ABSTRACT An experiment was carried out to verify the response to the Ca reduction levels of diets with different vitamin D sources on performance, bone mineral deposition, serum concentrations, digestibility, carcass characteristics, and meat quality of broiler chickens in the period from 1 to 42 days reared in thermoneutral environment. A total of 504 male broilers with one day of age and average weight of 43.27±1.08 g were housed in climatic chambers and distributed in a completely randomized design. The study consisted of a 4 × 2 factorial, with four Ca reduction levels (0, 10, 20, and 30%) and two vitamin D sources (2760 IU of D3 or 25-OH-D3). The performance of animals at 21 and 42 days of age was not affected by Ca reduction by up to 30%, regardless of the vitamin source used. Dietary reduction from 10% decreased serum Ca concentrations. The use of vitamin D3 provided a serum P level greater than the 25-OH-D3. Calcium reduction decreased serum 25-OH-D3 levels. No effect of vitamin source or Ca levels on broiler carcass characteristics was observed at 42 days. The vitamin source did not influence meat quality, while Ca reduction of the diet provided lower losses by thawing and cooking and higher initial pH values. The b* color was reduced in diets with lower Ca levels of the diet. Reducing Ca up to 30% does not affect the performance and carcass characteristics, regardless of the vitamin D source used. The quality of broiler meat is improved with the Ca reduction in the diet, but the vitamin used has no effect on such characteristics. We can conclude, based on the results of performance, blood, and bone, that the performance variables are not adequate to determine the actual requirement of Ca, since as it is a priority to maintain performance, bone mineral mobilization occurs, which may compromise the carcass quality of the birds.

RESUMO: Para avaliar níveis de inclusão e o efeito residual de dietas contendo extrato de levedura (ExL) associado ao plasma sanguíneo (PS) sobre o desempenho de leitões dos 36 aos 60 dias, foram utilizados 105 leitões (8,75±0,72kg), distribuídos em delineamento experimental de blocos ao acaso com cinco tratamentos (controle - 2,0% de PS; 1,0% PS, associado ao 0; 1,0; 2,0 ou 3,0% de ExL), sete repetições e três animais por unidade experimental. As dietas experimentais foram fornecidas dos 36 aos 49 dias e, dos 50 aos 60 dias de idade, os animais passaram a receber dieta única para avaliar o efeito residual dos tratamentos experimentais. Não foram observados efeitos dos tratamentos (P>0,10) sobre as variáveis de desempenho dos 36 aos 49 dias de idade. Dos 50 aos 60 dias de idade, houve efeito dos níveis de ExL sobre o consumo de ração diário (P<0,03), ganho de peso diário (P<0,01) e peso final (P<0,06) que aumentaram de forma quadrática até os níveis de 1,67, 1,67 e 1,55% de ExL, respectivamente. Leitões alimentados com a dieta contendo 1,0% de PS + 2,0% de ExL apresentaram melhor (P<0,01) conversão alimentar em relação à dieta controle (2% de PS). Por proporcionar melhor efeito residual, a inclusão de 1,67% de extrato de levedura pode substituir 50% do plasma sanguíneo na dieta de leitões dos 36 aos 49 dias de idade.

ABSTRACT: To evaluate inclusion levels and residual effects of diets containing yeast extract (YE) plus blood plasma (BP) on the performance of 36 to 60-days old piglets, 105 piglets were used (8.75±0.72kg), and they were distributed under a randomized block experimental design with five treatments (control - 2.0% BP; 1.0% BP plus 0.0, 1.0, 2.0, or 3.0% YE), seven repetitions, and three animals per experimental unit. Piglets were given experimental diets from 36 to 49 days of age. From 50 to 60 day of age, all piglets received the same diet. No effects from treatments (P>0.10) were observed on the performance variables from 36 to 49 day of age. From 50 to 60 day of age, an effect was observed from YE levels on the daily feed consumption (P<0.03), daily weight gain (p<0.01), and final weight (P<0.06), which increased quadratically up to 1.67, 1.67, and 1.55% YE levels, respectively. Piglets which were fed with the diet containing 1.0% BP + 2.0% YE were observed to have better feed conversion ratios (P<0.01) as compared to the control diet (2.0% BP). As it provides a better residual effect, the inclusion of 1.67% yeast extract may replace 50% of blood plasma in 36 to 49-days old piglet diets.

