Additivity of apparent and standardized ileal digestibility of phosphorus in mixed diets containing corn and soybean meal fed to broiler chickens.

Phosphorus (P) is an integral part of diet formulation for broiler chickens as P is required for various biochemical processes essential to life. A study was designed to examine the additivity of apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of P in mixed diets containing corn and soybean meal (SBM) with or without phytase supplementation. Birds were fed a commercial starter diet from day 0 to 21 after hatching and then allotted to 7 dietary treatments in a randomized complete block design with the BW as a blocking factor. Four semipurified diets were prepared to contain corn or SBM as the sole source of P with or without the addition of phytase at 1,000 phytase units/kg of diet. Two mixed diets were also prepared to contain corn and SBM with or without the addition of phytase at 1,000 phytase units/kg diet. A P-free diet (PFD) was formulated to determine the basal ileal endogenous loss of P. There were 16 replicate cages of the PFD and 8 replicate cages of the 6 experimental diets, with 8 birds per replicate cage for a total of 512 birds. Diets were fed for 3 d. The ileal digesta of birds were collected from the distal two-thirds of the ileum on day 24 after hatching. The SID of P in corn and SBM were 52.2 and 65.4%, respectively (SEM = 1.37). The addition of phytase improved (P < 0.05) both the AID and SID of P in the corn, SBM, and mixed diets. The determined AID or SID in the corn and SBM with or without phytase was used to predict the AID or SID in the mixed diets. There were no differences between the predicted and determined digestibility values in the mixed diets for either AID or SID of P and thus additive. Phytase supplementation of the mixed diet did not influence the additivity of AID or SID. In conclusion, the AID or SID of P in the corn and SBM was additive in the mixed diets containing corn and SBM with or without the addition of phytase.

Chitosan oligosaccharide supplementation alleviates stress stimulated by in-feed dexamethasone in broiler chickens.

This experiment was conducted to investigate the effect of dietary chitosan oligosaccharide (COS) on growth performance, nutrient digestibility, jejunal morphology, gene expression, and plasma antioxidant enzymes in male broiler chickens under experimentally induced stress via in-feed dexamethasone (DEX). On day 3 after hatching, male broiler chicks were assigned to 2 diets supplemented with COS at 0 or 1 g/kg in a randomized complete block design and fed to day 27 after hatching. Birds were pooled within each diet (0 or 1 g/kg COS) to equalize the average BW and fed 2 diets supplemented with 0 or 1 g/kg DEX, within each dietary COS, from day 20 to 27 after hatching. This resulted in a 2 × 2 factorial arrangement of treatments with 2 levels each of COS and DEX, 8 replicate cages of 7 birds per cage. On day 27 after hatching, birds were weighed and euthanized, and samples were collected. Dietary COS decreased (P < 0.05) DEX-induced effects (interaction; P < 0.05) on BW, BW gain, and gain:feed. Dietary COS supplementation attenuated the DEX effects (interaction; P < 0.05) on villus height, crypt depth, villus height to crypt depth ratio, and ileal digestibility of dry matter and energy. The DEX-induced effect of relative mRNA expression of jejunal mucosa IL-6, IL-10, and claudin-1 was reduced by dietary COS supplementation (interaction; P < 0.05). Responses (interaction; P < 0.05) in the activity of plasma superoxide dismutase, catalase, and glutathione peroxidase to COS and DEX were similar to those observed with the relative mRNA expression. Chitosan oligosaccharide supplementation increased (P < 0.05) the mRNA expression of IL-8 and occludin. In conclusion, dietary COS decreased the DEX-induced effect by improving growth performance, nutrient digestibility, jejunal morphology, gene expression, and plasma antioxidant enzymes in broiler chickens. This implies that dietary COS may be useful for ameliorating the negative effect of stress on gut health in broiler chickens.

Impact of dietary chitosan oligosaccharide and its effects on coccidia challenge in broiler chickens.

