Journal of Applied Poultry Research最新文献

Nutritional test pens are commonly used to segregate and geolocate birds in commercial-scale broiler houses to control spatial variation from the environment. Pens should subject test birds to similar environmental conditions as birds roaming free in the house, however, discussions on pen construction materials, design, and placement have focused on durability and handling with little regard for the pen's thermal environment. Simulated birds were constructed with a metal bowl and a light bulb heat source to mimic the heat generation of large commercial broilers. Bowl surface temperature (BST) was measured as a model for the surface temperature of a broiler housed in a nutritional pen. Effects of panel open area (100% (control), 89%, 85%, 70%, 50%, and 30%) and air velocity (2, 3, and 4 m/s) were factorially tested on BST in a wind tunnel. Panels with an open area of less than 70% were different (P < 0.0001) from free air (100% open area). There was a difference of 5°C (9°F) for BST between the most restrictive panel (30%) and free air (100%), demonstrating a large difference in the thermal environment that birds might experience if air is restricted. Air velocity treatments were different (P < 0.0001) with mean BST increasing as air velocity decreased. Panels should be constructed with open areas greater than 70% accounting for structural framing and other obstructions as well as expected dust accumulation. While pen durability and handling are important for on-site success, these parameters should not overshadow restrictive airflow pen designs that would potentially alter thermal environmental conditions in nutritional treatment comparisons.

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Probiotic bacteria could be administrated to broilers using the in ovo injection technique during 17.50 and 19.20 d of incubation to accelerate microbial maturation in the intestinal tract. The effects of Lactobacillus rhamnosus (LR) injected in-ovo on intestinal morphology, mRNA expressions of intestinal health-related genes, and selected intestinal microbial of yellow broilers with or without Eimeria challenge were studied. A total of 360 yellow broiler hatching eggs were randomly assigned into 6 treatments with 60 replicate eggs per treatment. Six treatments were arranged in a 3 (LR dosage at 0, 10⁶, and 10⁸ CFU/egg at 18.5 d of incubation) × 2 (Eimeria oocyst challenge vs. PBS challenge at 10 d of age) factorial design. Tissues and cecal contents were sampled on d 19 posthatch. Our results indicated that the coccidial infection increased duodenum, jejunum, and liver relative weights to body weight, duodenal crypt depth, and HSP90 expression, and reduced goblet cell density and Occludin expression. In ovo injection of LR at 10⁶ CFU/egg downregulated the Occludin expression and increased the Clostridium perfringens level in Eimeria-challenged broilers. When the LR dosage increased to 10⁸ CFU/egg, relative weights of duodenum, jejunum, ileum, and liver increased, villus length of lower small intestine and cecal Lactobacillus abundance in challenged broilers were reduced, and the Escherichia coli and Clostridium perfringens abundances in unchallenged broilers were increased. In summary, in ovo injection of LR at a dosage equal to or higher than 10⁶ CFU per egg exacerbated coccidial infection in the intestinal tract and resulted in cecal bacterial imbalance. The probiotic dosage must be considered for in ovo administration in broiler production.

Hematologic parameters and the levels of certain plasma metabolites offer an objective measure, and real-time insight into the physiological status of an animal. We hypothesized that blood chemistry analysis in brooding poults varies with even minor differences of temperature and can affect poult performance. A total of 2,240 one-day-old turkey hens were assigned randomly to 1 of 4 treatments [Control (C) = 32C and 60%RH; cold stress (CS) = 29C and 60%RH; heat stress (HS) = 35C and 60%RH; and heat stress plus humidity (HHS) = 35C and 75%RH]. In all the treatments, the temperatures were lowered 2°C the first week, and 1.5°C each week thereafter. The relative humidity was maintained constant, as much as possible, throughout the 35 d duration of the experiment. Brooding treatment affected pH, partial carbon dioxide (pCO₂), potassium (K), and sodium (Na). The treatments HS and HHS had higher pH and K, and lower pCO₂ and K in the blood. These changes suggest an attempt by the poults to cool down by increased water intake and panting. Furthermore, by the end of the experiment more birds in these 2 treatment groups had distended crops, possible to increased water intake also. The increase of ketone in the plasma, at 3 d of age, of poults from the 2 warmest brooding conditions (HS and HHS) suggests that these birds were consuming less feed and using more fat as its main fuel source. Furthermore, at 28 d of age significantly more poults from HS and HHS had reduced ventricular contractility of their hearts. However, no significant differences in the concentration of creatinine kinase (CK) or cardiac troponin I (cTnI) were found between treatments. In conclusion, this research revealed that blood parameters were influenced by minor temperature and humidity changes. Warmer brooding temperatures resulted in a higher incidence of pendulous crop. Overall, there were no significant differences in the estimated BW between the treatments. Further research is needed to optimize the number of samples needed and the time of sampling to optimize brooding conditions. We also need to investigate blood parameters that can reveal reduced contractility of the heart and if the reduced myocardial contractility from birds kept at a higher temperature and relative humidity predisposes them to dilated cardiomyopathy or other metabolic diseases.