ABSTRACT This study was conducted to evaluate the effect of reduction of the available phosphorus (avP) in diets supplemented with 500 FTU/kg phytase on performance, carcass characteristics, and bone mineralization of broilers aged 22 to 42 days kept in a high-temperature environment. A total of 336 Cobb broilers with an average initial weight of 0.883±0.005 kg were distributed in a completely randomized design with six treatments - a positive control (0.354 and 0.309% avP without addition of bacterial phytase for the phases of 22 to 33 and 34 to 42 days, respectively), and another five diets with inclusion of phytase (500 FTU) and reduction of the level of avP (0.354, 0.294, 0.233, 0.173, and 0.112%; and 0.309, 0.258, 0.207, 0.156, and 0.106% for the phases of 22 to 33 and 34 to 42 days, respectively) - eight replicates, and seven birds per cage. The experimental diets were formulated to meet all nutritional requirements, except for avP and calcium. Birds were kept in climatic chambers at a temperature of 32.2±0.4 °C and air humidity of 65.3±5.9%. Phytase acted by making the phytate P available in diets with reduction in the levels of avP, keeping feed intake, weight gain, feed:gain, and carcass characteristics unchanged. Treatments affected ash and calcium deposition and the Ca:P ratio in the bone; the group fed the diets with 0.112 and 0.106%, from 22 to 33 and 34 to 42 days of age, respectively, obtained the lowest values, although the phosphorus deposition in the bone was not affected. Diets supplemented with 500 FTU of phytase, with available phosphorus reduced to 0.173 and 0.156%, and a fixed Ca:avP ratio of 2.1:1, meet the requirements of broilers aged 22 to 33 and 34 to 42 days, respectively, reared in a high-temperature environment.

O experimento foi conduzido com o objetivo de avaliar cinco planos de nutrição baseados em sequências de lisina digestível verdadeira: 0,90-0,80-0,70; 1,00-0,90-0,80; 1,10-1,00-0,90; 1,20-1,10-1,00 e 1,30-1,20-1,10%, fornecidos dos 60 aos 99, dos 100 aos 129 e dos130 aos 148 dias de idade, respectivamente. Foram utilizadas oitenta leitoas, híbridas comerciais, selecionadas para deposição e carne, com peso inicial de 23,46±0,27kg. Os animais foram distribuídos em delineamento de blocos ao acaso, com cinco tratamentos, oito repetições e dois animais por unidade experimental. Não houve efeito (P>0,05) dos planos nutricionais no consumo de ração diário, no ganho de peso diário e na conversão alimentar. Os planos nutricionais não influenciaram (P>0,05) nenhum dos parâmetros de característica de carcaça avaliados (rendimento de carcaça quente, quantidade de carne e rendimento de carne). O plano nutricional de lisina digestível verdadeira de 0,90-0,80-0,70% fornecido dos 60 aos 99, dos 100 aos dos 129 e 130 aos 148 dias de idade, respectivamente, atende às exigências de lisina digestível verdadeira de leitoas dos 60 aos 148 dias de idade.

The experiment was conducted to evaluate five nutritional plans based on sequences of standardized ileal digestible lysine: 0.90-0.80-0.70, 1.00-0.90-0.80, 1.10-1.00-0.90, 1.20-1.10-1.00, and 1.30-1.20-1.10% fed to gilts from 60 to 99, 129 to 100, and 130 to 148 days of age, respectively. Eighty commercial hybrid gilts, selected for lean gain, with initial weight of 23.46±0.27kg were allotted in a randomized block design, with five treatments, eight replicates, and two pigs per experimental unit. No effect (P>0.05) of the nutritional plans was verified on daily feed intake, daily weight gain and feed conversion. The nutritional plans had no influence (P>0.05) on any of the carcass traits evaluated (carcass yield, meat amount, and meat yield). The nutritional plan of 0.90-0.80-0.70% standardized ileal digestible lysine fed to gilts from 60 to 99, 100 to 129, and 130 to 148 days of age, respectively, meets the standardized ileal digestible lysine requirements of gilts from 60 to 148 days of age.

