Ideal Protein Concept Research Articles

Performance and utilization of dietary energy and amino acids in piglets fed low protein diets

A total of 32 Piétrain×(Landrace×Large White) barrows were used to test the effect of reducing the dietary crude protein (CP) level on performance and composition of gain in piglets from 12 to 27 kg. Four diets based on corn, wheat, barley and soybean meal providing 1.01 g of ileal digestible lysine per MJ of NE (net energy) were prepared. Diet 1 was formulated without free amino acids (AA), while in diets 2–4, CP level was progressively reduced and free AA were supplemented according to the ideal protein concept. The CP levels were 224, 204, 184, 169 g/kg for diets 1, 2, 3 and 4, respectively. Piglets were housed individually and had free access to feed and water. The feed intake was measured daily. At the end of the experiment, animals were slaughtered and body composition was measured. The 12 control piglets were slaughtered at the beginning of the experiment and the composition of gain (water, ash, protein lipid, AA and energy) was calculated according to the comparative slaughter technique. Feed intake was the lowest ( P<0.05) with diet 1 (959 g/day) and similar for diets 2–4 (1049 g/day, on average). Nevertheless, average daily gain of the animals did not differ between treatments (666 g/day, on average). Reducing CP level resulted in a numerically reduced water consumption and urine production, but no effect on the occurrence of diarrhea was observed. The N excretion over the total experiment was reduced by 42% from diet 1 to diet 4. At identical ME (metabolizable energy) intakes (2.52 MJ/day per kg BW 0.60), protein and lipid composition of gain (18.9 and 13.0 g/day per kg BW 0.60, on average) were not affected by the diet. Energy gain (0.94 MJ/day per kg BW 0.60) and heat production (1.58 MJ/day per kg BW 0.60) were also not different between treatments. The amino acid pattern of deposited protein was not affected by dietary CP level, except that histidine deposition was significantly smaller with diets 3 and 4. These results indicate that a reduction of dietary CP level by up to 55 g/kg in association with adequate AA supplementation does not affect the level of performance and body composition of piglets and contributes to lower N excretion.

Study of the optimum ideal protein level for weaned piglets

The amount of ideal protein, represented by the first limiting valine (Val), for optimising the growth performances of weaned hybrid piglets was studied. Feeds were formulated based on the ideal protein concept and on a constant essential/nonessential amino acid (AA) ratio and net energy (NE) level. The animal performance trial was composed of five dietary treatments ranging from 0.57 to 0.81% calculated apparent (app.) ileal (il.) digestible (dig.) Val. The piglets, male and female in equal numbers (11 replicates x 6 piglets/pen x 5 treatments) entered the trial at about 4 weeks old (average live weight 8.1 kg). The piglets were a cross product of Piétrain sire x hybrid dam. Feed intake and weight were recorded every two weeks until the end of the trial at 10 weeks of age (average live weight 20.6 kg). The requirement was expressed in st. il. dig. AA-units, as this unit approaches available AA better than app. il. dig. AA. The standardised (st.) il. AA digestibility coefficients (DCAA) were determined for two feeds, close to the animal performance optima, in a digestion trial with four T-cannulated piglets of approximately 6 weeks old. The feed independent endogenous nitrogen excretion was measured with a protein-free feed; although this technique underestimates the actual endogenous N-losses, it provides a reasonable estimate of basal endogenous N-losses. The determined st. il. DCAA were lower than the calculated st. il. DCAA, based on the CVB (2000); this might be linked to the higher than expected crude fibre content of the experimental feeds. The Val-requirement necessary to optimise ADG and FCR was similar and amounted 0.70% st. il. dig. Val, which corresponded with a st. il. dig. Lys-level of 1.03%.

Substituição Parcial do Farelo de Soja pela Farinha de Vísceras de Aves em Dietas Balanceadas com Base na Proteína e em Aminoácidos Totais ou Digestíveis para Frangos de Corte

