FEED SAFETY ▶▶▶


Storage of poultry feeds: points to consider


Storage may have detrimental effects on the quality of raw feed materials.The following is a review of the effects of storage on feed quality and ways of minimising such effects.


BY SALAH H. ESMAIL, PHD A


Duration 2 4 6 8


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Source: J. O. Alabi et al (2017). 28 ▶ ALL ABOUT FEED | Volume 29, No. 4, 2021


study was conducted to examine the occurrence of insects, colour, weight loss, and nutrient com- position in finisher feed for broilers stored under unfavorable conditions for eight weeks. The re-


sults are shown in Table 1. The colour change and weight loss at the 6th and 8th week could be attributed to the feed- ing activity and the increased number of insects that trigger enzymatic reactions causing such physical changes. The fat percentage also decreases over time, thus providing an ener- gy level below that recommended for broiler chickens. The higher protein content at six and eight weeks could be at- tributed to the presence of the larvae and adult insects ob- served in the feeds. The protein value in this case is, however, reduced due to the metabolic activity of the insects, thus creating a modified atmosphere with high CO2


and low O2 conditions which, through respiratory heating, could raise


Table 1: Change of physical properties and nutritive value of broiler feeds during storage:


Occurrence of insects Color Weight loss (%) Fat (%) - -


Yellow Yellow White White


0.45 1.08 2.70 2.66


17.67 12.50 6.33 6.17


Protein (%) 18.61 18.50 21.14 19.13


Many problems can be alleviated if the feed is stored in silos.


the inner temperature of stored feeds thus destroying inher- ent amino acids by Maillard reactions when stored for a long period. In other studies, it was reported that carotene content and content of other carotenoid pigments decrease significantly due to ageing and storage with the consequent loss of vita- min A activity. Thiamine (B1) and vitamin E contents do not seem to be greatly diminished by several years of storage, es- pecially when the feed is stored under favorable conditions.


Effects of moisture content Table 2 shows the safe levels of moisture in different feed ma- terials stored over two different periods. An excess amount of moisture will cause such feed to heat and, if not given prompt attention, they will become mouldy and thus unsuitable for feeding purposes. Whenever a feed material exceeds its per- missible moisture level for safe storage, it should be dried down to this level before being placed in storage. For each percentage point of moisture which a grain contains over the permissible level, about a 2% reduction, or a little more, in the price of the grain is justified: 1.2% to cover the lower level of dry matter it contains, the rest to cover the cost of drying the grain down to an acceptable level.


PHOTO:BERT JANSEN


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