22 research outputs found
A review of heat stress in chickens. Part I: Insights into physiology and gut health
Get PDFHeat stress (HS) compromises the yield and quality of poultry products and endangers the sustainability of the poultry industry. Despite being homeothermic, chickens, especially fast-growing broiler lines, are particularly sensitive to HS due to the phylogenetic absence of sweat glands, along with the artificial selection-caused increase in metabolic rates and limited development of cardiovascular and respiratory systems. Clinical signs and consequences of HS are multifaceted and include alterations in behavior (e.g., lethargy, decreased feed intake, and panting), metabolism (e.g., catabolic state, fat accumulation, and reduced skeletal muscle accretion), general homeostasis (e.g., alkalosis, hormonal imbalance, immunodeficiency, inflammation, and oxidative stress), and gastrointestinal tract function (e.g., digestive and absorptive disorders, enteritis, paracellular barrier failure, and dysbiosis). Poultry scientists and companies have made great efforts to develop effective solutions to counteract the detrimental effects of HS on health and performance of chickens. Feeding and nutrition have been shown to play a key role in combating HS in chicken husbandry. Nutritional strategies that enhance protein and energy utilization as well as dietary interventions intended to restore intestinal eubiosis are of increasing interest because of the marked effects of HS on feed intake, nutrient metabolism, and gut health. Hence, the present review series, divided into Part I and Part II, seeks to synthesize information on the effects of HS on physiology, gut health, and performance of chickens, with emphasis on potential solutions adopted in broiler chicken nutrition to alleviate these effects. Part I provides introductory knowledge on HS physiology to make good use of the nutritional themes covered by Part II
A review of heat stress in chickens. Part II: Insights into protein and energy utilization and feeding
Get PDFWith the growing global demand for animal protein and rising temperatures caused by climate change, heat stress (HS) is one of the main emerging environmental challenges for the poultry industry. Commercially-reared birds are particularly sensitive to hot temperatures, so adopting production systems that mitigate the adverse effects of HS on bird performance is essential and requires a holistic approach. Feeding and nutrition can play important roles in limiting the heat load on birds; therefore, this review aims to describe the effects of HS on feed intake (FI) and nutrient digestibility and to highlight feeding strategies and nutritional solutions to potentially mitigate some of the deleterious effects of HS on broiler chickens. The reduction of FI is one of the main behavioral changes induced by hot temperatures as birds attempt to limit heat production associated with the digestion, absorption, and metabolism of nutrients. Although the intensity and length of the heat period influences the type and magnitude of responses, reduced FI explains most of the performance degradation observed in HS broilers, while reduced nutrient digestibility appears to only explain a small proportion of impaired feed efficiency following HS. Targeted feeding strategies, including feed restriction and withdrawal, dual feeding, and wet feeding, have showed some promising results under hot temperatures, but these can be difficult to implement in intensive rearing systems. Concerning diet composition, feeding increased nutrient and energy diets can potentially compensate for decreased FI during HS. Indeed, high energy and high crude protein diets have both been shown to improve bird performance under HS conditions. Specifically, positive results may be obtained with increased added fat concentrations since lipids have a lower thermogenic effect compared to proteins and carbohydrates. Moreover, increased supplementation of some essential amino acids can help support increased amino acid requirements for maintenance functions caused by HS. Further research to better characterize and advance these nutritional strategies will help establish economically viable solutions to enhance productivity, health, welfare, and meat quality of broilers facing HS
Formulation of Broiler Chicken Feeds Using Distillers Dried Grains with Solubles
No full textDistillers dried grains with solubles (DDGS) is a coproduct of corn-based ethanol production that can be a valuable source of energy, digestible amino acids, and available phosphorus in poultry feeds. Dietary incorporation of DDGS reduces the amount of primary ingredients such as corn and soybean meal needed to formulate poultry diets, improving the sustainability of both biofuel and poultry production. The nutritional value of DDGS has been extensively evaluated since it became increasingly available to feed producers in the early 2000s, but evolving methods of ethanol production and coproduct fractionation necessitate its continued characterization. Attempts to relate nutrient utilization of DDGS to its chemical composition have revealed that fiber content is a primary determinant of dietary energy value of DDGS for poultry. Distillers corn oil, which is extracted from thin stillage during production of distillers grains, can also be supplemented into poultry diets as an energy-dense lipid source in place of animal fats or other vegetable-based oils. Poultry feeding practices in the United States are also evolving, including increased adoption of all vegetable-based diets and reduced use of in-feed antimicrobials. Therefore, further characterization of both the nutritional value of DDGS and its impact on gastrointestinal health will support its continued use in poultry diets
Effects of Diet Type and Ingredient Composition on Rate of Passage and Use of In Vitro Assays to Predict Amino Acid Digestibility of Animal Protein Meals in Broilers
Get PDFIleal amino acid digestibility (IAAD) is used to characterize amino acid (AA) quality of animal protein meals (APM) for poultry, and IAAD assays utilize semi-purified (SP) diets. Nutrient utilization is influenced by rate of passage (ROP), and it has not been determined if differences exist in ROP between corn soybean-meal diets and semi-purified diets in IAAD assays. The IAAD assay is laborious and costly, and in vitro assays to predict IAAD of APM commonly used in the poultry industry would be useful tools for nutritionists.
