The incorporation of whole grain into pelleted broiler chicken diets: production and physiological responses

1. Pelleted diets, incorporating whole or ground triticale or wheat in the pellets, were fed to broiler chickens and the performance, gastro-intestinal development and health of those chickens recorded. 2. The use of whole triticale in the pelleted food produced similar bodyweight responses to when ground triticale was incorporated in the food. Food conversion efficiency was enhanced when whole triticale was used compared to ground triticale and was similar to when an exogenous enzyme was added to the ground triticale diet. The incorporation of whole wheat into the pelleted food produced similar production responses to the use of ground wheat. 3. The gastro-intestinal development of the birds was greater when they were fed the whole grain diet as gizzard weights were increased by the incorporation of whole grain into the diet. Gastro-intestinal development was thought to be related to the presence of large fibre particles in the food. 4. Proventricular dilatation and mortality due to ascites were reduced by feeding pelleted diets containing whole grain, which was possibly related to the early development of the gastro-intestinal tract relative to total body development. 5. It is suggested that the current use of exogenous enzyme additions to broiler diets may be reduced by incorporating whole grain into pelleted diets for broiler chickens.     

The influence of whole grain inclusion in pelleted broiler diets on proventricular dilatation and ascites mortality

1. Pelleted diets, incorporating whole or ground wheat or barley in the pellets, were fed to broiler chickens and proventricular dilatation, digesta characteristics and mortality were recorded. 2. The incidence of proventricular dilatation was reduced when whole grain was incorporated into pelleted diets at 200 g/kg. 3. Enzyme application did not influence proventricular dilatation. 4. Digesta contents of intestinal sections were greater and pH lower in anterior intestinal sections when birds had dilated proventriculi. 5. Consideration of overall ascites mortality suggests that the incidence of the condition may be curtailed by whole grain inclusion in pelleted diets. 6. Production efficiency may be enhanced with whole grain inclusion in pellets when feed processing costs and flock health responses are considered.     

Effect of whole and demucilaged linseed in broiler chicken diets on digesta viscosity,nutrient utilisation and intestinal microflora

1. A study was undertaken to evaluate the effects of the inclusion of linseed or demucilaged linseed in the diet on the performance, fat and fatty acid digestibilities, metabolisability of gross energy and intestinal microflora. 2. The dietary inclusions were 80 and 160 g/kg for linseed and 160 g/kg for demucilaged linseed. Diets were given to chickens from 1 to 23 d of age. 3. Incorporation of linseed in the diet, particularly at 160 g/kg, depressed weight gain and food utilisation. Digestibility of fat and single fatty acids and dietary metabolisable energy were reduced. 4. Inclusion of linseed in the diet markedly increased the viscosity of ileal digesta. Microbial activity in the ileum and caeca was not greatly affected, but there was a significant increase in the number of lactobacilli. 5. The antinutritional effects caused by feeding linseed were partially overcome by substituting demucilaged linseed for linseed in the diet. 6. Results from the current study suggest that the viscous properties of mucilage are a major factor in the observed antinutritional effects of linseed through increasing intestinal viscosity. Such effects might also be mediated by the gut microflora.     

Evaluation of keratinase stability in pelleted broiler diets

Versazyme (VZ) is an approved keratinase-based feed additive produced naturally as a fermentation product of Bacillus licheniformis PWD-1. The experiment was designed to test the recovery and efficacy of VZ using typical feed industry pelleting parameters. The pelleted diets were conditioned to 85°C for 30 s and pelleted using a 4 × 32 mm die, cooled, and crumbled. A total of 192 male broiler chicks were fed a corn-soybean meal starter diet formulated at 18.5% CP to 21 d of age. The 4 treatments used in the feeding study were as follows: VZ 0.0%-mash, VZ 0.0%-pellet, VZ 0.1%-mash, and VZ 0.1%-pellet. Body weight and feed consumption were determined at 21 d of age. The recovery of VZ in feed was 93% in the mash diet and 66% in the pelleted diet. There was a 55-g increase in BW gain and 0.17 improvement of FCR when birds were supplemented with 0.1% VZ. Pelleting improved BW gain (P < 0.05) but did not significantly improve the FCR. Growth performance results indicate that pelleting did not affect the efficacy of VZ.     

