Production data were collected on mature cows produced by mating Angus and Hereford (pooled AH), Brahman (Bh) and Boran (Br), and Tuli, a tropically adapted Bos taurus, sires by AI or natural service to Angus and Hereford cows. These cows were mated to Charolais bulls for the purpose of this study. Within each sire breed of cow, cows were assigned randomly to one of three feeding rates, 49 or 7...

The article presents the results of research on karyotype characteristics variability in purebred and crossbred dairy cows. material for was peripheral blood samples firstborn cows Ukrainian red-spotted black-spotted breeds, as well obtained from crossing with Montbeliard bulls (DG “Nyva” SE Institute Animal Breeding Genetics named after M. V. Zubets NAAS. Preparation cytogenetic preparations, ...

The objectives were to evaluate preweaning performance, body composition, and efficiency of calves representing straightbred Nellore (NL), F(1), and 3-breed-cross systems. Energy requirements, milk production, and efficiency of 39 cow-calf pairs were recorded from straightbred NL calves from NL cows (10), crossbred (Angus-sired) calves from NL cows (ANL: 9), and crossbred calves (CC; Canchim-si...

Indicine cattle have lower reproductive performance in comparison to taurine. A chromosomal anomaly characterized by the presence Y markers in females was reported and associated with infertility in cattle. The aim of this study was to investigate the occurrence of the anomaly in Brahman cows. Brahman cows (n = 929) were genotyped for a Y chromosome specific region using real time-PCR. Only six...

The development of breeding tools, such as genomic selection and sexed semen, has progressed rapidly in dairy cattle during the past decades. In combination with beef these tools are adopted increasingly at herd level. Dairy crossbreeding is emerging, but economic genetic consequences combining it other relatively unknown. We investigated 5 different semen schemes where 0, 50, 90% heifers; 50% ...

Spring-calving, crossbred (1/4 to 3/8 Brahman) primiparous (n = 56) and multiparous (n = 102) beef cows were used to evaluate the effects of progesterone, delivered via a controlled internal drug-releasing (CIDR) device, and prostaglandin F2α (PGF2α) on estrous behavior, synchronization rate, initiation of estrous cycles, and pregnancy rate during a 2-yr period. To determine luteal activity, we...

Maternal performance of 134 Hereford (H), Brangus (B), and reciprocal crossbred (H x B and B x H) cows from 2 to 7 yr of age was evaluated under semidesert conditions in this study. Calves produced by 2- and 3-yr-old cows were sired by Brangus and Hereford bulls. Calves produced by 4- to 7-yr-old cows were sired by Charolais bulls. Breed of sire and breed of dam of cow affected kilograms of wea...

The therapeutic potential of amoxicillin plus sulbactam and its effect on dynamics of milk leukocytes in bovine sub clinical mastitis were investigated in this study. Therapeutic efficacy was measured by somatic cell count and total bacterial count of the milk, whereas, the dynamics of milk leukocytes were assessed by measuring phagocytosis, hydrogen peroxide production, myeloperoxidase and lac...