Progress towards reduced-crude protein diets for broiler chickens and sustainable chicken-meat production

AbstractThe prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein (CP) diets and sustainable chicken-meat production may be best achieved. Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions; moreover, they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents. The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed. The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids. Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine, this emphasises the value of so-called “non-essential” amino acids. Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed, although the functions of insulin in avian species require clarification. Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets; if so, the identification of the underlying reasons for this difference should be instructive. Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance. Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance. If progress in these directions can be realised, then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.

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Synthetic and Crystalline Amino Acids: Alternatives to Soybean Meal in Chicken-Meat Production

Animals ◽

10.3390/ani10040729 ◽

2020 ◽

Vol 10 (4) ◽

pp. 729 ◽

Cited By ~ 3

Author(s):

Peter H. Selle ◽

Juliano Cesar de Paula Dorigam ◽

Andreas Lemme ◽

Peter V. Chrystal ◽

Sonia Y. Liu

Keyword(s):

Amino Acids ◽

Soybean Meal ◽

Broiler Chickens ◽

Crude Protein ◽

Chicken Meat ◽

Meat Production ◽

Dietary Crude Protein ◽

Reduced Crude Protein ◽

Crystalline Amino Acids ◽

Protein Diets

: This review explores the premise that non-bound (synthetic and crystalline) amino acids are alternatives to soybean meal, the dominant source of protein, in diets for broiler chickens. Non-bound essential and non-essential amino acids can partially replace soybean meal so that requirements are still met but dietary crude protein levels are reduced. This review considers the production of non-bound amino acids, soybeans, and soybean meal and discusses the concept of reduced-crude protein diets. There is a focus on specific amino acids, including glycine, serine, threonine, and branched-chain amino acids, because they may be pivotal to the successful development of reduced-crude protein diets. Presently, moderate dietary crude protein reductions of approximately 30 g/kg are feasible, but more radical reductions compromise broiler performance. In theory, an ‘ideal’ amino acid profile would prevent this, but this is not necessarily the case in practice. The dependence of the chicken-meat industry on soybean meal will be halved if crude protein reductions in the order of 50 g/kg are attained without compromising the growth performance of broiler chickens. In this event, synthetic and crystalline, or non-bound, amino acids will become viable alternatives to soybean meal in chicken-meat production.

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Effects of reduced crude protein levels, dietary electrolyte balance, and energy density on the performance of broiler chickens offered maize-based diets with evaluations of starch, protein, and amino acid metabolism

Poultry Science ◽

10.1016/j.psj.2019.10.060 ◽

2020 ◽

Vol 99 (3) ◽

pp. 1421-1431 ◽

Cited By ~ 4

Author(s):

Peter V. Chrystal ◽

Amy F. Moss ◽

Ali Khoddami ◽

Victor D. Naranjo ◽

Peter H. Selle ◽

...

Keyword(s):

Amino Acid ◽

Energy Density ◽

Broiler Chickens ◽

Crude Protein ◽

Amino Acid Metabolism ◽

Acid Metabolism ◽

Electrolyte Balance ◽

Protein Levels ◽

Reduced Crude Protein

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The effect of commercially formulated, reduced crude protein diets, formulated to 11 apparent ileal digestible essential amino acids, on nitrogen retention by growing and finishing boars

Livestock Production Science ◽

10.1016/s0301-6226(02)00193-8 ◽

2003 ◽

Vol 81 (1) ◽

pp. 89-98 ◽

Cited By ~ 4

Author(s):

P.A. Lee ◽

R.M. Kay

Keyword(s):

Amino Acids ◽

Crude Protein ◽

Nitrogen Retention ◽

Essential Amino Acids ◽

Reduced Crude Protein ◽

Protein Diets

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Apparent ileal digestibility of amino acids and metabolisable energy value in grains for broilers

Agricultural and Food Science ◽

10.2137/145960605775897704 ◽

2008 ◽

Vol 14 (4) ◽

pp. 325 ◽

Cited By ~ 7

Author(s):