Inclusion levels and modes of whole grain incorporation into wheat-based rations differentially influence the performance of broiler chickens

1. The objective was to compare three whole grain (WG) inclusion levels (7.5, 15 and 30%) offered to broiler chickens by three modes of WG incorporation: (i) pre-pellet WG inclusion, (ii) post-pellet WG inclusion as a blend of WG and pelleted concentrate and (iii) post-pellet WG inclusion where WG and pelleted concentrate were provided in separate feed trays against a ground-grain, wheat-based control diet.

2. Ten dietary treatments were offered to 6 replicate cages (6 birds per cage) of male Ross 308 chickens from 7 to 28 d post-hatch. The effects of treatment on relative gizzard weights, gizzard contents, pancreatic weights and pH of gizzard digesta were monitored. Parameters of growth performance, nutrient utilisation (apparent metabolisable energy [AME], metabolisable to gross energy [ME:GE] ratios, nitrogen [N] retention and N-corrected AME [AMEn]), apparent starch and protein (N) digestibility coefficients and disappearance rates in for small intestinal segments and concentrations of free amino acids in plasma taken from the anterior mesenteric vein were determined.

3. Whole grain feeding (WGF) did not influence weight gain, but 30% post-pellet blended and 15 and 30% post-pellet separated treatments significantly depressed (P < 0.05) feed intakes while the 30% post-pellet separated treatment improved (P < 0.01) feed conversion ratios (FCR). WGF regimes significantly increased relative gizzard weights.

4. Overall, WGF generated profound responses in AME, ME:GE ratios, N retention and AMEn that were highly correlated with relative gizzard weights. In general, WGF improved starch and protein (N) digestibilities and again there were some correlations with these outcomes and relative gizzard weights.

5. Post-pellet WG inclusions where WG and pelleted concentrate were offered separately provided chickens with the opportunity to choice feed. Birds showed a preference for the relatively high-protein pelleted concentrate and at 30% WG, this resulted in an improvement in FCR of 7.69% (1.260 versus 1.365; P < 0.001) relative to the ground-grain control diet.     

Differences in the digestive tract characteristics of broiler chickens fed on complete pelleted diet or on whole wheat added to pelleted protein concentrate

1. The effects of whole grains of wheat on the digestive tract of broiler chickens was studied. A complete pelleted feed was compared with free choice feeding of whole wheat and a pelleted protein concentrate, given from 7 to 29 d of age. 2. Pepsin activity in proventriculus tissue was lower in whole wheat-fed birds than in complete diet-fed birds. The weight (g/kg body weight) of the gizzard was higher in whole wheat-fed birds and its contents had a lower pH. 3. In the intestine, there were no differences in deoxyribonucleic acid (DNA) concentration, protein/DNA, ribonucleic acid (RNA)/DNA, RNA/protein ratios or alkaline phosphatase activity expressed per tissue weight. The weight (g/kg body weight) of the duodenum was lower in whole wheat-fed birds and its contents had a higher pH. Also the activities of alkaline phosphatase and leucine aminopeptidase in the duodenum, and maltase in the ileum, expressed per unit of bird weight, were lower in whole wheat-fed birds. 4. These results suggest that whole grain feeding increases the chemical (pepsin in proventriculus) and physical (gizzard muscle) functionality of the upper part of the digestive tract but decreases the digestive capacity of the intestine. Higher gizzard functionality may play a positive role in the control of bacterial populations. The lower digestive enzyme activities in the intestine may be detrimental in situations of mucosal deterioration caused by intestinal disease.     

Causes for improvement in nutritive value of broiler chicken diets with whole wheat instead of ground wheat

