Grazing endophyte-infected tall fescue (E+) negatively impacts cattle feed intake and growth negatively (Crawford et al., 1989). However, the interaction between environmental factors and animal genetics may influence important cattle growth measurements before and after the weaning process (Phillips et al, 2001). For example, polymorphisms (mutations) in the prolactin and cytochrome P450 genes...

The aim of the present work was (1) to study the relationship between cross-sectional computed tomography (CT) images obtained in live growing pigs of different genotypes and dissection measurements and (2) to estimate carcass composition and cut composition from CT measurements. Sixty gilts from three genotypes (Duroc×(Landrace×Large White), Pietrain×(Landrace×Large White), and Landrace×Large ...

Multiple linear regression equations predicting total skeletal muscle (TM) and total skeletal fat-free muscle (TFFM) weight were developed from data of 33 beef cows. Animals varied in weight (385 to 749 kg), age (3 to 10 yr), and fatness (.13 to 2.54 cm). A four-terminal impedance meter/plethysmograph measured resistance and reactance on the live animals, exsanguinated (bled) animals, and on th...

In Germany, until 1985, there was a more or less subjective carcass classification system in use which was mainly based on conformation of the ham. In 1985 this system changed into a carcass classification system based only on objective fat and muscle measurements using different instruments such as the Hennesy Grading Probe or the Fat-0-Meter (FOM). For each instrument one formula is used to e...

Live measurements of weight, height, length, girth, fat depth, stifleand hip-width were obtained prior to slaughter to develop prediction equations for carcass traits. The animals were boned out after slaughter and comprised 182 steers from the Southern Crossbreeding Program (progeny from Hereford cows crossed with seven sire breeds: Angus, Belgian Blue, Hereford, Jersey, Limousin, South Devon ...

Carcass traits have been successfully used to determine body composition of steers. Body composition, in turn, has been used to predict energy content of ADG to compute feed requirements of individual animals fed in groups. This information is used in the Cornell value discovery system (CVDS) to predict DM required (DMR) for the observed animal performance. In this experiment, the prediction of...

The accuracy of ultrasound measurements to assess goat carcass composition and the partition of body fat depots was evaluated. An ultrasound machine with a 5-MHz probe and image analysis was used to assess in vivo fat thickness and muscle depth in 56 Spanish Celtiberica adult goats, in lumbar and breast body regions. The goats were slaughtered and the weight of body fat depots recorded. Measure...

Market lambs from the state fair of Virginia (n = 172) were ultrasonically evaluated by 4 scan technicians and 3 image interpreters to determine accuracy of ultrasonic estimates of loin muscle area (ULMA), backfat thickness (UBF), and body wall thickness (UBW). Lambs were initially scanned at the preferred magnification setting of each technician; 2 chose 1.5x and 2 chose 2.0x. Lambs were then ...

Prediction equations for pork carcass lean percentage are widely used in Extension, teaching, and research. Prediction equations using carcass or live animal measurements are used in carcass contests, live animal evaluation, and marketing. Fat–free lean gain is used to estimate the daily lysine requirements for pigs in swine nutrition guides. The use of inaccurate equations has substantial econ...