Effects of feeding level, protein level, and sex of pig on carcass fatness measured by dissection and optical probe methods

Abstract

384 pigs (entire males, females, and castrates in equal numbers) were slaughtered at either 80 or 100 kg liveweight, and were used to compare two methods of estimating the fat content of the carcass. The pigs were fed in a factorial arrangement on four different levels of intake and four diets of varying protein content. Despite the wide variation in carcass fat content so produced, measurements made using an optical probe were always closely related to measurements derived from the 'fat trim', i.e., the combined weight of dissected subcutaneous fat, cavity fat, skin, and cutaneous muscle. The fat content of the carcass was increased by high feed intakes and decreased by high protein levels. Interactions occurred between sex, feeding level, and protein level. The largest differences in fat content among the three groups were between entire males and castrates, particularly at high protein and low feeding levels. Females were intermediate in response.

A comparison of pig backfat measurements using ultrasonic and optical instruments

“…In agreement with other workers (Sather et al, 1982;Davies et al, 1986) results of the current study suggest that gilts, at the same age and weight, were fatter than boars, with the average difference being approximately 1.2 mm ( Table 3). The results also indicate that the sex of the pig did not influence the outcome of the probe's prediction, since similar trends were apparent when the sexes were mixed (Table 1) or split (Table 3).…”

“…The results also indicate that the sex of the pig did not influence the outcome of the probe's prediction, since similar trends were apparent when the sexes were mixed (Table 1) or split (Table 3). This in agreement with Davies et al (1986) who concluded that the measure of fat depth was not affected by the sex of the pig. Small differences in the accuracy of the ultrasonic probes were observed when applied to the two sexes.…”

“…Davies et al (1986) noted that the subcutaneous fat cover on the pig can be considered a dcoatT of similar length and circumference but of varying thickness. The weight of subcutaneous fat will therefore vary in direct proportion to the thickness.…”