In an effort to determine whether tropical adaptation influences circulating concentrations of the growth-related hormone IGF-I, 3-breed diallel matings were conducted using temperate Bos taurus (Angus), tropical Bos indicus (Brahman), and tropical Bos taurus (Romosinuano). Purebred Angus, Braham, and Romosinuano and crossbred Angus-Braham, Angus-Romosinuano, and Braham-Romosinuano heifers and ...

An aqueous emulsion of amitraz (Bovitraz, Bayer AH), prepared and applied according to the manufacturer's recommendations, was evaluated for its activity against cattle ticks on a dairy farm in Ethiopia. Eight crossbred heifer calves aged between 6 and 8 months and heavily infested with ticks were selected and divided into equal treatment and control groups. The calves in the treatment group we...

Total insulin specific binding (IB) and the number and affinity of insulin receptors on mononuclear leukocytes (MNL) were used to predict carcass composition of heifers and steers. Dependent variables were kidney fat, body cavity fat, s.c. fat, intermuscular fat, lean and bone. Independent variables were parameters that could be measured on the live animal, including insulin receptor characteri...

The aim of this study was to provide farmers an efficient tool for supporting optimal decisions in the beef heifer rearing process. The complexity of beef heifer management prompted the development of a model including decisions on the feeding level during prepuberty (age <10 mo), the time of weaning (age, BW, calendar month), the feeding level during the reproductive period (age ≥10 mo), and t...

Research emphasis has been placed on heifer development strategies in recent years, comparing traditional, more intensive systems to more extensive systems using less feed and relying on compensatory gain to reach a target BW. Recent research has indicated that developing heifers to a lighter target BW at breeding (i.e., 50 to 57% of mature BW compared with 60 to 65% BW) reduced development cos...

A 10-month-old female Japanese black heifer presenting with sudden loss of appetite was diagnosed with extreme extension of the gallbladder. Laparotomy reaching from the right part of the 10th rib to the right flank showed an extended gallbladder greater than 50 cm in diameter. Cholecystectomy was performed as follows: 1) complete removal of the gallbladder distally from the base; 2) flushing v...

Crossbreding is predominant and intensively used in commercial meat production systems, especially in poultry and swine. Genomic evaluation has been successfully applied for breeding within purebreds but also offers opportunities of selecting purebreds for crossbred performance by combining information from purebreds with information from crossbreds. However, it generally requires that all rele...

Cow-calf producers require a consistent source of replacement females in order to maintain the size of the breeding herd at the desired level. Replacement females may be produced internally or acquired from external sources. This discussion will focus upon the critical control points that range from the selection criteria used in mating decisions to produce potential replacement heifers to the ...

This study was conducted to compare the carcass characteristics and meat quality characteristics of Duroc breed and crossbred pigs (Landrace × Yorkshire × Duroc, LYD). Duroc and crossbred pigs did not show differences in carcass characteristics. Crossbred pigs had higher moisture and protein content than Duroc breeds. However, Duroc breeds had a higher fat content than the crossbred pigs. In me...

Data on the reproductive traits of dairy heifers were analyzed using event-time techniques. Traits analyzed were age at first calving (n = 4631), days to first breeding, and days open (n = 1992) during the first lactation. A proportional hazard model was used that included fixed effects of herd-year, year-season, breed type, herd weight, and heifer weight. Body weights were recorded at 390 d of...