Browsing by Subject "carcass"
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Item Birth, weaning, carcass, and meat traits in Bos indicus-Bos taurus reciprocal backcross calves produced through embryo transfer(Texas A&M University, 2005-02-17) Amen, Tonya SueAngus - Bos indicus (Brahman or Nellore) reciprocal backcross embryo transfer calves belonging to 28 full-sib families were evaluated for differences in birth weight (BW), gestation length (GL), weaning weight (WW), carcass weight (HCW), longissimus muscle area (REA), fat thickness (adjusted (ADJFAT) and actual(ACTFAT)), intramuscular fat (MARB), and Warner-Bratzler shear force tenderness (WBSF). Family types with a greater proportion of Bos indicus in the sire in relation to the amount in the dam (F1 x A and B x F1) averaged longer GL and heavier BW than their respective reciprocal crosses (A x F1 and F1 x B). Calves had longer GL when the F1 parent was BA as opposed to AB. Small differences (statistically insignificant) were detected for BW, but no consistent difference was found between offspring of AB and BA parental types, with the exception of male F1-sired calves. F1 x A and B x F1 crosses also showed a large BW difference between males and females (about 5.0 kg), while A x F1 and F1 x B crosses showed no BW difference between males and females. Further examination within each sex showed a difference between male reciprocals that was two times that of females. Calves with a higher percentage of Bos indicus in the sire compared to the proportion in the dam showed the same trend, as they were still heavier at weaning, and produced heavier carcasses than the reciprocal crosses, though these differences were not significant. As a whole, A backcross calves had more ACTFAT, more ADJFAT, larger REA, more MARB, and lower WBSF than B backcross calves, though no significant differences were detected between reciprocal crosses for any of these traits. These results suggest that for weight related traits, especially BW, both the breed constitution of the calf and the cross that produces the calf play an important role in its ultimate performance for Bos indicus crossbred calves. For carcass and meat related traits, it appears that the breed make-up of the calf itself is more significant in influencing performance than the cross used to produce the calf.Item Evaluation of Gene Breed Type and Expression of Feed Efficiency Candidate Genes, and Their Associations with Carcass Traits in F2 Nellore-Angus Steers(2011-10-21) Cardin, Jessica MarieSteers produced in Cycle I of the Texas A & M University McGregor Genomics Project (n = 232, F2 Nellore-Angus) were evaluated for carcass composition, visceral organ weights, and model predicted residual consumption (MPRC), a measure of feed efficiency. Hot carcass weight was strongly correlated with liver weight (r = 0.70, P < 0.001) heart weight (r = 0.58, P < 0.001), and viscera weight (r = 0.55, P < 0.001) but not spleen weight (r = -0.01, P = 0.83). Liver, heart and viscera weights were moderately positively correlated with external and kidney pelvic heart fat (KPH), but not with marbling. None of the organ weights were correlated with MPRC. A subset of 54 animals was selected for extreme values of residuals of MPRC after a mixed model analysis that included fixed effects of sire and family nested within sire, and these animals were evaluated for insulin-like growth factor I (IGFI) expression in liver samples collected at harvest through quantitative real time polymerase chain reaction (qRT-PCR). IGFI relative quantity (IGFI RQ) was collected from qRT-PCR and was correlated with liver (r = -0.23, P = 0.09), spleen (r = 0.48, P <0.001) and viscera weight (r = 0.24, P = 0.08), but not any carcass trait or MPRC residual. Gene breed types were determined for 4 candidate genes of feed efficiency: insulin like growth factor-1 (IGF1), leptin (LEP), neuropeptide-Y (NPY) and ghrelin (GHRL). Gene breed types were represented as AA, AN, NA, and NN where A and N denote Angus and Nellore, respectively, and paternal inheritance is listed first. Given that contemporary group significantly influenced most traits (MPRC, all carcass traits, liver weight and viscera weight), effects of gene breed type and contemporary group were evaluated together in analyses. GHRL influenced liver (P = 0.02) and viscera weight (P = 0.02), IGF1 influenced kidney, pelvic, and heart fat (P = 0.05), NPY influenced liver weight (P = 0.03) and hot carcass weight (P = 0.04), and LEP influenced ribeye area (P = 0.05) and hot carcass weight (P = 0.04) with a tendency to influence liver weight (P = 0.06). Alternate heterozygotes for GHRL were statistically different in liver weight and viscera weight where NA was heavier than AN. Alternate heterozygotes for LEP did not differ in ribeye area, hot carcass weight, or liver weight. Alternate heterozygotes for NPY differed in liver weight (NA heavier than AN), but did not differ in hot carcass weight. Carcasses with AA for LEP and NPY were 18 to 19 kg heavier (P < 0.05) than those with NN, with heterozygotes intermediate.Item National Beef Quality Audit - 2011: Survey of Instrument Grading Assessments of Beef Carcass Characteristics(2012-11-16) Gray, Gatlan 1989-The instrument grading assessments for the NBQA-2011 evaluated seasonal trends of beef carcass quality and yield attributes over the course of the year. One week of instrument grading data?HCW, gender, USDA QG, and YG factors?were collected every other month (n = 2,427,074 carcasses) over a 13-month period (November 2010 through November 2011) from four beef processing corporations, encompassing 17 federally inspected beef processing facilities, to create an overview of carcass quality and yield attributes and trends from carcasses representing approximately 8.5% of the U.S. fed steer and heifer population. Mean yield traits were: YG (2.86), HCW (371.3 kg), FT (1.19 cm.), and LM area (88.39 cm^2). The