Foram utilizados 50 suínos machos castrados, com alto potencial genético para deposição de carne magra na carcaça e peso inicial de 60,5 ± 1,58 kg para avaliar diferentes níveis de lisina digestível sobre o desempenho e as características de carcaça. Foi usado o delineamento de blocos ao acaso, com cinco tratamentos, cinco repetições e dois animais por repetição. Os tratamentos consistiram de cinco níveis de lisina digestível (0,600; 0,700; 0,800; 0,900 e 1,000% de lisina) obtidos variando-se a proporção de milho e farelo de soja nas rações. Os animais permaneceram no experimento até atingirem o peso final de 95,8 ± 2,64 kg. Os níveis de lisina influenciaram de forma quadrática a conversão alimentar e a conversão alimentar em músculo, que melhoraram até o nível de 0,85% de lisina digestível, e o rendimento de carne magra, que aumentou até o nível de 0,840% de lisina digestível. O consumo de lisina diário aumentou de forma linear em razão dos níveis de lisina da ração. Não houve efeito dos tratamentos sobre o ganho de peso, consumo de ração, características de carcaça, rendimento de carcaça, rendimento de gordura e rendimento de pernil. Conclui-se que suínos machos castrados, dos 60 aos 95 kg, exigem 0,850% de lisina digestível, correspondente a um consumo diário estimado de 24,2 g de lisina digestível.

Fifty barrows with high genetic potential for lean gain and 60.5 ± 1.58kg of average initial live weight were used in a study to evaluate different lysine levels on performance and carcass traits. A randomized blocks experimental design, with five treatments, five replicates and two animals per replicate was used. Treatments consisted in five digestible lysine levels (0.600; 0.700; 0.800; 0.900; e 1.000%) obtained with the variation of corn and soybean meal proportion. Animals were kept in the experiment until they reached 95.8 + 2.64kg of final live weight. Lysine levels had a quadratic effect on feed conversion and feed conversion in muscle, which improved to the level of 0.85 % digestible lysine , and lean meat yield , which increased up to 0.840 % digestible lysine.The daily lysine intake increased linearly with the elevation of dietary levels of lysine. There was no effect of treatments on weight gain, feed intake, carcass traits, carcass yield, fat yield, and ham yield. It was concluded that barrows from 60 to 95 kg require 0.850% of total lysine, corresponding to a digestible lysine estimated intake of 24.2 g/day.

The objective of this study was to evaluate the effect of digestible lysine levels in diets with or without supplementation of industrial amino acids on performance, carcass characteristics and nitrogen excretion in broilers of 22 to 42 days of age. Birds were distributed in a completely randomized experimental design in a 4 × 2 factorial arrangement, with four digestible lysine levels (9.0, 10.0, 11.0 and 12.0 g/kg) and two methods to obtain the lysine levels (variation in the proportion of corn and soybean meal, without supplementation; or supplementation of industrial amino acids), eight replicates and 20 birds per replicate. There was an interaction effect on the performance characteristics and on the weights and yields of prime cuts. In both diets, feed conversion improved linearly as the lysine levels were increased. Feed intake; weight gain; carcass, thigh and drumstick weights; and boneless breast yield increased and abdominal fat reduced linearly as the lysine levels were increased in the unsupplemented diet. The lysine levels of the supplemented diets linearly reduced the yield of drumstick and quadratically reduced the yields of bone-in and boneless breast up to the estimated levels of 10.4 and 10.7 g/kg, respectively. Diets without supplementation increased the excretion and retention of nitrogen. The levels of 9.0 and 12.0 g/kg digestible lysine obtained with supplementation of industrial amino acids and without it, respectively, provide the best performance and yield of prime cuts in the birds. Diets in which the digestible lysine levels are obtained without supplementation provide better performance responses and carcass characteristics compared with supplemented diets.

