Poultry Nutrition Research Articles

Advances and Future Directions in Poultry Nutrition: An Overview

Institute of Food, Nutrition and Human Health, Massey University, Palmerston North 4442, New ZealandABSTRACT In the past, poultry nutrition has focussed on increasing the production efficiency to meet the progress achieved in the genetic potential of broilers and layers. Future directions in poultry nutrition will be driven by not only by the need to maximise biological and economic performance of birds, but also by societal issues (environment, antibiotic growth promoters, welfare, traceability and use of genetically modified ingredients). Key advances in poultry nutrition are discussed and future directions, which can be expected, are highlighted. Given the tightening supply and ever-increasing cost of raw materials, there will be more pressure to extract every unit of energy and nutrients from feed ingredients. In this context, a number of feed additives are expected to play an increasingly significant role. Feed enzymes and crystalline amino acids, in particular, will have a profound effect on future sustainability of the poultry industry. Future nutritional research need to focus on identifying the barriers to effective digestion and utilisation of nutrients and, to achieve this objective, nutritionists must combine their expertise with those of specialising in other biological sciences, including immunology, microbiology, histology and molecular biology.(Key words : nutrition, feedstuffs, feed additives, poultry)

Protein–phytate interactions in pig and poultry nutrition: a reappraisal

Protein-phytate interactions are fundamental to the detrimental impact of phytate on protein/amino acid availability. The inclusion of exogenous phytase in pig and poultry diets degrades phytate to more innocuous esters and attenuates these negative influences. The objective of the present review is to reappraise the underlying mechanisms of these interactions and reassess their implications in pig and poultry nutrition. Protein digestion appears to be impeded by phytate in the following manner. Binary protein-phytate complexes are formed at pH levels less than the isoelectric point of proteins and complexed proteins are refractory to pepsin digestion. Once the protein isoelectric points are exceeded binary complexes dissociate; however, the isoelectric point of proteins in cereal grains may be sufficiently high to permit these complexes to persist in the small intestine. Ternary protein-phytate complexes are formed at pH levels above the isoelectric point of proteins where a cationic bridge links the protein and phytate moieties. The molecular weights of protein and polypeptides in small-intestinal digesta may be sufficient to allow phytate to bind nutritionally important amounts of protein in ternary complexes. Thus binary and ternary complexes may impede protein digestion and amino acid absorption in the small intestine. Alternatively, phytate may interact with protein indirectly. Myo-inositol hexaphosphate possesses six phosphate anionic moieties (HPO(4)(2-)) that have strong kosmotropic effects and can stabilise proteins by interacting with the surrounding water medium. Phytate increases mucin secretions into the gut, which increases endogenous amino acid flows as the protein component of mucin remains largely undigested. Phytate promotes the transition of Na(+) into the small-intestinal lumen and this suggests that phytate may interfere with glucose and amino acid absorption by compromising Na(+)-dependent transport systems and the activity of the Na pump (Na(+)-K(+)-ATPase). Starch digestion may be depressed by phytate interacting with proteins that are closely associated with starch in the endosperm of cereal grains. While elucidation is required, the impacts of dietary phytate and exogenous phytase on the site, rate and synchrony of glucose and amino acid intestinal uptakes may be of importance to efficient protein deposition. Somewhat paradoxically, the responses to phytase in the majority of amino acid digestibility assays in pigs and poultry are equivocal. A brief consideration of the probable reasons for these inconclusive outcomes is included in this reappraisal.

Implications of changing immune function through nutrition in poultry

Many nutrients are capable of modulating the immune system. The concept of nutritional immunomodulation goes beyond impairments in function associated with deficient or toxic levels of various nutrients, and involves using specific nutrients to achieve a functional goal. Using diet to alter immune function has become especially important in a production environment in which the use of growth promoting antibiotics is not legal or desired by consumers. The purpose of this review is not to give a catalog of nutrients capable of altering immune function. Rather, a brief introduction to immune function in poultry will be given, the balance between the innate and acquired responses is discussed, and examples of potential unintended consequences of nutritional immunomodulation are given. Examples of non-nutritional manipulation of poultry immunity will be given to give the reader context of how changing specific aspects of immune function can have effects on other aspects of immunity and production performance. The intention is not to suggest that nutritional immunomodulation is not possible or practical, rather, the reader will be made aware of points to consider when designing experiments or reading the literature in this area. Nutritional immunomodulation holds great promise as a means to increase poultry productivity and health, however, the implications on production traits, the danger of ascribing too much confidence in studies that report only a single or few measures of immunity may lead to changes in immune function that predispose the birds to other diseases, or decrease production characteristics. Several examples of nutritional immunomodulation have been used successfully in the poultry industry, but a greater understanding of the avian immune system will be required in order to take full advantage of this approach.