1. Two experiments were conducted, the first to determine the optimum inclusion of chitosan oligosaccharide (COS) in broiler diets to support growth performance, digestive functions, intestinal morphology, and immune organs. The second experiment evaluated the immune-protective properties of COS on broiler chickens during coccidia challenge (CC).2. Experiment 1 investigated the effect of graded dietary concentration of COS in the diets of broiler chickens using eight cage replicates for each of the six diets. A corn-soybean meal-based diet was used as the basal diet and supplemented with 0.0, 0.5, 1.0, 1.5, 2.0, or 2.5 g of COS/kg feed to form the six treatments.3. The diet supplemented with 1.0 g COS/kg of feed provided the optimal inclusion level for broiler chickens regarding body weight (BW) gain, jejunal villus height, villus height to crypt depth ratio, and ileal energy digestibility at d 22 of age.4. Experiment 2 investigated the immune-protective properties of COS in broiler chickens during CC. A total of 224 male broiler chicks were randomly assigned to eight replicate cages in a 2 × 2 factorial arrangement of treatments with two COS concentrations (0 or 1 g of COS/kg of diet), with or without CC.5. On d 18 of age, birds in the CC group received twice the recommended coccidia vaccine dose of 30 doses/kg BW.6. Coccidia challenge reduced (P < 0.05) and dietary COS increased (P < 0.05) BW gain, and feed intake. Dietary COS mitigated (P < 0.05) the CC-induced effects on gain:feed. Dietary COS supplementation attenuated the CC-induced effects (P < 0.05) on the expression of occludin genes.7. In conclusion, dietary COS improved performance, and the immune-related beneficial impact of COS supplementation was associated with reduced expression of pro-inflammatory cytokine genes.

Response of broiler chickens to dietary soybean bioactive peptide and coccidia challenge.

Growth performance, nutrient digestibility, jejunal morphology, plasma cytokine, and gene expression responses of broiler chickens (Cobb 500) to graded concentrations of dietary soybean bioactive peptide (SBP) and coccidia challenge (CC) were investigated in 2 experiments. In experiment 1, 384 male broiler chicks were used to investigate the effect of graded dietary concentrations of SBP on growth performance, nutrient digestibility, and intestinal morphology in a randomized complete block design with 8 replicate cages and 6 diets. Corn-soybean meal-based diet was supplemented with 0, 1, 2, 3, 4, and 5 g of SBP/kg of diet. There were linear effects (P < 0.05) of graded concentrations of SBP on BW, BW gain, gain:feed, ileal villus height, and jejunal crypt depth at day 22 post hatching. There were linear effects (P < 0.01) of graded SBP concentrations on Ileal DM and energy digestibility. Experiment 2 was conducted to investigate the immune-protective properties of SBP on broiler chickens during a coccidia challenge. A total of 256 male broiler chicks were randomly assigned to 8 replicate cages in a 2 × 2 factorial arrangement of treatments with 2 SBP levels (0 or 4 g/kg of diet) and with or without CC. On day 14 post hatching, birds in the challenged group received 20×, which is twice the recommended coccidia vaccine dose of 25 doses/kg BW, whereas the non-challenged group received physiological saline. Dietary SBP ameliorated the CC-induced effect (P = 0.01) on gain: feed. Coccidia challenge reduced (P < 0.05) jejunal villi height, whereas dietary SBP supplementation increased (P < 0.05) jejunal villi height. Dietary SBP attenuated the CC-induced effects (P < 0.05) on the expression of plasma IL-1ß, transforming growth factor-ß, claudin-1, and occludin genes. In conclusion, dietary SBP improved growth performance, nutrient digestibility, and jejunal morphology. In addition, dietary SBP reduced the impact of coccidia challenge, and may be beneficial in the feed of broiler chickens for alleviation of health-related effects of coccidia infection.

Additivity of apparent and standardized ileal digestibility of amino acids in wheat, canola meal, and sorghum distillers dried grains with solubles in mixed diets fed to broiler chickens.