1. Two experiments were conducted with broiler chicks to compare nutritive values of ground and whole wheat diets containing titanium oxide as indigestible marker. 2. In Experiment 1, a wheat and soy isolate based cold-pelleted diet, in which all the wheat was ground in a hammer mill to pass through a 3 mm sieve, was compared with a diet in which about half (375 g/kg) of the ground wheat was taken out of the diet and supplied as whole wheat mixed into the diet after pelleting. 3. In Experiment 2, a diet based on ground wheat and soy isolate which was pelleted after preconditioning (final temperature 81 degrees C) was compared with a diet in which 500 g of the ground wheat was replaced by whole wheat mixed into the diet before pelleting. 4. In Experiment 1, replacement of ground wheat with whole wheat increased apparent metabolisable energy (AME) content and starch digestibility measured at ileal as well as faecal level, while weight gain and feed conversion efficiency (FCE) were not affected. Jejunal chyme showed increased amylase activity and bile salt concentration. 5. In Experiment 2, replacement of ground wheat with whole wheat increased dry matter content as well as bile content of gizzard, and stimulated an increase in gizzard as well as pancreas weight. Jejunal amylase and bile concentrations were not significantly affected and neither were growth, FCE or AME. 6. Results from this experiment indicate that the improved feed value sometimes observed with whole wheat may be associated with modulation of digestive processes resulting in increased pancreas and liver secretions.     

The effects of drought-affected grain and carbohydrase inclusion in starter diets on broiler chick performance

Two 18-d studies were conducted to evaluate the effects of drought stress and carbohydrase enzyme inclusion on broiler performance and nutrient digestibility in either yellow dent corn or sorghum. Both experiments employed a 2 × 2 factorial arrangement of treatments with 2 growing environments (normal or stressed), and carbohydrase enzyme cocktail (yes or no). In each experiment, 256 chicks were randomly assigned with 8 birds/pen and 8 replicates/treatment. Enzyme inclusion did not affect any variable in either experiment, and environment did not alter 18-d BW, mortality, or the digestibility of DM or CP. In Experiment 1, birds consuming normal corn had improved FCR compared to those fed drought-affected corn (1.27 vs. 1.33, respectively), which was potentially driven by the difference in apparent total tract digestibility (ATTD) of EE. Alternatively, FCR was not affected by environment in birds fed sorghum-based diets in Experiment 2, but those that consumed normal sorghum had lower feed intake than those fed drought-affected corn (750 vs. 796 g, respectively). In summary, commercial carbohydrase inclusion did not improve growth performance or nutrient digestibility in birds fed normal or drought-affected corn or sorghum. Birds fed drought-affected corn and sorghum affected growth performance variables, but environment did not affect final weight or mortality of broiler chicks.     

Comparison of performance and intestinal characteristics of broiler chickens fed on diets containing whole,rolled or ground barley

1. In two experiments, no consistent differences in weight gain or food intake appeared between broiler chickens given diets based on whole or rolled barley, but food: gain ratio and gizzard weight as a percentage of live weight were reduced (P<0.05) when barley was rolled. Grit addition did not affect performance or intestinal characteristics.

2. In a third experiment, whole barley diets gave significandy higher weight gain than ground barley diets; this was attributable to the significandy higher food consumption. Gizzard weight as a percentage of live weight increased (P< 0.05) when whole barley was fed, while foodrgain ratio was not significandy (P>0.05) affected by the form of barley.

3. The number of particles in the intestinal contents with sizes larger than 2.4 mm was not significantly (P<0.05) different between broiler chickens fed on whole barley and those fed ground barley, but the number of particles with sizes between 2.4 and 0.7 mm was lower (P< 0.05) when diets with whole barley were fed.

4. Enzyme addition increased (P< 0.05) weight gain and the DM of intestinal contents, and decreased (P<0.05) intestinal viscosity, food:gain ratio and pancreas weight as a percentage of live weight regardless of form of the barley.     

Soft wheat instead of hard wheat in pelleted diets results in high starch digestibility in broiler chickens