Nutrition and wet litter problems in poultry

The use and management of suitable bedding material is a crucial part of bird welfare in intensive production systems. Litter cushions the bird from the hard floor, provides insulation and has the capacity to both absorb and facilitate evaporation of faecal, urinary and spilled water.In poultry production, an increase in water excretion rate is commonly referred to as flushing, because urine and faeces are excreted simultaneously through the cloaca, making it difficult to distinguish elevated urine output or polyuria from increased faecal water loss or diarrhoea. In today's intensive production systems even relatively minor nutritionally induced osmoregulatory perturbation can cause flushing. Whilst this increase in water excretion is often initially the result of a physiological diuresis or diarrhoea, nutritionally induced pathological change may aggravate the polyuria by compromising water recovery, or increase the severity of the diarrhoea by causing enteritis.Flushing is commonly the result of a normal physiological response to nutritionally induced water, electrolyte, pH or osmotic imbalance, but sustained imbalance frequently leads to pathological change. Similarly, diets with a high proportion of non starch polysaccharides, animal protein, saturated free fatty acids, anti-nutritional factors or toxins can cause pathological change indirectly, by inducing a detrimental shift in the composition of the intestinal microbiota (dysbacteriosis), or directly, by causing toxic damage.Inflammation of the renal or gastrointestinal lining compromises water and nutrient transfer, which increases the amount of water, mucus and non-digested nutrients in the excreta. Apart from loading the litter with water, the mucus and non-digested lipid in particular, reduce the litter's water buffering capacity and exacerbate the consequences of flushing.

Characteristics of a β-1,4-D endoglucanase from Trichoderma virens wholly applied in a palm-fruit husk-based diet for poultry layers

The characteristics of an endoglucanase produced by a Trichoderma virens strain T9 newly isolated from a palm-fruit husk dump site, its physiological characteristics and enzyme production were studied. Whole cells of the depolymerizing-enzyme producing T. virens were applied to palm-fruit husk and bird performance characteristics when employed as poultry diet additive were considered. Endoglucanase activity in submerged fermentation was 1.6 nkat. Optimum activity was recorded at pH 6.0 and 55°C. The enzyme retained 50% residual glucanase activity at 70°C for 10 minutes. 1.0% Tween-80 and SDS yielded endoglucanase activity 2.15 times higher than the control. Activity was boosted by 20mM Ca2+ (115.0%); 10mM K+ (106.5%); and was totally inhibited by 1mM Hg2+. The addition of T. virens-fermented palm-fruit husk with other layer feed components on the bird characteristics showed that change in bird weight between the control and test birds were not significantly different (p>0.05) but differed in terms of daily feed ingested (p<0.05). The feed to weight-gain ratio was best with the unmodified palm-fruit husk based diet (8.59). There was no significant difference in the egg weights from modified palm-fruit husk based diet and control (p>0.05). The shell thickness (0.64mm) and yolk content (23.61%) were highest in the microbially-modified husk diet.The alternative to maize based diets proffered by the application of T. virens-modified palm-fruit husk in poultry nutrition in terms of bird weight and feed to weight-gain ratio affords the poultry farmer an economic advantage and allows for a greater utilization of the maize in human diets.

Prospects for the use of genetically modified crops with improved nutritional properties as feed materials in poultry nutrition

Genetically modified (GM) plants constitute an increasingly significant part of the crops available on the feed market. To date, the most common GM plants have been those with enhanced agronomic traits. Known as ‘first-generation transgenic plants’, they are substantially equivalent to materials from conventional, parental plant lines. Recently, intensive experimental work using genetic engineering methods, have resulted in the production of transgenic plants with substantial changes in chemical composition, these are referred to as second-generation GM plants. The main objective of such transgenesis is to improve the nutritional properties of crops by increasing the level of desirable substances or decreasing the quantity of harmful compounds in the seeds. This review discusses the use of GM crops with enhanced nutritional properties as feed materials for poultry. On the basis of the information presented, it can be concluded that GM crops with improved nutritional value, enhanced available phosphorus content, an increased concentration of limiting amino acids, or containing genes expressing transgenic enzymes or antimicrobial substances could offer poultry producers considerable benefits.

