THE ECONOMIC IMPACT OF FREE LYSINE ON THE PROTEIN FEEDS INDUSTRY IN N.S.W.

Free lysine, an amino acid produced industrially by microbial fermentation, is becoming increasingly important in intensive livestock production. Estimates are made of the economic impact of its wider use. The economic impact of doubling the current utilization rate of free lysine in pig production is also investigated. It is shown that the use of free lysine as a replacement for protein concentrates is marginally profitable at current utilization rates and prices. However, if experimental techniques of doubling free lysine utilization rates are adopted by the industry, the use of free lysine could lower costs of pig diets and substantially replace high lysine protein concentrates in pig diets

Sucrose as an energy source for growing pigs: Digestible energy content and energy utilization

Two experiments were conducted to determine the effect of including sucrose in diets on energy utilization by growing pigs. In the first experiment, the digestible energy (DE) content of sucrose was determined as 15·6 MJ/kg, indicating that gross energy was 0·96 digested. In the second experiment, iso-energetic diets were used to determine the effects of sucrose on growth and nutrient utilization. Sucrose was used to replace wheat gradually in four iso-energetic diets (15 MJ DE, 0·75 g lysine per MJ DE for pigs from 20 to 50 kg live weight and 15·1 MJ DE, 0·67 g lysine per MJ DE for pigs from 50 to 80 kg live weight). Pigs were fed ad libitum. Food intake (P 0·05). Sucrose inclusion decreased the crude fibre and crude protein content of the diet and energy utilization was improved. Differences in gut fill indicated that sucrose-based diets were rapidly digested and absorbed

THE ECONOMIC IMPACT OF FREE LYSINE ON THE PROTEIN FEEDS INDUSTRY IN N.S.W.

Free lysine, an amino acid produced industrially by microbial fermentation, is becoming increasingly important in intensive livestock production. Estimates are made of the economic impact of its wider use. The economic impact of doubling the current utilization rate of free lysine in pig production is also investigated. It is shown that the use of free lysine as a replacement for protein concentrates is marginally profitable at current utilization rates and prices. However, if experimental techniques of doubling free lysine utilization rates are adopted by the industry, the use of free lysine could lower costs of pig diets and substantially replace high lysine protein concentrates in pig diets.Livestock Production/Industries,

The effect of heat on amino acids for growing pigs

Two growth experiments were conducted to determine the effect of heat on the utilization of ileal-digestible lysine from field peas (Pisum sativum cultivar Dundale) fed to growing pigs. Five lysine-deficient diets (0–36 g ileal-digestible lysine/MJ digestible energy (DE)) were formulated using raw field peas, and field peas heated to either 110°, 135°, 150°, or 165° for 15 min respectively in a forced-air dehydrator. Additional diets were formulated with supplements of free lysine to verify that lysine was limiting in the diets containing the raw peas, and peas heated to 150° or 165°. The growth performance and retention of ileal-digestible lysine by pigs given the diets was determined over the 20–45 kg growth phase. Heat had a significant quadratic effect (P > 0–01) on growth rate, with responses declining from 543 g/d with pigs given the raw peas, to 407 g/d for those given the peas heated to 165°. Similarly, crude protein deposition declined in a quadratic manner (P > 0 001) from 76 to 36 g/d for pigs fed on raw peas and peas heated to 165° respectively. Retention of ileal-digestible lysine was 0.85 in the pigs given the raw field peas and declined in a quadratic manner (P > 0.001) with the application of heat to 048 in those pigs given the peas heated to 165°. Pigs fed on field peas heated to 165° had increased (P > 0 05) liver weights. The results indicate that heat applied to protein concentrates, even at mild temperatures, renders lysine in a form that is apparently absorbed but inefficiently utilized by the growing pig. Consequently, ileal digestibility values for lysine in heat-processed meals are unsuitable for diet formulations

Determinação das perdas endógenas e da digestibilidade ileal da proteína e dos aminoácidos em suínos utilizando-se duas técnicas Use of different techniques to determine endogenous losses and ileal digestibility of protein and amino acids for swine

