Apparent Metabolizable Energy Values Research Articles

Digestibility and energy value of cereal-based diets in relation to digesta viscosity and retention time in turkeys and chickens at different ages estimated with different markers

Digesta viscosity, ileal transit time of digesta, apparent ileal protein digestibility and apparent metabolisable energy (AMEN) of diets based on wheat and dehulled barley (WB), oats (O) or a mixture of these (WBO) fed as such or with enzyme supplementation in three- and six-week old turkeys and broilers were investigated. In addition, differences between ileal digestibility and AMEN calculated by using titanium dioxide (TiO2), chromic oxide (Cr2O3) or acid insoluble ash (AIA) as indigestible markers were compared. Digesta viscosities were generally moderate reaching from 2.5 mPa · s to 7.3 mPa · s. The highest viscosities were observed in WBO diets. Viscosities were reduced with age in broilers, and were generally higher in turkeys than in broilers, especially at six weeks of age. Digesta retention time in ileum was elongated with age of the birds, pronouncedly in broilers. Oat inclusion to the diets decreased retention time especially in broilers at six weeks of age. Apparent ileal digestibility of protein ranged from 0.64–0.83, was lower at six weeks of age than at three weeks of age and generally lowest in O diets, especially in turkeys. AMEN of the diets ranged from 11.2–13.4 MJ/kg being higher at six weeks of age than at three weeks of age. AMEN of Diets O was the lowest but AMEN of WBO diets was higher than that of WB diets indicating a synergistic interaction of cereals, this trend being more pronounced in broilers. Enzyme supplementation decreased viscosity and improved AMEN in most diets, but did not affect ileal protein digestibility. Differences between ileal digestibility estimates obtained with TiO2 or Cr2O3 were small and mainly not significantly different from 0. AMEN estimates were generally higher when calculated with Cr2O3 than with TiO2. AIA gave remarkably lower AMEN values than TiO2 (the significant differences ranging from 0.24–0.94 MJ/kg). In addition, effects of markers on AMEN estimates interacted with age of the birds and dietary treatments.

Composição química, valores energéticos e aminoácidos digestíveis verdadeiros de farinhas de vísceras para aves

Objetivou-se determinar a composição energética e aminoacídica, os coeficientes de metabolizabilidade da energia e a digestibilidade de farinhas de vísceras para aves. Utilizou-se o método da alimentação forçada com galos adultos cecectomizados. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro farinhas de vísceras (três de aves e uma de suínos e um jejum), seis repetições e um galo por unidade experimental. Os valores de energia metabolizável aparente foram 2.878, 3.179, 3.005 e 2.145, os de energia metabolizável aparente corrigida para balanço de nitrogênio (EMAn), 3.017, 3.487, 3.155 e 2.414 kcal/kg de matéria natural; os de EMV, de 3.720, 4.016, 3.840 e 2.981 kcal/kg de matéria natural e os de energia metabolizáv el verdadeira corrigida para balanço de nitrogênio (EMVn ), de 3.239, 3.367, 3.350 e 2.372 kcal/kg de matéria natural. De acordo com os valores energéticos e de energia bruta (EB), os coeficientes de metabolizabilidade aparente foram 53,65; 61,96; 60,20 e 46,13; os de metabolizabilidade aparente corrigida, 56,22; 67,96; 63,22 e 51,91; os de metabolizabilidade verdadeira, 69,33; 78,28; 76,94 e 64,11; e os de metabolizabilidade verdadeira corrigida, 60,36; 65,62; 67,12 e 51,01 para as farinhas de vísceras de aves e de suínos. Os coeficientes médios de digestibilidade verdadeira dos aminoácidos essenciais e não-essenciais para as farinhas de vísceras de aves e de suínos são, respectivamente, 81,20 e 74,55; 75,73 e 67,15; 88,45 e 85,20; 89,27 e 84,35.

