32 research outputs found
Remembering Carlton Rochell
No full textDr. Carlton C. Rochell, who served as Dean of Libraries at New York University (NYU) from 1976–1999, died in Nashville, TN, on Dec. 23 at the age of 85 after a brief illness.
Rochell came to NYU shortly after the University combined 38 separate collections into the dramatic new Philip Johnson-designed Elmer Holmes Bobst Library. He managed and integrated those disparate collections by introducing innovative technological solutions that became models for the nation. During his tenure, the library's collection size doubled, the book endowment grew 1,200 percent, and circulation of books and materials expenditures both tripled. Rochell asserted a leadership role that transformed the NYU Libraries into a world-class resource
A review of heat stress in chickens. Part I: Insights into physiology and gut health
No full textHeat 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
No full textWith 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
Eimeria acervulina infection and amino acid nutrition in broiler chickens
No full textCoccidiosis, caused by intestinal protozoan parasites of genus Eimeria, continues to be one of the most widespread and economically important diseases in commercial poultry production. A series of four experiments were conducted to evaluate the interrelationships of Eimeria acervulina infection and amino acid (AA) nutrition in broiler chickens. In Experiment 1, growth performance, apparent ileal digestibility (AID) of AA, and plasma concentrations of AA, carotenoids, and α1-acid glycoprotein, an acute-phase protein, were evaluated in broilers inoculated with graded doses of E. acervulina oocysts. With the exception of Trp and Gly, AID of all AA decreased linearly or quadratically with increasing infection dose. The greatest reductions were observed for Cys, Ala, Val, Ser, and Thr. Plasma AA levels generally did not correspond with reductions in AID, with decreases observed for Arg, Tyr, Gln, and Asn and increases observed for Lys, Leu, Ile, Val, Pro, and Orn. Plasma α1-acid glycoprotein of broilers was not influenced by E. acervulina infection. In Experiment 2, the effects of supplementing copper, which can influence nutrient utilization, in diets of varying in AA density (low and high) on growth performance, apparent metabolizable energy, nutrient digestibility, and plasma carotenoids were evaluated in broiler chicks infected with E. acervulina. Growth performance of broilers fed the high AA density diets was improved compared with those fed low AA density diets. Copper supplementation generally improved pre-inoculation feed intake and weight gain of broilers fed low AA density diets. Eimeria infection markedly reduced plasma carotenoids, growth performance, apparent metabolizable energy, and nutrient digestibility of broilers, with little influence of dietary AA density or copper supplementation. Various interactions among AA density, copper supplementation, and infection status were observed for AID of AA. Experiment 3 included 2 separate trials that were conducted to determine if E. acervulina infection affected the potential for individual AA to become limiting in low crude protein diets fed to broilers, as indicated by growth performance, plasma carotenoids, and gene expression of intestinal cytokines during the acute and recovery phases of infection. A low crude protein diet that adequately supported broiler growth and allowed flexibility to formulate large reductions in individual AA concentrations was validated. Broilers were then fed the validated diet with equal (40%) reductions in individual or pairs of metabolically-related AA (Met + Cys, Lys, Thr, Val, Ile, Arg, Phe + Tyr, and Gly + Ser). The impact of E. acervulina on growth performance varied among the dietary groups, but the overall relative ranking of growth responses to AA reductions was similar for infected and uninfected birds. Intestinal cytokine responses to E. acervulina were not influenced by any of the dietary AA reductions. Experiment 4 evaluated the effects of feeding high (1.23% digestible) or low (0.74% digestible) Arg diets during the acute and recovery phases of E. acervulina infection on broiler growth and plasma levels of carotenoids, AA, urea, and nitric oxide, an important molecule in the immune response to Eimeria infection for which Arg is the key substrate. Plasma ratios of Arg:Lys indicated that dietary reduction of Arg induced antagonism between these two AA, regardless of infection status. In contrast to Experiment 1, plasma levels of both Arg and Lys of birds fed the high Arg diet were increased with infection, but the relatively larger increase in Lys led to a lower plasma Arg:Lys ratio for infected birds. Infection had minimal effects on plasma levels of these AA in birds fed the low Arg diet. Dietary Arg reduction did not inhibit the large E. acervulina-induced increase in plasma nitric oxide for birds at peak infection, but did affect plasma nitric oxide at lower levels observed is uninfected birds and in infected birds after recovery. Overall, this research demonstrates that E. acervulina-induced losses in broiler growth performance extend beyond reduced AA digestibility and identifies potential inefficiencies in AA metabolism that arise during coccidiosis.Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2016-03-02 without embargo termsThe student, Samuel Rochell, accepted the attached license on 2015-11-23 at 15:53.The student, Samuel Rochell, submitted this Dissertation for approval on 2015-11-23 at 16:04.This Dissertation was approved for publication on 2015-11-24 at 14:00.DSpace SAF Submission Ingestion Package generated from Vireo submission #8828 on 2016-03-02 at 12:50:21Made available in DSpace on 2016-03-02T19:33:50Z (GMT). No. of bitstreams: 3