The first experiment evaluated the effects of diet type and ingredient composition on rate of passage (ROP) and apparent IAAD in broilers from 14 to 22 d of age. Experimental diets were formulated to contain 20% CP and consisted of: 1) corn-soybean meal-based (CSM) diet containing porcine meat and bone meal (MBM) (5% inclusion), 2) CSM diet containing distiller’s dried grains with solubles (DDGS) (5% inclusion), 3) SP diet containing MBM (38% inclusion), and 4) SP diet containing DDGS (76% inclusion). Time of 50% TiO2 excretion (T50) and mean retention time (MRT) indicated a faster (P < 0.05) ROP for SP-DDGS than the 2 CSM diets. There were no differences between T50 or MRT of SP-MBM and CSM-MBM. In general, apparent IAAD values were higher (P < 0.05) for the 2 CSM diets than for SP diets.
The second experiment evaluated a novel digestive enzyme assay (Poultry Complete IDEA, Novus International, Inc., St. Charles, MO) (PC IDEA) and the pepsin digestibility assay as predictors of standardized IAAD of 20 APM fed to broilers from 25 to 30 d of age. Standardized IAAD, pepsin digestibility, and PC IDEA predicted digestibility were determined for 10 meat and bone meals and 10 animal protein blends. Pepsin digestibility and PC IDEA were both significantly correlated (P < 0.001) with SIAAD. Prediction equations for SIAAD of Lys, Met, and Thr were: % Lys SIAAD = [‒9.65 + (0.38 × % PC IDEA predicted Lys digestibility) + (0.69 × % pepsin digestibility)], % Met SIAAD = [‒35.95 + (0.62 × % PC IDEA predicted Met digestibility) + (0.75 × % pepsin digestibility)], % Thr SIAAD = [‒77.5 + (0.39 × % PC IDEA predicted Thr digestibility) + (1.37 × % pepsin digestibility)]. Values of R2 for Lys, Met, Thr, Val, and Ile were 0.46, 0.47, 0.55, 0.51, and 0.49, respectively
EVALUATE THE EFFECTS OF FAT SOURCES AND DIFFERENT CALCIUM SOLUBILITY ON BROILER PERFORMANCE, NUTRIENT ABSORPTION, INTESTINAL PH, AND BONE DEVELOPMENT.
Get PDFA study was conducted to assess broiler performance when fed diets that differed in Calcium (Ca) source and concentration, following coccidia vaccinations. Vaccine level significantly affected all parameters throughout the present study except D0-14 FCR and D14-29 BW (P<0.05). Calcium source significantly affected average FI at D14-29 and D0-29 (P<0.05). A significant interaction was indicated for Ca source and concentration for D0-14 FI and BW (P<0.05). A significant interaction between Ca source and concentration for D14-29 BW and FCR (P<0.05). This trial supports previous data indicating that nutritionists should consider the interaction of Ca source, concentration, and vaccine to help mitigate the risk of NE. To further examine the interaction of Ca sourcing a preliminary study was conducted to evaluate the effects of dietary fat percentage, fat source and limestone particle size on D16 broiler performance. A three-way interaction was exhibited for average BW and BBS on D9 (P< 0.05). A three-way interaction was exhibited for average gizzard pH for D16 (P=0.0392). Fat level and Limestone particle size interaction was exhibited for FCR on D9 (P=0.0383). Fat source and fat level interaction was exhibited for average ileum pH on D9 (P=0.0398). Fat source and limestone particle size interaction was exhibited for average ileum pH on D9 (P=0.0393). Fat source and fat level interaction was exhibited for average BW, FI, FCR, BBS on D16 (P<0.05). Limestone particle size significantly affected FI on D9 (P = 0.0046). A study was conducted to evaluate the effects of fat sourcing and different limestone particle size on broiler performance in a D28 trial. Poultry fat at a 0.75% inclusion with fine particle limestone affected average BW and FCR for D14 (P<0.05). Soy oil at a 1.5% inclusion with a fine particle limestone affected FCR at D28 (P=0.0022). Poultry fat at a 0.75% and soy oil at a 1.5% inclusion with a limestone provided as a fine calcium particle size had a significantly less efficient overall FCR (P=0.0059). This trial supports previous data indicating interaction of fat percentage and source coupled with limestone particle size effect on broiler performance, intestinal health and bone mineralization and health
Effects of Starter Diet Energy Concentration on Nutrient Digestibility and Subsequent Growth Performance and Meat Yields of Broilers under Two Coccidiosis Control Programs