(1) The aim of the experiment was to re-examine variations in digestibilities of food components in 3-week-old broiler chickens fed on pelleted diets based on wheats differing in lipase activity and hardness. Fourteen wheat (Triticum aestivum) samples, each from a different cultivar, were included at 550 g/kg in 14 different diets given to male Ross broiler chicks from 7 d of age. The other main ingredients consisted of soyabean meal (353 g/kg) and rapeseed oil (55 g/kg). A 15th diet containing durum wheat (Triticum durum) was also tested. (2) Hardness of wheats (Triticum aestivum) varied between 14 (very soft) and 88 (very hard), and lipase activity of wheats varied from 1 to 13.1 (relative scale). No significant correlation was found between in vitro viscosities and other parameters such as hardness, particle size of wheat flours and lipase. Hardness was correlated with the mean particle size of wheat flours and durability of pellets. (3) Individual lipid digestibilities were negatively correlated with in vitro viscosities of wheats. (4) Individual starch digestibilities were negatively correlated with wheat hardness, particle size of wheat flour before pelleting, and pellet durability. The ratio of measured AME(N) to predicted AME(N) was also negatively correlated with wheat hardness. Simple regression calculation showed that a 100-point increase in wheat hardness resulted in a 3% decrease in the AME(N) value of diets. Multiple regression calculation showed the food/gain ratio (d 10 to d 21) to be positively related to wheat hardness and negatively related to pellet durability. (5) Wheat lipase activity was positively correlated with individual starch digestibility, which was the reverse of a result obtained in a previous experiment. Thus, wheat lipase activity did not seem consistent for predicting starch digestibility and AME(N) values. (6) Among all wheat samples, durum wheat showed the highest protein content and the lowest content of water-insoluble cell-wall. Starch digestibility of durum wheat tended to be lower than that of other wheats (0.916 vs 0.936). However, no significant difference in AME(N) was observed between the durum wheat sample and other wheats. (7) Gut morphometric data measured at d 24 did not show significant differences between dietary treatments.     

Hagberg falling number and the nutritional value of wheat in broiler chicken diets

1. Three experiments were performed to study the effect of Hagberg falling number in wheat on performance, nutrient digestibility and AMEN in broilers. In two experiments, one hard and one soft wheat variety were used to study the interaction between falling number and hardness of wheat with regard to nutritional value. In these experiments, wheat batches with high falling number when harvested under dry conditions were used in broiler diets. 2. Wheat with reduced falling numbers (high, medium and low) was obtained by controlled germination. In the third experiment, wheat with reduced falling numbers were obtained by delayed harvesting times. 3. In each experiment, a total of 4 cereal batches with different falling numbers from each wheat variety were used to produce corresponding experimental diets with wheat as the major ingredient. Each diet was fed to broiler chickens ad libitum from d 1 to d 17 of age. 4. There was no consistent effect of falling number on performance. Low falling number did not improve feed utilisation or AMEN compared to the original wheat, despite a higher AMEN associated with higher starch digestibility. This phenomenon was not observed after reduction of falling number by delayed harvesting. Apparently, natural reduction of falling number resulted in enhanced degradation of arabinoxylans compared to controlled germination.     

The effects of pelleting and glucanase supplementation in hulled barley based diets on feed manufacture,broiler performance,and digesta viscosity

Feeding broilers barley-based diets requires special consideration primarily due to effects on increased digesta viscosity and decreased nutrient digestion. Pelleting and glucanase supplementation are commonly performed prior to feeding broilers barley-based diets; however, the interaction of these practices is complex. The objective of this study was to establish a comprehensive evaluation of glucanase efficacy including: degree of processing, activity postpelleting, broiler performance, and digesta viscosity. Treatments were arranged in a 5 (diet formulation) × 2 (processing) factorial in a randomized complete block design with 8 replications/treatment. The 5 diet formulations consisted of positive control (PC), negative control (NC), glucanase A (GA) 125 or 1,000 β-Glu-U/kg feed, and glucanase B (GB) 1,000 β-Glu-U/kg feed. The PC and NC diets differed in metabolizable energy by 150 kcal/kg and enzymes were added to NC formulations. Diets were either fed as unprocessed mash or ground pellets. Diet formulation × processing did not interact for feed intake (FI), FCR, or total tract viscosity (P > 0.05); however, a trend was observed for ending bird weight, demonstrating that for ground pellets, GA 1,000 β-Glu-U/kg feed was improved relative to NC and similar to PC (P = 0.0903). Benefits associated with GB were not of similar magnitude, perhaps in part due to a 50% decrease in activity postpelleting. In addition, GA benefits were not suggested for unprocessed mash. The main effect processing was significant (P < 0.0001) demonstrating that broilers fed ground pellets resulted in greater pen ending bird weight, FI, and bird live weight gain (LWG) compared to birds fed unprocessed mash diets. Evaluations of glucanase should go beyond in vitro activity and include live bird performance using feed that has undergone pelleting.     