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Previous issue date: 2015-11-2
An Ecological Effect of the New England Hurrican
No full textAuthor Institution: College of New Rochell
The impact of increasing dietary amino acid density and feed allocation during the first three weeks of life for broilers vaccinated against coccidiosis
No full textThe objective of this research was to ameliorate growth depression and meat yield reductions associated with coccidiosis vaccination. Coccidiosis vaccination induces an enteric challenge to develop immunity from Eimeria infection. To achieve the research objective, 2 experiments were conducted providing diets with increased digestible (d) amino acid (AA) density during the starter period. The first experiment evaluated effects of starter diets formulated to either 1.15% dLys density or 1.25% dLys density in 3 different starter feed allotments to vaccinated broilers from 1 to 21 d of age on growth performance and meat yield during a 6 wk production period. The second experiment compared growth performance and meat yield responses of vaccinated broilers provided 6 dietary treatments resulting from combinations of pre-starter and starter diets from 1 to 19 d of age during a 6 wk production period. Combinations consisted of 3 pre-starter diets formulated to 1.35 % dLys density, 1.25% dLys density or 1.15% dLys density and 2 starter diets formulated to 1.25% dLys density or 1.15% dLys density. In experiment 1, vaccinated broilers fed the 1.25% dLys AA diet consumed 5.4 g more cumulative dAA, which translated to a 38 g increase in total breast meat weight (P = 0.002) compared with those given the 1.15% dLys AA diet. Additionally, increasing the starter feed allocation beyond the 0.45 kg/bird allotment reduced cumulative feed conversion ratios by 6.5 points and increased carcass weights by 98 g. In experiment 2, feeding the 1.35% dLys AA density pre-starter diet increased cumulative dAA intake by 11.9 g, translating to a 40 g increase in total breast weight ( P = 0.016) compared to broilers provided the 1.15% dLys AA density pre-starter diet. Growth performance and meat yield responses of broilers fed the 1.35% dLys density pre-starter diet were similar to those observed when feeding the 1.25% dLys diet from 1 to 19 d, which as likely due to the similar dAA intake between the 2 treatments. In both experiments, broilers fed the 1.15% dLys AA density displayed growth depression compared with non-vaccinated broilers fed the same dAA density. These results provide strategies for integrators utilizing coccidiosis vaccination to ameliorate growth performance and meat yield reductions
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
Effect of feeding diets with varying energy levels and conditioning temperatures on broiler performance, processing yield, and nutrient digestibility
No full textPelleting is the most common thermal processing method used in the manufacturing of broiler diets. It is a process that involves the use of heat, moisture, and pressure to agglomerate smaller feed particles into pellets. Previous research has demonstrated the benefits of pelleting, including increased feed intake (FI), reduced feed wastage (FW) and nutrient segregation, and increased digestibility of some dietary components. Therefore, pellets are the preferred feed form in the US broiler industry. However, there are many factors that may influence the response of birds fed pelleted diets, including conditioning temperatures and the level of metabolizable energy (ME) in the diet. For this reason, two trials were designed to evaluate the relationships between feed processing variables and the nutritional value of feed. The objective of the first experiment was to evaluate the main effects and interactions of two ME levels and three 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 six treatments (9 replicates/treatment). Diets were formulated to contain two 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 three conditioning temperatures (80, 84, and 88°C). Feed intake, body weight (BW), and feed conversion ratio (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. Broilers fed SE had improved FCR (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. A second study was conducted to evaluate the main effects and interactions of two ME levels and three feed forms on broiler performance, FW, and nutrient digestibility from 1 to 21 d of age. A total of 648 YPM x Ross 708 male broilers were randomly distributed in 72 battery cages (9 birds/cage) and assigned to six treatments (12 replicates/treatment). Starter diets were formulated to contain two ME levels (2,979 [E2979] and 2,875 kcal/kg [E2875]). Both diets were fed as mash, crumbles conditioned at 85°C, and crumbles conditioned at 90°C. Body weight gain (BWG) and FI were determined at 10 and 21 d of age and FCR was adjusted