A formulação com base no conceito de proteína ideal (PI) é mais eficiente quando são usados ingredientes alternativos ao milho (M) e ao farelo de soja (FS). Assim, o objetivo desse trabalho foi comparar formulações de dietas utilizando o conceito de PI, usando farinha de vísceras (FV) em substituição ao FS, em dietas de frangos de corte. Os tratamentos foram os seguintes: T1 = dieta com 22 % e 20% de proteína bruta (PB) nas fases inicial (FI) e de crescimento (FC) e 3200 kcal/kg de EM durante todo experimento; T2 = energia semelhante a dieta T1 e PI à base de M e FS (1,15% de lisina digestível na FI e 0,90% de lisina digestível na FC; T3=dieta semelhante a T2, com 20 % e 25 % de substituição do FS por FV nas FI e FC, respectivamente; T4=dieta semelhante a T3, com 40 e 50 % de substituição do FS por FV, nas FI e FC, respectivamente; T5=dieta semelhante a T4, porém com balanço por aminoácidos (AA) totais (1,10 e 1,00 % de lisina total nas FI e FC, respectivamente). Os resultados permitiram concluir que a formulação com base na PI é melhor do que aquela que considera a PB ou AA totais. A inclusão de 20 % FV na FI e 25 % na FC de frangos de corte, em substituição ao FS, melhorou o desempenho até os 21 dias e não alterou o desempenho até os 42 dias em dietas formuladas dentro do conceito de proteína ideal.

Exigência de Lisina, com Base no Conceito de Proteína Ideal, para Suínos Machos Castrados de Dois Grupos Genéticos, na Fase de Crescimento

Foi conduzido um experimento para determinar as exigências de lisina para suínos machos castrados, de dois diferentes grupos genéticos na fase de crescimento, com base no conceito de proteína ideal. Foram utilizados 16 suínos do grupo genético comum (GGC) e 16 suínos do grupo genético melhorado (GGM), distribuídos em um delineamento de blocos ao acaso, com quatro tratamentos, duas repetições e dois animais por baia. Os tratamentos consistiram de uma ração referência, à base de milho e farelo de soja, contendo 0,75% de lisina e outras três rações, acrescentando-se níveis crescentes de lisina para se obter 0,90, 1,05 e 1,20% de lisina total na ração. Adicionou-se aminoácidos sintéticos (L-lisina HCl, DL-metionina, L-treonina e L-triptofano) para manter os níveis de aminoácidos, de acordo com o perfil de proteína ideal. Para o GGC (20 a 50 kg de peso vivo), as variáveis, consumo de ração diário (CRD), ganho de peso diário (GPD) e conversão alimentar (CA) não sofreram efeito dos níveis de lisina (NL). Observou-se efeito quadrático dos NL sobre o CRD e GPD para o GGM (24 a 45 kg de PV) de 0 a 14 e de 0 a 18 dias, mas não no período total de experimento. Não houve diferença entre GGC e GGM para a variável nitrogênio da uréia plasmática. A exigência de lisina total, baseado no conceito de proteína ideal, para suínos machos castrados do GGM (24 a 45 kg de peso vivo) é de 1,00%, enquanto que para GGC (20 a 50 kg de peso vivo) é de 0,75%.

Proteína Bruta e Proteína Ideal para Frangos de Corte no Período de 1 a 21 Dias de Idade

Dois experimentos foram realizados com o objetivo de avaliar o desempenho de frangos de corte no período de 1 a 21 dias alimentados com dietas formuladas nos conceitos de proteína bruta e proteína ideal. No primeiro experimento, foram utilizados 400 pintos machos de um dia de idade da linhagem Cobb, distribuídos em delineamento inteiramente casualizado, com 2 tratamentos (proteína total e proteína ideal) e 5 repetições de 40 aves cada. No segundo experimento, foram utilizados 800 pintos, 400 machos e 400 fêmeas, em arranjo fatorial 2x2 (2 formulações - proteína bruta e proteína ideal e 2 sexos) com 4 tratamentos e 5 repetições de 40 aves cada. As dietas foram formuladas atendendo às exigências estabelecidas pela DEGUSSA (1997). Aos 21 dias, foram avaliados, o ganho de peso, o consumo de ração e a conversão alimentar. No experimento 1, as aves alimentadas com dietas formuladas no conceito de proteína ideal apresentaram maior ganho de peso e maior consumo de ração. No experimento 2, as aves que se alimentaram com a dieta formulada com base da proteína ideal apresentaram melhor ganho de peso e melhor conversão alimentar, não influenciando o consumo de ração. Os resultados demonstraram que as aves alimentadas com dietas baseadas no conceito de proteína ideal apresentam melhor desempenho.