Dois experimentos foram conduzidos para determinar os efeitos da energia líquida (EL) da ração no desempenho e nas características de carcaça de suínos, recebendo dietas com proteína bruta reduzida (PB). Os suínos (60,0±1,05kg, Exp. 1, 93,0±1,56kg, Exp. 2) foram distribuídos em delineamento de blocos casualizados, com três tratamentos. O Exp. 1 teve seis baias/tratamento e o Exp. 2 teve 8 baias/tratamento e todas as baias tiveram 2 animais. Os tratamentos foram: 199g kg-1 PB e 2566kcal kg-1 NE, 155g kg-1 PB e 2.631kcal kg-1 NE, 155g kg-1 PB e 2.566kcal kg-1 NE no Exp. 1, e 180g kg-1 PB e 2588kcal kg-1 NE, 145g kg-1 PB e 2638kcal kg-1 NE, 145g kg-1 de PB e 2588kcal kg-1 NE, no Exp. 2. No Exp.1, a ração com 155g kg-1 PB e 2566kcal kg-1 EL resultou em maior GPD. Não houve efeito dos níveis PB ou EL sobre os demais parâmetros. No Exp. 2, os melhores resultados de CRD e GDP foram obtidos com 145g kg-1 PB e 2588kcal kg-1 EL. Os suínos alimentados com a dieta com 180g kg-1 PB e 2.588kcal kg-1 NE apresentaram menor quantidade de carne na carcaça. Não houve efeito do conteúdo de PB ou EL da ração na espessura de toucinho. A ração contendo 155g kg-1 PB e 2.566kcal kg-1 NE resultou em maior GPD de suínos dos 60 aos 95kg. Dos 95 aos 120kg, a dieta com 145g kg PB e 2588kcal kg-1 EL resultou em maior GPD e carne na carcaça.

Two experiments were conducted to determine the effects of dietary net energy content (NE) on performance and carcass traits of finishing barrows fed low-crude protein (CP) diets. Pigs (60.0±1.05kg, Exp. 1, 93.0±1.56kg, Exp. 2) were allotted in a randomized block design to 3 dietary treatments. Exp. 1 had 6 pens treatment-1 and Exp. 2 had 8 pens treatment-1 and all pens had 2 pigs. The treatments were: 199g kg-1 CP and 2566kcal kg-1 NE, 155g kg-1 CP and 2631kcal kg-1 NE, 155gk g-1 CP and 2566kcal kg-1 NE in Exp. 1, and 180g kg-1 CP and 2588kcal kg-1 NE, 145g kg-1 CP and 2638kcal kg-1 NE, 145g kg-1 CP and 2588kcal kg-1 NE, in Exp. 2. In Ep.1, except for average daily gain (ADG) there was no effect of dietary CP or NE on any other parameter evaluated. The diet with 155g kg-1 CP and 2566kcal kg-1 NE resulted in greatest ADG. In Exp. 2, the greatest results of ADFI and ADG were obtained with 145g kg-1 CP and 2588kcal kg-1 of NE. Pigs fed the diet with 180g kg-1 CP and 2588kcal kg-1 NE had less carcass meat. There was no effect of dietary CP or NE on backfat. The CP diet containing 2566kcal kg-1 NE resulted in greatest ADG of 60- to 95-kg barrows. For 95- to 120-kg barrows the diet with 145gk g-1 CP and 2588kcal kg-1 of NE resulted in greatest ADG and carcass meat.

This experiment was conducted to evaluate nutritional plans of digestible lysine (DLys) for growing-finishing gilts. Eighty gilts with 63 days of age and an initial weight of 24.2±1.52 kg were distributed in a completely randomized block design, with five nutritional plans of DLys (9-8-7, 10-9-8, 11-10-9, 12-11-10, and 13-12-11 g/kg, from 63 to 103, 104 to 133, and 134 to 153 days of age, respectively) and eight replicates. Pigs were housed in pairs and fed their respective diets ad libitum throughout the experimental period (90 days). To monitor the animal development along the experiment at 103 and 133 days, gilts were weighed and subjected to analysis of ultrasound for evaluation of loin depth (longissimus dorsi) and backfat thickness. At the end of the experiment (153 days of age) the animals were weighed, and after slaughter carcasses were evaluated individually using a typifying pistol to evaluate the percentage and the content of carcass meat, loin depth and backfat thickness. From 63 to 133 days, there was no effect of the nutritional plans on daily feed intake, performance, or backfat thickness; however the loin depth was greater in the gilts that received plans with high levels of DLys (12-11; 13-12 g/kg) compared with the plan with the lowest level (8-7 g/kg). For the entire period (63 to 153 days), no influence of the nutritional plans was observed on the daily feed intake, performance variables, or carcass characteristics. A nutritional plan containing 9-8-7 g/kg of digestible lysine fed from 63 to 103, 104 to 133 and 134 to 153 days, respectively, meets the requirements for performance and carcass characteristics of growing-finishing gilts.

