Effects of whole wheat feeding on the development of the digestive tract of broiler chickens

Effect of dietary coarsely ground corn on broiler live performance, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and digesta particle size distribution and retention time

Dietary structural material has been reported to improve broiler live performance and gastrointestinal tract (GIT) function. In this 50 d cage study, the effects of coarsely ground corn (CC) inclusion on broiler live performance, GIT development, apparent ileal digestibility (AID) of energy and nitrogen (N), and digesta particle size distribution and retention time were investigated. This study included 3 CC inclusions (0, 25, and 50% fine corn [FC] replaced by CC), with 6 replicate cages of 10 birds per treatment. The feed conversion ratio (FCR) at 35 and 42 d was improved (P<0.01) as the dietary inclusion of CC increased without effect on feed intake. The 50% CC diet increased absolute and relative gizzard weight at 42 d of age as compared to diets with 0 and 25% CC (P<0.01). Dietary CC increased absolute proventriculus weight at 28 d of age (P<0.05). A numerically lower gizzard digesta pH (P<0.08) was observed at 28 d but not 42 d of age, and there was no difference in proventriculus, jejunum, or ileum digesta pH at 28 or 42 d of age. The 25 and 50% CC treatments increased the digesta retention time at 30 and 45 d of age (P<0.05 and P<0.01, respectively). The 25 and 50% CC treatments improved AID of energy by 7.1 and 8.2%, respectively, when compared with the 0% CC treatment, and they improved AID of N by 12.2 and 12.4%, respectively (P<0.01). The digesta particles in the jejunum exhibited a similar distribution, with a dgw (geometric mean diameter by mass) of 218, 204, and 181 μm when 0, 25, of 50% CC diets were consumed, respectively. In conclusion, birds fed pelleted and screened diets that contained 25 and 50% CC exhibited increased BW, improved FCR, and increased AID of energy and N, which was probably due to enhanced gizzard development and greater digesta retention time.

Whole-grain feeding for chicken-meat production: possible mechanisms driving enhanced energy utilisation and feed conversion

The practice of offering some whole grain to broiler chickens alongside a balancing concentrate is meeting increasing acceptance in certain regions, including Europe, Canada and Australia. Whole-grain feeding (WGF) regimes provide economic advantages by effectively reducing feed costs but, to varying extents, WGF regimes also generate improvements in energy utilisation and feed conversion efficiency. However, the context in which these improvements are best realised has yet to be defined adequately. The outstanding response to WGF is the development of heavier relative gizzard weights; however, the causative factors and biophysical and biochemical consequences of heavier, and presumably more functional, gizzards have not been properly investigated. It follows that heavier gizzards would enhance the initiation of protein digestion by pepsin and hydrochloric acid and facilitate amylase-induced starch digestion in the small intestine by the prior physical disruption of starch granules. However, it appears that improvements realised by WGF in energy utilisation and feed efficiency cannot be attributed entirely to heavier gizzards. One alternative or additional possibility is that WGF may influence starch digestive dynamics and provide more gradually or slowly digestible starch, which would benefit energy utilisation and feed efficiency. However, if this is the case, the genesis of this provision is not clear, although it may be associated with larger grain particle sizes and/or increased episodes of reverse peristalsis, but not retarded gut passage rates. The present paper reviews the essentially positive impacts of WGF on energy utilisation and feed conversion efficiency and considers the contexts in which these responses may be best realised and the possible mechanisms driving better performance under WGF regimes for chicken-meat production.

