A study was conducted to evaluate the effect of sire growth potential, steer age, and cow size on intake, growth, and production efficiency in grazing cattle. Data were collected on 24 cow-calf pairs during each of four summers (1989 to 1992) and on 12, 7-mo-old and 12 yearling steers during three summers (1990 to 1992). Suckling calves and older steers were sired by either high-(Charolais with...

The objective of this research was to evaluate the effects of residual feed intake (RFI) determined under ad libitum feeding conditions on DMI and performance of yearling ewes fed either chopped or pelleted alfalfa hay. In Exp. 1, 45 ewe-lambs had ad libitum access to a pelleted grower diet for 63 d and individual DMI was determined using an electronic feed delivery system. Residual feed intake...

Heterosis, assumed proportional to expected breed heterozygosity, was calculated for 6834 individuals with birth, weaning and yearling weight records from Cycle VII and advanced generations of the U.S. Meat Animal Research Center (USMARC) Germplasm Evaluation (GPE) project. Breeds represented in these data included: Angus, Hereford, Red Angus, Charolais, Gelbvieh, Simmental, Limousin and Compos...

Serum levels of T3, T4, and TSH hormones, some elements, and glucose with regard to their involvement for growth retardation in yearling rams were investigated. A total of 70 yearling rams of the Akkaraman breed, 50 of which were classified with a retarded growth, and the remaining 20 were classified as normal, were included in the study. Serum total T3, total T4, and TSH were measured using ch...

Sexual size dimorphism (SSD) has received considerable attention from evolutionary biologists, but relatively little is known about the physiological mechanisms underlying sex differences in growth that lead to SSD. Testosterone (T) stimulates growth in many male-larger vertebrates, but inhibits growth in the female-larger lizard Sceloporus undulatus. Thus, opposite patterns of SSD may develop ...

the data set employed in this study was comprised of a number of 6,800 records of lamb’s longevity and their survival rate, collected from 1989 through 2009, from the lori-bakhtiari experimental flock at the shooli station in shahrekord, iran. the data were analyzed using linear models and proportional hazard models with weibull function. these models included fixed factors and direct additive ...

It is important to realize during an upper respiratory tract evaluation of the weanling and yearling that there are subtle differences from such an evaluation of the adult horse. It can be difficult to predict future pharyngeal and laryngeal function based on one endoscopic exam of the upper respiratory tract of the weanling and yearling. Author’s address: Rood and Riddle Equine Hospital, 2150 ...