This study was conducted to verify the effects of dietary crude protein reduction on growth and carcass performance of 22-42-day-old broilers reared under different temperatures. Treatments were set up in a five by two factorial arrangement, with five crude protein levels (220, 210, 200, 190 and 184 g/kg) and two temperatures (21.6 and 32.2 ºC). Diets were isocaloric and essential amino acid-to-lysine ratio was maintained constant in all treatments. There was no interaction between crude protein reduction and environmental temperature for any of the parameters evaluated. Crude protein had no influence on feed intake. Nevertheless, weight gain and feed conversion ratio were linearly influenced by crude protein reduction. Worse performance was also observed in birds exposed to heat stress as compared with birds kept under thermoneutral temperature. There was no effect of crude protein reduction on breast and legs. Birds kept under heat stress had lower breast yield and higher leg yield as compared with broilers reared at 21.6 ºC. Any crude protein reduction in the range of 220 to 184 g/kg for 22 to 42-day-old broilers has a negative effect on their performance. Heat stress worsens broiler performance and breast yield.

Oitenta leitoas (24,2±1,52kg) com alto potencial genético para deposição de carne na carcaça foram distribuídas em experimento de blocos ao acaso para avaliar cinco níveis de lisina digestível (Ld) (9, 10, 11, 12 e 13g kg-1) durante a fase de crescimento (63 a 103 dias de idade). Os animais foram alojados em pares e alimentados à vontade. No início e ao final do período experimental, as leitoas foram pesadas e submetidas à análise de ultrassom para avaliação da área de olho de lombo (AOL) e espessura de toucinho (ET). Os níveis de Ld proporcionaram aumento linear (P<0,05) do ganho de peso diário (GPD) e, apesar dessa variação, não houve aumento no valor absoluto do GPD a partir do nível de 12g kg-1 de Ld. A conversão alimentar (CA) reduziu (P<0,01) de forma quadrática até o nível estimado de 11,9g kg-1 de Ld. A AOL das leitoas aumentou (P<0,05) de forma linear. No entanto, o modelo "Linear Response Plateau" foi o que melhor se ajustou aos dados, estimando em 12,5g kg-1 o nível a partir do qual ocorreu platô. Não foi verificada influência (P>0,05) dos níveis de Ld sobre o consumo de ração diário (CRD) e ET. Os níveis de 12,0 e 12,5g kg-1 de Ld na dieta, correspondentes, respectivamente, ao consumo de lisina digestível diário (CLdD), de 23,6 e 24,6g, proporcionam os melhores resultados de desempenho e área de olho de lombo de leitoas em fase de crescimento (63 aos 103 dias de idade).

Eighty gilts (24.2±1.52kg) with high genetic potential for lean gain were used in a randomized complete block design to evaluate five digestible lysine levels (9, 10, 11, 12 and 13g kg-1) during the growing phase (63 to 103 days of age). Gilts were housed in pair and fed their respective diets ad libitum. At the begging and the ending of the experimental period, gilts were weighed and scanned by ultrasound to measure loin area, as well as fat depth. The digestible lysine levels linearly increase (P<0.05) average daily gain and loin area of gilts in growing phase. However, there was no difference for average daily gain at levels above 12g kg-1 while the "Linear Response Plateau" model was that better fitted to the loin area data that stabilized in a plateau starting from the level of 12.5g kg-1. The feed:gain ratio was improved (P<0.01) quadratically until the estimated level of 11.9g kg-1 of digestible lysine. There was no effects (P>0.05) of the treatments on the fat depth and feed intake. The digestible lysine levels of 12 and 12.5g kg-1, corresponding to the intake of 23.6 e 24.6g dia-1, provide the best results of performance and loin area of growing gilts (63 to 103 days old).

