The effect of different dietary levels of hybrid rye and xylanase addition on the performance and egg quality in laying hens.

1. In this study, 240 ISA Brown hens were fed diets containing different levels of hybrid rye, and the influence of xylanase addition on laying performance and egg quality was evaluated. 2. Birds were allocated to 10 treatment groups with 12 replicates (cages) of two hens and were fed, from week 26 to 50, isocaloric and isonitrogenous experimental diets. A 5 × 2 experimental arrangement was applied, using diets with increasing level of rye (0%, 10%, 15%, 20% or 25%) with or without xylanase supplementation (200 mg/kg of feed; Ronozyme WX (CT) with minimum xylanase activity of 1,000 FXU/g). 3. Increasing dietary level of rye did not affect daily mass of eggs, mean egg weight or feed conversion ratio (P > 0.05). Laying rate decreased in all groups fed with rye. Egg and eggshell quality indices were unaffected by dietary rye grain (P > 0.05); however, rye inclusion significantly decreased yolk colour on the DSM scale (P < 0.05). In comparison with the control group, high dietary levels of rye (25%) significantly increased viscosity of small intestine content (P < 0.05). Diet supplementation with xylanase had no significant effect on egg production indices and egg quality (except for yolk colour) but decreased the viscosity of intestinal content in laying hens fed high levels of rye (P < 0.05). 4. The results of this experiment suggest that rye may be incorporated to a level of 25% in the diet of laying hens without any strong negative effect on egg performance, while xylanase added to high-rye grain reduced the viscosity of intestinal content; however, it did not positively affect the laying performance or egg quality.

Enzyme complex containing carbohydrases and phytase improves growth performance and bone mineralization of broilers fed reduced nutrient corn-soybean-based diets.

One experiment was conducted to investigate the benefits of a multi-enzyme complex, containing carbohydrases (from Penicillium funiculosum) and phytase (bacterial 6-phytase) activities, on the performance and bone mineralization of broiler chickens fed corn-soybean meal diets. A total of 2,268 male broilers were allocated to 9 treatments, replicated 6 times, in a randomized complete block design from 1 to 43 d. A positive control (PC) diet formulated to be adequate in nutrients and 4 reduced nutrient diets (NC1 to NC4), with gradual decrease on AME, CP, and digestible amino acids (CP-dAA) and available P (avP) and Ca contents, with or without enzyme supplementation, were tested. The nutrient reductions applied were NC1 (-65 kcal/kg, -1.5% CP-dAA) and NC2 (-85 kcal/kg, -3.0% CP-dAA) both with -0.15 percent point avP and -0.12 percent point Ca and NC3 (-65 kcal/kg, -1.5% CP-dAA) and NC4 (-85 kcal/kg, -3.0% CP-dAA) both with -0.20 percent point avP and -0.16 percent point Ca. Supplementation of the NC diets with the enzyme complex increased ADFI (P<0.001), ADG (P<0.001), and reduced feed:gain (P<0.01). The magnitude of the enzyme effect in increasing feed intake and weight gain was greater for the diets with greatest reductions in avP and Ca. Enzyme supplementation increased (P<0.001) feed intake of birds fed on NC diets close to the level of feed consumption of the PC. Enzyme supplementation to NC diets resulted in all cases in lower (P<0.05) feed:gain than the PC. Enzyme supplementation to NC1 and NC3 diets restored bone mineralization to that of the PC, whereas ash and Ca with NC2 and NC4 diets and P with NC4 diet remained lower (P<0.05). These results suggest that the dietary supplementation with a multi-enzyme complex containing nonstarch polysaccharide enzymes and phytase is efficient in reducing the P, energy, protein, and amino acid specifications of corn-soybean meal diets.

Influence of enzyme supplementation and heat processing of barley on digestive traits and productive performance of broilers.

