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Pellet Quality
There have been a number of recent enquiries about pellet quality and the influence of "fines" on bird performance. The article on "Fines", which was published over 20 years ago, seemed to answer many of the questions asked and thus it was decided to reproduce it.
Work reported in relatively recent years, from the Agricultural Research Station in Kentville, shows that the percentage of fines in a ration has to get to a level beyond 25% to significantly alter the performance of broilers and probably even higher before turkey performance is affected.
A recent paper from Dr. Moran's laboratory at the University of Alabama, shows that a lignosulfonate binder could improve the percentage of intact pellets by 56%. However, body weight and carcass yield of 44 day old broilers, fed the pelleted diets, with and without the pellet bender were equal. There was a small improvement in feed:gain ratio and a slight increase in abdominal fat for birds fed the diet containing the pellet binder. This could have been due to less energy expenditure for the birds consuming the better pellets thus leaving more energy available for fat synthesis in the body.
It is obvious that the problem of "quality pellets" has been around for quite some time. There is no question but that a higher percentage of "fines" can lead to problems in feed handling, bridging in bins, perhaps increased feed waste and if the percentage is high enough, reduced bird performance. However, as long as a feed has gone through the proper pelleting process (subjected to proper time, temperature and moisture level) in the pellet conditioner then the nutritive value of those "fines" are very close to that of the intact pellets. How to get this message across to many of the growers in the field still remains a challenge to the feed manufacturer.
Fines- Do they reduce the performance of a steam pelleted or crumbled ration?
J. D. Summers
Department of Poultry Science, O.A.C University of Guelph
Feed manufacturers are still faced with complaints concerning the percentage of "fines" in pelleted or crumbled rations. Although it is true that the composition of the ration, degree of handling and type of unloading equipment can often lead to a high percentage of "fines", the important question is, to what extent do these "fines" reduce the performance of a steam pelleted or crumbled ration? A number of reports have appeared in the literature demonstrating that there is a chemical as well as a physical effect on a ration with steam pelleting and that the chemical effect is still apparent even when the pellets are reground and fed as mash.
While it is true that much of the physical effect of pelleting (that is density of diet and hence less time spent by the bird in apprehending food) is lost with "fines", it would appear that this effect is of lesser importance as far as ration performance is concerned than is the chemical effect.
During the past few years, work has been conducted at the Department of Poultry Science on the effects of steam pelleting of ingredient and ration performance. Data has been drawn from certain phases of this work to demonstrate the contribution of steam conditioning to the enhanced performance of a ration regardless of the physical form of the feed.
In Table 1 is shown data derived from an experiment on the effects of steam pelleting on metabolizable energy values. The corn, soya diet used (diet 1) contained a high level of protein. Diet 2 was made by mixing 50% of Diet 1 with 50% of alfalfa meal. Hence diet comparisons are not valid here, but rather the effects of the different forms of feed should be noted. Steam pelleting the corn, soya diet resulted in approximately a 5% increase in weight gain, with no improvement in feed utilization. The important point to note is that the reground crumbles performed equally as well as the crumbled ration. With the high alfalfa meal diet a marked improvement in feed utilization and growth occurred when the diet was steam pelleted and reground.
A further but much smaller improvement of feed utilization and weight gain was obtained by feeding the diet in the form of crumbles. Since this diet was very bulky, the physical form of the ration (e.g. crumbles versus mash or reground pellets) would be of far greater importance to the bird in apprehending food than would be the case with the higher energy, higher density diet (diet 1). Also in this test the complete diet was reground while in practice there would only be a portion of the diet in the form of "fines".
Hence one would not expect to note differences of the magnitude shown in the above work, under commercial conditions, of "good" crumbles versus "poor" crumbles, even if a ration as bulky and as low in energy was employed.
In Table 2 is shown a further test similar to that described above. The corn, soya diet used in this test contained 24% protein and hence is typical of a regular broiler starting diet.
Again a major improvement in ration performance was noted for the steam pelleting treatments regardless of the physical form in which the diet was fed. Only a very small improvement in performance was noted for the crumbled as compared to the steam pelleted and reground diet, even for the ration containing 30% wheat bran.
The two tests described above demonstrate that the major improvement noted for steam pelleted diets is the chemical effect of pelleting and not the physical effect. Since reground steam pellets perform almost equally as well as identical rations fed in crumble form, it is reasonable to assume that steam, crumbled or pelleted diets containing a relatively high percentage of "fines" will give almost, if not equally as good performance as compared with pelleted feeds devoid of "fines".
It is difficult, if not almost impossible to make a good or hard pellet with a corn, soya diet, especially with 5% added tallow.
A grower is better advised to accept a certain percentage of "fines" with this type of diet, rather than demanding a "good" pellet which is usually made by substituting some lower energy ingredient such as wheat, oats or barley for a portion of the corn, or by adding some non-nutritive binder to the diet.
When one considers the degree of pellet breakdown that takes place in many automatic feeders, the percentage of "fines" in a ration when delivered would appear to be of minimum concern.
Some growers complain about bridging in bulk bins and feeders. This condition is obviously aggravated by the percentage of "fines" in a pelleted ration. Another point often made by the grower is the problem of feed wastage with a diet high in "fines". Bridging and feed wastage are problems that can be overcome by the grower with the proper equipment and good management practices. Hence, they should not be a major concern to a well managed poultry operation.
| Table 1. Performance of birds fed diets in the form of mash, crumbles and reground crumbles.* | ||||||
|---|---|---|---|---|---|---|
| Mash | Reground Crumbles | Crumbles | ||||
| Diet | Av. Wt. gm | F/G | Av. Wt. gm | F/G | Av. Wt. gm | F/G |
| 1. Corn, soya 2. As 1, plus 50% alfalfa | 217 104 | 1.78 4.82 | 228 125 | 1.81 3.82 | 223 133 | 1.80 3.62 |
*Leghorn cockerel chicks were used and the experiment was of 3 weeks duration.
| Table 2. Performance of birds fed diets in the form of mash, crumbles and reground crumbles.* | ||||||
| Mash | Reground Crumbles | Crumbles | ||||
| Diet | Av. Wt. gm | F/G | Av. Wt. gm | F/G | Av. Wt. gm | F/G |
| 1. Corn, soya 2. As 1, plus 30% bran | 407 388 | 2.06 2.16 | 461 413 | 1.96 1.97 | 471 417 | 1.90 2.00 |
*Broiler type chicks were used and the experiment was of 3 weeks duration.