Feathering abnormalities in bronze turkeys associated with amino acid deficiencies in organic diets

EUROPEAN Council Regulation 834/2007 prohibits the use of supplementary amino acids such as DL-methionine and lysine hydrochloride in the diets of organic livestock. As a result, organic poultry diets cannot...

Scientific Opinion on safety and efficacy of sodium benzoate, propionic acid and sodium propionate for pigs, poultry, bovines, sheep, goats, rabbits, horses

The product is a mixture of sodium benzoate (140 g/kg), propionic acid (370 g/kg) and sodium propionate (110 g/kg). This product is authorised for the preservation of cereals with a humidity content ≥ 15 %, at an inclusion rate of 3000–22000 mg/kg cereal, for use in pigs and dairy cows and cattle for fattening. The applicant is now asking for the re-evaluation of the safety and efficacy of the additive for use in pigs, dairy cows and cattle for fattening, for an extension of use of this product as preservative of complete feedingstuffs at a maximum content of 10000 mg/kg and for the use of treated feed (cereals and complete feedingstuffs) in the nutrition of poultry, bovines, sheep, goats, rabbits and horses. Safety for pigs, cattle for fattening and dairy cows has already been established by SCAN and FEEDAP at a level of 22 g/kg complete feed. The FEEDAP Panel concludes that the highest dose applied for complete feed (10 g/kg) is safe for chickens and turkeys for fattening and laying hens and consequently for all poultry species, with a small margin of safety that cannot be established. This conclusion is extended to other ruminants, rabbits and horses. The additive is safe for the consumer and environment and for the user, provided that the precautions indicated in the MSDS are followed. The additive is effective in the preservation of high moisture cereals at a minimum application rate of 13 g/kg. The FEEDAP Panel has reservations about the effectiveness of the product in complete feedingstuffs with a typical moisture content of ≤ 12 %. However, in practical storing conditions the moisture content of the feed may rise above this level. Under these circumstances, the additive would be effective in preventing deterioration at concentrations between 5 and 10 g/kg complete feed.

Selenium in poultry nutrition and its effect on meat quality

This review focuses on a selected micro mineral, where the highlight is its role in meat quality. Minerals are important for optimising livestock and poultry performance. Initial symptoms of mineral imbalances, subclinical inadequacies, or severe deficiencies include depressed growth, body weight gain, poor feed utilisation efficiency, and reproductive efficiency. Dietary trace elements, particularly selenium, are able to induce physiological changes in muscle tissue, and they can alter meat quality in livestock and poultry. Bearing in mind the role of selenium in the quality of meat produced, the limited research into the association of selenium and skin health has been included in the review.

L-carnitine and its functional effects in poultry nutrition

L-carnitine has indispensable functions in intermediary metabolism and is received by endogenous synthesis and from exogenous sources. It plays an obligate role in fatty acid metabolism by directing fatty acids into the mitochondrial oxidative pathway through the action of specialised acyltransferases. In poultry production, L-carnitine has a multi functional purpose, which includes: growth promotion, strengthening the immune system, antioxidant effects and improving semen quality. The concentration of L-carnitine in animals varies widely across species, tissue type, and nutritional status of the animal. It has been suggested that the L-carnitine requirement may be increased under certain circumstances such as via higher performance, various stress conditions and where the diet is deficient in animal protein sources. The review of L-carnitine functions uniquely includes the main aspects of this consequential feed supplementary inclusion in poultry nutrition.

Intestinal cell conversion ofdl-2-hydroxy-(4-methylthio)butanoic acidin vitro: dietary up-regulation by this methionine precursor

DL-2-Hydroxy-(4-methylthio)butanoic acid (HMTBA) is a synthetic source of dietary methionine (Met) widely used in poultry nutrition. HMTBA is transported in the intestinal epithelium by the monocarboxylate transporter 1, after which its biological utilisation relies on its conversion to L-Met. This process involves stereospecific HMTBA oxidation to 2-keto-(4-methylthio)butanoic acid (KMB) and transamination to L-Met. In the present study, we examined HMTBA conversion to L-Met, further incorporation into cellular proteins and the regulation of both processes by HMTBA supplementation in differentiated intestinal Caco-2 cells. The results showed D- and L-HMTBA oxidation in the enterocytes, this process being up-regulated by HMTBA. The data also revealed that KMB transamination is not linked to a specific amino group donor. However, the branched-chain amino acid L-leucine is the preferred amino group donor. Furthermore, transamination was not affected by HMTBA availability. The incorporation of radioactivity from HMTBA into cellular proteins was not significantly different from that of L-Met and was not affected by HMTBA supplementation. In conclusion, the results reveal the capacity of Caco-2 cells to convert HMTBA to L-Met and the up-regulation of conversion by nutritional HMTBA supplementation, thus highlighting the contribution of the intestinal epithelium in the utilisation of HMTBA as a dietary source of Met.