An experiment was conducted to investigate which method, apparent ileal digestibility (AID) or standardized ileal digestibility (SID), more accurately predicts the digestibility of crude protein (CP) and amino acids (AA) in mixed diets fed to broiler chickens. Male Ross 308 broiler chickens received a standard starter diet from d 0 to 16 post hatching, thereafter grouped into 8 blocks, based on body weight (BW), of 10 birds/cage, and randomly allotted to 6 diets in a randomized complete block design. The 6 diets consisted of a nitrogen-free diet, 3 semi-purified diets, and 2 mixed diets to test the additivity of AID and SID in mixed diets. On d 21 post hatching, digesta from two-thirds of the distal ileum was collected. Using the determined AID or SID for CP and AA in wheat, canola meal (CM), or sorghum distillers dried grains with solubles (DDGS), the AID or SID for 2 mixed diets based on wheat-CM or wheat-CM-DDGS were predicted and compared with determined AID or SID, respectively. The results revealed that the predicted SID of CP and AA in the wheat-CM mixed diet were consistent with determined values except for Asp and Ser, and all the predicted SID of CP and AA were consistent with the determined values in the wheat-CM-DDGS mixed diet. The determined AID of Ile, Met, Thr, Val, Ala, Cys, Ser, and Tyr in the wheat-CM mixed diet were greater (P < 0.05) than predicted AID values. For the wheat-CM-DDGS mixed diet, the determined AID of Trp, Cys, and Glu were greater (P < 0.05) than the predicted AID values. However, there were more inconsistencies between the determined and predicted values in AID values for wheat-CM than the wheat-CM-DDGS mixed diet than SID values for both diets. In conclusion, the present study confirmed that the SID of CP and AA was more additive than the AID of CP and AA when a mixed diet contained wheat, CM, and DDGS as protein sources in broiler chickens.

Comparison of goblet cell staining methods in jejunal mucosa of turkey poults.

This study compared the intestinal goblet cell density of turkey poults at 2 different ages using Alcian blue-periodic acid-Shiff (AB-PAS) and mucicarmine stains. Neutral mucins are stained with periodic acid-Shiff whereas acidic mucins are stained with Alcian blue. Mucicarmine and AB-PAS are specific to the mucins of epithelial origin. Mucicarmine has only been used for the assessment of goblet cells in human specimens, and it may have advantages for use in animals as a result of the methodological simplicity of staining as compared to AB-PAS. A mid-section of jejunum was taken from 80 turkey poults at 21 and 28 d, and fixed in 10% buffered formalin for 48 h. Each fixed tissue was dehydrated with ethanol, cleared with Sub-X, placed in paraffin wax, prepared on 2 slides, cleared and hydrated. The 2 slides were randomly assigned to 2 treatments which consisted of AB-PAS and mucicarmine stains in a completely randomized design. Goblet cell counts were taken from four villi per slide and the villus height was measured and averaged. There was no difference in the goblet cell density between the staining methods AB-PAS and mucicarmine at 21 or 28 d posthatch. These results show that both staining methods are viable for assessment of goblet cell density in turkey poults.

Effects of beak amputation and sex on the pecking rate damage and performance parameters of turkey.

This study was carried out to evaluate the effect of sex and beak trimming on pecking and the performance of turkeys. Five hundred and forty unsexed, day old British United Turkey poults were was divided into 3 treatments based on beak trimming at 0, 1/4, 1/3 measured from the tip of the beak inwards with 3 replicates of 60 poults each experiment 1 while 480 turkeys (240 each of male and female) were transferred and allotted to 4 treatment groups of 120 birds each and 4 replicates of 30 turkeys each in experiment 2. Data on performance response and severity of pecking were taken and subjected to one-way analysis of variance in a completely randomised design (experiment 1) and 2x2 factorial layout (factors were sex and beak trimming). Results showed that beak trimming had no significant (p>0.05) effect on all the performance parameters of turkey poults except feed intake while sex and beak trimming had significant (p<0.05) effect on performance indices of turkey. Debeaked male and female recorded higher feed intake, protein intake and feed conversion ratio. There was higher rate of aggressive pecking among the Toms than in the Hens and severity of damage was higher in undebeaked turkeys than the debeaked. Beak trimming can greatly reduce the severity of damage caused by aggressive pecking and should be done twice (6 and 14th week) at 1/4 measured from the tip of the beak.