Effect of low or medium energy contents in organic feed mixtures on fattening and slaughter performance of slow or fast growing genotypes in organic turkey production

The present investigation examined whether feed mixtures with low (L) compared to medium (M) contents of apparent metabolizable energy (10.4 - 11.0 and 11.0 - 12.0 MJ AME/kg) at the same amino acids: AME ratios (g lysine resp. g methionine/MJ) can be successfully used in organic turkey fattening. The effect of the two types of feed mixtures was investigated in male and female turkeys of the breeds BIG 6 and BBB. In the fattening trial 240 day-old chicks of each breed were segregated according to sex and were fed the experimental mixtures L and M in 3 and 4 phases for hens and toms, respectively. The experimental mixtures offered in phase 1 (wk 1-6) contained on average (g/MJ AME) 1.31 lysine and 0.50 methionine. These ratios were reduced to 1.06 and 0.42 in phase 2 (wk 7-12), to 0.79 and 0.34 in phase 3 (wk 13-18), and to 0.58 and 0.25 in phase 4 (wk 19 -22) for lysine and methionine, respectively. BIG 6 and BBB hens reached 11.0 and 8.7 kg and toms 20.0 and 15.4 kg final BW, respectively. From week 7 onwards, birds receiving diet L were not able to consume AME in comparable amounts to those in groups supplied with the M diet. Average final BW of toms reached 18.9 kg (M) and 16.5 kg (L). Breast meat of toms on diet L was reduced by 13% compared to those on diet M. There were no interactions between type of feeding and turkey breed.