Growth Patterns of Bovine Muscle, Fat and Bone

Sire carcass breeding values affect body composition in lambs — 1. Effects on lean weight and its distribution within the carcass as measured by computed tomography

“…This contradicts previous findings from smaller studies where PWWT had no effect , though it does support the general principle that lambs selected for high post weaning weights would have a larger mature size (Huisman & Brown, 2008) and therefore they will be physiologically less mature when compared at the same weight (Berg & Butterfield, 1968;Butterfield et al, 1983;Hegarty, Shands, et al, 2006) …”

“…Based on the relative rate of maturation of lean tissue it is likely that the Terminal sired animals were less mature when compared at the same weight or age, resulting in proportionately more lean tissue in the carcass (Berg & Butterfield, 1968). This is in contrast to Ponnampalam et al (2007) who showed that Merinos had a greater lean % than Poll Dorset sired lambs at the same age, however this observation was based on only 4 sires.…”

“…None-the-less the magnitude of the effect in the Hopkins et al (2007) study was markedly smaller than that reported here, and pertained only to a small number of Poll Dorset sires (n=20). One explanation for this result could be associated with a larger mature size, leading to proportionately more muscle when compared at the same weight (Berg & Butterfield, 1968;Butterfield et al, 1983). However if maturity was implicated then there should also have been proportionately more bone (Berg & Butterfield, 1968;Butterfield, Zamora, Thompson, Reddacliff, & Griffiths, 1984;Fourie et al, 1970).…”

“…One explanation for this result could be associated with a larger mature size, leading to proportionately more muscle when compared at the same weight (Berg & Butterfield, 1968;Butterfield et al, 1983). However if maturity was implicated then there should also have been proportionately more bone (Berg & Butterfield, 1968;Butterfield, Zamora, Thompson, Reddacliff, & Griffiths, 1984;Fourie et al, 1970). Furthermore, Huisman & Brown (Huisman & Brown, 2008) have demonstrated no phenotypic or genetic correlation between PEMD and mature weight.…”

Adipose tissue growth, distribution and cellularity in steers of two biological types

“…Excellent reviews on the topic were provided by Hedrick (1968), Berg and Butterfield (1968) and more recently by Allen et al (1976). Waters (1909) was probably one of the first to indicate that not only the total amount of fat present in the carcass was relevant but also its distribution among the different depots.…”