Journal of Animal Production, Print ISSN: 2008-6776., Online ISSN: 2382-994X

Abstract In the current study, the effect of source and level of copper in the diet on production and health of dairy cows using 105 multiparous pregnant Holstein cows from -21 until +15 days relative to calving in randomized complete block design with 3 treatments and 35 replications were investigated. The experimental treatments include: 1) diet containing copper at the NRC recommended levels from copper sulfate source (NRC-S), 2) diet containing copper at twice the NRC recommended levels from copper glycinate source (2NRC-Gly) and 3) diet containing copper at twice the NRC recommended levels from copper sulfate source (2NRC-S). Milk yield and composition were not affected by experimental treatments, but treatment by time interaction showed that cows fed by 2NRC-Gly had more milk than NRC-S group (P<0.05) at 60, 90,120 DIM and cow in 2NRC-Gly produced more milk at 90 and 120 days in milk compared to NRC-S (P<0.05). The somatic cells count for 2NRC-Gly cows was lower compared to NRC-S cows (P 0.05). The incidence of subclinical mastitis at 15 DIM in 2NRC-Gly was lower compared to the other two treatments (P = 0.05). No difference in body weight and body condition score changes were observed across treatments. Blood metabolites and liver enzymes were not affected by adding different Cu sources, but serum albumin postpartum was increased in 2NRC-Gly group relative to the other two groups (P 0.05). Based on the results, adding copper especially by copper glycinate source at twice the NRC recommended levels led to an increase in the serum albumin concentration, a decrease in milk somatic cells count and lower incidence of subclinical mastitis, which could indicate an improvement in health of cows during transition period.

Abstract The objective of this study was to compare growth performance, birth and weaning body weights, and survivability between purebred Balouchi (n=53) and crossbred Balouchi×Romanov (n=114) lambs. In addition, carcass characteristics (n=24) were determined. Balouchi ewes were inseminated with Romanov semen to produce crossbred lambs. All experimental lambs were weaned at 77 d of age and slaughtered at 10 months of age. Birth body weight of the purebred Balouchi lambs was significantly greater than for the crossbred lambs (3.75 vs. 3.56 kg, P<0.01). However, weaning body weight and average daily gain from birth until weaning and slaughter were greater (P<0.05) for the crossbred lambs than for the purebred lambs. Slaughter body weight at 10-month age were not different brtween the tow groups  (P=0.08). Litter size was also increased by crossbreeding and using hormone (1.13 vs. 1.00), but lamb survivability was not different between the two groups. The fat yield decreased with crossbreeding. Crossbreeding increased (P<0.05) the weights of testis, liver, heart, and lung. It is concluded that crossbreeding Balouchi ewes with Romanov semen resulted in improved litter size, weaning and slaughter body weights, average daily gains from birth until weaning and slaughter, and carcass characteristics without affecting lamb survivability. Therefore, crossbreeding can be a profitable strategy to increase lamb (meat) production in Balouchi sheep.

Abstract The objective of present study was to investigate the effect of different levels of sesame meal in early lactation cow's ration on dry matter intake, milk
yield and composition, apparent digestibility of nutrients and blood metabolites. Six dairy lactating Holstein cows with average DIM 26± 3 (n=3
primiparous and n=3 multiparous cows) were randomly assigned to 1 of 3 experimental treatments (different levels of sesame meal) in repeated 3×3
Latin square design. Experimental treatments were control (without sesame meal), 4.33% sesame meal and 8.66% sesame meal (DM basis). The
experimental periods consisted of 21 d with the first 14 days as adaptation and the last 7 days as sampling days. Increasing level of sesame meal in
early lactation rations did not affect dry matter intake, milk yield and composition (fat, protein and lactose), feed utilization efficiency, apparent
digestibility of nutrients and blood metabolites (P  0.05), while milk urea nitrogen decreased with increasing the level of sesame meal (p < 0.05).
Blood urea nitrogen concentrations also tended (P = 0.1) to decrease with increasing levels of sesame oil. In general, the lack of response in feed
intake and milk yield with increasing the levels of sesame meal in early lactation cow's ration showed that sesame meal could be a proper protein
source in early lactation cow's ration.

Abstract The aim of this study was to compare feedlot performance, carcass characteristics, blood metabolites, and economic profits between pure and crossbreeds Holstein calves. Crossbreeds were produced by crossing Holstein (H) cows with Angus (A), Charolais (C), Limousin (L) and INRA 95 (I) bull’s semen. The performance of 25 calves of each breed (125 calves in total) was compared in a fattening period of eleven months. The average daily gain was significantly higher in crossbred calves compared to pure Holstein calves. The interaction of breed and time was significant (p < 0.01). The Charolais crossbred calves and pure Holstein had significantly lower dry matter intake than other crossbreeds, and feed conversion ratio in the C×H calves was remarkably more favorable than other groups (p < 0.01). Dressing percentage and saleable meat yield for C×H, L×H and I×H crossbreeds were higher than for pure Holstein and A×H. Concentrations of plasma urea of Charolais crossbred calves was more than other groups (p < 0.01). Economic calculations demonstrated that the respective highest profit for the whole fattening period belonged to crossbreeds of C×H, I×H, L×H, A×H, and pure Holsteins. In conclusion, the calves from Holstein-beef crosses had higher feedlot performance, dressing percentage and economic productivity than pure Holstein calves.