No full textAn experiment was conducted to evaluate the live performance, processing characteristics, and apparent ileal digestibility (AID) of nutrients and energy (IDE) in broilers under two coccidiosis control programs (CCP) and fed three starter diet energy levels. Treatments were a factorial arrangement of CCP [in-feed diclazuril (ACD) or vaccinated after hatch (VAC)] and three starter diet energy levels [3008 (standard), 3058 (moderate), and 3108 (high) kcal/kg apparent MEn] achieved with different soybean oil concentrations. Birds were reared in floor pens (12 per pen) and received experimental starter diets from 0 to 18 d and common grower and finisher diets to 43 d. At d 11, VAC birds had higher (p p p p p p p Eimeria-induced reductions in lipid digestibility during the starter period of coccidiosis-vaccinated broilers may exacerbate, rather than ameliorate, these impacts on bird performance
Effects of Hatch Window and Nutrient Access in the Hatcher on Performance and Processing Yields of Broilers Reared with Equal Hatch Window Representation
Get PDFThe objective of this experiment was to investigate the effects of feed and water availability in hatching baskets on broiler performance, processing yield, and organ weights while considering the influence of hatch window. Cobb 500 eggs were transferred into illuminated hatchers with two hatching basket types [control (CTL) hatching baskets with no nutrients provided or baskets containing feed and water (FAW)]. Chicks were pulled sequentially to establish four hatch window periods (HWP): early, pre-peak, post-peak, or late. Chicks were then held for 4 h at the hatchery without nutrient access and subsequently reared in 26 floor pens designated as CTL (n = 13) or FAW (n = 13), with 13 chicks from each of the 4 HWP per pen (52 chicks per pen). At 43 d, 16 males from each pen were processed. Chicks from FAW baskets were 1 g heavier (p < 0.001) than those from CTL baskets at placement and were heavier through 28 d (p = 0.003) but similar (p > 0.05) in body weight (BW) for the remainder of the 42 d. No differences (p > 0.05) in feed conversion ratio, mortality, or processing data were observed between CTL and FAW groups. Early-hatching chicks were lighter (p < 0.001) than those from all other HWP at placement, but were only lighter (p < 0.001) than the post-peak group by 42 d. In summary, it was found that hatching basket nutrient access increased the BW of broilers during the first 4 wk of growth, with no other effects on performance or yield. Also, earlier-hatching chicks were generally able to compensate for a lighter placement BW
Recent Findings on Phosphorus Digestibility of Feed Ingredients in Broilers
Get PDFAccurately meeting the dietary P needs of broilers is critical to ensure optimal bird performance, health, and welfare without causing undue environmental burdens associated with excess dietary P excretion. Phosphorus is commonly supplied in broiler diets from inorganic phosphates derived from non-renewable sources, but it has been estimated that peak P production will occur between 2030-2040 and that the global supply of P could be depleted within this century (Cordell and Drangert, 2009; Nest and Cordell, 2012). To address these concerns, inorganic P use in agriculture, including use in broiler diet formulation, requires careful stewardship. To this end, the dietary inclusion of animal protein meals can help reduce or eliminate the need for inorganic phosphate use, especially when paired with phytase (van Harn et al., 2017). However, the proportion of P available to the bird within commonly used inorganic phosphate and animal protein sources is often not well-defined.With increasing adoption of ileal digestibility of P in feed formulation, additional data are needed to develop robust databases for commonly used and important sources of P. Therefore, the aim of this study was to generate values of AID and SID of P for different inorganic phosphates and meat and bone meal sources using the direct method. In addition, relative P digestibility of these sources was determined using monosodium phosphate as the reference ingredient to provide a basis for comparing quantitative digestibility results with relative values
Bacillus Isolate Compositions and Methods of Using and Producing the Same
No full textThe present invention provides Bacillus isolates, as well as probiotic and animal feed compositions comprising said isolates, which may be included in the diet of poultry to improve growth performance with reduced energy diets. Methods of using these compositions to improve nutritional uptake or to reduce the incidence of footpad dermatitis in poultry are also provided