Influence of prepelleting inclusion of whole corn on performance, nutrient utilization, digestive tract measurements, and cecal microbiota of young broilers

The objective of the present study was to examine the effects of prepelleting inclusion of graded levels of whole corn on performance, digestive tract measurements, nutrient utilization, and cecal microbiota in broiler starters. Five diets, containing 600 g/kg of ground corn or 150, 300, 450, and 600 g/kg of whole corn replacing (wt/wt) ground corn, were formulated and cold-pelleted at 65°C. Each diet was offered ad libitum to 6 replicates (8 birds per replicate cage) from d 1 to 21 posthatch. The proportion of coarse particles (>1 mm) increased with increasing prepelleting inclusion of whole corn. Pellet quality, measured as pellet durability index, increased (quadratic effect, P < 0.001) with the inclusion of whole corn to 450 g/kg and then plateaued. Weight gain and feed intake decreased (linear effect, P < 0.001) with increasing prepelleting inclusion of whole corn. Feed per gain (quadratic effect, P < 0.05) increased as the inclusion level of whole corn increased to 300 g/kg and then plateaued with further inclusions. Relative gizzard weight (quadratic effect, P < 0.05) increased with increasing inclusion of whole corn up to 300 g/kg and then levelled off. The AME (quadratic effect, P < 0.05) increased up to 300 g/kg of whole corn inclusion and then decreased with further inclusion. Apparent ileal digestibility of DM (P < 0.001), N (linear effect, P = 0.07), and starch (linear effect, P < 0.001) increased with increasing inclusion levels of whole corn. Based on the fluorescence in situ hybridization method, a linear (P < 0.05) effect was determined for cecal microbiota numbers. Lactobacillus spp. counts increased and counts of Clostridium spp., Campylobacterium spp., and Bacteroides spp. decreased with increasing inclusion levels of whole corn. The present data showed that, despite increased gizzard weight and nutrient utilization, weight gain of broilers was poorer with prepelleting inclusion of whole corn due to reductions in the feed intake.

The influence of choice feeding and cereal type (corn or triticale) during the finishing period on performance of mule ducks

The aim of this trial was to study the influence of choice feeding and cereal type (corn or triticale) during the finishing period on performance of ducks. In total, 624 one-day-old male mule ducks (Cairina moschata × Anas platyrhynchos) were divided into 3 groups differing in the diet they received between 56 and 84 d of age: a commercial complete pelleted diet (control group; AMEn 12.1 MJ/kg, CP 15%), or corn whole seeds (AMEn 14.4 MJ/kg, CP 7.3%) and protein-rich pellets (AMEn 9.9 MJ/kg, CP 22.7%) in 2 separated feeders [choice feeding with corn (CFC) group]; or triticale whole seeds (AMEn 13.0 MJ/kg, CP 10.5%) and protein-rich pellets (AMEn 11.2 MJ/kg, CP 19.5%) in 2 separated feeders [choice feeding with triticale (CFT) group]. From 85 to 96 d, 96 birds/group were overfed with corn. Feed intake (complete pellets or cereal and protein-rich pellets) per pen was measured at 60, 62, 65, 69, 78, and 84 d of age. Body weight and body traits were measured at 56 to 84 d of age. Over the entire period, from 56 to 84 d, the feed intake of the CFC group was 7% lower than the control group, and 5% lower than that in the CFT group (P = 0.002). Whatever the diet tested, at 56 and 84 d of age, the BW (4,099 and 4,779 g, P = 0.42 and P = 0.35, respectively) and the carcass traits (P > 0.05) of ducks were similar in the 3 groups. During and after overfeeding, the performances of the ducks were also similar (P > 0.05). The present results suggest that CFC during the finishing period is a solution to reduce the cost of diet destined to ducks. Indeed, using locally grown grains could reduce the economic and environmental impacts of duck feeding, reducing the transportation and crushing processes.

Effects of grinding method, particle size, and physical form of the diet on gastrointestinal morphology and jejunal glucose transport in laying hens

