Journal of Applied Poultry Research最新文献

An experiment was conducted to evaluate the effects of pure benzoic acid (PBA) or enteric-released benzoic acid (EBA) on performance, intestinal histology, apparent ileal digestibility (AID), cecal coliform and enterococci abundance, and litter moisture of broilers raised on used litter. Day-old male broiler chicks were assigned to control (Con), nontreated diet; positive control (BMD), Con + 50 ppm bacitracin methylene disalicylate; PBA, Con +1,000 ppm of PBA; EBA, Con +330 ppm of EBA. From 0 to 28 and 0 to 42 d, BMD outperformed the Con in either BW gain (BWG) or mortality corrected FCR (FCRm) (P ≤ 0.05). Over 0 to 28 d, EBA and PBA improved BWG and FCRm compared to the Con (P ≤ 0.05). When the entire 0 to 42 d period was considered, EBA improved both BWG and FCRm in comparison to Con (P ≤ 0.05). Supplementation with EBA and PBA resulted in inconsistent responses in duodenum and jejunum morphology; specifically, PBA decreased 28 d duodenal crypt depth and increased villus height to crypt depth ratio, while EBA decreased 28 d jejunum crypt depth (P ≤ 0.05). There were no differences in AID or cecal coliform counts (P > 0.05) due to treatment. However, PBA significantly reduced enterococcus counts at 42 d by 0.48 Log₁₀ CFU/g compared to CON. These results suggest that EBA can increase BWG and decrease FCRm, while PBA performance was similar to CON. Additionally, benzoic acid decreased crypt depth, with the response being tissue-specific depending on the form of benzoic used.

The chicken's cellular immune response to invasion by Eimeria tenella, the cause of cecal coccidiosis, a destructive parasitic disease of poultry, generates reactive oxidative species (ROS). The antioxidant, performance, and parasitological effects of prebiotic (Sugarcane molasses), probiotic (Saccharomyces cerevisiae), and synbiotic (cocktail of probiotics and prebiotics) supplementation in drinking water on cecal coccidiosis were investigated in this report. Ninety day-old broiler chicks were divided into 6 groups (A, B, C, D, E, and F), each with 15 chicks. At 21 d of age, Groups B – F were inoculated with 2.0 × 10⁴ Eimeria tenella sporulated oocysts/chick. Group A was used as negative control. The positive control Group B, was not supplemented. Throughout the experiment, Group C was given sugarcane molasses, Group D was given probiotics and Group E was given synbiotics. Group F received prophylactic amprolium treatment. Results revealed inoculated groups had significant (P < 0.05) increases in glutathione peroxidase (GPx) activities; 4.59 ± 3.89, 3.47 ± 0.92, 4.03 ± 1.89, 4.44 ± 1.99, 3.47 ± 1.44 U/ml in Groups B, C, D, E and F respectively compared with Group A (1.90 ± 0.21 U/ml) at 1-wk post inoculation (PI). Malondialdehyde (MDA) concentration likewise increased significantly in the same groups and period. However, superoxide dismutase (SOD) activities decreased significantly in the inoculated groups; 1,210.57 ± 29.59, 2,536.83 ± 108.82, 3,049.97 ± 86.68, 2,776.80 ± 399.69, 1,868.83 ± 45.04 U/ml in Groups B to F respectively compared with Group A (3,502.47 ± 224.35 U/ml) while catalase (CAT) activities were increased. Oocysts shed in feces were significantly increased 1-wk postinoculation in B but least in F, cecal lesion scores were similar. Feed intake declined significantly in inoculated groups especially B, alongside weight gain. Feed conversion ratio increased in the inoculated groups. The differences in the activities of the enzymes and MDA level between the supplemented groups and the positive control alongside evaluated parasitological parameters show the antioxidant effect of these supplements.

An experiment was conducted to verify the effectiveness of butyrate (BA) in diets of broiler chickens raised without antibiotics and exposed to used litter. Dietary treatments included: negative control (NC), a nonsupplemented diet on fresh shavings; positive control (PC), the same nonsupplemented diet on used litter; 500 BA, similar diet with 500 ppm BA on used litter; 1,000 BA, similar diet with 1,000 ppm BA on used litter; 500/250 BA, similar diet with 500 ppm BA from 0 to 8 d and 250 ppm BA from 8 to 42 d on used litter; 1,000/250 BA, similar diet with 1,000 ppm BA from 0 to 8 d and 250 ppm BA from 8 to 42 d on used litter. From 0 to 8 d, the PC resulted in a 6.8 g decrease in BW gain (BWG) compared to NC, but this response was lost from 0 to 25 d or 0 to 42 d. There were no differences in mortality corrected, FCR (FCRm) between PC and NC. All BA treatments increased BWG in comparison to PC from 0 to 8 d, with no differences from NC. Butyrate improved 0 to 8 d FCRm compared to both PC and NC (P ≤ 0.05), but these responses were lost over time (P > 0.05). Butyrate increased apparent ileal digestibility of energy and DM (P > 0.05). Butyrate had no effect on oocyst shedding compared to PC (P > 0.05). Butyrate was able to ameliorate the negative performance effects with reused litter over the 8-d starter period and was able to increase ileal digestibility of energy and DM.

