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ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #109965
Title: DIETARY PROTEIN LEVEL AND SOURCE FOR POSTWEANING PRODUCTION OF F1 CATTLE FROM HEREFORD, LIMOUSIN, OR PIEDMONTESE SIRES

Author
item Grings, Elaine
item Short, Robert
item Macneil, Michael

Submitted to: Research Update for Fort Keogh Livestock and Range Research Laboratory
Publication Type: Other
Publication Acceptance Date: 10/1/1999
Publication Date: N/A
Citation: GRINGS, E.E., SHORT, R., MACNEIL, M.D. DIETARY PROTEIN LEVEL AND SOURCE FOR POSTWEANING PRODUCTION OF F1 CATTLE FROM HEREFORD, LIMOUSIN, OR PIEDMONTESE SIRES. RESEARCH UPDATE FOR FORT KEOGH LIVESTOCK AND RANGE RESEARCH LABORATORY. 1999. pages G5.1-4.

Interpretive Summary: Increased production of lean meat may be achieved by using cattle breeds that express various degrees of muscle hypertrophy. This trait can increase muscle size and decrease carcass fat. Our objective was to evaluate dietary protein level on growth and carcass characteristics of male crossbred cattle from normal muscled Hereford sires, moderate muscled Limousin sires or hypermuscular Piedmontese sires. Sire breeds were chosen for their potential differences in muscling but similarities in size and growth rate. After weaning, bulls and steers were fed growing diets from weaning to 850 pounds and were then switched to finishing diets for 90 or 132 days. Cattle were fed either high or low protein (year 1) or highly or lowly degradable protein (year 2) throughout growing and finishing periods. In year 1, cattle fed the higher protein diet gained faster than cattle on the lower protein diet during the growing phase, resulting in a decreased number of days to reach 850 pounds and an improvement in feed efficiency. In year 2, cattle fed the less degradable protein diet gained faster and had better feed efficiencies than cattle fed the high degradable protein diet during the growing phase. These results indicate that a higher level of undegradable protein in the diet improved weight gain during the growing period. There was no effect of dietary protein level or type on weight gains during the finishing phase or on carcass characteristics. Hypermuscular cattle did not respond differently to increased undegradable protein than normal cattle.

Technical Abstract: Increased production of lean meat may be achieved by using cattle breeds that express various degrees of muscle hypertrophy. This trait can increase muscle size and decrease carcass fat. Our objective was to evaluate dietary protein level on growth and carcass characteristics of male crossbred cattle from normal muscled Hereford sires, moderate muscled Limousin sires or hypermuscular Piedmontese sires. Sire breeds were chosen for their potential differences in muscling but similarities in size and growth rate. After weaning, bulls and steers were fed growing diets from weaning to 850 pounds and were then switched to finishing diets for 90 or 132 days. Cattle were fed either high or low protein (year 1) or highly or lowly degradable protein (year 2) throughout growing and finishing periods. In year 1, cattle fed the higher protein diet gained faster than cattle on the lower protein diet during the growing phase, resulting in a decreased number of days to reach 850 pounds and an improvement in feed efficiency. In year 2, cattle fed the less degradable protein diet gained faster and had better feed efficiencies than cattle fed the high degradable protein diet during the growing phase. These results indicate that a higher level of undegradable protein in the diet improved weight gain during the growing period. There was no effect of dietary protein level or type on weight gains during the finishing phase or on carcass characteristics. Hypermuscular cattle did not respond differently to increased undegradable protein than normal cattle.