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Five experiments were conducted to determine Lys and P bioavailabilities of distillers dried grains with solubles (DDGS), which was derived from corn fermentation in a modern nonbeverage ethanol plant. In experiment 1, we used the precision-fed cecectomized rooster assay and estimated the true digestibility of Lys in DDGS to be 75%. In experiments 2, 3, 4, and 5 the relative bioavailabilities of Lys and P were assessed using slope-ratio chick growth experiments. In experiments 2 and 3, Lys-deficient basal diets containing 0.40 or 0.60% digestible Lys respectively, were formulated. A linear growth response (P < 0.05) was observed from the addition of 0.10 and 0.20% L-Lys from L-Lys x HCl and 10 and 20% DDGS to the basal diets. Body weight gain was regressed on Lys intake from L-Lys x HCl and DDGS, and the ratio of the slopes indicated the relative bioavailable Lys in DDGS. The values as a percentage of total Lys (0.83) in DDGS yielded availability estimates of 80% for experiment 2 and 100% for experiment 3. In experiments 4 and 5, a P-deficient basal diet containing 0.12% nonphytate P was formulated. A linear growth and tibia bone ash (%) response (P < 0.05) were observed from the addition of 0.05 and 0.10% P from K2HPO4 and 2 levels of DDGS (5 and 10% for experiment 4 and 7 and 14% for experiment 5). Tibia bone ash (%) was regressed on P intake from K2HPO4 and DDGS, and the ratio of slopes indicated the relative bioavailability of P in DDGS. The values as a percentage of total P (0.74%) in DDGS yielded availability estimates of 68% for experiment 4 and 54% for experiment 5.

SUMMARY A major emphasis on ethanol production in the US has led to the construction of new ethanol plants and an increased production of distillers dried grains plus solubles (DDGS). In the past DDGS came largely from the beverage industry and consisted of several grains used during fermentation. Recently, a majority of the DDGS produced is from corn fermentation for ethanol production. Little research has been conducted to test the use of this new generation DDGS from modern ethanol plants in laying hen diets. Hy-line W-36 laying hens were used to test an elevated inclusion level of DDGS from modern ethanol plants that can be incorporated into layer diets. Hens were fed a commercial or low-density diet formulated to contain 0 or 15% DDGS for 25 to 43 wk of age. No differences were observed in the majority of parameters evaluated between hens fed 0% or 15% DDGS. However, there was a significant (P < 0.05) reduction in hen-day egg production through 35 wk of age when hens were fed the low-density diet with 15% DDGS. Hens fed the commercial diet with 15% DDGS had numerically lower egg production to 32 wk of age, but this was not statistically significant. Distillers dried grains plus solubles proved to be an acceptable feed ingredient for laying hen diets. A suggested maximal inclusion level of 10 to 12% DDGS, based on these data and previous research, may be used in commercial diets, but it is speculated that DDGS should be incorporated at lower levels in low-density diets.

When decreasing the energy value of broiler diets, nonstarch polysaccharide degrading enzymes, such as xylanase, are often used. In doing so, they are assigned an energy value and considered to contribute energy to the diet. The aim of this study was to determine the effect of decreasing energy in a broiler diet by 100 kCal/kg on performance and whether the expected drop in performance could be recovered with the use of xylanase. Two formulations were used to provide decreased energy diets, both with and without supplementary fat. Six hundred 1-d-old male Cobb broilers were placed in a 2 × 3 full factorial design in 5 randomized complete blocks. The treatments were enzyme dose at 0 or 16,000 U/kg, and the 3 different diets [positive control (PC), negative control 1, without fat (NC1), and negative control 2 with fat (NC2)]. At no point were there any interactions between diet type and enzyme inclusion; where there was an effect of xylanase, it was consistent regardless of the diet type. There was a significant effect of diet type on feed intake between d 0 to 35; NC1 and NC2 had significantly increased feed intake compared with the PC (P = 0.006). The feed conversion ratio was significantly increased in birds fed the negative control diets during 0 to 35 d and 0 to 42 d (P = 0.003 and P = 0.002, respectively). However, feed conversion ratio was significantly improved by the addition of enzyme during periods 0 to 35 d and 0 to 42 d. There were no significant main effects between d 0 and 21 (all responses P > 0.1). Liveability was not affected by any of the treatments (P > 0.1). Decreasing energy in broiler diets results in worsened performance. The use of xylanase may improve feed conversion ratio. The use of some fat may help, so the whole diet composition should be considered in conjunction with enzyme dose to achieve the best advantage.

The gastrointestinal tract (GIT) of each animal species provides a unique niche for specialized intestinal bacterial communities to thrive, and in poultry this is no exception. However, little is known about how the bacterial community varies among these different genetic lines of chickens, especially of those with various growth rates. Therefore, an experiment was conducted to observe and evaluate the changes in the bacterial community and GIT development of a modern multipurpose strain, high-yield strain, and a historic strain, Athens Canadian Random Bred (ACR), of broilers. All birds were fed a standard nonmedicated corn-soybean meal broiler starter diet ad libitum from 0 to 35 d of age. Intestinal measurements and bacterial analysis of the ileum were conducted at 4, 8, 14, 21, and 35 d of age. Bacterial DNA was isolated from the digesta, and the distribution of bacterial 16S rRNA sequence polymorphisms was analyzed by a combination of denaturing gradient gel electrophoresis and terminal restriction fragment length polymorphisms. The multipurpose chicks performed the best from 0 to 14 d of age; however, overall performance was similar for the multipurpose and the high-yield broilers. The ACR birds had the poorest performance at all periods measured. The overall relative weight of the jejunum and ileum was not different between the 3 genetic lines, but the ACR birds had the longest relative jejunum and ileum lengths. Furthermore, the multipurpose birds had the longest villi height, whereas the ACR birds had the shortest villi height in the jejunum and ileum at all measuring periods. Based on denaturing gradient gel electrophoresis, the multipurpose and high-yield broilers had similar bacterial communities at all ages. Regardless of the genetic line of broiler, the bacterial community changed with age. Performance, GIT measurements, and bacterial community of the ACR differed compared with the modern broilers. The results indicate that the different genetic lines of broilers have varying rates of intestinal development, which may affect performance and the bacterial community.

