Fat distribution in steer carcasses of different breeds and crosses. 1. Distribution between depots

Abstract

SUMMARYDissection data from 643 carcasses of castrated male cattle (steers) of 15 breed-type × feeding system groups were used to examine the distribution of total fat (TF) between subcutaneous (SF), intermuscular (IF), kidney knob and channel (KKCF) and cod fat depots. The breed-type groups, which were from cereal or grass/cereal feeding systems, included Ayrshire, Simmental × Ayrshire, British Friesian and Friesian crosses with Aberdeen Angus, Hereford, Limousin, Charolais, South Devon and Simmental. Means for percentage TF in side ranged from 21·4 to 36·2 with a pooled within group SD of 3·87.The growth of each depot relative to TF was examined using the allometric equation. Significant but not large differences existed between groups for the growth coefficients of SF and IF while the coefficients for KKCF differed widely among groups. The coefficient for SF was greater than that for IF in every group (pooled within-group b values±SE were 1·20±·02 and 0·87±0·01 respectively).At constant TF weight, carcasses from Ayrshire and Ayrshire crosses tended to contain less SF and more IF+KKC F than those from Friesian and beef breed × Friesian. Important differences in distribution were recorded between the various beef breed × Friesian groups. The proportion of SF was lower for cattle fed on grass/cereal diets than for cattle of the same breed type fed on cereal diets.The differences in fat distribution led to substantial bias for some groups when the percentages of IF and TF in the side were predicted from percentage SF. The bias was less when both KKCF and SF were used as predictors.

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

“…Smaller steers, however, started to deposit fat at an early age and lighter weights than the larger ones, and differences in fat distribu tion were suggested when the amount of fat in each depot was adjusted to a constant total dissectible fat in the body (Tables 6 and 7). Kempster et al(1976a) also found consid erable variation in fat distribution among breeds of different biological types at the same level of fatness.…”

“…Kempster et al (1976a), working with differ ent breeds, and Berg et al (1978a), using cattle of the three sexes, reported an increase in the ratio of subcutaneous: intermuscular fat with fattening. The discrepancies may be explained by differences in the cattle used and by the inclu sion of omental and mesenteric fat depots in our study.…”

“…Kidney fat was the most variable depot and intermuscular fat the least variable fat depot in a study with 643 carcasses from different breeds (Kempster et al,1976a). Furthermore, diet influenced fat distribution as cattle fed cereal diets had a higher proportion of their total fat deposited subcutaneously than cattle from a grass-cereal system.…”

“…Kempster et al (1976a) stressed the importance of increasing the knowledge of fat distribution in the carcass based on the fact that some cuts are more valuable than others while Charles and Johnson (1976) indicated that differences in fat distribution could mean al terations in the association between subcutaneous fat thick ness and carcass composition.…”

The prediction of retail beef yield from real time ultrasound measurements on live animals at three stages through growout and finishing

“…At slaughter, the effect of a change in P8 fat depth had a greater impact on RBY for Angus and Murray Grey animals than was the case for Herefords and Shorthorns, which most likely reflect differences in fat distribution and partitioning between the breeds. Research by Kempster et al (1976) supports the conclusion that animals of different breeds display different fat distribution patterns, which are not described by measurements of fat depth at only 1 site.…”