The objective of this study was to evaluate the inclusion of yeast extract as a partial replacemer of blood plasma in piglet diets and its effect on the performance and intestinal morphometry of pigs weaned at 21 days of age. One hundred and twenty animals were randomized into blocks, with five diets (4.0% blood plasma; 2.0% blood plasma with 0.0; 1.0; 2.0 or 3.0% yeast extract), six replicates and four pigs per experimental unit. At 35 days of age, one pig per experimental unit was slaughtered in order to evaluate duodenal and jejunal morphometry. The levels of yeast extract had a quadratic impact on daily feed intake and final weight, which increased up to the estimated level of 1.91%. Daily weight gain and feed conversion rate were not affected. A comparison between diets containing different levels of yeast extract and the basal diet showed that the diets containing 2.0% and 1.0% yeast extract provided the highest final weight and the worst feed conversion rate, respectively. Duodenal villus height and crypt depth were quadratically affected by yeast extract levels and the best results were achieved with the estimated levels of 1.64 and 1.16%, respectively. The levels of yeast extract provided a linear increase in the duodenal villus:crypt ratio, but did not change the morphometric variables of the jejunum. No difference was found in the morphometric variables of the duodenum and jejunum when diets containing different levels of yeast extract were compared with the basal diet. The results suggest that the inclusion of 1.91% yeast extract allows for a partial replacement for plasma in the diet, decreasing plasma inclusion from 4.0 to 2.0%.

With the objective of evaluating available phosphorus (aP) levels in diets for barrows selected for lean meat deposition, eighty commercial hybrid pigs with initial weight of 94.05±1.05 kg were used in this experiment. Pigs were allotted in a completely randomized block design, with five treatments (0.092, 0.156, 0.220, 0,284, and 0.348% of aP), eight replicates and two pigs per experimental unit. The average daily weight gain of pigs increased and the feed conversion improved quadratically with increasing aP in the diets up to the estimated levels of 0.21 and 0.20%, respectively. There was no effect of the dietary aP on average daily feed intake. However, aP intake, bone strength and concentration of phosphorus in the bones increased linearly with increasing aP in the diets. The levels of aP did not affect carcass traits; however, the alkaline phosphatase activity was improved and the values of serum inorganic phosphorus increased quadratically up to the estimated levels of 0.26 and 0.27% of aP, respectively. The available phosphorus levels of 0.21, 0.27, and 0.35%, corresponding to daily aP intakes of 6.34, 8.13, and 10.44 g result, respectively, in greatest performance, blood and bone parameters of 95 to 120 kg barrows selected for lean gain.

Utilizaram-se 50 leitoas de alto potencial genético para deposição de carne magra na carcaça, com peso inicial de 30,17 ± 2,03, a fim de avaliar o efeito de níveis crescentes de lisina digestível sobre o desempenho e características de carcaça. Os animais foram distribuídos em delineamento experimental de blocos ao acaso, com cinco tratamentos (0,83; 0,93; 1,03; 1,13 e 1,23% de lisina digestível), cinco repetições e dois animais por unidade experimental. Na distribuição dos animais dentro de cada bloco foi adotado como critério o peso inicial dos animais. Não foi observado efeito dos níveis de lisina digestível sobre o consumo de ração diário e ganho de peso diário. Observou-se efeito quadrático dos tratamentos sobre a conversão alimentar, que melhorou até o nível estimado de 1,11% de lisina digestível. Foi observado efeito linear dos níveis de lisina sobre a taxa de deposição de proteína diária, entretanto, o modelo Linear Response Plateau foi o que melhor se ajustou aos dados e estimou o nível de 1,09% de lisina digestível para melhor deposição de proteína diária. Não foi observado efeito dos tratamentos sobre a taxa de deposição diária de gordura. Conclui-se que o nível de 1,11% de lisina digestível proporciona os melhores resultados de desempenho e de taxa de deposição de proteína diária na carcaça de fêmeas suínas de alto potencial genético para deposição de carne magra na carcaça, dos 30 aos 60kg.

