EXPERIMENT 1

REPLACEMENT VALUE OF NATUZYME SUPPLEMENTED WHEAT BRAN FOR MAIZE IN BROILER DIET.

Wheat bran (WB) is one of the agro-waste products that is available and relatively cheap. NRC (1994) reported that wheat bran has a crude protein content of about 16% and crude fiber of 11%.

Although wheat bran is relatively inexpensive and readily available for use as feed ingredient, it is high in fiber and low in ME (1300kcal/kg, NRC 1994). Thus, it is limiting in its nutritive value because of its high fiber content, and as such is used often as energy diluents in rations of poultry.

Recent works have shown that supplementary enzymes do improve the nutritive value of hitherto neglected feedstuffs. Atteh (2000) observed an increase in diet energy in xylanase supplemented wheat bran compared to wheat bran without enzyme supplementation. This shows that the enzyme increase fiber digestion. This experiment was designed to investigate the suitability of Natuzyme (a bacterial enzyme) in poultry diets in which 50% of the maize was replaced with wheat bran.

MATERIALS AND METHODS.

One hundred and forty-four (144) day-old broiler chicks (mixed sexes) of a commercial strain were housed in an electrically heated battery brooder and fed the experimental diets shown in Table 1.1. The experiments consisted of a 2x3 factorial combination of dietary levels of Wheat bran (WB) at the expense of maize and levels of Natuzyme. There was a control diet with 50% maize as source of energy (50% maize, 0% wheat bran) and a second diet in which 50% of the maize in the control diet was replaced with wheat bran (25% maize, 25% wheat bran). Each of these 2 diets had 0, 250 or 500ppmsupplementary Natuzyme. Thus there were 6 treatments each with 3 replicate cages of 8 chicks.

The experimental diets and water were supplied ad libitum during a trial period that lasted for 4 weeks. Data collected during the trial period included feed intake, weight gain, and the feed/gain ratio was calculated.

There was no significant effect of the dietary treatments on mortality among the birds.

COST-BENEFIT OF WHEAT BRAN AND NATUZYME.

Addition of Natuzyme to maize based diets increased the cost of feed while increasing savings on the cost of producing 1kg of broiler by 0.75 and 5.45% for 250ppm and 500ppm respectively. Substituting wheat bran for maize caused a significant savings in feed cost but a loss in the cost of feed required to produce 1kg of weight gain. Supplementing the wheat bran with 250 and 500ppm Natuzyme on the other hand caused a 13.26 and 16.56% savings respectively on the cost of feed required to produce 1kg of broiler.

Results of the nutrient retention trial showed that replacement of maize with wheat bran reduced protein and fat retention. This is thought to be associated with the high fiber content of wheat bran which has negative effect on nutrient retention in general. Addition of Natuzyme at both 250 and 500ppm improved retention of protein and fat and diet ME. The improvement in protein, fat and diet ME in the presence of Natuzyme supplementation is thought to be associated with the breakdown of crude fiber, thereby releasing more nutrients energy for absorption. Result of the ME trial showed that the ME of Natuzyme supplemented wheat bran is 2301kcal/kg as against 1656kcal/kg without enzyme supplementation. There is also evidence to suggest that Natuzyme supplementation reduced rate of feed passage in the GIT, thereby allowing more time for enzyme-digesta contact, digestion and retention. Atteh (2000) had observed similar increase in FITT in birds fed diet with xylanase supplementation.

Use of Natuzyme in poultry diet makes economic sense even if marginal for maize based diet. However, for diets with high levels of wheat bran, there is substantial savings for both the feed miller and the poultry producer. Although the performance of birds fed diets with 250 and 500ppm Natuzyme are comparable, the profit margin on the cost to produce 1kg of broiler is higher with 500ppm than with 250ppm. Therefore the 500ppm recommendation by the manufacturer is recommended for optimum profit.

EXPERIMENT 2

RESPONSE OF LAYING HENS TO DIETARY LEVELS OF WHEAT BRAN AND NATUZYME.

PREAMBLE

Although the energy requirement of the laying hen is lower than that of broilers, maize still constitute close to 40% of the diet. With the current high cost of maize (N36 – N40/kg), farmers welcome any innovation that reduces the proportion of maize in the diet without detrimental effect on laying hen performance. The current trend is to increase the quantities of agro-industrial wastes like maize offal, wheat bran, spent grains, etc in the diets of chickens. It is well known that there is a limit to which chickens can utilize high fiber diets because of their innate limitation to produce the necessary enzymes.

The advent of enzymes as a feed additive has increased the prospects of using high fiber diet for chickens. The laying hen may be able to utilize higher fiber diets and need less supplementary enzymes than broilers. This is because there is evidence to suggest that the digestive system of the adult bird is physiologically more mature than that chicks (Carew, 1972). The recommended dietary inclusion level of Natuzyme is 500ppm. In view of the above hypothesis of a more mature digestive system, this experiment was designed to investigate the effects of various dietary levels of wheat bran (at the expense of maize) and Natuzyme on the performance, egg quality and nutrient retention of laying hens.

MATERIALS AND METHODS

FEEDING TRIAL

Ninety (90) laying hens of a commercial strain (45 weeks old) were housed in cages and fed the experimental diets shown in Table 2.1. The diets consisted of a 3X3 factorial combination dietary levels wheat bran (Honeywell flourmill, Apapa, Lagos) and Natuzyme.>Wheat bran was added to the diet at 0, 25, and 50% at the expense of maize while

Natuzyme was added at 0, 250 or 500ppm. Thus, there were 9 treatments, each with 5 replicate cages of two birds.

Feed and water were supplied ad libitum during the trial period that lasted for 6 weeks. During the trial period data were collected on feed intake and egg production. Eggs were collected once a week for weighing. After weighing, the eggs are cracked, shell thickness was determined using a micrometer screw gauge.

COST-BENEFIT ANALYSIS OF THE USE OF WHEAT BRAN AND NATUZYME AT THE EXPENSE OF MAIZE IN LAYER DIET.

Increase in the dietary level of wheat bran at the expense of maize significantly reduced cost of feed, cost/dozen eggs and increased the profit margin (Table 2.4).

The level of profit is higher when wheat bran replaced all the maize in the diet.

Supplementation with Natuzyme marginally increased the cost of feed, substantially reduced the cost of feed/dozen eggs and increased the profit margin. The use of 500ppm has a much higher profit margin than 250ppm.