The effects of the proportion of concentrates in grass silage-based diets and of restricted dry matter (DM) intake were examined using 156 Simmental cross Friesian steers which were initially 389 kg live weight. The animals were reared on high-forage diets until 14 months of age and were then given grass silage ad libitum and supplemented with rolled barley which constituted (1) 0, (2) 120, (3)...

Weanling crossbred pigs (Sus scrofa; 72 barrows and 72 gilts; BW = 7.4 ± 1.1 kg) were used to evaluate dietary supplemental trace mineral (Cu, Fe, Mn, and Zn) source (inorganic vs. organic) and deletion (0, 2, 4, and 6 wk preharvest) on growth performance, carcass characteristics, and pork quality. Pigs were blocked by BW, ancestry, and sex, and randomly allotted to 24 pens, and fed a diet cont...

A multi-trait selection index designed to improve the overall economic performance of hill sheep, including both maternal and lamb traits, has been developed and tested in a selection experiment over 7 years. Two versions of the index were tested, with different economic weights applied to the traits, on two different hill farms: one version including maternal and growth traits; the other versi...

to investigate the possibility of using ultrasound to estimate carcass composition, 38 moghani male lambs were made use of. subcutaneous fat depth (usft) and longissimus dorsi muscle depth (ulmd) and area (ulma) were assessed in the site between 12th and 13th ribs by using ultrasound equipped with an 8 mhz probe. the lambs were then slaughtered. carcasses were cold stored at 4°c for 24 hours an...

In a 4-yr study, early-weaned Simmental steers (n = 192) of known genetics were individually fed to determine genetic, performance, and carcass factors explaining variation in carcass value and profitability. Steers were weaned at 88.0 +/- 1.1 d of age and pen-fed a high-concentrate diet (108.99 dollars/t) for 84.5 +/- 0.4 d before allotment. Calves were implanted with Synovex C at weaning and ...

The objectives of this study were to study the relationship between in vivo ultrasound measurements and cold carcass measurements at 4 anatomical points of the backbone, and to establish regression equations to estimate carcass composition within the cold carcass weight range for Ternasco lambs (8 to 12.5 kg) by using ultrasonic measurements taken at a single location. Measurements of subcutane...

Dual-energy x-ray absorptiometry (DXA) was used as a noninvasive method to measure the composition of pig carcasses. A total of 181 half-carcasses (10 to 51 kg, from pigs slaughtered at approximately 30, 60, 90, and 120 kg) were scanned using a Lunar (Madison, WI) DPX-L densitometer. The DXA measurements of fat, lean, bone mineral, and total tissue mass were compared with chemical analysis for ...

Feed efficiency is of particular importance to the beef industry, as feed costs represent the single largest variable cost in beef production systems. Selection for more efficient cattle will lead to reduction of feed related costs, but should not have adverse impacts on quality of the carcass. In this study, we evaluated phenotypic and genetic correlations of residual feed intake (RFI), RFI ad...

This is the second in a series of peer-reviewed practice tip articles, each including two or three fact sheets on feed additives for swine. The previous practice tip, published in the September-October issue of the Journal of Swine Health and Production, included fact sheets on acidifi ers and antibiotics (J Swine Health Prod. Future fact-sheet topics will include fl avors; high dietary levels ...