 21 and lasted in 42d of age. Diets for all profiles contained 3200kcal AMEn/kg, and L-glutamic acid was used to make all diets equal in crude protein at 14.25% of the diet. Chicks fed diets formulated with RPAN had significantly lower weight gain and feed efficiency than IICP, NRC and feedstuff which is probably consequence of high Lys: Leu ratio in this profile. There were no significant differences in feed intake, weight gain and feed: gain among chicks fed IICP, NRC (1994) and feedstuff. Since IICP ratios in the case of all AAS (except Met+Cys in NRC) are lower than or close to the ratios in NRC (1994) and feedstuff, it can be concluded that IICP ideal ratios is sufficient for supporting maximal weight gain and feed efficiency. Chicks fed diets which their AA requirements calculated by feedstuff ratios had higher breast meat yield than IICP and NRC (1994) which may be due to higher Lys: Met+Cys ratio in this profile. Results of this experiment suggest that although male and female broiler chicks have different body composition and consequently different AA requirements, but they respond similarly to different ideal AA ratios

Effect of pre-calving body condition score and previous lactation on BCS change, blood metabolites, oxidative stress and milk production in Holstein dairy cows

The aim of study was to determine the effect of pre-calving body condition score (BCS) and previous milk yield on BCS change, blood metabolites, oxidative stress and milk production in Holstein cows. At 3 wk before expected calving, 100 multiparous cows were grouped according to their BCS and then classified based the previous 305 milk yield. The four experimental groups (25 cows each) were medium BCS and moderate milk yield (MM), medium BCS and high milk yield (MH), high BCS and moderate milk yield (HM), and high BCS and high milk yield (HH). The cows’ BCS was recorded at −21, 0, 21, 50 and 80 d related to parturition time. Daily milk production of cows was recorded after parturition. Blood samples were taken at d −21, −7, +1, +7 and +21 postpartum. The HH cows had lower (p <.05) plasma insulin than MH group. Also, the HH cows had lowest (p <.05) plasma insulin at 7 d after calving. Cows with high BCS had greater (p <.05) NEFA and BHBA concentration than medium BCS groups. Cows with high BCS had lower activity of antioxidant enzymes (p <.05) compared to medium BCS groups. Milk production, fat-corrected milk (FCM) and energy-corrected milk (ECM) were affected (p <.05) by pre-calving BCS and previous milk yield. Pre-calving BCS and previous milk yield affect (p <.05) milk fat production. In conclusion, the HH cows have greater milk production; however they are susceptible to oxidative stress and metabolic disorders risk based on their blood metabolites

Cervical dilation and improvement of reproductive performance in fat-tailed ewes via cervical dilator treatments

Objective: To determine the effect of different cervical dilators on cervical dilation and reproductive performance of fat-tailed ewes.Methods: In experiment 1 140 ewes were divided into seven groups with seven different treatments as following: 10 mL normal saline (control group), 100 IU oxytocin (OT group), 100 μg estradiol and 100 IU oxytocin (E2+OT group), 5 mL relaxin (R group), 2 mL sensiblex (SEN group), 200 μg misoprostol (MIS group) or 200 μg dinoprostone (DIN group). In experiment 2, artificial insemination was applied for evaluation of reproductive performance in experimental groups.Results: In experiment 1, the highest cervical dilation was observed in OT (90%) and E2+OT (100%) groups (P<0.05), while no significant differences was found among DIN, MIS, SEN and R groups (80%, 75%, 70% and 65%, respectively). In addition, the lowest cervical dilation was observed in control group. Experiment 2 found no significant differences among control, OT and E2+OT groups. The highest pregnancy rate, parturition rate and lambing rate were observed in OT groups (60%, 60% and 70%, respectively) and E2+OT groups (65%, 60% and 70%, respectively) compared to SEN, R, MIS and DIN groups (P<0.05).Conclusions: Oxytocin treatment alone or with estradiol could be used as a suitable dilator for improving reproductive efficiency during artificial insemination in fat-tailed ewes