Several studies illustrated that the structure of feed, i.e., the particle size, particle-size distribution, and the physical form of the diet, affects the avian gastrointestinal function and health leading to changes in productive performance. However, investigations concerning the effects of feeding differently processed diets on laying hens are limited and primarily concentrated on bird performance. The current study examines the effect of feed processing on the gastrointestinal morphology and on the jejunal glucose transport of laying hens. In 8 replicates, a total of 384 hens (Lohmann Brown) aged 20 wk were randomly allocated to 8 different groups and fed over a period of 21 d in a 3-factorial design. Diets differed in 1) grinding method, either hammer or roller mill; 2) physical form, either mash or expandate; and 3) particle size, either coarsely or finely ground. During the experimental trial, the laying performance of each feeding group was recorded daily and the feed intake and BW determined weekly. After slaughtering, the weights of the pancreas, proventriculus, gizzard, and small intestine were measured. Villus lengths and crypt depths of the duodenum, jejunum, and ileum were determined. The jejunal electrogenic glucose transport was studied in Ussing chambers. Hens that received mash instead of expandate had higher proventriculus (P = 0.011), gizzard (P < 0.001), and pancreas (P = 0.019) weights, whereas the feeding of coarsely instead of finely ground diets led to higher gizzard weights (P < 0.001). Mash-fed hens showed longer duodenal (P < 0.001) and shorter ileal villi (P = 0.047) and increased duodenal villus height-to-crypt depth ratios (P < 0.001) than those given the expandate. Mash-fed hens had higher glucose transport rates than expandate-fed hens (P < 0.001). In conclusion, the feeding of coarsely ground as well as mash diets had stimulating effects on the development of the gastrointestinal organs. Moreover, the feeding of mash influenced the intestinal microstructure of the epithelium that was accompanied by higher glucose transport capacities.

Effect of feeding diets based on coarse maize on productive performance, gizzard development and energy utilisation of laying hens

1. A total of 2200 White Leghorn layers were used to study the effect of feeding coarse maize on productive performance, gizzard weight, apparent metabolisable energy (AME) and egg quality parameters. 2. The experiment was a completely randomised design with 5 treatments, each being replicated 5 times (88 birds per replicate). Dietary treatments included a control diet with 600 g/kg of ground maize (6 mm sieve) and experimental diets with 150, 300, 450 or 600 g/kg coarse maize (10 mm sieve) replacing (w/w) ground maize. Diets, in mash form, were offered from 39 to 62 weeks of age. 3. Over the entire experimental period, dietary treatments had no effect on any of the production parameters, except on feed intake. A quadratic effect was observed for feed intake, where intake increased at 150 g/kg coarse maize inclusion. At higher inclusion levels of coarse maize, feed intake was similar to that of the control diet. But the differences in daily intake between dietary treatments were only around 1 g/bird and may not be of any biological significance. 4. Dietary treatments had no effect on gizzard weight, AME or egg quality. 5. The results indicate that coarse maize could completely replace maize in layer diets with no adverse effect on egg production, egg quality and dietary energy utilisation. In the current work, although the proportion of coarse particles (over 1 mm) increased with increasing inclusion levels of coarse maize, the differences in the percentage of particles above 1 mm between the fine control (0 g/kg coarse maize) and coarsest (600 g/kg coarse maize) diets was only 15%, and this may limit the value of the findings reported herein.

Effects on performance of ground wheat with or without insoluble fiber or whole wheat in sequential feeding for laying hens

Sequential feeding (SF) is an innovative system for laying hens consisting of nutrients separating energy, protein, and calcium supplies to fulfill nutrient requirements at the relevant time of day. In previous studies, hens received whole wheat in the morning and a balancer diet (rich in protein and calcium) in the afternoon. To improve SF utilization, the aim was to substitute whole wheat in the morning by an alternative energy supply: ground wheat and ground corn, with or without a proportion of whole wheat and insoluble fiber. The goal was to obtain the advantages observed in previous experiments with whole wheat [bigger gizzard, thinner hens, reduced feed conversion ratio (FCR)]. Four hundred thirty-two ISA Brown hens were housed in collective cages from 20 to 35 wk of age divided into 8 different treatments: a continuous control diet, a sequential diet with whole wheat in the morning, 3 wheat-based diets (ground wheat, ground wheat and 20% whole wheat, and ground wheat with 5% insoluble fiber) and 3 ground corn-based (ground corn, ground corn and 20% whole wheat, and ground corn with 5% insoluble fiber) provided in the morning. All sequential regimens received the same balancer diet rich in protein and calcium in the afternoon. Whole wheat SF gave the best results with an improved FCR compared with continuous control and all other SF diets. Wheat- and corn-based diets showed intermediate results between whole wheat SF and continuous feeding. Gizzard weight was higher and hens were lighter than with conventional continuous feeding, leading to an average FCR improvement of 3.2% compared with a continuous control. Thus, it is possible in SF diets to substitute, at least partially, whole wheat by ground wheat or ground corn with added insoluble fiber or some whole wheat, allowing more flexibility and economic optimization.