Nutritional value of faba beans ( Vicia faba L.) for broilers: Apparent metabolisable energy, ileal amino acid digestibility and production performance

Two experiments were conducted to evaluate the nutritional value of four cultivars (PGG Tic, Spec Tic, South Tic and Broad) of faba beans ( Vicia faba L.) for broilers. In experiment 1, the apparent metabolisable energy (AME) and ileal amino acid digestibility coefficients of these four cultivars were determined. The cultivar effects were significant (P<0.05) for AME, but ileal amino acid digestibility coefficients were not different (P>0.05) between the four cultivars. The AME value of South Tic cultivar was higher (P<0.05) than those of Spec Tic and Broad cultivars, but similar (P>0.05) to that of PGG Tic. In Experiment 2, using the AME and ileal digestible amino acid values determined in Experiment 1, diets containing 200 g kg −1 of the four cultivars of faba beans were formulated and the effects of feeding these diets on the performance and the digestive tract development of broiler starters were investigated. Weight gain, feed intake and feed per gain of broilers fed faba bean diets were similar (P>0.05) to those fed the maize–soybean meal diet. The performance of birds fed diets containing different cultivars of faba beans was similar (P>0.05). In general, the digestive tract development was unaffected (P>0.05) by the inclusion of faba beans. The exceptions were the relative empty weight and digesta weight of gizzard which were found to be higher (P<0.05) in birds fed diets containing faba beans than those fed the maize–soy diet. Birds fed faba bean diets had better (P<0.05) excreta quality scores than that of the basal diet. These results suggest that faba beans are good sources of energy and amino acids, and that faba beans can be included at 200 g kg −1 inclusion level as a partial replacement for soybean meal in broiler diets without any adverse effects on the performance.

Composição química, valores de energia metabolizável e aminoácidos digestíveis de subprodutos do arroz para frangos de corte

Dois experimentos foram conduzidos para determinar a composição química, os valores de energia e os coeficientes de digestibilidade dos aminoácidos, do farelo de arroz integral (FAI) e da quirera de arroz (QA). No primeiro estudo, foram utilizadas 144 aves, com 21 dias de idade, machos, linhagem Cobb, que tiveram suas excretas totalmente coletadas para determinação da energia metabolizável aparente (EMA) e energia metabolizável aparente corrigida (EMAn). O delineamento experimental foi inteiramente casualizado, com três tratamentos e seis repetições, com oito aves cada. No segundo experimento, foi utilizado o método de alimentação forçada para a determinação dos coeficientes de digestibilidade dos aminoácidos. O delineamento foi inteiramente casualizado, com dois alimentos e um jejum e seis repetições com um galo cada. Os valores de MS, PB, EE, FB, EMA e EMAn foram, respectivamente, para FAI: 88,6%; 11,8%; 15,3%; 10,2%; 2968kcal kg-1 e 2804kcal kg-1 e para QA: 93,5%; 9,1%; 0,73%; 0,45%; 3338kcal kg-1 e 3239kcal kg-1. Os valores médios encontrados dos coeficientes de digestibilidade de aminoácidos essenciais e não essenciais foram, respectivamente, de 75,9% e 73,9%, para FAI, e 77,9% e 76,5%, para QA. Embora tenham apresentado níveis inferiores de energia, FAI e a QA podem ser utilizados nas rações de aves em substituição ao milho, uma vez que tiveram níveis maiores de proteína bruta e aminoácidos digestíveis.

Avaliação de modelos para predição da energia metabolizável do milho para aves

O estudo foi realizado com o objetivo de avaliar modelos de predição do valor de energia metabolizável aparente corrigida (EMAn) do milho para aves. Foi organizado um banco de dados contendo informações de experimentos, publicados na literatura nacional entre os anos de 1994 a 2007. Foram utilizados dados de composição química, valores de energia bruta e EMAn de 97 amostras de milho, provenientes de estudos em que os valores de EMAn foram determinados pelo método tradicional de coleta total de excretas com pintos de linhagem de corte. Avaliaram-se cinco modelos, sendo quatro deles sugeridos para estimar a EMAn do milho e um para estimar EMAn de alimentos energéticos. Os modelos estudados foram: EMAnC1 = 36,21*PB + 85,37*EE + 37,26*ENN; EMAnC2 = 37,50*PB + 85,37*EE + 38,21*ENN; EMAnC3 = 4021,8 - 227,5*MM; EMAnC4 = 4337,27 - 57,17*FDN; e EMAnC5 = 4371,18 - 26,48*PB + 30,65*EE - 126,93*MM - 52,26*FB - 25,14*FDN + 24,40*FDA. Os valores de EMAn estimados pelos modelos foram comparados com os valores observados utilizando-se a análise de regressão. Em todos os modelos avaliados, houve rejeição (P&lt;0,001) da hipótese de nulidade, demonstrando diferenças entre os valores de EMAn observados e calculados. No desdobramento do quadrado médio do erro de predição (MSD) em seus componentes, constatou-se que os dados simulados pelos modelos EMAnC1, EMAnC3 e EMAnC5 apresentam desvios de magnitude e padrão de flutuação em relação aos dados observados. Por outro lado, verificou-se que as estimativas realizadas com os modelos EMAnC2 e EMAnC4 tiveram predomínio do componente que expressa o vício de predição, indicando o viés constante observado na relação entre os valores observados e preditos. Concluiu-se que nenhum dos cinco modelos estudados permitiu estimar com precisão e acurácia os valores de energia metabolizável aparente corrigida do milho para aves.

