Different Protein Levels with and without Antibiotics for Growing-Finishing Swine: Effect on Carcass Leanness

Gain, Feed Conversion and Carcass Traits of Swine Fed under Two Nutritional Regimes

“…The mean differences (table 5) indicate that pigs fed the 14% C-S diet had leaner carcasses than pigs fed the 10% HL diet. Leaner carcass with increased levels of dietary protein have also been reported by Ashton et al (1955), Baker et al (1967, Lee et al (1967) and Davey and Morgan (1969).…”

“…Pigs fed the 14% C-S diet gained 0.18 kg/day faster than pigs fed the 10% HL diet. Numerous other workers have shown that increasing the level of dietary protein increases growth rate for barrows and/or gilts (Jensen et al, 1955;Baker et al, 1967;Clawson, 1967;Jurgens et al, 1967;Lee, McBee and Howath, 1967;Davey and Morgan, 1969). However, Gilster and Wahlstrom (1970) reported a reduction in gain of only 0.06 kg/day for pigs fed high lysine corn in a sequence of 12 to 10% protein compared to normal corn in a sequence of 16 to 14% protein.…”

“…Therefore, the data would indicate that pigs fed an inadequate level of dietary protein may have a higher ratio of fat to lean than pigs fed a higher level of dietary protein. Ashton et al (1955) and Baker et al (1967) found no effect of level of dietary protein on carcass backfat with protein levels at 2% intervals from 10 to 20 and 10 to 16%, respectively. In contrast, when comparing 16 and 12% protein diets, Kropf et al (1959) found pigs fed a 16% protein diet had less backfat.…”

Carcass Characteristics of Swine as Influenced by Levels of Protein Fed on Pasture and in Dry Lot

“…This finding is in agreement with the results of Crampton and (1958). Ashton (1946) and Ashton et al (1955) who reported no significant difference in carcass quality of pigs consuming rations that varied only 2 % in protein content. The pigs fed in dry lot seemed to be slightly fatter than the pasture-fed pigs as evidenced by a thicker backfat and a higher percentage of estimated fat in the carcass.…”

Substitution rates and economic optima in corn-soybean rations for growing-finishing swine

“…Least cost rations for swine Previous investigations at the Iowa Station measured the rate and efficiency of gain by growing-finishing swine fed various combinations of corn and soybean meal (Ashton et al, 1955;Speer e_t^., 1956). Production functions derived from these data expressed pounds of gain beyond weaning as a function of pounds of corn and soybean meal consumed beyond weaning.…”