Production value and cost-effectiveness of pig fattening using liquid feeding or enzyme-supplemented dry mixes containing rye grain

The aim of this study was to assess the cost-effectiveness of a fermented liquid feeding and enzyme supplementation of dry fodders containing rye grain for pig fattening. Two experiments were performed on 126 gilts (82 in Experiment 1 and 44 in Experiment 2) of hybrid Pig Improvement Company (PIC) lines. In both experiments, the pigs were randomly divided into two equinumeric groups (treatment vs control). In Experiment 1, the treatment group received a diet containing 25% of rye grain (cultivar Visello) in the grower and 50% in the finisher period, replacing a proportion of barley from control mixes, and the fodders were given as pre-fermented liquid feed twice daily. In Experiment 2, both the control and experimental diets contained rye grain at the same quantities as the experimental group in Experiment 1, but the mixes for the treatment groups were supplemented with 0.01% of xylanase and fed in dry form. There were no differences in the mean growth rate or feed conversion ratio between the control and experimental groups of gilts. In Experiment 1, there was no effect of rye feeding on backfat thickness, loin depth, and meatiness, and hence the final carcass price, but the overall cost of fattening was lower by 5.1% in rye-fed pigs, which resulted in an 11.3% surplus. In Experiment 2, the backfat thickness was significantly greater and the lean meat content lower in the experimental compared with control group of animals. In spite of these differences, the lower cost of feeding (by 3.4%) resulted in a 5.2% increment in the economic efficiency of production of pigs receiving enzyme-supplemented mixes. It can be concluded that, in comparison to traditional barley-based nutrition, the pig fattening utilizing rye grain in wet fermented mixes is more profitable. The increased bottom-line profits of using dry rye mixes with carbohydrate-hydrolyzing enzymes appear to be associated with declining carcass quality.