The Influence of Limited Feeding, using High Fiber Rations, upon Growth and Carcass Characteristics of Swine. I. Effects Upon Feed-Lot Performance

Restricting the TDN level by incorporating fibrous feeds into swine rations significantly decreased average daily gains. Feed consumption per 100 lb. gain was increased by restricting the digestible nutrients of the ration, but TDN consumed per 100 lb. of gain was essentially equal in all lots, except lot 8. Significant differences were observed between the pigs of the basal and hand-fed lot for the number of days on experiment and average daily gain. More efficient gains were also obtained in the hand-fed lot. No significant differences were found between protein levels. The level of crude fiber in the ration was found to be more highly correlated with the results of growth and carcass data than either TDN or protein level. The differences between treatments were not significant when the crude fiber content of the ration was less than 10%. In lot 8 pig performance was more severely affected by the high level of fiber or low TDN content of the alfalfa hay in the ration than the 70% restriction of the hand-fed lot.