A study was conducted to investigate the effect of method of whole wheat inclusion on performance and caecal microbiota profile of broiler chickens. Fluorescence in situ hybridisation analysis was used to characterise the microbiota by using genus-specific probes. Three treatments, namely, ground wheat (GW) or 200 g/kg whole wheat (WW) replacing GW before or after pelleting were evaluated. A total of 144, one-day-old male broilers (Ross 308) were allocated to 18 cages (eight broilers per cage) based on body weight and six cages were randomly assigned to each treatment. The diets were offered ad libitum from day 11 to 35 post-hatch. The WW fed birds, regardless of the method of inclusion, resulted in poorer weight gain (P < 0.05) and reduced feed intake (P < 0.001), but a similar feed per gain (P > 0.05) compared to those fed the GW diet. The WW diet, regardless to the method of inclusion, had no effect (P > 0.05) on the populations of Lactobacillus and Bacteroides spp. compared with the GW diet. The Bifidobacterium spp. population was higher (P < 0.05) in birds fed the GW diet compared with WW feeding, regardless of the method of inclusion. A reduction (P < 0.05) in the numbers of pathogenic Clostridium and Campylobacter spp. were observed in caecal samples from birds fed WW diets, regardless of method of inclusion, compared with those fed the GW diet, which was attributed to increased gizzard activity. Birds fed WW diets, regardless to the method of inclusion, showed a reduction in gizzard pH (P < 0.05), microbial gas production (P < 0.05), and an increase in gizzard weight (P < 0.05) relative to the GW treatment. The results indicated that the gizzard has an important function as a barrier organ, one that prevents pathogenic bacteria from entering the distal digestive tract.

The impact of sequential feeding of whole or ground wheat on the performance of layer hen was investigated using ISABROWN hens from 19 to 42 weeks of age. In addition, the effect of reduced dietary energy content of a complete diet was also investigated. Four treatments were tested. Whole wheat was alternated with a protein–mineral concentrate (balancer diet) in a treatment (sequential whole wheat: SWW), while another treatment alternated ground wheat (sequential ground wheat: SGW) with the same balancer diet. The control (C) was fed a complete layer diet conventionally. Another treatment (low energy: LE) was fed a complete diet conventionally. The diet contained lower energy (10.7 v. 11.6 MJ/kg) compared to the C. Each treatment was allocated 16 cages and each cage contained five birds. Light was provided 16 h daily (0400 to 2000 h). Feed offered was controlled (121 g/bird per day) and distributed twice (2 × 60.5 g) at 4 and 11 h after lights on. In the sequential treatment, only wheat (whole or ground) was fed during the first distribution and the balancer diet during the second distribution. Left over feed was always removed before the next distribution. The total feed intake was not different between SWW and SGW, but the two were lower than C (P < 0.05). Wheat intake was however, lowered with SGW compared to SWW (P < 0.05). Egg production and egg mass (EM) were not different between treatments. Egg weight was lower with SGW than with SWW (P < 0.05), but the two were similar to C. Body weight (BW) was lowered (P < 0.01) with SGW relative to SWW and C, SWW BW being also lower than the C one. The efficiency of egg production was increased (P < 0.01) with the SWW and SGW relative to the control. Birds fed LE had higher feed intake (P < 0.05) but they had similar egg production and EM compared to the two sequential treatments. The efficiency of feed utilization was also reduced (P < 0.01) with LE compared to SWW and SGW. It was concluded that sequential feeding is more efficient than conventional feeding. In addition, whole wheat appeared more efficient than ground wheat in terms of egg and BW.

Structural characteristics and baking conditions influence the metabolic responses to carbohydrate-containing foods. We hypothesized that consumption of whole wheat or sourdough breads would have a favourable effect on biomarkers of glucose homeostasis after first and second meals, compared with those for white bread. Ten overweight volunteers consumed 50 g available carbohydrate of each of the four breads (white, whole wheat, sourdough, whole wheat barley) followed 3 h later by a standard second meal. Blood was sampled for 3 h following bread ingestion and a further 2 h after the second meal for determination of glucose, insulin, paracetamol (indirect marker of gastric emptying), glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Glucose and GLP-1 responses to sourdough bread were lower (P < 0·05) than whole wheat and whole wheat barley breads. Glucose area under the curve (AUC) for sourdough bread was lower than those for whole wheat (P < 0·005) and whole wheat barley (P < 0·03) breads for the entire study. GIP AUC after sourdough bread ingestion was lower compared to white (P < 0·004) and whole wheat barley (P < 0·002) breads following the second meal. There were no significant differences in insulin and paracetamol concentrations among the test breads. Ultra-fine grind whole wheat breads did not result in postprandial responses that were lower than those of white bread, but sourdough bread resulted in lower glucose and GLP-1 responses compared to those of these whole wheat breads following both meals.

To test the hypothesis that inclusion of whole cereals in the diet of broiler chickens reduces the severity of a coccidial infection, the effects were investigated, in birds infected with Eimeria acervulina, of feeding a complete pelleted control food, the control food diluted with whole wheat (400 g/kg), or a diet in which ground wheat in the pellets was substituted with whole wheat (400 g/kg) so as to achieve the same composition as the control diet. In the weeks prior to and after infection, (days 14–20 and days 21–27), no significant differences in performance were observed between birds fed the complete pellet and substituted feeds. Birds fed the diluted feeds had significantly lower gains per unit of feed and numerically lower weight gains than the birds fed the control and substituted feeds during this period. No significant differences in performance were observed between treatments from days 28–34. Diluting feeds with whole wheat (400 g/kg) significantly increased ileal digesta viscosity levels, compared with feeding the control and substituted feeds in birds dissected on day 21, although no significant differences in digesta viscosity levels were observed in birds dissected on day 35. Whole wheat feeding, either by dilution or substitution, significantly increased gizzard sizes in birds dissected on day 21 and day 35. Neither dilution nor substitution of feeds with whole wheat (400 g/kg) significantly affected the level of an Eimeria acervulina infection, as measured by daily and total faecal oocyst yields.