Influence of feeding sorghum on the growth, gizzard development and carcass traits of growing geese

The aim of this trial was to study the influence of feed form on the performance, gizzard development and carcass traits of growing geese. Between 42 and 98 days of age, 360 geese (type Maxipalm(®)) were fed a diet containing 500 g sorghum/kg (nitrogen-corrected apparent metabolizable energy 12.6 MJ/kg, 15.1 g/kg CP). Birds were divided into three groups differing in feed form: complete pellets (Control group, n = 120); a coarse-ground meal (CG group, n = 120); or a mixture containing protein-rich pellets and sorghum whole grains (M group, n = 120). Feed intake per pen (40 birds/pen) was measured weekly between 42 and 98 days of age, and individual live weight (LW) was measured every 2 weeks. At 84 and 98 days of age, 12 birds were slaughtered in each group to measure the gizzard development and body traits. Irrespective of the goose sex, LW at 98 days was lower for the CG group than for the Control group (5555 v. 5888 g, P < 0.05 for males and 5039 v. 5215 g, P < 0.05 for females). The feed intake over the entire period was 5.5% higher in the M group (P < 0.05) than in the Control and CG groups but the feed conversion ratio (6.91, P > 0.05) was similar in the three groups. The gizzard development (as % of LW) was higher in birds of the CG group than those of the Control and M groups at 84 days of age (+13.98% and +13.51%, respectively; P < 0.05) but was similar in all three groups at 98 days of age (4.01%, P > 0.05). The relative liver development was lower in the birds of the CG group than those of the other two groups at 84 and 98 days of age (-20%, P < 0.001 and -10%, P < 0.05, respectively). The other body traits were similar in the three groups at both 84 and 98 days of age. The present results suggest that a simplified diet presented in the form of a mixture of sorghum whole grains and protein-rich pellets did not reduce the performance of growing geese.

Influence of graded levels of brewers dried grains on pellet quality and performance in broiler chickens

The aim of the current study was to evaluate the effect of a gradual substitution of wheat and soy with brewers dried grains (BDG) on pellet quality, performance, and organ weights in broiler chickens. Five diets were formulated in which 0, 10, 20, 30, or 40% BDG replaced wheat and soy, with a concomitant gradual reduction in the calculated AME level. Each of the 5 experimental diets was fed to 12-d-old broiler chickens (Ross 308) kept in 6 pens, with 12 birds/pen. The birds had ad libitum access to feed and water until termination of the experiment at d 33. Feed intake was not affected by BDG inclusion and compensatory feed intake did not occur, perhaps having been neutralized by a significant (P < 0.001) reduction in the pellet durability index. The pellet durability index was 85% in the control diet (0% BDG) and decreased significantly (P < 0.001) to 68% in the diet with 40% BDG. Increased levels of BDG reduced BW gain significantly (P < 0.001) and led to a significant (P < 0.001) increase in the feed:gain ratio. The feed:gain ratio was significantly (P < 0.05) higher in birds fed 30 and 40% BDG compared with birds fed 0, 10, and 20% BDG. The apparent ileal digestibility values of protein and energy were significantly reduced by BDG inclusion (P < 0.01 and P < 0.001, respectively), whereas starch digestibility increased significantly (P < 0.001). The relative gizzard weight increased significantly (P < 0.001), whereas the relative cecal weights were not affected by BDG inclusion. To conclude, 10 to 20% inclusion of BDG supports acceptable growth and feed utilization, and favors the development of a well-functioning gizzard.