Effects of liver abscess severity and quality grade on meat tenderness and sensory attributes in commercially finished beef cattle fed without tylosin phosphate.

Strip loin steaks (n = 119) were used to evaluate the association between liver abscess severity and USDA quality grade and meat tenderness and sensory attributes of steaks from finished feedlot cattle. Steaks were used in a 3 × 2 factorial treatment structure using a completely randomized design and were collected at a commercial abattoir located in northwest Texas. All cattle were sourced from a single feedlot and fed a common diet that did not include tylosin phosphate. Treatments were USDA quality grades of Select (SEL) and Low Choice (LC) and liver abscess scores of normal (NORM; healthy liver, no abscesses), mild (M; 1 abscess less than 2 cm in diameter to 4 abscesses less than 4 cm in diameter), and severe (SV; 1 abscess greater than 4 cm in diameter or greater than 4 small abscesses). All steak samples were collected on the same day, approximately 36-h post-mortem and were cut from the left side of the carcass at the 13th rib by a trained abattoir employee. Steaks were vacuum-packaged, and aged at 3 ± 1°C for 14-d post-mortem. Warner-Bratzler Shear Force (WBSF) and Slice Shear Force (SSF) analyses were conducted and cook-loss percentage was measured. A trained sensory panel analyzed samples for juiciness, tenderness, and flavor attributes. There were no differences among liver abscess scores for WBSF or SSF (P > 0.52). Warner-Bratzler Shear Force was lower for LC-SV than SEL-SV (P = 0.04). Sensory attributes of initial and sustained juiciness, and overall tenderness were all greater for LC than for SEL steaks (P < 0.04) and connective tissue amount was less for LC steaks when compared to SEL (P = 0.03). Liver abscess score had no effect on any sensory attributes (P > 0.70); however, there was an interaction between quality grade and liver score for myofibillar tenderness (P = 0.03). Within LC steaks, liver abscess score had no effect on myofibrillar tenderness (P > 0.05), however, in SEL steaks, M steaks were more tender than SV steaks (P < 0.03). These results indicate that within quality grades, meat tenderness or sensory attributes were not influenced by liver abscess score but that mild liver abscesses may affect the myofibrillar tenderness of SEL steaks.

A survey of recommended practices made by veterinary practitioners to cow-calf operations in the United States and Canada.

Practicing veterinarians (n = 148) who service commercial beef cow-calf herds responded to a survey describing general recommendations made to their clients in terms of vaccine protocol, health, and production practices. Responding veterinarians represented 35 states in the United States and 3 provinces in Canada. More than 50% of responding veterinarians devote over 50% of their practice to service commercial cow-calf producers. The largest group (33%) of veterinarians have been in practice for over 30 yr. Thirty-nine percent of responding veterinarians serviced more than 10,000 cows. Genetic advice is provided by 54% of practicing veterinarians. When vaccinating at branding, the most common recommended vaccines are clostridial (96%), infectious bovine rhinotracheitis (IBR; 94%), bovine respiratory syncytial virus (BRSV; 91%), parainfluenza-3 (PI-3; 90%), and bovine viral diarrhea (BVD) Types 1 and 2 (78 and 77%, respectively). When vaccinating before weaning, the most common recommended vaccines are IBR (99%), BRSV (98%), BVD Types 1 and 2 (96%), PI-3 (93%), clostridial (77%), and Mannheimia haemolytica (77%). When vaccinating after weaning, the most common recommended vaccines are BVD Type 2 (97%), IBR (97%), BVD Type 1 (96%), BRSV (96%), and PI-3 (91%). Over 60% of responding veterinarians recommended that the last preventative vaccine should be administered to cattle 7 to 21 d before shipping. The largest number of respondents (38%) recommended that the earliest age their clients should wean their calves is 90 to 120 d. Castrating bull calves at an age of 0 to 7 d was recommended by 34% of respondents. Calf nutrition is considered as extremely important during a preconditioning program by 82% of responding veterinarians.

The effects of dry-rolled corn particle size on performance, carcass traits, and starch digestibility in feedlot finishing diets containing wet distiller's grains.

Crossbred yearling steers ( = 360; 395 ± 33.1 kg initial BW) were used to evaluate the effects of dry-rolled corn (DRC) particle size in diets containing 20% wet distiller's grains plus solubles on feedlot performance, carcass characteristics, and starch digestibility. Steers were used in a randomized complete block design and allocated to 36 pens (9 pens/treatment, with 10 animals/pen). Treatments were coarse DRC (4,882 µm), medium DRC (3,760 µm), fine DRC (2,359 µm), and steam-flaked corn (0.35 kg/L; SFC). Final BW and ADG were not affected by treatment ( > 0.05). Dry matter intake was greater and G:F was lower ( < 0.05) for steers fed DRC vs. steers fed SFC. There was a linear decrease ( < 0.05) in DMI in the final 5 wk on feed with decreasing DRC particle size. Fecal starch decreased (linear, < 0.01) as DRC particle size decreased. In situ starch disappearance was lower for DRC vs. SFC ( < 0.05) and linearly increased ( < 0.05) with decreasing particle size at 8 and 24 h. Reducing DRC particle size did not influence growth performance but increased starch digestion and influenced DMI of cattle on finishing diets. No differences ( > 0.10) were observed among treatments for any of the carcass traits measured. Results indicate improved ruminal starch digestibility, reduced fecal starch concentration, and reduced DMI with decreasing DRC particle size in feedlot diets containing 20% wet distiller's grains on a DM basis.