DESEMPENHO DE FRANGOS DE CORTE, SEXADOS, SUBMETIDOS A DIETAS FORMULADAS PELOS CONCEITOS DE PROTEÍNA BRUTA versus PROTEÍNA IDEAL

O trabalho foi conduzido no Setor de Avicultura do Departamento de Zootecnia da Universidade Federal de Santa Maria com o objetivo de verificar as respostas de desempenho de frangos de corte, criados com sexos separados, alimentados pelo conceito tradicional (Proteína Bruta - PB) em comparação a dietas formuladas pelo critério de Proteína Ideal (PI), num período de 1 a 42 dias de idade. A análise econômica comparativa entre os dois métodos de alimentação também foi realizada. Foram utilizados 960 pintos de corte de um dia de idade (480 machos, 480 fêmeas) da linhagem ROSS. As dietas experimentais baseadas no conceito de PB foram formuladas segundo as recomendações do NRC (1994) e as dietas formuladas pelo conceito de PI foram adaptadas de HAN &amp; BAKER (1994). O delineamento experimental foi o inteiramente casualizado, constituindo 4 tratamentos com 12 repetições de 20 aves cada. Foram estudados os parâmetros: consumo alimentar, ganho de peso e peso corporal, ganho médio diário, conversão alimentar e índice de eficiência nutricional. Os resultados obtidos indicaram que os parâmetros estudados foram mais influenciados na fase inicial. As dietas formuladas pelo conceito de PI, baseada no conteúdo de aminoácidos digestíveis (AAD), influenciaram positivamente os parâmetros estudados, proporcionando significativos melhores ganhos de peso e eficiência alimentar, tanto para os machos quanto para as fêmeas nas fases inicial e total, sendo similares nas demais fases. As aves alimentadas com AAD apresentaram uma maior lucratividade nas fases inicial e crescimento. Esses dados permitem concluir que dietas à base de milho e farelo de soja, formuladas para atender às exigências de AAD, proporcionam melhores desempenhos biológico e econômico, em relação àquelas formuladas à base de PB, do primeiro até os 35 dias de idade. A fase final mostrou o contrário, sendo o conceito de PB mais econômico do que a Pl.

A strategy to solve environmental concerns caused by poultry production

Poultry manure and litter have the potential to be either land resources or pollutants of surface and ground water as well as giving rise to unpleasant odours. Provided proper attention is paid to nutrient management, they can be used as fertilisers, soil amendments and feed ingredients. Furthermore, the contents of nitrogen, phosphorus and other minerals in poultry manure and litter can be reduced by paying careful attention to diet composition – for example, by applying the concept of ideal protein, supplementation with synthetic amino acids, the addition of various types of enzymes including phytase, the lowering of the protein and phosphorus contents and the use of highly available sources of supplementary phosphorus and vitamin D. Good nutrient management also depends on obtaining representative samples of feed, manure, litter, water and soil from each handling system and having these analysed on a regular basis in a reliable laboratory. This not only ensures that proper quantities of nutrients are added to the native soil on which the crops that are ultimately to be used as feed sources are to be grown, but also means that lower amounts of nitrogen, phosphorus and other elements are present in the feed. One outcome of the latter effect is that the poultry manure and litter excreted contains fewer potential pollutants and reduces the criticism levelled at the poultry industry that it runs roughshod over environmental concerns. It would be beneficial if all of these analytical procedures were handled in one laboratory specialising in animal agriculture with specialists advising farmers on how best to apply the analytical data.

Níveis de lisina para leitoas selecionadas geneticamente para deposição de carne magra, dos 30 aos 60 kg, mantendo constante a relação entre lisina e metionina+cistina, treonina, triptofano, isoleucina e valina

Foram utilizadas 40 leitoas mestiças (Hampshire, Landrace Belga, Pietran) com peso inicial médio de 30,1±1,25 kg e alto potencial genético para deposição de carne magra na carcaça, para avaliar diferentes níveis de lisina. Foi usado delineamento de blocos ao acaso com quatro tratamentos, cinco repetições e dois animais por unidade experimental. Os tratamentos corresponderam a uma ração basal com 17,5% de proteína bruta, suplementada com quatro níveis de L-lisina HCl, resultando em rações com 1,00; 1,10; 1,20; e 1,30% de lisina. As rações foram suplementadas com níveis crescentes de treonina, metionina, isoleucina, valina e triptofano, resultando em rações nas quais a relação entre estes aminoácidos e a lisina se manteve constante em 67, 62, 60, 68 e 19%, respectivamente, com base na digestibilidade verdadeira. Não se observou efeito dos tratamentos sobre consumo de ração, ganho de peso diário e concentração de uréia no soro sangüíneo dos animais, entretanto, os animais pareceram ter atingido o potencial genético máximo para ganho de peso no nível de lisina de 1,10% (0,329%/Mcal de ED), correspondente a um consumo de lisina de 22 g/dia. Observou-se efeito linear sobre o consumo de lisina diário, que aumentou, e a conversão alimentar, que reduziu com o aumento do nível de lisina da ração. O nível de 1,30% (0,389%/Mcal de ED) ou 1,19% (0,356%/Mcal de ED), correspondente a um consumo de lisina total e digestível, respectivamente, de 24 e 22,1 g/dia, proporcionou os melhores resultados de conversão alimentar de leitoas dos 30 aos 60 kg, quando se utilizou o conceito de proteína ideal na formulação das rações experimentais.