The effect of gender on the growth, carcass yield, and nutritional requirements of chickens has been well documented, but little is known about how the sex of a chicken affects the bacterial population of the gastrointestinal tract. Therefore, our objective was to evaluate the biodiversity of the bacterial community in the gastrointestinal tract of male and female broilers. An experiment was conducted with Cobb 500 broiler chicks that were vent sexed at 0 d of age and allocated to 8 pens of 25 chicks per gender. All birds were fed a nonmedicated corn-soybean meal starter diet from 0 to 21 d of age. At 3, 7, 14, and 21 d of age, chicks were randomly selected and ileums were taken for bacterial sampling. Bacterial DNA was isolated from the digesta of the ileum, and denaturing gradient gel electrophoresis was used to examine PCR-amplified fragments of 16S ribosomal DNA. Denaturing gradient gel electrophoresis analyses revealed that the bacterial communities separated into 2 gender-specific groups, with less than 30% similarity between populations. Furthermore, as the birds aged, the similarity of the intestinal bacterial community decreased within each gender. Although ileal bacterial population differences within and between genders were noted as early as d 3, differences in growth rate between males and females were not noted until d 21 (data not shown). This suggested that non-growth-related factors influenced the composition of intestinal bacterial communities.

Four experiments (Exp.) were conducted with Cobb 500 chicks to evaluate variations in the estimated digestible sulfur amino acid (DSAA) requirement of broilers due to rearing environment, sex, or growth performance during the starter period (7 to 19 d), and live performance response and carcass yield characteristics during the grower period (21 to 42 d). In the first 3 experiments conducted during the starter period, chicks were allocated to battery or floor pens, and in the fourth experiment birds were reared in floor pens. For Exp. 1, 2, and 3 a sulfur amino acid deficient corn-soybean meal-corn gluten meal basal diet and for the grower experiment a corn-soybean meal-peanut meal basal diet was formulated to be isocaloric and isonitrogenous within experiment. Graded levels of DSAA ranged from 0.54 to 0.94% in Exp. 1, 0.53 to 1.03% in Exp. 2, 0.49 to 0.89% in Exp. 3, and 0.43 to 0.83% in Exp. 4. True digestibility of the diets was determined using the precision-fed rooster assay. The DSAA requirements were estimated using 1-slope broken-line methodology. During the starter period, the average DSAA requirement of males and females was similar when based on the gain to feed ratio (G:F; 0.71 and 0.71%, respectively) and BW gain (BWG; 0.67 and 0.67%, respectively). In Exp. 3 involving battery and floor pens, males and females had similar DSAA requirement estimates, but the DSAA requirement based on maximal G:F (0.68%) was higher than the maximal BWG requirement (0.61%). In the grower period, the estimated DSAA requirement for males based on G:F was higher than that based on BWG, but the BWG and G:F requirements were similar for females. The DSAA requirement estimates were similar for males and females based on BWG (0.55%), but the DSAA requirement based on G:F was higher for males than females. The DSAA requirement for maximum breast meat yield was similar for males (0.55%) and females (0.56%), and the requirement for maximal breast meat yield was similar to that for maximal BWG. The DSAA requirements were similar based on sex, rearing environment, or both; however, there was a difference in the estimated DSAA requirements between growth and carcass responses.

Two experiments were conducted to evaluate the use of distillers dried grains with solubles (DDGS) from modern ethanol plants in broiler diets. Experiment 1 was a 2 x 2 factorial experiment with diets containing 2 levels of DDGS (0 and 15%) and 2 diet densities (high and low). The high- and low-density diets were formulated to contain 22% CP and 3,050 kcal MEn/kg and 20% CP and 3,000 kcal MEn/kg, respectively. Eight pens of 6 chicks were fed an experimental diet from 0 to 18 d of age. Weight gain and feed efficiency (gain:feed ratio) of the chicks receiving the high-density diets were (P0.05) better than those of chicks fed the low-density diets. However, within the 2 density levels there was no difference in performance of chicks fed diets with 0 or 15% DDGS. In experiment 2, 6 replications of 50 chicks were fed 1 of 4 dietary treatments for 42 d. The diets were formulated to be isocaloric and isonitrogenous and contained 0, 6, 12, or 18% DDGS. There was no significant difference in performance or carcass yield throughout the 42 d experiment except for a depression in BW gain and feed conversion when chicks were fed diets with 18% DDGS in the starter period. These studies indicate that DDGS from modern ethanol plants is an acceptable feed ingredient for broiler diets and can be safely used at 6% in the starter period and 12 to 15% in the grower and finisher periods.