Utilisation of sesame (Sesamum indicum) seed meal in broiler chicken diets

1. Soybean meal (SBM) was replaced with sesame seed meal (SSM) at proportions of 0.00, 0.33, 0.67 and 1.00 on a protein basis in broiler diets (2 to 42 d of age). Each diet was fed to 8 replicates of 5 birds each. 2. Body weight gain, food efficiency, ready-to-cook (RTC) yield, relative weights of giblet, liver and abdominal fat were not affected by including SSM up to 0.67 proportion of SBM in starter and finisher diets (360 and 310 g/kg, respectively). The relation between level of SSM and growth performance variable (weight gain, food efficiency and RTC yield) was non-linear. 3. Weight, breaking strength and ash content of tibia decreased non-linearly with the proportion of SSM in diet. 4. The activity of alkaline phosphatase and protein concentration in serum decreased linearly with the amount of SSM in the diet.     

Site of protein digestion in steers fed sorghum grain diets. II. Effect of grain processing methods

Seven crossbred, abomasally fistulated yearling steers (400 kg) were used in two digestion trials (crossover design) to study the effect of processing sorghum grain on the site and extent of feed and microbial protein digestion. Steers were fed an 81.5% sorghum grain diet in which the grain was either dry-rolled (DR; four steers) or steam-processed, flaked (SPF; three steers). At the end of the first trial steers were switched to the opposite treatment. Dysprosium (21 to 23 micrograms/g of feed) was used as a digesta marker. Feed, abomasal contents and fecal grab samples were collected at 12-h intervals during a 6-d total fecal collection period. Organic matter (OM) intake for SPF and DR grain diets averaged 6,426 and 6,787 g/d, respectively. Compared with DR, SPF increased (P less than .05) the apparent total digestibility and ruminal digestibility of OM. Trichloroacetic acid precipitable protein consumed by the steers was lower (P less than .05) for SPF than the DR treatment. Processing method had no effect on ruminal digestion of crude protein (CP), bacterial protein (BP) synthesis, quantity of CP entering the small intestine or on total digestion of feed protein. There was a trend for increased total and post-ruminal digestion of CP with the SPF diet. Post-ruminal digestion of BP was increased (P less than .05) by SPF grain as compared with DR. Percentage of non-BP digested ruminally, post-ruminally or in the total tract was not significantly affected by processing method.(ABSTRACT TRUNCATED AT 250 WORDS)     

Xylanase in broiler diets with differences in characteristics and content of wheat

1. Experiments were conducted to measure the effect of xy‐lanase supplementation on the performance of broilers fed on wheat‐based diets containing high and low extract viscosity wheat (experiment 1), baking and feeding quality wheat (experiment 2) and with variation in wheat content (experiment 3).

2. Xylanase supplementation improved food conversion ratios by 2·2–2·9% and body weight gain by 0·2–2·5%. This was independent of wheat characteristics but slightly dependent on the wheat content of the diet. These effects were related to a lowering of digesta viscosity.

3. Differences in extract viscosity of wheat were not reflected in broiler digesta viscosity.

4. Reduction of digesta viscosity resulted in only a slight improvement of litter score. Reduced intestinal viscosity decreased relative pancreas weight and to a lesser extent relative small intestinal weight.

5. Baking quality wheat Baldus gave better performance than the feed quality wheats Apollo and Slejpner.

6. It was concluded that xylanase supplementation of wheat‐based diets invariably had a positive effect on broiler performance.     

The radiation pasteurisation of broiler chicken carcasses

Irradiation of standard broiler carcasses within 24 hr. of slaughter with a dose of 0.15 Mrad of gamma radiation was sufficient to give a shelf life of more than six days at 5° C. followed by one day at 15° C. The carcasses were treated and stored in air and remained unchanged in appearance and odour. After cooking, treated and stored carcasses were indistinguishable, when tasted in blind comparison tests, from un‐irradiated material held at —20° C. for the same time. The storage conditions chosen were taken to represent the upper limits of commercial and domestic handling during distribution of unfrozen broiler chicken. The economics of the radiation process are discussed.     