Canulación de cerdos posdestete para pruebas de digestibilidad ileal: desarrollo de una metodología

Reis de Souza TC, Mar BB, Mariscal LG. Tec Pecu Mex 2000,38(2)143-150. The new standards in swine nutrition use the ideal protein concept, because they demand a better knowledge of raw materials used in feed formulation, and the rations should provide an amino acid profile at ileal level. To obtain this goal, the amino acid ileal digestibility value must be known. The majority of the research has been performed in growing pigs, nevertheless, it is accepted that the piglet has an immature digestive tract so their digestive capacity is lower than in the growing pigs. In this technical note, we describe a technique to implant a simple T cannula at ileal level in growing pigs and in weaning piglets of 21 days of age. This technique permited to measure ileal digestibility in piglets of 28 and 35 days of age (first and second postweaning week) and growing pigs with 40 kg of live weight.

Lysine: Ideal protein in turkeys

This paper will review current and previous research related to our work on ideal proteins for turkeys. The concept of ideal protein is not new, but has not been researched in turkeys to any extent. Ideal proteins may be defined as the exact balance of amino acids needed for maximal growth. Ideal proteins are based on digestible amino acids. Several pieces of information need to be in place before one can actually run an experiment on the digestible amino acid requirements and ideal protein. The first of these is data on digestible amino acid content of feedstuffs for turkeys. The second necessity is a low protein diet that can be used to titrate the amino acids on a digestible basis. These requirements led us to formulate a very low protein starter diet (approximately 18% intact crude protein + amino acids) with corn and soybean meal that would support maximal growth. To formulate a diet at this crude protein level, it was necessary to use the ideal protein research from other species and previous research with turkeys. We now have an estimate of the ideal protein for turkeys. The future of this work and amino acid nutrition of turkeys will be reviewed.

Use of the Ideal Protein Concept for Precision Formulation of Amino Acid Levels in Broiler Diets

Ideal amino acid ratios for chicks during the early growth period (0 to 21 days) are well documented by empirical evidence, but suggested ratios for older birds are in need of confirmation. Based on best empirical estimates of lysine, SAA, and threonine requirements of broiler chicks during 0 to 21, 21 to 42, and 42 to 56 days of age, together with new knowledge of maintenance contributions to the total requirement for these amino acids, it appear that the ideal ratio of SAA and threonine to lysine may change very little as birds advance in age and weight toward a 56-day market weight. This paper presents regression equations that predict both digestible and total lysine, SAA, and threonine requirements at any age or weight between hatching and 56 days.

The effect of reducing excess dietary amino acids on growing-finishing pig performance: an elevation of the ideal protein concept.

Seventy-two gilts were used to determine the effect of reducing excess amino acid intake on growing-finishing pig performance. Separate diets were formulated for the growing (20 to 55 kg BW) and finishing (55 to 100 kg BW) periods. For each period, three diets were formulated that varied in total crude protein level and contained similar levels of digestible ideal protein. Crystalline amino acids were added to the low protein diets to overcome potential deficiencies. The grower diets contained .66% apparent ileal digestible lysine and contained 16.6, 15.0, and 13.0% CP, respectively; for the finisher diets, these values were .55% digestible lysine and 14.2, 12.8, and 11.0% CP, respectively. Amino acid analyses and a separate digestibility trial were conducted to confirm digestible amino acid levels in the dietary ingredients. During the growing and the overall growing-finishing period, daily gain, feed intake, and gain:feed were not affected (P > .10) by dietary treatment. Daily gain tended to be lower (P = .06) and gain:feed was poorer (P < .05) for pigs fed the 11.0% CP diet during the finishing phase. Although backfat thickness tended to be greater (P = .07) for pigs fed the lower-CP diet, estimated carcass lean yield was not affected (P > .10) by dietary treatment. Results of this study show that dietary CP can be reduced to 13% in the growing and 12.8% in the finishing diets of pigs as long as crystalline amino acids are added to match the apparent ileal digestible amino acid ratios in an assumed ideal protein.