Journal of Applied Poultry Research最新文献

This study evaluated the main effects and interactions of 2 ME levels and 3 conditioning temperatures on broiler performance, processing yield, footpad lesions, tibia ash, and nutrient digestibility from 1 to 42 d of age. A total of 1,350 d-old YPM x Ross 708 male broilers were randomly distributed in 54 floor pens and assigned to 6 treatments (9 replicates/treatment). Diets were formulated to contain 2 ME levels (standard energy [SE] and -130 kcal/kg reduced energy [RE]) in all feeding phases. Basal diets for each ME level were manufactured using 3 conditioning temperatures (80, 84, and 88°C). Feed intake (FI), BW, and FCR were determined at 14, 28, 35, and 42 d of age. On d 42, ileal digesta (5 birds/pen) was collected for nutrient digestibility analysis and broilers were processed on d 43. Data were analyzed as a 2 × 3 factorial arrangement using the GLIMMIX procedure of SAS and means separated using Tukey's test. Broilers fed SE had improved FCR (P < 0.05) compared to broilers fed RE in every evaluated period. Performance parameters from 15 to 42 d and processing yields were unaffected (P > 0.05) by conditioning temperatures. Apparent ileal digestibility (AID) of fat and energy was higher (P < 0.05) in broilers fed SE compared to broilers fed RE. Broilers fed diets conditioned to 88°C had lower (P < 0.05) AID of Ca and P compared to broilers fed diets conditioned to 80 and 84°C. Overall, most performance parameters were unaffected by conditioning temperatures, but broilers fed SE diets had improved performance and AID of fat and energy compared to broilers fed RE diets.

The effects of the nutritional characteristics of the diet fed from 18 to 29 wk of age on egg production and the development of the gastrointestinal tract (GIT) were studied in brown egg-laying hens from 18 to 61 wk of age. The experimental design was completely randomized with 4 pre-peak diets that contained 2.68 Mcal AMEn/kg, organized as a 2 × 2 factorial, with the standardized ileal digestible lysine content (DLys, 0.78 vs. 0.86%) and level of crude fiber (CF, 3.40 vs. 4.80%) of the diets as main effects. From 30 to 61 wk of age all hens were fed a common commercial diet with 2.78 Mcal AMEn/kg, 0.71% DLys, and 3.40% CF. Each treatment was replicated 16 times. The composition of the pre-peak diet did not affect hen production, egg quality, or any of the GIT traits studied at any age, except ceca length that was longer at 29 wk of age in hens fed the high CF diet (12.5 vs. 11.5 cm/kg BW; P < 0.05). In summary, an increase in DLys from 0.78 to 0.86% or of CF from 3.40 to 4.80% of the diet fed from 18 to 29 wk of age, did not affect hen production, egg quality, or GIT traits of the hens from 18 to 61 wk of age. The data indicate that pre-peak diets with 2.68 Mcal AMEn/kg, 0.78% DLys, and 3.40 to 4.80% CF are adequate to sustain egg production throughout the whole egg cycle, once the hens were fed a common commercial diet.

Research has indicated that the size of the pellet can be increased beyond the current industrial practice of using 3-4 mm pellets, without negative effects on performance and with improvement in pelleting efficiency as a result. To further elucidate the capacity of broilers for large pellets, a coarse wheat- and maize-based diet ground using either a hammer mill or a roller mill was pelleted using either a 3 mm diameter die or a 5 mm diameter die, and were cut to a length of 6 mm. For the 5 mm diameter die, pellets with a length of 8 and 10 mm were also made. Feeder rate and conditioning temperature were varied to assure similar physical quality among diets. More coarse particles were preserved during pelleting when the die diameter was 5 mm. The diets were fed to male Ross 308 broiler chickens from 10 to 34 d of age. Neither increasing the diameter nor the length of the 5 mm pellets had any negative effect on weight gain between 10 and 16 or 17 and 34 d of age. A feed preference test showed that birds willingly ate particles larger than 4.8 mm even at 16 and 22 d of age. At 29 d of age, they strongly preferred these largest particles. In conclusion, broiler chickens can be given larger pellets than current industrial practice, potentially increasing pelleting capacity and reducing energy consumption, while simultaneously preserving more of the gizzard-stimulating coarse microstructure of the particles constituting the pellet.

Poultry extension programs, which target international audiences, can both be challenging and rewarding. Part of the challenge, for example, is to learn about problems associated with a poultry operation and being able to communicate effective recommendations to management personnel effectively, particularly when there is a language barrier. Benefits from international work include: 1) new ways to look at problems, 2) better understanding of challenges faced by developing communities, 3) learning to present educational materials to those with limited literacy and varying education levels, 4) adapting to challenging situations and learning to use “what's on hand,” 5) working with individuals who have access to limited resources, 6) learning how to work with other cultures and climates, and 7) experience working with audiences who may not speak English. These rewards and benefits far outweigh the time and effort put into the work. The opportunity to work internationally can come from several different approaches, including, professional organizations, religious groups, consulting for private companies, and non-government organizations (NGO) that do international development. One of the easiest to get started with is the John Ogonowski and Doug Bereuter Farmer-to-Farmer Program (F2F), funded by the U.S. Agency for International Development (USAID). While the program is funded by USAID, it is implemented by several different organizations that recruit individuals with experience in agriculture to volunteer for assignments that support development in the targeted areas. US-based volunteers (citizens or permanent residents) are sent on technical assignments to provide hands-on training. Its main objectives are to increase agricultural sector productivity and profitability, to improve conservation and sustainable use of environmental and natural resources, to expand agricultural sector access to financial services, and to strengthen agricultural sector institutions. In this particular program, you will work with local farmer associations, cooperatives, women's groups, agribusinesses, and educational institutions throughout Africa, Asia, Eastern Europe, Latin American, and the Middle East. Working with international audiences is rewarding, but is not without its challenges.

Fowl adenovirus (FAdV), Avian influenza (AI), and Newcastle disease (ND) are prominent viral infectious diseases that pose a significant threat to the global poultry industry, resulting in substantial economic loss. To mitigate the occurrence of hydropericardium syndrome (HPS), a triple vaccine was developed by combining the nanoparticle-like fibre-2 protein with the inactivated H9N2 AI virus antigen derived from the A/chicken/Shandong/SZ/2008 strain, as well as the inactivated Newcastle disease virus (NDV) antigen obtained from the N7a strain, which was rescued from the NDV strain PLK-N-06. This particular strain was isolated during a chicken outbreak of ND and identified as velogenic. The immunological effect was evaluated by specific pathogen-free chicken challenge test. There was no significant difference in the specific antibody level in specific pathogen-free chickens between the triple vaccine and the monovalent vaccine (P > 0.05), which was significantly higher than that of the control group (P < 0.0001). The protective effect of triple vaccine against the 3 viruses could reach 100% after being challenged. No obvious lesions of FAdV, AI, or ND were observed in the target tissues and organs of the triple vaccine immunization group. Viral shedding test results showed that no three kinds of viruses were detected in larynx and cloaca on the fifth day after challenge. In conclusion, the immune protection effect against the 3 pathogens does not interfere with each other and can provide complete protection. The triple vaccine can be used as a candidate vaccine to prevent chickens from the three kinds of diseases, has high clinical application value, and can produce greater economic benefits.

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.

Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the authors or the U.S. Department of Agriculture.

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.