Effect of high moisture storage of pearl millet (Pennisetum typhoides) with or without feed enzymes on growth and nutrient utilization in broiler chickens

Effect of reconstitution of pearl millet with or without enzymes on its utilization in broiler chickens was studied. The pearl millet grains were reconstituted by adding water to raise the moisture level to 30%, followed by storage in sealed plastic buckets with or without feed enzymes (0.5 g/kg) for 21 days at room temperature (25 degrees C). Subsequently, the grains were sun-dried to reduce the moisture content up to 10% to avoid mould growth. Nine dietary treatments were formulated incorporating pearl millet either raw with or without enzymes or reconstituted with or without enzymes in maize-soya based control diet replacing maize at 50 and 75% levels. The birds fed on diets containing enzyme reconstituted pearl millet accrued higher body weight than maize based control diet. Addition of enzymes to raw pearl-millet based diet improved the body weight gain significantly. The reconstitution of pearl millet with or without enzymes increased (P < 0.01) the dietary nitrogen corrected apparent metabolizable energy (AMEn) values and the highest improvement (6.11%) was recorded in diets containing pearl millet reconstituted with enzymes at 75% level of maize replacement. The percent nitrogen retention in pearl millet based diets was comparable to maize based control diet. It may be concluded that the supplementation of the feed enzymes or reconstitution of pearl millet may improve the utilization of pearl millet in broiler chickens.

Composição físico-química e valores energéticos dos resíduos de goiaba e tomate para frangos de corte de crescimento lento

Objetivou-se determinar a composição físico-química e o valor energético dos farelos de goiaba e de tomate para frangos de corte de crescimento lento. Analisou-se a composição químico-fisica e, em seguida, realizou-se ensaio de metabolismo utilizando-se 60 frangos da linhagem Caipirão, com 65 dias de idade, distribuídos ao acaso em três tratamentos e cinco repetições de quatro aves por unidade experimental. Os tratamentos consistiram de uma ração-referência e duas rações-teste, formuladas com 70% da ração-referência e 30% de farelo de goiaba ou tomate. O experimento teve duração de dez dias, cinco para adaptação das aves às rações e cinco para coleta total das excretas. A composição químico-física dos farelos de tomate e de goiaba (na matéria natural) foi: 90,81 e 91,96% de matéria seca (MS); 10,09 e 21,74% de proteína bruta (PB); 11,71 e 12,01% de extrato etéreo (EE); 1,25 e 4,76% de matéria mineral (MM); 55,62 e 43,66% de fibra bruta (FB); 64,06 e 51,53% de fibra em detergente neutro (FDN); 57,38 e 42,22% de fibra em detergente ácido (FDA); 6,67 e 9,32% de hemicelulose; 4.290 e 4.368 kcal/kg de energia bruta (EB), 576,32 e 201,90 g/L de densidade; e 1.271,56 e 1.092,66 µm de diâmetro geométrico médio, respectivamente. Para os aminoácidos, os valores encontrados foram: 0,17 e 0,33% de metionina; 0,32 e 0,30% de cistina; 0,16 e 1,12% de lisina; 0,23 e 0,75% de treonina; 1,47 e 1,57% de arginina; 0,32 e 0,78% de isoleucina; 0,71 e 1,27% de leucina; 0,39 e 0,90% de valina; 0,25 e 0,43% de histidina; 0,44 e 0,93% de fenilalanina; 0,85 e 1,08% de glicina; 0,42 e 0,99% de serina; 0,30 e 1,05% de prolina; 0,35 e 0,945 de alanina; 0,97 e 2,19% de ácido aspartico; 1,91 e 3,105 de ácido glutâmico, respectivamente. Os valores de energia metabolizável aparente corrigida, com base na matéria natural, foram 1.436 e 1.969 kcal/kg, respectivamente.

