Some effects on the growth and composition of the car cass of the bacon pig of feeding micronized or ground maize or barley based diets to give three different digestible energy intakes

In a 2 × 2 × 3 factorial experiment 144 Large White pigs were individually fed, between 25 and 90 kg live weight, maize (M) or barley (B) based diets in ground (g) or micronized (m) forms at three different levels of digestible energy (DE) intake. Relative to live weight all pigs received similar daily quantities of crude protein and total lysine. At the lowest energy intake (L) each gram of crude protein was fed with 74J of DE: at the two other intakes the DE was increased by 10.5% (E) and 21.0% (H). The daily intake of total lysine was 4.8% of the crude protein intake. In formulating the diets the difference in DE content between gM and gB was taken as 16.7% and the differences between mM and gM and mB and gB were taken as 6.4% and 4.3% respectively.There were no significant first- or second-order interactions for growth rates or carcass composition data. The B and g based diets induced growth rates which were significantly greater than the M and m based diets by 2.7% and 4.6% respectively. There were no significant differences between cereals or processing treatments in carcass composition. Increasing energy intake significantly increased growth rates and killing-out percentages but decreased eye muscle areas and lean percentages in the carcass.