G05-425 2005 Beef Report Summaries

Reports on recent beef research are briefly summarized

Breeding Values for the Commercial Cattleman

Breeding values should be used as a vital part of the selection goals for bulls being evaluated by commercial cattlemen. When commercial cattlemen buy bulls, they are really buying what those bulls will transmit to future calf crops. Breeding values estimate what will be transmitted

Selecting for Carcass Marbling and Muscling – Benefits and Pitfalls

Large premiums for Choice quality grade carcasses versus Select carcasses and substantial discounts for Yield Grade 4 carcasses provide incentive for beef cattle breeders to select for carcass traits. Marbling may only account for a small share of the variation in palatability of cooked beef products and is less important than tenderness, but it serves as an insurance policy for eating satisfaction and is more easily measured. Thus breeders have responded to increased consumer demand for beef quality and consistency by selecting for marbling as it is one of the few tools available to them. Without doubt, success of programs such as Certified Angus Beef have drawn attention to quality grade as a tangible component of many grid based programs. Although discounts for poor Yield Grade exist, there are only minimal premiums for superior lean yield in Y1 and Y2 carcasses. As long as single trait selection for either marbling or muscling is avoided and balanced multiple trait selection is used, small but positive gains in carcass traits should be realized. The difficulty lies in achieving the optimum balance of traits especially considering the powerful impact of reproduction and production traits on ranch profitability. Ranchers should match their cattle (cows) to ranch resources first and adjust carcass traits only as much as ranch resources reasonably allow. There is a need to explore the antagonisms that exist between carcass traits and other reproduction and production traits. The number of bulls, within a given breed, that have genetic estimates (EPD) for carcass traits has grown rapidly in recent years. Commercial DNA tests exist for a component of marbling and tenderness. Ultrasound has contributed greatly to the carcass database and will likely increase even more because it is a direct, non-invasive measure that can be used directly on seedstock. The advent of sophisticated identification procedures and greater traceability of cattle will enhance the collection of even more carcass data. Although not all ranchers will choose to track carcass quality and quantity traits , it is clear that many of their competitors will

2006 Beef Report Summaries

Reports on recent beef research are briefly summarized in this publication. Summaries of the research featured in the 2006 Beef Report appear here. Topics include cow-calf, growing, finishing and beef products

G05-425 2005 Beef Report Summaries

Reports on recent beef research are briefly summarized

Selecting for Carcass Marbling and Muscling – Benefits and Pitfalls

Large premiums for Choice quality grade carcasses versus Select carcasses and substantial discounts for Yield Grade 4 carcasses provide incentive for beef cattle breeders to select for carcass traits. Marbling may only account for a small share of the variation in palatability of cooked beef products and is less important than tenderness, but it serves as an insurance policy for eating satisfaction and is more easily measured. Thus breeders have responded to increased consumer demand for beef quality and consistency by selecting for marbling as it is one of the few tools available to them. Without doubt, success of programs such as Certified Angus Beef have drawn attention to quality grade as a tangible component of many grid based programs. Although discounts for poor Yield Grade exist, there are only minimal premiums for superior lean yield in Y1 and Y2 carcasses. As long as single trait selection for either marbling or muscling is avoided and balanced multiple trait selection is used, small but positive gains in carcass traits should be realized. The difficulty lies in achieving the optimum balance of traits especially considering the powerful impact of reproduction and production traits on ranch profitability. Ranchers should match their cattle (cows) to ranch resources first and adjust carcass traits only as much as ranch resources reasonably allow. There is a need to explore the antagonisms that exist between carcass traits and other reproduction and production traits. The number of bulls, within a given breed, that have genetic estimates (EPD) for carcass traits has grown rapidly in recent years. Commercial DNA tests exist for a component of marbling and tenderness. Ultrasound has contributed greatly to the carcass database and will likely increase even more because it is a direct, non-invasive measure that can be used directly on seedstock. The advent of sophisticated identification procedures and greater traceability of cattle will enhance the collection of even more carcass data. Although not all ranchers will choose to track carcass quality and quantity traits , it is clear that many of their competitors will

Use of Expected Progeny Differences for Marbling in Beef: I. Production Traits

Six Angus bulls with HIGH (\u3e.4) and six bulls with LOW (\u3c-.16) expected progeny differences (EPD) for marbling were used to evaluate the impact of marbling on progeny production and carcass traits. Bulls were randomly bred to MARC II (¼ Hereford, ¼ Simmental, ¼ Angus, ¼ Gelbvieh) composite cows in each of 2 yr to calve in the spring. At weaning, steers and heifers were separated and managed in different production systems. Steers (n = 131) were fed a growing diet (1.1 Mcal of NEg/kg) for 48 d followed by adaptation to a 93% concentrate finishing diet. Heifers (n = 125) were fed a growing diet (.79 Mcal of NEg/kg) for 191 d followed by adaptation to the same 93% concentrate diet. Steers and heifers from each treatment were slaughtered at two times spaced about 60 d apart within both years. Marbling EPD class had no effect on fat thickness, USDA yield grade, carcass weight, finishing daily gain, finishing DMI, or finishing efficiency ( P \u3e .18). More ( P \u3c .05) carcasses of calves from sires with HIGH EPD for marbling graded USDA Choice than from LOW EPD sires, 74% vs 47%, respectively. Angus sires can be selected to produce progeny that have increased ability to grade Choice without increasing yield grade or decreasing animal growth or feed efficiency

Cost-Effectiveness Analysis of Diagnostic Options for Pneumocystis Pneumonia (PCP)

Diagnosis of Pneumocystis jirovecii pneumonia (PCP) is challenging, particularly in developing countries. Highly sensitive diagnostic methods are costly, while less expensive methods often lack sensitivity or specificity. Cost-effectiveness comparisons of the various diagnostic options have not been presented.We compared cost-effectiveness, as measured by cost per life-years gained and proportion of patients successfully diagnosed and treated, of 33 PCP diagnostic options, involving combinations of specimen collection methods [oral washes, induced and expectorated sputum, and bronchoalveolar lavage (BAL)] and laboratory diagnostic procedures [various staining procedures or polymerase chain reactions (PCR)], or clinical diagnosis with chest x-ray alone. Our analyses were conducted from the perspective of the government payer among ambulatory, HIV-infected patients with symptoms of pneumonia presenting to HIV clinics and hospitals in South Africa. Costing data were obtained from the National Institutes of Communicable Diseases in South Africa. At 50% disease prevalence, diagnostic procedures involving expectorated sputum with any PCR method, or induced sputum with nested or real-time PCR, were all highly cost-effective, successfully treating 77-90% of patients at $26-51 per life-year gained. Procedures using BAL specimens were significantly more expensive without added benefit, successfully treating 68-90$189-232 per life-year gained. A relatively cost-effective diagnostic procedure that did not require PCR was Toluidine Blue O staining of induced sputum ($25 per life-year gained, successfully treating 68$109 per life-year gained) compared with several molecular diagnostic options.For diagnosis of PCP, use of PCR technologies, when combined with less-invasive patient specimens such as expectorated or induced sputum, represent more cost-effective options than any diagnostic procedure using BAL, or chest x-ray alone