Effect of prepubertal body weight gain and breed on carcass composition at puberty in beef heifers.

Fourteen prepubertal Angus heifers, all of which reached puberty, and 11 Santa Gertrudis (SG) heifers, eight of which reached puberty, were divided into two treatment groups. There was no breed difference in age at puberty for those that reached puberty. Treatment 1 (T1) heifers, fed to gain .5 kg/d, tended (P < .11) to be older than Treatment 2 (T2) heifers, fed to gain 1 kg/d, at puberty. Body weight and height were greater (P < .01) in SG than in Angus heifers at puberty. Angus heifers in T2 deposited more fat over the rump during the 15 wk before puberty, whereas T1 SG heifers deposited the least amount of fat (P < .05). Heifers in T2 were heavier at puberty (P < .05), had faster growing longissimus muscle areas (P < .05), and deposited more fat over the rib (P < .01) as they approached puberty. The T2 (P < .05) and Angus (P < .05) rib sections had more dissectible subcutaneous fat than did T1 and SG rib sections. Angus heifers had higher marbling scores (P < .05), as well as higher total lipid percentages for seam fat (P < .05), longissimus muscle (P < .01), other lean tissue (P < .05), and subcutaneous fat (P < .01). Predicted total lipid content for the edible portion of the dressed carcass was higher for T2 heifers (P < .09).

Effects of feeding diets containing different fat supplements to swine on the visual properties and storage stability of low-fat sausage.

Sixty barrows and gilts were assigned to one of five dietary treatments consisting of a control diet of corn and soybean meal and four similar test diets that contained a 10% replacement of either animal fat, safflower oil, sunflower oil or canola oil, to determine the effects of high levels of oleic acid in the diet of swine on the storage stability of fresh pork sausage. Pork trim from each treatment was used to formulate sausage that contained two fat levels (25% and 35%), and two levels of added water (3% and 11%). Thiobarbituric acid values did not differ between the control, safflower oil or sunflower oil treatments and all treatments were acceptable after 10 weeks of storage. Microbial numbers increased with the level of added water and during time in storage (up to 3 weeks). Visual evaluation showed that the control was the most red and least discolored, while the canola oil treatment was the least red and the most discolored. Results from the present study suggest that a 105 replacement of a typical corn/soybean meal diet to swine with safflower or sunflower oil did not alter the storage-stability of fresh pork sausage.

Effect of hot-fat trimming on factors associated with the subprimal yield of beef carcasses.

Thirty-two crossbred cattle (steers = 17; heifers = 15) exhibiting an ultrasound fat thickness at the 12 to 13th rib region of at least 10 mm were selected from a slaughter shift at a commercial packing plant. After splitting, alternating sides of each carcass were trimmed of 1) subcutaneous fat in excess of 6.4 mm; 2) all kidney, pelvic, and heart fat; and 3) all cod or udder fat and fat in the flank region. Both sides of each carcass were fabricated into subprimals (final trim level of 6.4 mm) according to normal industry procedures. Effect of hot-fat trimming, yield grade (3, 4, and 5), and gender on hot-fat trim, fabrication fat trim, major subprimal, and total subprimal yield of untrimmed and trimmed carcasses were determined. Higher numerical yield grade (YG) corresponded with higher (P less than .05) percentages of hot-fat trim. Hot-fat trimming increased (P less than .05) the difference in fabrication fat trim between steers and heifers and between YG 3 and YG 5. Steers and heifers differed (P less than .05) in percentage of major subprimals and total subprimals when processed conventionally, whereas hot-fat trimming eliminated this difference (P less than .05). Untrimmed YG 3 carcasses had 3.1 and 5.0% higher major subprimal yield (P less than .05) than untrimmed YG 4 and YG 5 carcasses, respectively, whereas hot-fat trimming reduced this difference to 2.5% for YG 4 and to 3.7% for YG 5.(ABSTRACT TRUNCATED AT 250 WORDS)