C. P. Campbell

Effects of diet and slaughter endpoint on carcass composition and beef quality in Charolais cross steers

One hundred and eight Charolais cross steers were used to compare forage versus grain feeding as affected by slaughter endpoint on carcass composition and palatability attributes of beef. Diets included a 97% alfalfa silage ration or 68% high moisture corn, 25% alfalfa silage ration from start of test to finish or a ration of 97% alfalfa silage from start of test to day 42 of the trial followed by the 68% high moisture corn ration until slaughter. Cattle were slaughtered at either 4, 7, or 10 mm ultrasound backfat. Grain feeding increased (P = 0.01) average daily gain and decreased (P = 0.01) days to finish, while carcass weight and grade fat were similar (P > 0.10) between diets. Palatability attributes were generally unaffected by diet with the exception of slightly less (P = 0.09) beef flavour and more (P = 0.01) off flavour in forage-fed beef versus grain-fed beef. Higher (P = 0.01) concentrations of linolenic acid and lower (P = 0.09) concentrations of oleic acid in forage-fed beef may be partially r...

The effects of skeletal separation and moisture enhancement for improving the eating quality of cull cow beef.

Sixty-two cull beef cows were slaughtered to investigate effects of skeletal separation and moisture enhancement on beef eating quality. Muscles from each carcass side were randomly assigned to 1) no postmortem processing (NPP), 2) prerigor skeletal separation (SS), 3) moisture enhancement (ME) using calcium ascorbate or 4) a combination of SS and ME (SS/ME). Postmortem processing treatment (PPT) by ageing (PM) interactions (P<0.01) for shear force were present for longissimus. As PM ageing increased from 7 to 21 d, there was a greater decrease (P<0.05) in shear force with NPP vs. all other PPT. Trained taste panellists found SS, ME and SS/ME improved (P<0.05) palatability attributes vs. NPP. An additive effect of combining SS and ME improved palatability traits versus SS or ME alone. Panellists found no differences (P>0.14) in softness and tenderness between SS/ME and Canadian AA or AAA beef. Postmortem processing of beef cows may produce beef as tender and juicy as beef from younger carcasses.

Effects of skeletal separation method and postmortem ageing on carcass traits and shear force in cull cow beef

Mandell, I. B., Campbell, C. P., Quinton, V. M. and Wilton, J. W. 2006. Effects of skeletal separation method and postmortem ageing on carcass traits and shear force in cull cow beef. Can. J. Anim. Sci. 86: 351‐361. Sixty-six cull cow carcasses were subjected to skeletal separation methods for improving beef tenderness as evaluated using shear force. Forty-one carcasses were used to evaluate the effect on longissimus muscle shear force from skeletal separation at various sites including: (1) the 11th thoracic vertebra, (2) the 12th thoracic vertebra, and (3) the 6th thoracic and 5th lumbar vertebrae. Longissimus muscle steaks from the posterior and anterior loin and posterior rib were aged for 2, 7, 14, and 28 d. Twenty-five carcasses underwent skeletal separation processing in the round with severing of the ischium and the junction between 4th/5th sacral vertebrae. Semimembranosus, semitendinosus, biceps femoris, vastus lateralis, and rectus femoris muscles were processed into steaks and aged for 2, 7, 14, and 28 d. Skeletal separation techniques involving thoracic and lumbar vertebrae decreased (P < 0.04) shear force in the posterior rib and anterior loin but not in the posterior loin. Shear force continued to decrease (P < 0.01) as postmortem ageing duration increased. The semimembranosus was the only muscle in the round in which shear force decreased (P < 0.01) with skeletal separation. Postmortem ageing for at least 14 d decreased (P < 0.06) shear force in semimembranosus and vastus lateralis steaks while there were no further decreases in shear force after 7 d ageing for semitendinosus and rectus femoris steaks. Skeletal separation increased (P < 0.10) sarcomere length in all muscles studied. Skeletal separation techniques have the potential to improve tenderness in the longissimus and semimembranosus muscles, which may increase utilization of cull cow beef.

Herbage biomass and intake of beef cows with calves grazing a grass-legume pasture in southern Ontario

Intake and performance of 40 spring-calving cows with calves was investigated under a rotational grazing management system across three consecutive summers. A 19.2 ha pasture was divided into sixteen 1.2 ha fields with each field being further subdivided into eight 0.15 ha paddocks. Five cows with calves belonging to one of two breed groups (large vs. medium framed) and two body conditions (high vs. low) were randomly assigned to graze each of eight field pairs from May to October of each year. Paddocks not grazed by cow-calf pairs were grazed by yearling heifers or mechanically harvested as hay or silage. Grazing was managed by setting target sward heights for exit of each paddock at 8 to 10 cm and allowing a minimum of 25 to 30 d for regrowth. Paddocks were topclipped and fertilized with 34 kg ha−1 of nitrogen (N) immediately following the second grazing of each paddock. Sward surface height data were collected from 40 measurements taken immediately pre- and post-grazing in each paddock as well as durin...

Effects of hot boning and moisture enhancement on the eating quality of cull cow beef

The effects of chilling method and moisture enhancement were examined for improving eating quality of semimembranosus (SM) and longissimus lumborum (LL) from 62 cull beef cows. Chilling method included hot boning muscles after 45 to 60 min postmortem or conventional chilling for 24 h. Moisture enhancement included 1) a non-injected control (CONT) or injection processing (10% of product weight) using 2) Sodium Tripolyphosphate/salt (Na/STP), 3) Sodium Citrate (NaCIT), 4) Calcium Ascorbate (CaASC), or 5) Citrus Juices (CITRUS). Chilling method by moisture enhancement treatment interactions (P<0.09) were due to decreased hue, chroma and sarcomere length values in hot boned vs. conventionally chilled product (SM and LL) for CaASC vs. other moisture enhancement treatments. Chilling method by moisture enhancement treatment interactions (P<0.05) were due to decreased shear force and increased tenderness in conventionally chilled vs. hot boned LL using CaASC vs. Na/STP. Moisture enhancement can improve tenderness of cull cow beef depending on combinations of chilling method and moisture enhancement treatments used.