Trace minerals are essential components in standard broiler diets, playing a vital role in growth performance and skeletal development in broiler chickens. Conventionally, trace minerals have been included in broiler diets as inorganic salts. However, inorganic trace minerals are highly water soluble and reactive in the feed, thus, can potentially react with other dietary antagonists, such as phytate, fiber, and other minerals. This reduces their bioavailability for the birds. Alternatively, dietary trace minerals from complexed sources have displayed better stability and consequently bioavailability. The present study was completed to evaluate the efficacy of different sources and concentrations of zinc, manganese, and copper on growth performance, carcass parameters and tibia characteristics in broiler chickens reared to 35 d of age. There were 5 dietary treatments, including a control diet with ZnSO₄, MnSO4, and CuSO4 as inorganic trace minerals, while the other 4 dietary treatments consisted of organic or hydroxychloride forms of Zn, Mn and Cu at different inclusion rates as complexed trace minerals. Diets supplemented with complexed trace minerals supported more efficient feed conversion than inorganic trace minerals from 1 to 35 d posthatch. Therefore, broilers offered diets with organic and hydroxychloride trace mineral blends exhibited improved FCR over inorganic trace minerals at notionally lower inclusion rates. Interestingly, complexed trace mineral inclusions at a lower level than those of inorganic sources did not result in any significant reduction in tibia breaking strength (P = 0.575), or toe ash (P = 0.406). This study shows that trace mineral supplementation as complexed sources in broiler diets exhibited superior efficacy than inorganic trace mineral sources as reflected in growth performance and tibia strengths.

Eggshell quality is one of the most significant factors affecting the egg industry as it economically influences the quantity of saleable eggs. Eggshell quality can be improved through optimization of genotype, housing system, and mineral nutrition. This study aimed to compare genotypes and evaluate the morphological, physical, and chemical properties of eggs (weight, breaking strength, Haugh units, and dry matter) by hens of two different strains fed a 1940 and 2016 representative diet. Egg production was measured daily and there were four periods with 10-wk intervals in which eggs were analyzed starting at 30 wk and ending at 60 wk of age measuring quality parameters. This study was set as a 2 × 2 factorial. The factors consisted of 2 leghorn genetic strains that were a 2016 commercial layer (W36) and a 1940 random-bred leghorn line, then 2 diets based on 2016 and 1940 dietary standards. The treatment groups: 1) 2016 hen on 1940 diet, 2) 2016 hen on 2016 diet, 3) 1940 hen on 1940 diet, and 4) 1940 hen on 2016 diet had 8 replicates with 10 hens per treatment housing 2 hens per cage. Body weights were higher in the 2016 hens when compared to the 1940 hens, however, the feed conversion ratio fluctuated in hens with the 2016 hens on the 1940 diet consuming the most feed throughout the majority of the trial. The 1940s hens came into production later than the 2016 hens; however, the rate of production was consistent with one another. Oviduct and ovary weights were heavier in the 2016 hens when compared to the 1940 hens. Egg quality, both interior and exterior was greater in the 2016 hens when compared to the 1940 hens. Parameters measured demonstrated significant differences (P ≤ 0.05) among treatment groups suggesting that genetics and nutrition both played a role in production rate and egg quality.

Commercial laying hens have been housed in conventional caged systems in Australia for many years where they have achieved maximum production through close management of temperature, lighting, diet, waste removal, automated egg collection, and secure food safety. However, the birds were limited in expressing natural behaviors including perching, nesting, and dust bathing. Increased public awareness of hen welfare prompted a shift in the housing type and there is now a predominance of cage-free housing including barn and free-range systems in Australia. In these houses the designated egg laying nesting areas are included in the indoor area and are designed to keep eggs clean while facilitating automatic egg collection. However, some hens choose to lay their eggs outside of the designated nesting areas. These eggs, referred to as mislaid, ground or floor eggs, cost the farming operation as they must be collected manually and are downgraded. This study was an opportunistic investigation into the putative risk factors for floor eggs from 69 commercial Australian brown egg-laying flocks. Two contexts of floor egg production were evaluated: where the farmer was concerned with the level of floor eggs or, where floor eggs were ≥2% production at peak lay. Flocks housed with cool white lighting or, that had experienced feather pecking, were associated with the farmer being concerned with the level of floor eggs. One strain of brown egg-layer contributed to ≥2% floor eggs at peak lay. These findings can assist farmers with operational decisions to minimize the number of floor eggs.