Effect of dietary lysine on yield losses occurring during early feed restriction to reduce ascites

This study evaluated additions of dietary lysine to restore yield losses from feed restriction to reduce ascites. Feed restriction was used to limit daily feed intake of the birds to 75% of the metabolizable energy required for normal growth, based on the ad libitum intake of the birds. Grower and finisher diets contained normal lysine (NL) or high lysine (HL). Final body weight of feed-restricted birds was 96% of birds fed ad libitum, indicating that "catch-up" growth was not sufficient to equalize the body weights by 56 d of age between birds on feed restriction and those fed ad libitum. Feed-restricted birds were fatter than those birds fed ad libitum. HL reduced the deficit in the percentage pectoralis minor muscle yield compared with birds fed NL diets, whereas the percentage yield of pectoralis major muscle remained unaffected by dietary lysine. Feed restriction reduced the total ascitic mortality in the cool and control environments. It was concluded that increased lysine did not have any beneficial effect on the final body weight, percentage carcass yield, or any of the carcass characteristics, with the exception of pectoralis minor muscle yield, which was increased when birds were fed HL.