Avaliação econômica e desempenho de frangos de corte alimentados com diferentes níveis de milheto em substituição ao milho

Two experiments were carried out to determine the energy value, performance and economical feasibility of broiler chickens feeding on different levels of ADR 7010 pearl millet. Experiment 1 was conducted by using 72 broilers with 21 days of age distributed in metabolism cages. A completely randomized experimental design was conducted, with two treatments, six replicates and nine broilers per experimental unit. Pearl millet replaced 40% of reference diet. Values of apparent metabolizable energy of ADR 7010 pearl millet were 3,362 kcal kg -1 (as dry matter) and 3,066 kcal kg -1 (as feed basis) and 12.6% crude protein. Experiment 2 utilized 960 1-day-old chicks distributed in a completely randomized experimental design, with six treatments (0; 20; 40; 60; 80 and 100% of pearl millet inclusion), five replicates and 32 birds per unit. A linear effect was reported of increasing dietary pearl millet levels on weight gain and feed intake in the starting period (1-21 days) and total period (1-41 days). The results were satisfactory for 100% replacement corn, meaning ADR 7010 pearl millet can be included at about 60% in broiler diets without compromising bird performance. Considering the performance results, pearl millet is economically efficient.

Valores de energia metabolizável de alguns alimentos obtidos com aves de diferentes idades

Foram realizados quatro ensaios de metabolismo com a finalidade de determinar a energia metabolizável aparente (EMA) e a energia metabolizável aparente corrigida (EMAn) de dez alimentos em aves em diversas idades. Os alimentos testados foram: milho, farelo de soja, sorgo, farelo de trigo, farelo de arroz integral, duas farinhas de penas, duas farinhas de vísceras e plasma sangüíneo. Utilizou-se o método de coleta total de excretas, em delineamento experimental inteiramente casualizado, com 11 tratamentos (dez alimentos e uma ração-referência) e seis repetições. No primeiro ensaio, foram utilizados 528 pintos de corte machos de 10 a 17 dias de idade, totalizando oito aves por repetição; no segundo ensaio, 396 frangos de corte machos de 26 a 33 dias de idade, com seis aves por repetição; no terceiro ensaio, 264 frangos de corte machos de 40 a 47 dias de idade, com quatro aves por repetição; e, no quarto ensaio, 132 galos, com duas aves por repetição. A idade das aves influenciou os valores de EMA e EMAn do farelo de soja, do sorgo, do farelo de arroz integral, das farinhas de penas e do plasma sangüíneo, enquanto, para o farelo de trigo, teve efeito apenas sobre a EMAn.

DIGESTIBILIDADE DOS AMINOÁCIDOS E VALORES ENERGÉTICOS DO FARELO DE GIRASSOL E SUA INCLUSÃO NA RAÇÃO DE FRANGOS DE CORTE

Five experiments were carried out at Department of Animal Science of Federal University of Vicosa to determine the energetic and nutritional values of sunflower meal (SFM) and the use of SFM in diets for broiler chickens. Two experiments were carried out to determine corrected apparent metabolizable energy (AMEn), through the method of total excreta collection with broiler chickens, and corrected true metabolizable energy (TMEn) and true digestibility of amino acids of (SFM), through the method of forced feeding with cecectomized roosters. The SFM used presented 89.95% of DM, 28.09% of CP, 4,429 kcal/kg of CE, 22.37% of CF, 2.87 of EE, 0.83% of P and 0.30% of Ca. The TMEn and AMEn were 2,200 and 1,983 kcal/kg, respectively. The values of lysine, methionine, and threonine were 0.68, 0.54, and 0.82, respectively. A trial was carried out at to evaluate the performance, carcass yield and cuts, and economic viability of broilers fed with diets containing different levels of inclusion 0, 5, 10, 15, and 20% of SFM. With inclusion of SFM the feed intake reduced linearly in the initial phase and the feed:gain ratio improved linearly in the total period, while there was quadratic effect to feed:gain ratio in the initial phase. No significant differences were found for carcass yield and cuts. And two experiments were carried out in order to evaluate the performance, carcass yield and cuts, and economic viability of broiler chickens fed with diets containing two different levels of SFM (0% and 20%), with or without enzymatic complex supplementation (EC) (Cellulase, β-glucanase, xylanase and phytase) and the values of AMEn of initial diets. No interactions were observed between the SFM and EC on the performance of animals. While the SFM has significantly decreased the feed intake in the initial phase and the total period, weight gain did not differ during these phases. In all stages there was improvement in feed:gain ratio with the use of SFM, probably due to the inclusion levels of oil in the diet, which might have improved digestibility. There was a significant increase in weight gain with the use of EC in the initial phase. There was no significant effect of SFM and EC on carcass yield or cuts. There was no significant effect of adding EC on the values of AMEn of diets, but the addition of EC significantly improved apparent coefficients of metabolizability of phosphorus and calcium.