YG distribution was YG 1 (15.7%), YG 2 (41.0%), YG 3 (33.8%), YG 4 (8.5%), and YG 5 (0.9%). Distribution of HCW was <272.2 kg (1.6%), 272.2 kg to 453.6 kg (95.1%), ?453.6 kg (3.3%). Monthly HCW means were: November 2010 (381.3 kg), January 2011 (375.9 kg), March 2011 (366.2 kg), May 2011 (357.9 kg), July 2011 (372.54 kg), September 2011 (376.1 kg), and November 2011 (373.5 kg). The mean FT for each month was November 2010 (1.30 cm), January 2011 (1.22 cm), March 2011 (1.17 cm), May 2011 (1.12 cm), July 2011 (1.19 cm), September 2011 (1.22 cm), and November 2011 (1.22 cm). The mean marbling score was Small49. USDA QG distribution was Prime (2.7%), Top Choice (22.9%), Commodity Choice (38.6%), and Select (31.5%). Interestingly, from November to May, seasonal decreases (P < 0.001) in HCW and FT were accompanied by increases (P < 0.001) in marbling. These data present the opportunity to further investigate the entire array of factors that determine the value of beef. Datasets utilizing the online collection of electronic data will likely be more commonly used when evaluating the U.S. fed steer and heifer population in future studies. These data indicate the wide array of carcasses produced by the beef cattle industry, and how the frequency of both YG and QG traits change from month-to-month.Item National Beef Quality Audit-2011: In-Plant Survey of Targeted Carcass Characteristics Related to Quality, Quantity, Value, and Marketing of Fed Steers and Heifers(2012-11-26) Moore, Melanie 1989-The National Beef Quality Audit ? 2011 assessed the current status of quality and consistency of fed steers and heifers. Beef carcasses (n = 9,802), representing approximately 10 percent of each production lot in 28 beef processing facilities, were selected randomly for the survey. Carcass evaluation for the cooler assessment of this study revealed these traits and frequencies: steer (63.5%), heifer (36.4%), cow (0.1%), and bullock (0.03%) sex classes; dark-cutters (3.2%); blood splash (0.3%); yellow fat (0.1%); calloused ribeye (0.05%); A (92.8%), B (6.0%), and C or greater (1.2%) overall maturities; native (88.3%), dairy-type (9.9%), and Bos indicus (1.8%) estimated breed types; and United States (97.7%), Mexico (1.8%), and Canada (0.5%) country of origin. Certified or marketing program frequencies were age and source verified (10.7%), ? A40 (10.0%), Certified Angus Beef (9.3%), top Choice (4.1%), natural (0.6%), and Non-Hormone Treated Cattle (0.5%), and there were no organic programs observed. Mean USDA YG traits were USDA YG (2.9), HCW (374.0 kg), AFT (1.3 cm), LM area (88.8 cm2), and KPH (2.3%); Frequencies of USDA YG distributions were YG 1 (12.4%), YG 2 (41.0%), YG 3 (36.3%), YG 4 (8.6%), and YG 5 (1.6%). Mean USDA QG traits were USDA QG (Select93), marbling score (Small40), overall maturity (A59), lean maturity (A54), skeletal maturity (A62). Frequencies of USDA QG distributions were Prime (2.1%), Choice (58.9%), Select (32.6%), and Standard or less (6.3%). Marbling score distribution was Slightly Abundant or greater (2.3%), Moderate (5.0%), Modest (17.3%), Small (39.7%), Slight (34.6%), and Traces or less (1.1%). Carcasses with QG of Select or greater and YG of 3 or numerically less represented 85.1% of the sample. This is the fifth benchmark study measuring targeted carcass characteristics, and information from this survey will continue to help drive progress in the beef industry. Results will be used in extension and educational programs as teaching tools to inform beef producers and industry professionals of the current state of the U.S. beef industry.Item The use of different nutritional strategies and mathematical models to improve production efficiency, profitability, and carcass quality of feedlot cattle(Texas A&M University, 2007-04-25) de Vasconcelos, Judson TadeuForty eight crossbred steers (BW = 296 ???? 16.7 kg) were fed four dietary treatments for 56 d: AL-LS (low starch diet fed ad libitum for a rate of gain of 1 kg/d), AL-HS (high starch diet fed ad libitum), LF-HS (a limit fed high starch diet designed to be isocaloric with AL-LS), and AL-IS (a diet fed ad libitum for the midpoint daily energy intake between AL-LS and AL-HS). On d 57 all steers were placed on AL-HS for finishing until d 140. Steers that consumed more total energy (AL-HS and AL-IS) throughout production achieved greater carcass fatness in the end of the 140 d period, although these responses were difficult to evaluate via real-time ultrasound measurements. No differences in insulin and glucose kinetics were observed. Data suggested that energy source may influence energy partitioning during the growing period, but these effects may be overcome by differences in energy intake. Higher marbling scores (AL-HS and AL-IS) rewarded higher grid values and greater premiums, which increased profitability. This data set was also used for a model evaluation that showed that mathematical models (CVDS and NRC) were able to explain most of the variation in individual feed requirements of group- fed growing and finishing cattle. Another data set was used for evaluation of a decision support system Cornell Net Carbohydrate and Protein System (CNCPS) as a tool to minimize nutrient excretion from fed cattle. One-hundred eight-four group- fed steers were fed a 13% crude protein (CP) diet until reaching 567 kg of BW, when their diets were either maintained at 13% or reduced to 11.5% or 10% CP. Data from the second half of the experiment were modeled to predict urinary, fecal, and total N excretion. As dietary CP decreased from 13 to 11.5%, the model indicated a total N excretion of 16%. An even greater reduction in total N excretion (26%) occurred when dietary CP was decreased from 11.5% to 10%. The overall decrease from 13 to 10% CP resulted in a reduction of total N excretion by 38%. Data suggest that decision support sys tems can be used to assist in balancing diets to meet environment restriction.