The effect of beta-glucanase supplementation of barley- and oat-based diets on growth performance and fermentation in broiler chicken gastrointestinal tract

1. The aim of the present study was to investigate whether grain type (barley or oats) and ss-glucanase inclusion influence the performance and the gastrointestinal ecosystem of broiler chickens, taking the concentrations of short-chain fatty acids and lactic acid, pH, ileal viscosity, and the weight of the caeca and liver into consideration. 2. The inclusion of beta-glucanase in the oat-based diet improved body weight gains. Enzyme supplementation of barley-based diets improved feed conversion efficiency and reduced intestinal viscosity. 3. Irrespective of the type of cereal, beta-glucanase supplementation increased the lactic acid concentration and lowered the pH of the crop contents. No such changes in fermentation were observed in the contents of the gizzard and ileum. 4. Larger amounts of total dietary fibre and its fractions (arabinoxylans and beta-glucans) in oats decreased the weight of the caeca. 5. Molar ratios of acetate, propionate and butyrate in the caecal chyme were affected by cereal type but not by enzyme supplementation. The barley-based diet increased the butyrate:propionate ratio but the opposite effect was observed with the oat-based diet.     

Evaluation of ground grain versus pre- and post-pellet whole grain additions to poultry diets via a response surface design

1. The objective of this study was to compare the effects of pre- and post-pellet whole grain wheat additions to diets on growth performance, gizzard and pancreas development, nutrient utilisation and starch and protein (N) digestibility coefficients in broiler chickens via an equilateral triangle response surface design.

2. The three apical treatments of the equilateral triangle comprised (1A) a standard diet containing 600 g/kg ground wheat, (2B) the same diet containing 600 g/kg pre-pellet whole wheat and (3C) the same diet containing 300 g/kg ground wheat and 300 g/kg post-pellet whole wheat. Seven blends of the three apical diets were located within the triangle to complete the design and a total of 360 male Ross 308 chicks were offered the ten experimental diets from 7 to 28 d post-hatch. Model prediction and response surface plots were generated with R 3.0.3 software.

3. The most efficient FCR of 1.466 was observed in birds offered an almost equal mixture of the pre- and post-pellet whole grain apical dietary treatments, which corresponded to 172 g/kg ground grain, 256 g/kg pre-pellet whole grain, 172 g/kg post-pellet whole grain in a diet containing 600 g/kg wheat.

4. The most efficient energy utilisation (ME:GE ratio of 0.766) was observed in birds offered a blend of the ground grain and pre-pellet whole grain apical dietary treatments which corresponded to a mixture of 384 g/kg pre-pellet whole grain and 216 g/kg ground grain.

5. Pre-pellet whole grain feeding generated the most pronounced responses in increased relative gizzard contents, reduced gizzard pH and increased relative pancreas weights. Consideration is given to the likely differences between pre- and post-pellet whole grain feeding.     

Nutritive characteristics of pearl millet grain in beef cattle diets

Two trials were conducted to compare pearl millet grain with corn and grain sorghum in cattle diets. Grain portions of diets in metabolism and feedlot experiments contained 73% corn and 6% soybean meal (C); 76.2% grain sorghum and 2.8% soybean meal (GS); and 79% pearl millet (PM). In the metabolism trial (replicated 3 x 3 latin squares; six steers), apparent digestibilities of DM and OM were higher (P less than .05) for C than for GS or PM diets. Ether extract and CP digestibilities were higher (P less than .05) for C and PM than GS. Dietary TDN was higher (P less than .05) for C compared with GS or PM diets. Fecal N was higher (P less than .05) for GS than for C or PM, urinary N was higher (P less than .05) for PM than C or GS, but retained N was similar (P greater than .05) for C, GS and PM diets. In a 90-d feedlot trial (18 individually fed heifers), a trend was observed for higher (P less than .20) ADG on C compared with PM; however, feed/gain was similar for C, GS and PM diets (8.2, 9.1 and 8.5 kg feed/kg gain, respectively). Ruminal fluid acetate:propionate ratios were lower (P less than .05) at 3.5 and 7 h postfeeding for PM compared with C or GS diets on d 83. Pearl millet grain may be used as a feed grain for beef cattle, but diets should be formulated to efficiently utilize the high quantity of protein (about 14% of DM) in this grain as a substitute for supplemental protein.