The influence of growth stage on carcass composition and factors associated with marbling development in beef cattle.

Subcutaneous fat and marbling both increase in beef cattle during the feeding phase but are antagonistic in regard to their contribution to beef carcass value. The objective of this study was to determine whether cellular factors associated with marbling development change with growth stage throughout the feeding period and whether they are correlated to marbling relative to carcass composition. Twenty-four steers of known origin with the cytosine and thymine (CT) leptin genotype were allotted to 3 harvest groups.

Effects of oregano oil brine enhancement on quality attributes of beef longissimus dorsi and semimembranosus muscles from various age animals.

Unlabelled: The study reports whether or not oregano oil can reduce lipid oxidation and evaluate palatability variations in beef longissimus dorsi and semimembranosus muscles from various age animals (approximately 18 mo; 18 M, 30 to 60 mo; 30 M, and >60 mo; 60 M). Six muscles of each age group were halved and enhanced with a control brine containing no antioxidants (CN) or a brine containing oregano oil (OR), cut into steaks, and stored in modified atmosphere packaging for 0, 4, 7, and 11 d. Each sampling day, surface color (Minolta L, a, b), lipid oxidation (TBARS), cook yield, sensory analysis, and Warner-Bratzler shear force (WBSF) were measured.

Effect of distillers dried grains with solubles and ractopamine (Paylean) on quality and shelf-life of fresh pork and bacon.

Pigs (n = 240) were allotted in a 5 x 2 factorial arrangement with 5 levels of distillers dried grains with solubles (DDGS): 0, 15, 30, 45, and 60%, and 2 ractopamine (RAC) levels: 0 and 5 mg/kg. Four pigs per pen (2 barrows, 2 gilts) closest to pen mean BW were used for meat quality evaluation. Loins (n = 119) were evaluated for objective color; moisture and fat; subjective color, marbling, and firmness; and drip loss.

Comparative effects of ractopamine hydrochloride and zilpaterol hydrochloride on growth performance, carcass traits, and longissimus tenderness of finishing steers.

Ractopamine hydrochloride (RAC) and zilpaterol hydrochloride (ZH) are beta-adrenergic agonists that improve growth performance and affect carcass characteristics. The objective of this study was to evaluate the comparative effects of RAC and ZH when fed to beef steers during the last 33 d of the finishing period. Three hundred crossbred beef steers (516 +/- 8 kg) were grouped by BW, BCS, and breed type and randomly assigned to 1 of 3 treatments (10 steers per pen; 10 pens per treatment).

The effect of zilpaterol hydrochloride on meat quality of calf-fed Holstein steers.

The objective of these studies was to evaluate the effects of zilpaterol hydrochloride (ZH), fed for 0, 20, or 30 d, on meat quality attributes of calf-fed Holstein steers. Steers were slaughtered at a commercial facility, and carcasses were selected by HCW to represent the pen mean. Further carcass selection was based on quality grade (Choice and Select) and yield grade.