S. PERTTILÄ ◽

J. VALAJA ◽

T. JALAVA

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Broiler Chickens ◽

Crude Protein ◽

Dry Matter ◽

Nitrogen Excretion ◽

Ileal Digestibility ◽

Metabolisable Energy ◽

Feed Protein ◽

Digestible Amino Acids

Using ileal digestible amino acids in feed optimising will intensify feed protein utilizing and decrease nitrogen excretion to the environment. The study determined the apparent ileal digestibility (AID) coefficients of amino acids in barley, wheat, oats, triticale, maize, and dehulled oats in the diets of 180 Ross broiler chickens (aged 2435 days). The birds were fed semi-purified diets that contained grain as the sole protein source and chromium-mordanted straw as an indigestible marker. The AID coefficients of the nutrients were assessed using the slaughter technique, and the apparent metabolisable energy (AME) was determined using total excreta collection. The ileal digestibility of the dry matter and organic matter were the highest in maize. The AME of maize was higher than that of other cereals. The ileal digestibility of crude protein was higher in wheat than that in barley, oats and dehulled oats. The AME of wheat was similar to that of barley and oats but lower than that of triticale and dehulled oats. The amino acid AID was highest in wheat (0.86) and triticale (0.85) and lowest in oats (0.79) and barley 0.77). The average amino acid AID was 0.81 in dehulled oats. The threonine AID was the same in all tested ingredients. The lysine, methionine, and cystine AID coefficients were 0.81, 0.79, and 0.71 respectively for barley; 0.86, 0.84, and 0.38 respectively for oats; 0.87, 0.86, and 0.53 respectively for dehulled oats; 0.84, 0.90, and 0.66 respectively for maize; 0.89, 0.88, and 0.77 respectively for triticale; and 0.87, 0.85, and 0.71 respectively for wheat. Results indicated that AME values of domestic grains (barley, oats and wheat) are in the same level. Especially, low AME value of wheat needs further investigation.;

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High protein wheats for poultry. 1. Use in broiler diets

Australian Journal of Experimental Agriculture ◽

10.1071/ea9710619 ◽

1971 ◽

Vol 11 (53) ◽

pp. 619 ◽

Cited By ~ 3

Author(s):

W Turner ◽

GG Payne

Keyword(s):

Amino Acids ◽

Growth Rate ◽

Amino Acid ◽

Crude Protein ◽

Maximum Level ◽

Essential Amino Acids ◽

High Protein ◽

Amino Acid Supplementation ◽

Dietary Factor ◽

Protein Diets

High protein wheat was the sole cereal in 20 and 25 per cent crude protein broiler starter diets. On the. 25 per cent protein diet, performance was maximized without amino acid supplementation. Using high protein wheat in 20 per cent protein diets, growth rate was improved by l-lysine supplementation of 0.3 per cent. However, this growth rate was not at a maximum level. Some other dietary factor was necessary, and this did not appear to be essential amino acids, singly or in combination.

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Effect of diet and infusion of volatile fatty acids into the rumen on the concentration of plasma free amino acids in sheep

British Journal Of Nutrition ◽

10.1079/bjn19820137 ◽

1982 ◽

Vol 48 (3) ◽

pp. 519-526 ◽

Cited By ~ 3

Author(s):

J. R. Mercer ◽

E. L. Miller

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Free Amino ◽

Volatile Fatty Acids ◽

Plasma Concentrations ◽

Essential Amino Acids ◽

Protein Nitrogen ◽

Post Infusion ◽

Limiting Amino Acid ◽

The Mean

1. The effect of supplementing barley diets with urea (U), extracted decorticated groundnut meal (GNM) or Peruvian fish meal (PFM) on plasma free amino acid concentrations in sheep have been examined and the first limiting amino acid has been indicated by measuring the changes in the concentration of the plasma essential amino acids (PEAA) during a rumen infusion of a volatile fatty acid (VFA) mixture.2. Three wethers fitted with rumen and re-entrant duodenal cannulas were given isonitrogenous, isoenergetic diets containing (g/kg dry matter (DM)) U 20, GNM 106 or PFM 78, the crude protein (nitrogen × 6.25) contents being 139, 145 and 148 respectively. The sheep were fed hourly, the mean daily dm intake being 0.634 kg.3. Plasma concentrations of valine, threonine, lysine, isoleucine and leucine were linearly related to their concentrations in duodenal digesta.4. A VFA mixture was infused into the rumen for 6 h to supply (mmol/min) acetate 1.47, propionate 0.22 and n-butyrate 0.27. Blood samples were taken 6 h before, during and 12 h after the end of the infusion.5. The concentration of all PEAA decreased relative to the pre-infusion and post-infusion controls but there were no significant differences between diets.6. The mean decreases in concentration averaged over all three diets showed that the decrease in concentration of methionine (41.5%) was far greater than for any other essential amino acid suggesting that under these conditions methionine was the first limiting amino acid.

