Complete feed plant feed generally finer grinding, and provided in the form of particles, from the farm with coarse pulverization feed often, and usually powder.

Producing a finely pulverized granule diet requires more energy than a coarsely comminuted powder diet and is therefore more expensive and requires additional mechanical equipment. However, previous studies have shown that pellets can improve feed conversion efficiency.

In addition, other studies have shown that feed conversion efficiency is better when the particle size is small (that is, finer pulverization) than when the particle size is coarse. However, few studies have examined the additive effect of both granulation and fine pulverization on feed conversion efficiency.

Two trials were conducted in this study. The raw materials used in the two trials (main raw materials were barley [41%], wheat [36%] and soybean [19%]) and nutritional indicators (digestible energy 13.6 MJ/kg, crude protein 16.7%, total lysine 9.6 g/) Kg) are the same. The only difference is the form of the diet, ie the powder or granules, and the comminution size.

The finely comminuted diet was processed with six 4 mm screens and the coarsely comminuted diet was combined with two 14 mm and four 10 mm screens. The comparison of the coarse and fine granulation process of the diet is shown in Table 1. The particle size of the coarsely comminuted diet is similar to that produced by the comminution process typically employed in family farms.

In both tests, a dry and wet single level feeder (Verba feeder) was used for feeding.

In Trial 1, a commercial farm in the middle of Ulster (using Tempo and PIC337 hybrid progeny) grew pigs with similar effects (881 g/day) in feeding powder and pellets in the 55 to 110 kg body weight range. However, in terms of feed conversion efficiency, there was a 3% improvement in the number of feed pellets compared to the powder, although there was no significant difference. For commercial herds, when the diet is blown into the silo, there is a problem with the separation of the dietary components in the powder. Although reducing aerodynamic winds can alleviate this problem, the delivery of powder in the auger pipeline is indeed a concern.

In the second trial, two pulverized particle sizes or pellets were fed in the AFBI test herd (Tempo hybrid progeny). Table 2 reports the production performance and feed cost calculations for the four pigs fed the test herd. Similar to the commercial herd, the daily gains from all diets were similar (917 g/day) (Table 2). However, in the trial 2, compared to the powder, the daily feed intake of the pellets was 4.5% lower and the feed conversion efficiency was improved by 5.5% (Table 2). And the feed conversion efficiency of the finely comminuted diet was better than that of the coarsely comminuted diet (a difference of 3.1%) (Table 2). The effects of granulation and fine comminution appear to be additive and also show large differences in the calculation of feed costs.

Studies have shown that compared to fine comminution, the production cost per ton of ration with a coarse comminution requires a savings of £20 to offset the shortcomings in feed conversion efficiency. In general, the cost per kilogram of live weight is 1.8p higher in the case of the use of powder in the finishing stage compared to the pellets. In both trials, neither the appearance of the diet (powder or pellets) nor the size of the comminuted (fine or coarse) had any effect on the gastric ulcer. In addition, there is no effect on carcass quality, ie backfat thickness or slaughter rate.

in conclusion

Consistent with previous studies, feed conversion efficiency using pellets is better than powder. Finely pulverized feed conversion efficiency is also better than coarse comminution. In addition, the effect of granulation and pulverization particle size appears to be additive, and the difference in feed production costs between the two should be large to compensate for differences in feed conversion efficiency.