Diet learning through post-ingestive consequences in sheep: the case of starch and casein variously combined in the same foods

Ruminants generally succeed in selecting an appropriate diet relative to their nutrient requirements, and macronutrients such as energy and protein are considered as playing a primary role in their food preferences. Diet learning through post-ingestive consequences, evidenced by many studies that involved situations with simple discrimination tasks, may explain this ability to select a suitable diet. However, in more complex feeding environments where animals are faced with many plants varying both in their energy and protein contents, the extent to which such a mechanism operates is still uncertain. Our objective was to investigate a more complex feeding situation than previously tested and to determine whether lambs were able to associate three forages with both energy-based and protein-based post-ingestive consequences of various intensities. The doses of starch and casein used to elicit these post-ingestive consequences were chosen so that the apparent metabolisable energy and crude protein values of hays were within the range found in plants normally encountered under field conditions. We applied five treatments: EmPm, EhPm, EmPh, EhPh, where medium (m) or high (h) levels of nutrients (E = energy and P = protein) were associated with different hays, and E0N0 where no stimuli were associated. Each animal experienced only three treatments: E0N0–EmPm–EhPm or E0N0–EmPh–EhPh, each one being associated with one hay during conditioning, on the basis of one treatment per day over three consecutive days. Animals then had a choice between the hay associated with E0N0 and one of the two others, successively on the two following days. This procedure was repeated through five 1-week-long periods, and applied to two groups of lambs (n = 12) maintained at feeding levels sufficient for maintenance or for a 150 g/day growth rate. This experiment was complemented by a methodological trial that aimed to estimate the doses of starch and casein eliciting preferences and a post-trial that aimed to evaluate the effect of our treatments on sheep ruminal environment. The methodological trial showed that lambs perceived the stimuli and the doses, and the post-trial showed that treatments affected the ruminal environment. In the main experiment, the lambs preferred the rewarded hays but did not discriminate in their choices the variation of post-ingestive consequences due to energy and protein. This suggests that in situations closer to reality where animals experience many foods varying in nutrient contents, the learning process may be impaired. The lambs do not seem to have strictly relied on it for shaping their diet choices.

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

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 24–35 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.;

Composição química e valores de energia metabolizável de subprodutos agroindustriais determinados com diferentes aves

This experiment was conducted to determine the chemical composition and the values of apparent metabolizable energy (AME) and nitrogen-corrected apparent metabolizable energy (AMEn) of cashew nut meal (CNM), coconut meal (CONM) and two types of sugar cane yeast (SCY1 and SCY2) for chicks, roosters end Japanese quail. Three digestibility trials were carried out using the methodology of the total excreta collection. Treatments consisted of a reference-diet and four test-diets (40% of feedstuffs and 60% of reference-diet). The values of metabolizable energy determined with Japanese quail and roosters were higher than those obtained with chicks. For CONM and SCY2, the AME and AMEn determined with Japanese quails were lower than those determined for roosters, but the highest values of AME and AMEn for CNM were obtained with Japanese quail. Independente of the bird type the SCY1 showed higher values of AME and AMEn than those of SCY2.

Relationship between digesta transit time and apparent metabolisable energy value of wheat in chickens