Objetivou-se neste estudo determinar os coeficientes de digestibilidade ileal verdadeira da proteína e dos aminoácidos digestíveis de um extrato protéico de levedura utilizando-se duas técnicas - dieta isenta de proteína (DIP) e dieta com caseína hidrolisada enzimaticamente (CHE) - para determinação das perdas endógenas de proteína, aminoácidos e nitrogênio. Foram utilizados 12 suínos mestiços, machos castrados, com peso médio de 35 kg, submetidos previamente a cirurgia para implantação da cânula T simples. O delineamento experimental foi o inteiramente casualizado com três tratamentos (dieta com CHE; dieta isenta de proteína (DIP); e dieta com 23% do extrato protéico de levedura - ingrediente teste), quatro repetições e um animal por unidade experimental. As perdas endógenas de ácido glutâmico, ácido aspártico, lisina, arginina e serina diferiram entre as dietas; os maiores valores foram obtidos nos animais que receberam a dieta com CHE. O maior valor de perda endógena do aminoácido glicina foi determinado nos animais alimentados com a dieta DIP. Os coeficientes de digestibilidade ileal verdadeira de metionina, treonina, triptofano e serina determinados pelas perdas endógenas utilizando-se a dieta CHE foram superiores àqueles determinados utilizando a dieta DIP. As quantidades das secreções protéicas e de aminoácidos obtidas pela técnica da CHE foram maiores que as determinadas pela técnica da DIP. Os coeficientes de digestibilidade verdadeira da proteína foram menores e os dos aminoácidos, maiores, quando determinados pela técnica CHE.<br>The objective of this study was to determine the true ileal digestibility coefficients of the protein and digestible amino acid of a yeast protein extract using two techniques - diet without protein (DIP) and diet with enzime-hydrolysed casein (CHE) - for the determination of protein amino acid and nitrogen losses. Twelve half-breed barrows were used, with average weight of 35 kg, previously submitted to a surgery for "T" simple cannula implantation. A completely randomized experimental design with three treatments, four replications and one animal per experimental unit was used. The treatments diets with CHE, DIP diet with 23% CP were constituted by yeast protein extract. Endogenous losses of glutamic acid, aspartic acid, lysine, arginine and serine differ among diets, the higher values were observed for animals consumed CHE diet. The higher endogenous losses values observed for glycine was determined in the animals fed DIP diet. The true ileal digestibility coefficients of methionine, threonine, tryptophan and serine determined with the endogenous losses using CHE diet were higher than those determined using DIP diet. The amounts of protein and amino acids secretions obtained by using CHE technique were higher than those obtained by the DIP technique. True protein digestibility coefficients of protein were lower and amino acid higher when determined by CHE technique

Exigências de treonina de leitões dos 7 aos 12 e dos 12 aos 23 kg Threonine requirements of piglets from 7 to 12 and from 12 to 23 kg

Foram realizados dois experimentos (E) com 204 leitões Large White (E1: dos 7,23 aos 12,32 kg; e E2: dos 12,64 aos 23,81 kg). O delineamento experimental foi de blocos ao acaso com quatro níveis de treonina na ração (E1: 0,80; 0,87; 0,93 e 0,99 %; e E2: 0,69; 0,74; 0,80 e 0,85 %); oito (E1) e nove (E2) repetições para o consumo diário de ração (CDR), ganho diário de peso (GDP), ganho diário de peso ajustado (GDPA) e conversão alimentar (CA); e cinco repetições para uréia plasmática (U). Não se observaram diferenças no CDR e GDP (P>0,10). Verificaram-se efeitos quadráticos da treonina no GDPA do E1 (P=0,086) e E2 (P=0,052), na CA do E2 (P=0,035) e na U do E1 (P=0,002), bem como efeito linear negativo na CA do E1 (P=0,030) e U do E2 (P=0,044). O nível de 0,89% de treonina minimizou o teor plasmático de uréia e o de 0,94% maximizou o ganho diário de peso ajustado no E1, enquanto no E2 0,76% de treonina na ração maximizou o ganho diário de peso ajustado e minimizou a conversão alimentar.<br>Two experiments (E) were conducted, using 204 Large White piglets (E1: from 7.23 to 12.32 kg; and E2: from 12.64 to 23.81 kg). A randomized block design was used, with four levels of threonine in the ration (E1: 0.80; 087; 0.93 e 0.99%; e E2: 0.69; 0.74; 0.80 e 0.85 %); eight (E1) and nine (E2) replicates for daily intake (DI), daily weight gain (DWG), adjusted daily weight gain (ADWG) and feed conversion (FC) and five replicates for plasma urea (U). No treatment differences (P>0.10) were observed for either DI or DWG. Quadratic effects of threonine were observed on ADWG in E1 (P=0.086) and E2 (P=0.052), on FC in E2 (P=0.035) and on U in E1 (P=0.002); as well as a linear effect on FC in E1 (P=0.030) and on U in E2 (P=0.044). U was minimized at 0.89% threonine in E1, whereas ADWG was highest at 0.94%, in E2, 0.76% threonine maximized ADWG and minimized FC