Energy is an expensive component of diets with lipids providing a concentrated energy source to meet these needs; in addition, supplementary lipids affect milling efficiency and diet palatability. Because of the increased use of lipids as feedstocks in renewable energy production, typical fats and oils are becoming more limited and costly to the livestock industry necessitating the need to source and understand the caloric values of alternative lipids. The experiments reported herein determined the caloric value of typical and non-typical fats when supplemented to growing broilers and compared these empirical values to values predicted by commonly used equations. Thirteen sources of lipids consisting of an animal-vegetable fat blend, poultry fat, 3 soybean oils, 3 distillers corn oils, palm oil, acidulated canola-soybean oil soapstock, acidulated palm oil-soybean oil soapstock, flaxseed oil, and canola oil were evaluated. Differences in the determined nitrogen corrected apparent metabolizable energy (kcal/kg) were observed among the lipids tested (animal-vegetable fat blend, 7,671; poultry fat, 7,984; 3 soybean oils, 8,118, 7,535, and 8,767; 3 distillers corn oils, 8,205, 7,990, and 9,364; palm oil, 7,408; acidulated canola-soybean oil soapstock, 8,056;, acidulated palm oil-soybean oil soapstock, 7,685; flaxseed oil, 8,588; and canola oil, 7,854) and the use of a commonly used prediction equation did not adequately estimate the caloric value compared with the empirical values. Data presented also shows the difficulty of determining and predicting energy values of lipids when used at low inclusion levels.

As hens age, egg production and quality decline. Producers are interested in extending the production of their hens to help with production costs and demand. The objective of this study was to investigate the role of the ratio of fine (F) and coarse (C) limestone and exogenous phytase at standard and superdosing levels on performance and egg quality of post-peak hens from 40 to 60 wk of age. A total of 560 Hy-Line W-36 hens (20 replicates of 4 hens per treatment) were randomly assigned into 7 experimental diets in a 2 × 3 + 1 factorial arrangement. The positive control (PC) was formulated to an industry standard that consisted of a 40F:60C limestone ratio without phytase and contained 4.4% calcium (Ca) and 0.44% available phosphorus (avP) for both layer 2 and layer 3 diets. A common negative control (NC) diet was created by reducing Ca and avP by 0.19% and 0.17% respectively compared with the PC. The factorial treatments consisted of 2 limestone ratios (40F:60C and 15F:85C) and 3 Escherichia coli-derived phytase levels (0, 400, and 1,500 FTU/kg) formulated from the NC. Results indicated that 40F:60C at 0 and 400 FTU/kg increased hen-day egg production (HDEP). Limestone ratios of 15F:85C decreased feed intake (FI), increased both eggshell thickness (ST) and weight (SW), but also increased unsaleable eggs (UE) compared to 40F:60C. Additionally, 0 and 400 FTU/kg increased egg quality parameters such as Haugh unit (HU) and albumen height (AH) but 1,500 FTU/kg increased inositol phosphate breakdown as well as bone quality.

The aim of the current study was to evaluate the influence of stressors on histomoniasis development and lateral transmission of Histomonas meleagridis. In the following experiments, half of the birds in each pen were inoculated with H. meleagridis to study disease transmission and progression. Birds were infected at 5 wk of age (experiments 1 and 3) or at 2 wk of age (experiment 2). Disease progression was evaluated by infection rate, mortality rate, and pathologic lesions in the ceca and liver. Reported results were applicable for directly infected birds as lateral transmission was not induced in these experiments. In experiment 1, the results showed high electrolyte, low-density diet (HE + LD), feed withdrawal (FW), caused higher infection rates and increase lesion scores in the liver and ceca compared to con. Experiment 2 further investigated the influence of low-density diet (LD) in conjunction with coccidiosis (LD + C) or feed withdrawal (LD + FW). All treatments had higher infection rates, mortality rates, ceca and liver scores compared to PC. In experiment 3, birds were fed diets containing naturally occurring aflatoxin at 0 ppb (AFLB1), 6.26 ppb (AFLB1 Low), or 19.82 ppb (AFLB1 High). No significant differences among treatments were observed. Though lateral transmission was not induced by theses stressors, the results of these experiments demonstrated that low-density diets, feed withdrawal and/or coccidial infection facilitated more severe histomoniasis infection.