1. This study tested the hypotheses that: (a) apparent metabolisable energy (AME) values and whole tract transit time (WTTT) were related, and that (b) the relationship between AME and WTTT differed between male and female Ross broiler chickens. 2. Enzyme products with xylanase activity were added to a basal diet to provide 4 dietary treatments comprising control (no enzyme), Avizyme 1300 (1 kg/tonne), Kemzyme W1 (1 kg/tonne), and Bio-Feed Wheat CT (200 g/tonne). The basal diet comprised (in g/kg), 800 wheat, 155 casein, 20 dicalcium phosphate, 11 limestone, 7 D,L-methionine, 2 vitamin and mineral premix, 3 sodium chloride and 2 choline chloride (60%). 3. AME values for diets were determined in a 7-d energy balance study commencing when chickens were 21 d of age. WTTT was the time elapsed (in min), from time of administration by oral gavage of 200 mg ferric oxide in a gelatine capsule, to time of first observation of the distinctive red colouration in droppings. 4. The mean AME value for the wheat was high (15·7 MJ/kg dry matter) and ranged from 14·4 to 16·3 MJ/kg dry matter for individual birds. Mean WTTT was 206 min and ranged from 105 to 429 min. AME and WTTT were unaffected by enzyme addition to the diet, and the interaction between diet and gender was not significant. 5. There was a significant but weak positive relationship between AME and whole tract transit time, with AME increasing by 2·2 kJ/min. This relationship was unaffected by gender of the chicken.

Metabolizable energy in Chinese Tallow fruit for Yellow-rumped Warblers, Northern Cardinals, and American Robins

The invasive exotic Chinese tallow tree (Triadica sebifera) produces an abundant fruit crop, which is primarily bird-dispersed. The fruit pulp of tallow is lipid-rich, high in saturated fatty acids, and consumed by many bird species. Long-chained fatty acids can be difficult for many birds to digest and we investigated the ability of tallow consumers to assimilate energy in the pulp. We used the total collection method and compared apparent metabolizable energy (AME) of tallow fruit for three species of birds with differing fruit composition in their natural diets. All birds exhibited nitrogen deficits and lost body mass during the trials. Northern Cardinals (Cardinalis cardinalis) lost more mass (8.73%/day) than Yellow-rumped Warblers (Dendroica coronata) (5.29%/day) and American Robins (Turdus migratorius) (5.48%/day), and had larger nitrogen deficits (−120.1 mg N/g diet) than both species as well (−36.4 mg N/g diet and −68.9 mg N/g diet, respectively). Food intake relative to metabolic body mass was highest in Yellow-rumped Warblers (0.70 g-dry/g0.75·day). Northern Cardinal and American Robin food intake was lower and did not differ from each other (both species: 0.13 g-dry/g0.75·day). Nitrogen corrected values of AME were used to make species comparisons. Yellow-rumped-Warblers exhibited the highest values of AME (30.00 kJ/g), followed by American Robins (23.90 kJ/g), and Northern Cardinals (14.34 kJ/g). We suggest tallow may be an important winter food source for Yellow-rumped Warblers where their ranges overlap.

Effect of graded levels of rapeseed oil in isonitrogenous diets on the development of the gastrointestinal tract, and utilisation of protein, fat and energy in broiler chickens

The effect of feeding 0, 4, 8 and 16% rapeseed oil from 12–42 days of age was studied in broiler chickens on performance, digestibility of nutrients, and development of gastrointestinal tract, protein and energy metabolism. Thirty six female chickens (Ross 208) with initial body weight average 246 g were allocated to the four groups and kept pair-wise in metabolism cages. The chickens were fed similar amounts of metabolisable energy (ME) per day and similar amounts of essential amino acids relative to ME by adjusting with crystalline amino acids. The chickens were subjected to four balance periods each of five days with two 24 h measurements of gas exchange in two open-air-circuit respiration chambers inserted on the second and third day of each period. The addition of rapeseed oil increased the amount of gutfill indicating a reduced rate of passage and causing a hypertrophy of the gastrointestinal tract. There was a positive effect on feed utilisation as well as on digestibility especially of dietary fat together with higher utilisation of protein with addition of rapeseed oil. The partial fat digestibility of rapeseed oil estimated by regression was 91.1% and the partial metabolisability (ME/GE) of the rapeseed oil was estimated to 85% yielding an apparent metabolisable energy value of 34.30 MJ/kg.

