Effect of feed form and nutrient density on growth performance, blood parameters, and intestinal traits in broiler breeder pullets.

This study was conducted to evaluate the effect of feed form and nutrient density on growth performance, blood parameters, and intestinal traits of broiler breeder pullets during grower (7-19 wk) and pre-breeder (19 weeks to 5% production) periods. A total of 450 female broiler breeder pullets were used in a completely randomized design with a 3 × 2 factorial arrangement including 3 feed forms (mash, crumble, and pellet) and 2 nutrient densities (standard diet with the nutrient requirement of Ross 308 parent stock nutrition specification, and diluted diet by using sunflower hull to have 10% lower nutrient than the standard diet). Five replicates with 15 pullets per replicate were allocated to each of the 6 treatments. Blood samples were collected at 19 wk of age. Egg production reached 5% in the mid of 25 wk. Results showed that pullets fed crumble or pellet diets had greater body weight gain and a lower feed to gain ratio (F:G; P < 0.001). Diet dilution led to a decrease in body weight gain while increasing the F:G (P < 0.05). Pullets fed the pellet diets had shorter eating times than those fed crumble diets, whereas the longest eating time belonged to pullets fed mash diets (P < 0.001). Pullets fed pellet diet had a greater heterophil to lymphocyte (H/L) ratio than those fed crumble or mash diets (P = 0.007). Diluting the diet led to a decrease in the H/L ratio (P = 0.026). Neither feed form nor nutrient density had a significant effect on body weight uniformity, blood glucose and lipid concentrations, liver enzyme activities, and intestinal traits (P > 0.05). It can be concluded that pelleted or crumbled diets with lower nutrient density can be considered in broiler breeder's pullets feeding with no detrimental effect on their performance or health state.

Research Note: Effect of corn silage and alfalfa meal as alternative induced molt methods to improving Salmonella Enteritidis resistance in laying hens.

This experiment was conducted to evaluate diets containing a high level of corn silage and alfalfa meal in inducing molt and reducing susceptibility to Salmonella Enteritidis (SE) colonization in laying hens. Thirty-two healthy hens were examined by cloacal swab samples to be free of Salmonella. Then they were weighed individually and distributed to 4 experimental groups containing 8 hens each, including Full-fed (control, FF); total feed withdrawal (positive control for molt induction, FW); 80% corn silage (CS) + 20% layer diet (CS80), and 80% alfalfa meal (AM) + 20% layer diet (AM80). The molting program was initiated at 71 wk of age. On d 4 of the experiment, all hens were inoculated with SE by oral gavage. All hens were first weighed at the ending molting period on d 10 and then euthanized by CO2 gas. The internal organs including the ovary, oviduct, liver, and spleen, were excised aseptically and weighed. Cloacal swab and feed samples at the beginning and organ samples (liver, ovary, spleen, and cecum) were collected from each hen at the end of the experiment and examined for SE colonies. Molted birds lost roughly 14 to 27%t of their body weight and had significantly lower organ weight and egg production compared to FF group (P < 0.05). No significant difference was observed in the number of days to zero egg production between molted treatments. The SE positive organs did not significantly differ between CS80 and AM80 with FF treatment. Treatment CS80 had the lowest crop pH and differed substantially from treatment FW. In conclusion, results indicate that using corn silage and alfalfa meal, can improve resistance to salmonella Enteritidis during molt inducing compared to traditional feed withdrawal.

Study of antioxidant and antibacterial activities of depolymerized fucoidans extracted from Sargassum tenerrimum.

This work was performed to compare the effect of two water-extraction methods of fucoidan from Sargassum tenerrimum on their chemical composition, antioxidant capacity and antimicrobial activity after hydrothermal depolymerization. The number of extraction steps and ethanol concentration used for extraction were different between the two methods. Extraction yield of fucoidan obtained from the first method (DFM1) and the second method (DFM2) were 3.68 and 1.09%, respectively (P < 0.05). The IC50 value of DPPH radical scavenging activity for DFM1 was 1.93 times more than DFM2. The Fe+2 ions chelating activity were 78.3% for DFM1 and 89.4% for DFM2 at 10 mg/mL concentration. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration of DFM2 were lower compared to DFM1 for Enterococcus faecalis and Escherichia coli The DFM2 was more effective to decrease the MIC value of chloramphenicol on the gram negative strains than DFM1. Both of the fucoidans showed a synergistic effect in combination with chloramphenicol to inhibit the growth of Escherichia coli Based on the results of this study, depolymerized fucoidans can also be more considered as effective antibacterial agent with synergistic potential in combination with antibiotics to decrease the prescribed doses of antibiotic drugs in humans and animals.