Growth performance, gastrointestinal tract responses, and meat characteristics of broiler chickens fed a diet containing the natural alkaloid sanguinarine from Macleaya cordata

SUMMARY Until the end of 2005, antibiotics were used in Europe in poultry nutrition as growth-promoting agents. The general European Union ban on antibiotic growth promoters, beginning in 2006, has encouraged the search for effective alternatives. Research not only on performance, but also on the physiological responses of birds is still sparse. This experiment was conducted to characterize, in addition to performance indices, the physiological effect of an alkaloid preparation, Sangrovit, obtained from the aerial parts Macleaya cordata, on the gastrointestinal tract (mainly ceca) of broiler chickens. Carcass meat characteristics and the fatty acid profile of breast meat were evaluated as well. One-day-old broiler chicks (Cobb 500) were fed a wheat-corn-soybean meal control diet without (control) or with a 30 mg/kg dose of the alkaloid preparation for 5 wk. The Sangrovit treatment did not significantly improve final BW, FCR, or breast muscle weight when compared with the control treatment. The n-6:n-3 fatty acid ratio in breast meat was significantly increased by the Sangrovit treatment. The sensory evaluation of breast and thigh meat did not reveal any negative influence of dietary supplementation with the alkaloid preparation. Supplementation of 30 mg/kg of the alkaloid-containing preparation Sangrovit in broiler diets without growth promoters can help perpetuate a beneficial cecal environment, reducing the activities of bacterial β-glucosidase (P = 0.095) and β-glucuronidase (P = 0.075) as well as decreasing pH of the digesta (P = 0.060).

Box-Behnken Design: alternative multivariate design in broiler nutrition research

The focus of the review is to show how the Box-Behnken Design (BBD) could be applied in poultry nutrition research. BBD is a multivariate experimental design which uses less treatment combinations and allows researchers to estimate and optimise processes. Box-Behnken design was used in an experiment to estimate growing broiler requirements for total sulphur amino acids (TSAA), lysine (Lys) and threonine (Thr). In the experiment BBD has shown to be a useful tool in estimating and optimizing nutrient requirements in growing broilers.

Trace Mineral Nutrition in Poultry and Swine

Trace minerals such as zinc, copper, and manganese are essential cofactors for hundreds of cellular enzymes and transcription factors in all animal species, and thus participate in a wide variety of biochemical processes. Immune development and transcription factors in all animal species, and thus participate in a wide variety of biochemical processes. Immune development and response, tissue and bone development and integrity, protection against oxidative stress, and cellular growth and division are just a few examples. Deficiencies in trace minerals can lead to deficits in any of these processes, as well as reductions in growth performance. As such, most animal diets are supplemented with inorganic and/or organic forms of trace minerals. Inorganic trace minerals (ITM) such as sulfates and oxides form the bulk of trace mineral supplementation, but these forms of minerals are well known to be prone to dietary antagonisms. Feeding high-quality chelated trace minerals or other classes of organic trace minerals (OTM) can provide the animal with more bioavailable forms of the minerals. Interestingly, many, if not most, published experiments show little or no difference in the bioavailability of OTMs versus ITMs. In some cases, it appears that there truly is no difference. However, real differences in bioavailability can be masked if source comparisons are not made on the linear portion of the dose-response curve. When highly bioavailable chelated minerals are fed, they will better supply the biochemical systems of the cells of the animal, leading to a wide variety of benefits in both poultry and swine. Indeed, the use of certain chelated trace minerals has been shown to enhance mineral uptake, and improve the immune response, oxidative stress management, and tissue and bone development and strength. Furthermore, the higher bioavailability of these trace minerals allows the producer to achieve similar or improved performance, at reduced levels of trace mineral inclusion.

