Estudo comparativo de três rações no crescimento-engorda de suínos das raças Duroc e Piau

Resumo

A feeding trial was carried out to compare three swine rations, namely:

1. common ration of corn + mineral + pasture which is widely used by farmers;

2. commercial ration + pasture, and 3. corn soybean meal fortified 'with minerals, vitamins and antibiotic. In the experiment 36 pigs (18 Durocs and 18 Piaus) wereused for growing-finishing assigning the 3 experimental treatments and 3 replications, each comprising 2 Durocs and 2 Piaus.

A composition between the breeds of pigs, the Duroc and the Piau was also made in terms of live weight gains and feed efficiency.

The trial lasted 98 days and the folowing conclusions were reached:

For treatment 1, the common ration, the average liveweight gain was only 22.1 kg and the feed efficiency was 429. 4 hg of feed to 100 kg of gain. This gain in weight givesan index of 39, considering ration 2 as an index 100.

Animals on tratment 1 showed rough hair, depraved apetite, poor conditions and constanthunger due to the deficiency of the ration they consumed. When turned on pasture the pigs spent most of the time rooting instead of grazing in an effort to balance their ration. As a consequence thepasturewas seriously damage and without grass cover by the end of the experiment.

Animals on treatment 2, the commercial ration, gained on the average 54.2 kg and had a feed efficiency of 445.8 kg of feed to 100 kg of gain. These animals gained 2.45 times more weight than those on treatment 1. These animals always looked well-fed and whenever turned on pasture they showed normal grazing behavior without damaging the grass cover.

For treatment 3, the fortified corn-soybean meal ration, the average live-weight gain was 67.1kg and the feed efficiency was 370.0kg of feedto 100 kg of gain. This gain in weight gives an index of 126, considering ration 2 as an index 100.

As to the differences between the two breeds used, following observations were made:

When on treatment 1 both the Durocs and the Piaus showed the same average gain, namely 22 kg of live-weight, Percentagewise, however, the Piaus gained 203.6% of their average initial weight while the Durocs gained only 122,2% of their initial weight.

The Piau pigs were in better condition than the Durocs, and therefore, better adapted to the deficient ration.

As to treatments 2 and 3 the Durocs had better gains than the Piaus, which were respectively 1.7and 1.5 times the average gains made by the Piaus on treatment 2 and 3. However, percentagewisethegains were about the same for either breed on both treatments.