Evaluation of different non-fasting molting methods on laying performance and egg quality during molting and post molting periods.

The study evaluated different molt-inducing methods to achieve the main goal of molting in commercial layers during molting and post-molting periods. A total of 400 60-week-old Lohmann Brown layers were randomly divided into five groups (eight replicates of 10 birds for each group). Laying hens in the fasting control group received no diet from day 1 to day 10. The second group received a molt-inducing diet recommended by the breeding company. The third group received a wheat bran-based diet. The fourth group received a commercial layer diet with 8,000 ppm zinc (as zinc oxide, ZnO). The fifth group received an induced molting diet given to the second group with 8,000 ppm zinc, respectively. Egg production in the fasting control group and groups fed a diet with ZnO were significantly lower (p < 0.001) than those in groups fed the molt-inducing and wheat bran-based diets without ZnO during molting. Egg laying in the fasting control group was rapidly reduced and stopped on the 5.9th day of molting. In both groups having molt treatment with ZnO, egg production was similarly reduced and ceased on the 6.9th day and 7.0th day of molting, respectively, none of them differed significantly from the control. Layers fed molt-inducing diet or wheat bran-based diet did not reach the cessation of laying even on the 28th d of molting period. Relative weights of the ovary and growing oocytes of layers subjected to fasting or fed diets with ZnO were significantly lower than those of other groups. During the first two weeks of post molting, layers fed molt-inducing diet with ZnO showed higher egg production than the other two groups (p < 0.01). The eggshell strength in the group fed the commercial diet with ZnO was significantly higher than those fed the molt-inducing diet or wheat bran-based diets at 6 weeks of post molting (p < 0.05). These results suggest that the non-feed withdrawal molting using ZnO is more effective in inducing molting and increasing post-molt egg production and egg quality than other methods using a molt-inducing diet alone or wheat bran-based diet without ZnO.

Potential Probiotic Acceptability of a Novel Strain of Paenibacillus konkukensis SK 3146 and Its Dietary Effects on Growth Performance, Intestinal Microbiota, and Meat Quality in Broilers.

This study evaluates the in vitro probiotic characteristics of P. konkukensis sp. nov. SK-3146, which was isolated from animal feed, and its dietary effects on growth performance, intestinal characteristics, intestinal microbiota, and meat quality in broilers. In vitro experiments revealed that P. konkukensis was non-hemolytic with variable antibiotic susceptibility, and acid as well as bile tolerance. To assess the effect of P. konkukensis on broilers, a total of four hundred eighty 1-day-old Ross 308 broiler chicks were allocated to 3 treatment groups with 4 replicates of 40 birds each; the negative control group was fed a basal diet without any feed additives (NC), the positive control group was fed a basal diet containing 0.01% enramycin (PC), and the experimental group was fed a basal diet containing P. konkukensis bacterial culture (PK) at 104 CFU/g of the diet based on bacterial count. The experiment lasted for 35 days. Results indicated that there were no significant differences in any growth performance parameters among the dietary treatments (p > 0.05). In addition, the inclusion of P. konkukensis in the broilers' diet did not affect meat cooking loss, color, and pH but increased the relative weight of breast meat (p < 0.05). The PK group showed heavier intestinal weight and shorter intestinal length than the NC group (p < 0.05). The ratio of the intestinal weight to length of jejunum was the highest in the PK group (p < 0.05). The PK group showed increased counts of Streptococcus thermophilus (p < 0.05) with no adverse effects of P. konkukensis on other intestinal microbiota in the jejunum. This study implies that P. konkukensis might have the potential to be applied as a probiotic feed additive in poultry.

Feasibility of sodium long chain polyphosphate as a potential growth promoter in broilers.

The objective of this study was to evaluate in vitro antimicrobial and anti-biofilm activity of sodium long chain polyphosphate (SLCPP) and effect of dietary supplementation of SLCPP on growth performance, organ characteristics, blood metabolites, and intestinal microflora of broilers. Antimicrobial activities of SLCPP were observed against Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica ser. Pullorum, Shigella sonnei, Klebsiella pneumonia, Pseudomonas aeruginosa in agar well diffusion assay. In addition, SLCPP demonstrated good anti-biofilm activity against K. pneumonia and P. aeruginosa. Furthermore, to investigate the dietary effect of SLCPP, a total of 480 1-day-old male Ross 308 broiler chicks were randomly allotted to three dietary treatment groups (4 replicates per group, 40 birds in each replicate): an antibiotic-free corn-soybean meal basal diet (NC); basal diet + enramycin 0.01% (PC); and basal diet + 0.1% SLCPP (SPP). The experiment lasted for 35 days. Results showed that birds fed with SLCPP had higher body weight (BW) and average daily gain (ADG), and lower feed conversion ratio (FCR) during the grower phase (days 7 to 21) (p < 0.05). Except for blood urea nitrogen, all other blood biochemical parameters remained unaffected by the dietary supplementation of SLCPP. Compared to the control group, lengths of the duodenum and ileum in the SPP group were significantly shorter (p < 0.05). Moreover, counts of lactic acid bacteria (LAB), total aerobes, and Streptococcus spp. in jejunum as well as LAB in cecum were increased in the SPP group than in the PC group (p < 0.05). These results suggest that dietary supplementation of SLCPP might promote the growth of broilers in their early growth phase.

Evaluation of energy and amino acids of brown rice and its effects on laying performance and egg quality of layers.

Two experiments were conducted to determine apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and ileal digestible amino acid (AA) content of brown rice (BR) and to investigate the effect of dietary supplementation of BR on laying performance and egg quality of laying hens. In Exp. 1, 72 Hy-line Brown layers (49-week-old) were allocated to two treatments using a completely randomized block design, and each treatment included six cages per treatment and six hens per cage. A semi-purified diet was formulated to include BR as the sole source of AA and energy and an N-free diet was used to determine basal endogenous loss of AA. The hens were fed a commercial layer diet for adaptation to the experimental environment and diet for 7 days from d 0, and then fed experimental diets for 5 days from d 7. Excreta were collected from d 10 to 11 and ileal digesta were collected on d 12. On a dry matter (DM) basis, the AME and AMEn of BR was determined at 3,773 and 3,729 kcal/kg, respectively. The apparent ileal digestibility (AID) of BR ranged from 32.7% for Thr to 73.7% for Arg. The range of the standardized ileal digestibility (SID) value was between 79.4% for Met and 96.6% for Lys. In Exp. 2, 252 Hy-line Brown layers (44-week-old) were divided into four groups, comprising seven replicates of nine birds each and assigned to four experimental diets containing 0 (Control), 5%, 10%, or 15% BR for 5 weeks. The BR-containing diets were formulated to be equal in the content of AMEn and digestible AA to those of the diet without BR. No significant differences were observed in laying performances. Egg quality and blood profiles were not linearly or quadratically affected by dietary treatments. These results suggest that up to 15% BR can be included into layer feed without any adverse effects on laying performance and egg quality, if its energy and digestible AA values are well evaluated.