Preparation of fish waste silage and its effect on the growth performance and meat quality of broiler chickens.

BACKGROUND: This experiment was conducted to evaluate the effects of replacing soybean meal with fish-waste silage (FWS) in diets on growth performance and meat quality in broiler chickens. Fish waste (FW) was fermented with molasses and Lactobacillus plantarum and Aspergillus oryzae for 15 days. A total of 240 day-old male Cobb 500 broiler chickens were used in a 42-day experiment in which the birds were randomly allotted to one of five dietary treatments (containing 0, 30, 60, 90, and 120 g kg-1 FWS) in a completely randomized design. RESULTS: Results indicated that the fermentation process significantly reduced pH and ether extract, but it increased crude protein content and lactic acid bacteria count in FW. The use of FWS significantly improved daily weight gain and feed conversion ratio of broilers. The amount of thiobarbiturate-reducing substances and lipid content in chicken's meat fed diet containing FWS was significantly lower than in the group fed a control diet. CONCLUSION: In conclusion, the microbial fermentation process is effective in improving nutritive values of FW. Feeding up to 120 g kg-1 FWS also improves the performance and meat quality of birds and can be used as a suitable protein source in broiler chickens' diet. © 2018 Society of Chemical Industry.

Fermented rapeseed meal is effective in controlling Salmonella enterica serovar Typhimurium infection and improving growth performance in broiler chicks.

The aim of present experiment was to assess the effects of fermented rapeseed meal (FRSM) on Salmonella enterica serovar Typhimurium (S. Typhimurium) colonization and growth performance in broiler chicks. Two hundred forty day-old male Cobb 500 broiler chicks were divided into six experimental treatments with four replicates and 10 birds per each. The treatments were including two positive and negative controls which birds received a basal corn-soybean diet as well as four others which birds received the diets that rapeseed meal (RSM) or FRSM was replaced with soybean meal at 50 and 100% levels. All chicks except the negative control birds were challenged orally with 105 CFU of S. Typhimurium at 3days of age. Results showed that birds were fed FRSM had significantly greater lactic acid bacteria populations and lesser S. Typhimurium colonization in ileal and cecal sections compared to others (P<0.05). The less percentage of liver and bursa of fabricius was belonged to negative control group. At 10day, feeding chicks with diet containing FRSM, but not RSM, significantly decreased the organ invasion by S. Typhimurium (P<0.05). Heterophil to lymphocyte ratio was significantly lesser in chicks were fed FRSM compared to those fed RSM or positive control (P<0.05). Birds were fed FRSM had significantly higher weight gain and better feed conversion ratio compared to those birds were fed RSM (P<0.05). The findings of present experiment concerning positive effects of feeding FRSM on reducing S. Typhimurium and improving growth performance show that this processed protein source can be considered as a nutritional effective strategy to control Salmonella contamination in broiler chicks.

Effect of dietary nutrient density and vitamin premix withdrawal on performance and meat quality of broiler chickens.

BACKGROUND: The objective of this study was to evaluate the effects of feeding high- and low nutrient density diets, and three different vitamin premix withdrawal regimes on broiler performance and meat quality. Male broiler chicks (480 days old) were reared on the floor in a 2 × 3 factorial arrangement for 42 days. Chickens were slaughtered at 42 days of age and meat samples kept at -20 ± 1°C and analysed after 1, 90 and 180 days of storage. RESULTS: Broiler performance was significantly affected by dietary nutrient density. Vitamin premix withdrawal had no significant effect on body weight. The results showed no significant differences between nutrient density and vitamin premix withdrawal on lightness (L*), redness (a*) and yellowness (b*). Oxidative stability of thigh muscle lipids during frozen storage was significantly affected by nutrient density, while vitamin premix withdrawal had no significant impact on lipid oxidation. High nutrient density diet led to a significantly (P < 0.05) decreased pH compared with the low nutrient density diet. CONCLUSION: Increasing dietary nutrient density improved broiler performance but impaired meat quality while vitamin premix withdrawal during finisher periods had no negative effect on broiler performance and meat quality.