Ensuring good water quality is one of the key management strategies to promote optimal broiler health and performance. A few studies have assessed the microbial status of drinking water for poultry, but there is insufficient information on biofilm in the drinking water lines within the poultry housing facilities. The buildup of microbes in the drinking water system could potentially result in biofilm formation which eventually deteriorates water quality. Hence, in this preliminary study, we sought to evaluate biofilm formation in the drinking water lines of selected broiler houses and characterize their microbial composition. Three random houses in each of 5 farms were visited representing 15 total houses used in this study. Using a borescope, we confirmed the presence of biofilm in 4 water lines per house on each farm, and a sterile gauze swab was used to collect the biofilm from these water lines. All biofilm samples were analyzed for the total aerobic plate count (APC), presence of yeasts and molds (YM), and Enterobacteriaceae (EB). The data were analyzed with ANOVA, and means were separated with Tukey's HSD test at P ≤ 0.05 using JMP software. All 15 houses evaluated had aerobic bacteria population and YM, whereas 7 out of the 15 houses had EB counts. For APC, there were significant differences across the farms (P < 0.0001) with Farm 1 having the highest APC (3.65 Log₁₀ CFU/mL) and Farm 5 having the lowest APC (2.05 Log₁₀ CFU/mL). For YM, significant differences existed across farms (P < 0.0001), Farm 2 had the highest counts (4.44 Log₁₀ CFU/mL), whereas Farm 5 had the lowest count (1.19 Log₁₀ CFU/mL). EB was detected in 3 out of the 5 farms and the counts were not statistically different (P = 0.07). Based on a sample size of 15 commercial broiler houses, these results suggest the need to evaluate water lines for biofilm and develop effective mitigations.

Feeding breeder hens diets enriched with omega-3 fatty acids (n-3 FA) has previously been shown to increase their progeny's immunocompetence. During an experiment to assess the effects of maternal-fed n-3 FA on broiler behavior, broiler chickens experienced an unexpected disease outbreak. Here, we present the broiler offspring's body weight, uniformity, and feed intake data. Broiler breeders were fed diets with or without flaxseed (n-3 FA source) in the rearing or laying period. Two cohorts of broiler offspring were hatched and placed in 24 mixed-sex pens per cohort. Broiler offspring were weighed weekly, and uniformity (CV%) was calculated by sex on a pen level. Cumulative feed intake was recorded, and feed conversion ratio (FCR) was estimated per pen. Cohort 1 was diagnosed with infectious bronchitis at 2 wk, and Cohort 2 at 5 d of age and was further diagnosed with avian reovirus. Broiler offspring weighed 41% less than the target weight at 6 wk of age. Flaxseed fed to breeders during the laying period resulted in lighter offspring weight at 6 wk of age (z = 3.98, P < 0.001). Uniformity was not affected by maternal diet (χ² = 6.51, P = 0.26). Maternal rearing diet (F = 3.35, P = 0.07), but not laying diet (F = 0.65, P = 0.42) nor their interaction (F = 2.34, P = 0.13) affected feed intake. Flaxseed rearing (F = 4.54, P = 0.04) and laying (F = 6.24, P = 0.02) diets increased offspring FCR, broilers from broiler breeders fed flaxseed throughout had the poorest feed conversion (P < 0.03). The study showed that maternal-fed flaxseed diets did not modulate the impact of disease on the growth performance of broiler chickens.

The presence of pathogens, e.g., Escherichia coli (E. coli), in chicken manure can potentially lead to serious infections and foodborne diseases when spread on land as organic fertilizer. Therefore, it is essential to inactivate these bacteria before land application. The aim of the present study was to determine the survival of E. coli and the temperature development in compost piles during composting of chicken manure with a typically low carbon/nitrogen (C/N) ratio and moisture content (MC). In a summer and winter trial, chicken manure piles were stacked in 1) uncovered static piles, 2) covered static piles, and 3) periodically turned piles. Samples were inoculated with a nonpathogenic E. coli strain at levels of 10⁷ cfu/g and placed at subsurface and center locations of the piles. Within 24 h, E. coli were undetectable by direct count in all piles and at all sample locations. By d 28, all samples were also negative for E. coli by enrichment. Despite the suboptimal composting conditions with an initial C/N ratio of 10:1 and an MC below 40%, temperatures within all piles mainly exceeded 50°C within the first 24 h. Statistical analyses showed that the sample location and the total hours at temperatures ≥50 and 55°C in the piles had significant influences on the survival of E. coli in the chicken manure compost. The season and manure treatment method had no significant effects on the presence of E. coli.

In addition to the whole white-flowered pea, pea protein concentrates and pea hulls can be utilized in animal nutrition. In particular, fermentable carbohydrates and fibers in peas and pea products seem to contribute to intestinal health and health maintenance in poultry, due to their prebiotic effect on the intestinal microbiota. This study was conducted to investigate the effect of different proportions of peas (P), pea protein concentrate (PPC) and pea hulls (PH) in complete feed mixtures for broilers on growth and slaughter performance as well as intestinal microbiota. Twenty diets with varying proportions of peas and pea products were fed to male broilers from d 1 to 34. Short-chain fatty acid analysis and 16S sequencing were used to examine the ileal and cecal microbiota for selected feeding groups. Overall, the attained fattening performances were at a high level. The use of peas and pea products did not affect body weight on d 34 or slaughter performance. The use of pea hulls up to 6% resulted in the highest overall feed intake and overall feed conversion ratio (P < 0.001). Microbiota composition and ileal bacterial metabolites were unchanged. Microbiota changes in the cecum were found between dietary treatments for several subdominant microbial genera that preferentially ferment carbohydrates. This study has shown that peas and pea products are well-suited as feedstuffs for feeding broilers when used appropriately. Furthermore, the intestinal microbiota responded with an increased abundance of nonpathogenic genera that may help maintain intestinal microbial homeostasis.