Master of Science / Biomedical Sciences / Daniel U. Thomson / Two studies were conducted to evaluate two animal welfare issues in the beef industry today. The welfare of animals has become a major discussion among consumers and producers. The objective of these studies was to evaluate if certain production practices are beneficial to the wellbeing of the animals in a production setting.
The first study evaluated if castration and implementation of growth promotion technologies of physically mature male beef cattle, which failed the breed soundness exam (BSE), improved carcass quality compared to male beef cattle left intact. Sixteen month old Angus bulls (n = 24; 606 + 11.4 kg) were stratified by weight and randomly assigned to 2 treatments: intact control (BULL) and castrated with growth promotion technology (STR) to evaluate performance and carcass quality. Cattle assigned to STR treatment were implanted with 120 mg trenbolone acetate (TBA) and 24 mg estradiol on d 0, and were fed ractopamine hydrochloride (300 mg/d) the final 28 d prior to slaughter. Cattle were fed a dry-rolled corn-based finishing diet (1.41 Mcal/kg NEg) for 62 d (final wt = 697 +/- 24.3 kg) then harvested at a commercial abattoir. Carcass characteristics were recorded and longissimus muscle samples were obtained. There were no differences between treatments for quality grade, yield grade, HCW, back fat thickness, or dressing percent. Steak tenderness values based on Warner Bratzler shear force (WBSF), and sensory panel evaluation showed no difference between BULL and STR steaks in myofibrillar tenderness, juiciness, beef flavor intensity, connective tissue, overall tenderness, and off flavor intensity. Cattle within the BULL treatment tended to have improved average daily gain (ADG) and feed efficiency, with no difference in carcass characteristics, WBSF, or sensory panel measurements compared to STR administered growth promotion technology.
The second study evaluated if cohorts with horns within a pen lot of cattle caused an increase in carcass bruising, and to determine if horn tipping and dehorning is necessary. Carcasses from (n = 4,287) feedlot cattle were observed at one commercial beef packing plant in southwest Kansas to investigate the relationship between the presence and size of horns in cattle and the prevalence, anatomical location, and severity of bruising of carcasses. Horn measurements taken were the length of the longest horn from base to tip and the tip-to-tip distance between the tips of both horns. Bruises were evaluated by location and severity. Bruise severity was scored at 3 levels: minor: ≤ 5 cm, moderate: 5 to 15 cm, and severe: > 15 cm. Within pen lots of cattle, the percentage of cattle with horns ranged from 0 to 26%. There were 4,287 carcasses evaluated and 2,295 had one or more bruises for a total, overall bruise prevalence of 53.5%. Of the total number of bruises, 25.6% were severe, 35.6% were moderate, and 38.8% were minor. The majority of bruises (61.8%) occurred on the dorsal mid-line with similar rates of bruising occurring on the left (18.6%) and right (19.5%) sides. There was no relationship found between the prevalence of horns and prevalence of bruising in a pen lot of cattle (P = 0.90).
These two studies conclude that feeding of bulls that fail the BSE could eliminate an animal welfare concern while removing the cost and management of growth promotion technology administration. Additionally to that there may be other factors causing carcass bruising at other than cohorts with horns.
| Identifer | oai:union.ndltd.org:KSU/oai:krex.k-state.edu:2097/20408 |
| Date | January 1900 |
| Creators | Stephens, Margaret Eryan |
| Publisher | Kansas State University |
| Source Sets | K-State Research Exchange |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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