for mortality. On d 10, 15, and 18, the feed spilled was collected from trays placed under each battery cage to calculate FW as g/kg. Ileal digesta (7 birds/cage) was collected for nutrient digestibility analysis on d 21. Broilers fed E2979 diets had lower (P < 0.05) FCR (1.28 vs. 1.36 g:g) from 1-21 d compared to broilers fed E2875 diets. Additionally, broilers fed mash diets had lower (P < 0.05) FI (1049 vs. 1223 and 1215 g) and higher (P < 0.05) FCR (1.34 vs. 1.30 and 1.32 g:g) and FW (28.6 vs. 2.3 and 3.0 g/kg) from 1-21 d compared to broilers fed crumbles conditioned to either 85 or 90°C. The lowest (P < 0.05) apparent ileal digestibility AID of dry matter (DM) was observed in broilers fed mash diets with E2875. Broilers fed E2979 diets had improved (P < 0.05) AID of crude protein (CP) compared to broilers fed E2875 diets. Starch digestibility was lower (P < 0.05) in broilers fed crumbles conditioned to 90°C compared to broilers fed crumbles conditioned to 85°C and mash. Overall, these studies suggest that broiler performance and nutrient digestibility are influenced by different feed processing parameters as well as by the nutritional value of feed. The obtained results highlight the importance of understanding that the response of birds to diet formulation and processing variables is closely related. Therefore, this relationship should be considered to make decisions that improve broiler performance and nutrient utilization
The Impact of Feed Additives and Calcium Concentration and Source on Broiler Performance, Nutrient Utilization, and Intestinal Health Under Different Disease States
No full textOptimizing broiler nutrition is essential for maintaining performance, enhancing nutrient utilization, and supporting intestinal health, especially when birds face various disease challenges. The reduction or removal of antibiotic growth promoters (AGP) in broilers has presented additional challenges for nutritionists, necessitating the development of alternative feeding strategies that sustain broiler performance and health while minimizing feed costs. These feeding strategies should aim to replicate performance outcomes previously achieved with AGP, though this remains difficult due to the complex mode of action of AGP. The present research explored two nutritional strategies to address AGP removal in broiler feeding: (1) feed additives and (2) diet manipulation. Feed additives like phytase and butyrate may help to alleviate the negative effects of AGP removal on broiler growth. Phytase, an exogenous enzyme, is commonly included in broiler diets to degrade phytate and enhance phosphorus (P) digestibility. Butyrate, an organic acid, improves intestinal health by modulating the microbiota and providing energy to intestinal epithelia. To evaluate the first nutritional strategy, broilers were provided with 1 of 9 treatments that included varying levels of phytase, calcium butyrate (CB), and bacitracin methylene disalicylate (BMD). Supplementing BMD increased early broiler body weight (BW), particularly when combined with 1,500 FTU/kg of phytase, but not with 500 FTU/kg. Depending on phytase inclusion, broilers fed a diet with CB exhibited similar BW compared to those fed BMD. Additionally, phytase at 1,500 FTU/kg enhanced fat and P digestibility, and apparent ileal digestible energy (AIDE). Intestinal physiology and cecal microbiota composition were influenced by CB and BMD, with changes in villus height, tight-junction gene expression, and cecal microbial evenness, depending on dietary phytase concentrations. These findings highlight the complex interactions between feed additives and their potential to modulate broiler performance and intestinal health. The second nutritional strategy involved manipulating dietary components, such as calcium concentration and limestone particle size, to help mitigate performance and mortality impacts from enteric diseases. Broiler diets are often unintentionally formulated with excess calcium, which may exacerbate necrotic enteritis by supporting NetB and α-toxin activity, leading to reduced nutrient utilization and compromising broiler health. Excess calcium can also increase calcium-phytate formation, resulting in undigested nutrients that become available to intestinal microbiota, potentially promoting proliferation of pathogenic bacteria. To evaluate this strategy, broilers were assigned to 1 of 7 treatments, including an unchallenged control and 6 enterically challenged groups fed diets with varying limestone particle sizes and calcium concentrations. The enteric challenge reduced broiler performance without affecting mortality. Reducing dietary calcium by 0.10 percentage units from recommended levels maintained broiler performance, tibia mineralization, and AIDE during an enteric challenge. Furthermore, calcium and P digestibility increased when dietary calcium was reduced. However, feed conversion and nutrient utilization responses varied depending on limestone particle size. Understanding the interaction between dietary calcium and limestone particle size could help to mitigate the impact of enteric diseases. Ultimately, to develop sustainable solutions that enhance broiler growth and health, broiler nutritionists must continue exploring AGP alternatives and further understand interactions between feed additives and dietary components