We studied the influence of enzyme supplementation (ES) of the diet and heat processing (HP) of barley on digestive traits and productive performance of broilers from 1 to 42 d of age. There were 6 diets arranged factorially with 2 doses (0 and 500 ppm) of a fungal enzyme complex with beta-glucanase and xylanase activity and 3 HP of barley (raw, micronized, and expanded). In addition, a control diet based on raw corn without ES was also included from 1 to 21 d of age. Enzymes reduced intestinal viscosity (IV) at all ages (P < or = 0.001) and water intake at 21 d of age (P < or = 0.01) and increased DM of the ileal contents at 28 d (P < or = 0.001). Also, ES increased total tract apparent retention of nutrients and BW gain and feed conversion ratio from 1 to 42 d of age (P < or = 0.001). Heat processing of barley increased IV at 7 and at 28 d of age, and DM of ileal contents (P < or = 0.05) at 28 d of age. In addition, HP improved feed intake (P < or = 0.01) and BW gain (P < or = 0.001) from 1 to 7 d of age, but the effects disappeared after 21 d of age. From 1 to 7 d of age, chicks fed micronized barley had higher IV, gained less weight, and had poorer feed conversion ratio than chicks fed expanded barley (P < or = 0.05). It is concluded that barley with enzymes can substitute for all of the corn in diets fed to broilers from 1 to 21 d of age. Enzymes improved digestive traits, retention of nutrients, and broiler performance from 1 to 42 d of age, and HP of barley improved performance from 1 to 7 d of age. The effects of HP of barley on broiler performance were more evident with expansion than with micronization.

Heat processing of barley and enzyme supplementation of diets for broilers.

The influence of heat processing (HP) of barley and enzyme supplementation (ES) of the diet on digestive and performance traits of broilers to 21 d was studied. There were four treatments arranged factorially with two barley-processing treatments (raw or heated), two levels of ES (0 or 500 ppm), and five replicates per treatment. Chicks fed HP barley grew faster than broilers fed raw barley until 8 d of age, but the effect disappeared thereafter. In general, ES improved broiler performance at all ages. Intestinal viscosity was increased by HP of barley (P < or = 0.05) and reduced by ES (P < or = 0.001), and the decrease in viscosity caused by ES was greater for HP than for raw barley diets (HP x ES; P < or = 0.05). Heat processing of barley and ES of the diet improved apparent retention of nutrients (P < or = 0.001). Age affected apparent retention of nutrients differently. For starch and neutral detergent fiber, retention increased linearly with age (P < or = 0.01), but for the remaining nutrients the retention decreased from d 4 to 8 and then increased until d 21 (P < or = 0.001). Also, the beneficial effects of HP on retention of nutrients were more pronounced at younger ages (HP x age; P < or = 0.05). Both HP (P < or = 0.001) and ES (P < or = 0.01) increased liver weight, and enzymes reduced the weights of pancreas (P < or = 0.05) and small intestine (P < or = 0.001). Villus height was improved by HP (P < or = 0.001) and ES (P < or = 0.01), but villus surface area was only improved by enzymes (P < or = 0.01). It was concluded that broiler performance is improved by HP of barley at early ages and by ES of the diet throughout the trial. Also, HP and ES increased apparent retention of nutrients, AMEn of the diet, and villus height.

Effects of dietary fat type and non-starch-polysaccharide-hydrolysing enzyme addition to rye-based diets on muscle protein turnover in broilers.

1. Muscle protein turnover was measured in broilers fed on rye-based diets containing either beef tallow (T) or soybean oil (S) at an inclusion rate of 100 g/kg. Each of these diet types was tested either in the absence (S[-], T[-]) or presence (S[+], T[+]) of a xylanase-containing enzyme preparation. Protein turnover was measured in gastrocnemius muscle (GM) and pectoralis major muscle (PM). 2. Fractional rate of protein synthesis (FSR) was measured by the large dose technique using [15N]-labelled phenylalanine whereas fractional protein growth rate (FGR) was estimated by regressing tissue protein content over time. Fractional breakdown rates (FBR) were calculated by the difference between FSR and FGR. 3. In PM, FSR (%/d) was 22.1, 23.4, 21.5 and 24.4 in groups S[-], S[+], T[-] and T[+], respectively, and FBR (%/d) was 8.3, 9.8, 4.5 and 10.8 with the xylanase effect being significant. The FGR of 17.0%/d calculated for the broilers fed on the T[-] diet tended to be higher than for the other groups (13.6 to 13.8%/d). No significant effects were detected for these parameters in the GM. 4. The absolute amounts of protein which were synthesised daily and accreted in both muscles were significantly higher with xylanase supplementation in both fat type diets but at a significantly higher level when soybean oil was the dietary fat type. 5. The observed effects on protein turnover have to be seen in the context of an overall adverse effect of dietary soluble pentosans from rye in combination with tallow on physico-chemical chyme conditions, digestion and absorption of energy and nutrients and tissue-specific metabolic changes.