Composição química e energética de alguns alimentos para frangos de corte em duas idades

Este experimento foi conduzido com a finalidade de determinar os valores de energia metabolizável aparente (EMA) e energia metabolizável aparente corrigida pelo balanço de nitrogênio (EMAn) e analisar a composição química de alguns alimentos. Utilizou-se o método tradicional de coleta total de excretas com pintos de corte machos nos períodos de 21 a 30 dias e de 41 a 50 dias de idade. As aves foram distribuídas em delineamento inteiramente casualizado, com 11 dietas, 10 com alimentos-teste e uma dieta-referência), cada uma com seis repetições de seis e quatro aves por unidade experimental para o primeiro e o segundo período, respectivamente. Os alimentos estudados foram: quirera de arroz; farelo de arroz integral; milho; sorgo; farelo de trigo; farelo de soja; farelo de amendoim; farelo de algodão 28% PB; e duas leveduras de cana-de-açúcar (40 e 43% PB). Os valores de EMAn (kcal/kg matéria natural, MN), no primeiro e segundo períodos experimentais foram, respectivamente: para levedura 40%PB: 2.395 e 2.483; para levedura 43%PB: 2.626 e 2.726; para o farelo de soja: 2.202 e 2.306; para farelo de algodão 28%: 1.605 e 1.786; para farelo de amendoim: 2.155 e 2.471; para farelo de trigo: 1.683 e 1.877; para sorgo: 3.165 e 3.364; para milho: 3.351 e 3.524; para farelo de arroz integral: 2.446 e 2.650; e para a quirera de arroz: 3.138 e 3.278. Os valores EMA e EMAn, de todos os alimentos, foram superiores no segundo período experimental, indicando que, com o avançar da idade, as aves melhoram o aproveitamento dos alimentos.

Nutrient digestibility and energy utilisation of diets based on wheat, sorghum or maize by the newly hatched broiler chick

1. Two experiments were conducted to measure changes in nutrient utilisation in the newly hatched broiler chicken. The first experiment determined the nitrogen-corrected apparent metabolisable energy (AMEN) and total tract digestibility of starch and fat in diets based on wheat, sorghum and maize during the first two weeks post-hatch. The second experiment was conducted to confirm the results of Experiment 1 using wheat- and maize-based diets and was of 21 d duration. 2. In both experiments, changes to AMEN with age were similar irrespective of the diet type, declining from d 3 to d 5–9 and then increasing after d 9. 3. In Experiment 1, the total tract digestibility of starch and fat exhibited a pattern similar to that of AMEN. 4. In Experiment 1, cereal effects were significant, with maize- and sorghum-based diets having higher AMEN values than the wheat-based diet. Total tract starch digestibility determined for d 5, 7 and 14 showed no cereal differences. Total tract fat digestibility on d 7 was significantly lower for the wheat- and sorghum-based diets than for the maize-based diet, but no cereal differences were observed on d 5 or 14. 5. In Experiment 2, cereal effects were significant, with the maize-based diet having a higher AMEN than the wheat-based diet. 6. These results showed that nutrient utilisation is compromised during the first week of life of the broiler chick.

Lack of relationship between either specific weight or presence of the 1B1R gene and nutritive value of wheat in broiler diets