The effect of germination on the phytase activity, phytate and total phosphorus contents of some Nigerian-grown grain legumes

Grain legumes are under-exploited as possible sources of phytase for the poultry industry. The current study was conducted to assess the effect of germination on phytase activities, phytate and total phosphorus content in samples of Nigerian-grown grain legumes. The legumes screened were African yambean (AYB, Sphenostylis stenocarpa), lima bean (Phaseolus lunatus), pigeon pea (Cajanus cajan), cowpea (Vigna unguiculata) and groundnut (Arachis hypogea). Phytase activity was low in AYB, lima bean and pigeon pea but high in cowpea and groundnut. Phytate content ranged between 3.01 g kg(-1) and 8.95 g kg(-1) while total phosphorus content ranged between 2.63 g kg(-1) and 5.93 g kg(-1). The grain legumes with higher phytase activity recorded the lowest phytate and phosphorus content. During germination there was an initial 4-fold to 35-fold increase in phytase activity after 6-7 days of germination followed by a decrease until 10 days (P < 0.05). The increase in phytase activity during germination was accompanied by a significant reduction in phytate (P < 0.05) and a small but significant increase in total phosphorus. The increase in phytase activity and the accompanying decrease in phytate content could have a positive implication for the nutrition of poultry and ruminants and for the environment.

Pois et tourteau de colza : deux matières premières complémentaires pour l’alimentation animale

Pea and rapeseed meal are protein rich feedstuffs. Despite their differences regarding composition their amino acid profiles are quite complementary. For growing and finishing pigs it is easy to formulate diets with pea and rapeseed meal all together without any soybean meal. Prices of feed are not increased. For poultry diets, peas and rapeseed meal can replace soybean meal in diets for slow growing birds but price of feed increases. Prices ratio of pea and wheat and rapeseed and soybean meals have to decrease to make pea and rapeseed meal more competitive for poultry nutrition.

Use of phytobiotics in broiler nutrition – an alternative to infeed antibiotics?

After the ban of antibiotic growth promoters (AGP) in the EU many alternative substances have been investigated for their potential to replace AGPs. Phytobiotics are discussed as one promissing alternative due to their high content of pharmacologically active compounds. A huge number of in vitro and in vivo studies have confirmed a wide range of activities of phytobiotics in poultry nutrition like stimulation of feed intake, antimicrobial, coccidiostatic and anthelmintic effects. The present paper gives a short review on the characteristics of phytobiotics, on the potential mode of action and on the observed effects of phytobiotics in diets on performance, carcass and meat quality and health status in broilers. Furthermore, it addresses safety concerns which may arise during application of phytobiotics.

Amino acid digestibility and poultry feed formulation: expression, limitations and application

The nutritional value or quality of dietary proteins used for poultry feed formulation varies: amino acid availability is an important measure of protein quality. Determination of ileal digestibility values has become the preferred method for estimating amino acid availability. This review discusses the different approaches to the expression of digestibility results, including correction for endogenous loss and the derivatisation of standardised values. Sources of variation in values include, the assay protocol, anti-nutritional factors in feedstuffs and feed milling. Feed formulating with ileal digestibility values should allow higher dietary inclusion levels of protein feedstuffs of lower quality provided that values of different feedstuffs are additive, the age of the bird and the use of feed enzymes are considered. An Australian data set of "ileal digestible amino acid values in feedstuffs for poultry" that has recently be published is described. This overview is intended to stimulate interest in the generation and application of ileal digestibility as a method for estimating amino acid availability in poultry nutrition.

Amino Acid Profile of Biodegraded Brewers Spent Grains (BSG)

The amino acids profiles of biodegraded brewers spent grains (BSG) were determined. The analysis revealed the presence of 17 amino acids including the major amino acids (cysteine, lysine and methionine) required in poultry nutrition. The concentrations of the amino acids however varied with the microbial species used in the degradation process. After 10 days of solid state fermentation at room temperature glusine, alanine and phenyalanine were detected at very high concentration in Aspergillus niger TF-4 degraded BSG. Glusine, alanine and proline were the major amino acid components of BSG degraded by Saccharomyces cerevisiae FP-4, while glusine, alanine and leucine were found to be the major components of BSG degraded by Streptomyces sp UU-2. The concentrations of the required amino acids except lysine were short of the standard requirement for poultry. However their concentrations were positively affected over time by biodegradation.

Potentials of Jatropha Seeds as Substitute Protein in Nutrition of Poultry

Potentials of Jatropha Seeds as Substitute Protein in Nutrition of Poultry