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Response of adult rats to deficiencies of different essential amino acids

British Journal Of Nutrition ◽

10.1079/bjn19740007 ◽

1974 ◽

Vol 31 (1) ◽

pp. 47-57 ◽

Cited By ~ 18

Author(s):

A. K. Said ◽

D. M. Hegsted ◽

K. C. Hayes

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Nutritive Value ◽

Plasma Concentrations ◽

Essential Amino Acids ◽

The Body ◽

Adult Rats ◽

Short Period ◽

Body Weights ◽

Fatty Livers

1. Adult rats were fed on diets free of either lysine, methionine, threonine or protein. The threonine- and protein-deficient animals lost weight at approximately the same rate, about 100 g in 14 weeks, at which time several were moribund. In contrast, lysine-deficient animals lost only about 30 g in 14 weeks and had lost only 46 g after 22 weeks, when they were killed. Methionine-deficient animals showed an intermediate response. Losses in weight of several tissues – kidney, heart and two muscles – were related to, but not necessarily proportional to, the loss of body-weight. Liver weights relative to body-weights were large in lysine- and threonine-deficient animals and smallest in methionine-deficient animals.2. Adult rats were fed on diets containing zero, a moderate amount (about twice the estimated minimal requirement) or an excess (about four times the estimated requirement) of lysine or threonine in all combinations (3 × 3 design). Analysis of variance of the body-weights, tissue weights and tissue nitrogen contents indicated, in general, a significant effect of each amino acid, as expected, but also, in most instances, a significant interaction. Plasma concentrations of lysine and threonine were affected by the intakes of the respective amino acids, but plasma lysine concentrations were also affected by the threonine intake.3. Liver histology also suggested significant interactions between the two amino acids. Animals given no lysine but moderate amounts of threonine developed severely fatty livers; next most severely affected were animals receiving excess of both amino acids. Threonine deficiency, in the presence or absence of lysine, produced moderately fatty livers similar to those seen in protein-deficient animals.4. Since animals have varying ability to conserve body nitrogen when they are fed on diets limiting in different essential amino acids, measurements of biological value (BV) and net protein utilization by conventional methods, over a short period of time, over-estimate nutritive value relative to amino acid score and probably over-estimate the true nutritive value of poor-quality proteins, particularly those limiting in lysine. If so, this is a serious error, since it leads to underestimates of the protein requirements if BV is used. The fact that certain tissues, particularly the liver, do not necessarily lose nitrogen in proportion to total body nitrogen and may show specific pathological effects depending on the limiting amino acid or the proportions of amino acids in the diet also indicates that general measures of nitrogen economy may not be sufficiently discriminating tests of the nutritive value of proteins.

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FEATHER GROWTH AND FEATHER COMPOSITION OF BROILER CHICKENS

Canadian Journal of Animal Science ◽

10.4141/cjas81-093 ◽

1981 ◽

Vol 61 (3) ◽

pp. 769-773 ◽

Cited By ~ 29

Author(s):

MARY-LOU FISHER ◽

S. LEESON ◽

W. D. MORRISON ◽

J. D. SUMMERS

Keyword(s):

Amino Acids ◽

Broiler Chickens ◽

Crude Protein ◽

Research Council ◽

National Research Council ◽

Essential Amino Acids ◽

Controlled Environment ◽

Broiler Chicks ◽

Amino Acid Requirements ◽

Methionine Content

Feather-sexed broiler chicks were reared in litter floor pens in a controlled environment building and offered mash diets meeting National Academy of Science-National Research Council specifications. Ten birds of each sex were killed at weekly intervals and individual feather weight recorded. These feathers were analyzed for crude protein and essential amino acids. From within five replicate pens of each sex, litter was removed weekly from 28 to 49 days, and molted feathers removed, cleaned and weighed. Feather weight was consistently correlated (P < 0.05) with body weight only from 5–7 wk of age. Females lost consistently more feathers than male birds, with this differential being a factor of 3.5. The methionine content of feathers decreased with age, while that of threonine, isoleucine and valine increased with age. The data are presented for use in model prediction of broiler amino acid requirements.

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Connection of protein and amino acid content of forage and medium quality winter wheat varieties

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/36/2799 ◽

2009 ◽

pp. 101-107

Author(s):

Zoltán Mezei ◽

Ágnes Pongrácznl Barancsi ◽

Péter Sipos ◽

Zoltán Győri ◽

János Csapó

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Protein Content ◽

Acid Content ◽

Crude Protein ◽

Amino Acid Content ◽

Essential Amino Acids ◽

Crude Protein Content ◽

Wheat Varieties ◽

Winter Wheat Varieties

We analysed the crude protein content, amino acid content, amino acid composition of four forage and milling III. quality winter wheat varieties (Magor, Hunor, Róna and Kondor) from their samples from five following years (2003, 2004, 2005, 2006, 2007). We found that quantity of essential and non-essential amino acids rose with increase in crude protein content. On examination of protein amino acid composition in relation to crude protein content we found that the crude protein content increased the quantities of the non-essential amino acids also rose, while those of the essential amino acids decreased as the lysine, the limiting amino acid of wheat. We also established that, as crude protein content increased, the biological value of the protein decreased.

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