1. A study of the relationship between specific weight (SW) and nutritive value of wheat in diets offered to broilers up to 4 weeks of age was carried out using 10 varieties of wheat grown at three different locations; this gave rise to a range of specific weights from 59 to 76 kg/hl. 2. Because five varieties contained the 1B1R translocation and 5 did not, this allowed the effects of 1B1R on the performance of birds given high concentrations of dietary wheat to be further investigated. 3. The diets, which contained wheat at 744 g/kg with casein (142 g/kg) as the sole protein supplement, were heat-treated and pelleted. They were fed ad libitum to male, Ross broiler chicks from 7 to 28 d, in individual cages in a controlled environment room. 4. A 7 d excreta collection was made from 14 to 21 d for determination of apparent metabolisable energy (AME) content and wheat AME was calculated from the diet values. A separate determination of true metabolisable energy (TME) was undertaken using the method of McNab and Blair (British Poultry Science, 29: 697-707, 1988). 5. Wheat samples were analysed for proximate constituents, starch, total and soluble non-starch polysaccharides (NSP), amino acid content and gross energy and specific weight, thousand grain weight and in vitro viscosity were recorded. They were also subjected to near infrared reflectance spectroscopy (NIRS) with a view to establishing relationships with chemical constituents and performance parameters. 6. At 28 d the birds were humanely killed and in vivo viscosity was determined on the jejunal digesta supernatant. 7. There was quite a narrow range of crude protein content (N x 5.83) across the 30 wheat samples, the means for the three locations (Crossnacreevy, Downpatrick and Limavady, respectively) being 112, 121 and 122 g/kg. Starch contents of individual samples ranged from 604 to 679 g/kg, total NSP from 92.1 to 122.6 g/kg, soluble NSP from 17.6 to 32.6 g/kg and in vitro viscosity from 10.6 to 26.3 cps. 8. There were no significant varietal effects for dry matter intake (DMI), live weight gain (LWG) or gain:feed ratio. Apparent metabolisability of energy (ME:GE) for the diets ranged from 0.738 (Hussar) to 0.778 (Harrier) the effect being significant (P 0.05). TME values ranged from 16.3 to 16.6 MJ/kg DM (NS). 9. In vivo viscosity ranged from 12.3 (Ritmo) to 23.7 cps (Hussar), the varietal effects being significant (P < 0.001). Viscosity was significantly higher for the 1B1R varieties than for the non-1B1R (22.7 vs 16.3 cps) but there were no significant effects on mean DM intake, LWG, gain:feed, ME:GE, calculated wheat AME, ME:gain (MJ AME per kg gain) or TME. 10. Wheat AME was negatively correlated (P < 0.05) with total NSP (slope -0.035) but was significantly affected by variety, constants ranging from 16.74 to 17.79. For wheat TME there were significant variety*total NSP interactions with slopes ranging from 0.29 to -0.07. There was no significant relationship between wheat AME and soluble NSP and there were significant variety*soluble NSP interactions for TME with slopes ranging from 0.09 to -0.14. 11. Despite the relatively wide range of in vitro viscosity there was no significant correlation of either calculated wheat AME or wheat TME with in vitro viscosity. For TME there were significant variety*viscosity interactions with slopes ranging from 0.21 to -0.13 (P < 0.001). There was also no significant correlation between soluble NSP and in vivo viscosity. 12. AME values for the NIRS calibration set varied from 13.7 to 15.6 MJ/kg and averaged 14.6 MJ/kg, whereas for the validation set, the values ranged from 14.0 to 16.1 MJ/kg with the mean value being 14.7 MJ/kg. The best correlation coefficient (r(2)) of 0.90 was obtained when the calibration sample set was subjected to SMLR using the second-order derivatised data. However, moving to validation, the outcome was extremely poor with 1-VR values being 0.12 and 0.09, respectively, for the external validation and an internal validation subset. 13. In summary, none of the production characteristics showed a good correlation with specific weight. Using the linear estimates for wheat AME and TME the effect of a 10 kg/hl change in SW equates to a 3 or 1.4% change, respectively. The estimate for AME is likely to be a worst-case value due to the high inclusion level of wheat. The range of calculated wheat AME (approximately 1 MJ) across the 30 wheat samples is similar to that seen in previous studies for wheat grown in Northern Ireland and much lower than in some other studies. 14. None of the other parameters examined gave any better relationship with nutritive value (assessed as AME or TME) than SW. This is a disappointing outcome, particularly in view of some previous studies which suggested that in vitro viscosity provides a good prediction of nutritive value.

Valor nutritivo de grãos de sorgo com diferentes texturas do endosperma para leitões

Utilizaram-se 20 leitões machos castrados, com 28kg de peso, em ensaio biológico baseado em coleta total de fezes e de urina para a determinação dos valores de digestibilidade aparente da matéria seca (DAMS), de digestibilidade aparente da proteína bruta (DAPB), de energia digestível aparente (EDA) e de energia metabolizável aparente (EMA) de grãos de sorgo com diferentes texturas do endosperma. Os genótipos avaliados foram BR 007B (textura macia), BR 304 (textura intermediária) e SC 283 (textura dura). As dietas-teste foram compostas por 70% de dieta referência, à base de milho e de farelo de soja, e por 30% de grãos de sorgo. O experimento foi montado em esquema inteiramente ao acaso, com quatro tratamentos e cinco repetições. Os valores de DAMS, de DAPB, de EDA e de EMA, expressos na matéria seca, dos grãos do genótipo BR 007B foram 97,1%, 89,7%, 3.840kcal/kg e 3.685kcal/kg; os do genótipo BR 304 foram 92,0%, 82,9%, 3.645kcal/kg e 3.544kcal/kg; e os do genótipo SC 283 foram 83,3%, 78,5%, 3.078kcal/kg e 3.021 kcal/kg, respectivamente. Todas as quatro variáveis analisadas apresentaram valores mais altos (P&lt;0,05) para o genótipo BR 007B em relação ao genótipo SC 283, demonstrando a influência negativa da textura do endosperma sobre o valor nutritivo dos grãos de sorgo para suínos.