Fifty gilts were used, with initial weight of 30.17 ± 2.03kg, to evaluate the effect of increasing levels of digestible lysine on performance and carcass characteristics. The animals were distributed in a random block experimental design, with five treatments (0.83; 0.93; 1.03; 1.13 and 1,23% of digestible lysine), five replicates and two animals which were considered one experimental unit. The criteria for the formation of the blocks were the animals initial weight. There was no effect of levels of digestible lysine on daily feed intake and daily weight gain. A quadratic effect was observed on feed conversion that improved until an estimated level of 1.11% of digestible lysine. A linear effect was observed on daily protein deposition, however, the data were adjusted through the Linear Response Plateau model, which indicated the estimated level of 1.09% of digestible lysine for best daily protein deposition. No effect was observed on daily fat deposition among the treatments. It conclude that the level of 1.11% of digestible lysine provided the best performance and daily protein deposition results for gilts with high potential for lean deposition, from 30 to 60kg.

Foi conduzido um experimento para avaliar sequências de lisina digestível sobre o desempenho e características de carcaça de suínos machos castrados. Foram utilizados 96 animais de duas linhagens selecionadas para deposição de carne, com peso inicial de 23,80 ± 1,07kg. Os suínos foram distribuídos em um delineamento experimental de blocos ao acaso, em um esquema fatorial 4 x 2 (quatro sequências de lisina digestível e duas linhagens), com seis repetições e dois animais por unidade experimental. Os tratamentos corresponderam às seguintes sequências de lisina digestível: S1 = 0,80 - 0,70 - 0,60%; S2 = 0,90 - 0,80 - 0,70%; S3 = 1,00 - 0,90 - 0,80% e S4 = 1,10 - 1,00 - 0,90%, fornecidos respectivamente nas fases de 63 a 103; 104 a 133 e de 134 a 163 dias de idade. Não houve interação entre as sequências de lisina e linhagem. Os tratamentos não influenciaram o desempenho (ganho de peso diário, consumo de ração diário e conversão alimentar) e as características de carcaça (espessura de toucinho e quantidade de carne). O consumo diário de lisina digestível aumentou de forma linear com o aumento dos níveis de lisina digestível. A sequência de lisina digestível S1 (0,80; 0,70 e 0,60%) atende as exigências para desempenho e características de carcaça.

One experiment was conducted to evaluate sequences of digestible lysine on the performance and carcass traits of castrated male pigs. Ninety six barrows from two lines selected for meat deposition with initial weight of 23.78±1.07kg were used. The animals were allotted in a completely randomized block design, with a 4 x 2 factorial scheme (four digestible lysine sequences and two lines of pigs), with six replicates and two pigs per experimental unit that was represented by the pen. Treatments corresponded to the following sequences of digestible lysine levels: S1 = 0.80 - 0.70 - 0.60%; S2 = 0.90 - 0.80 - 0.70%; S3 = 1.00 - 0.90 - 0.80%, and S4 = 1.10 - 1.00 - 0.90% provided in the phases of 63 to 103, 104 to 133, and 134 to 163 days old, respectively. There was no interaction between the sequences of lysine and the lines of pigs for any variable of performance and carcass traits assessed. The sequences of digestible lysine did not influence performance parameters (average daily gain, average feed intake, and feed conversion) and carcass traits (backfat thickness, meat amount). The daily lysine intake increased linearly by increasing digestible lysine levels. The sequence of digestible lysine S1 (0.80; 0.70, and 0.60%) meets pig's requirement of both lines of pigs for performance and carcass traits.

With the objective to evaluate levels of available phosphorus (aP) in diets with or without ractopamine, 112 gilts with high genetic potential for meat deposition with initial weigh of 94.0±2.28 kg were allotted in a completely randomized block design, in a 4 × 2 factorial arrangement (0.109, 0.209, 0.309, and 0.409% aP and 0 or 5 ppm of ractopamine), with eight treatments, seven replicates, and two gilts per experimental unit. There were no interactions between aP levels and ractopamine. The levels of available phosphorus influenced both daily weight gain and daily phosphorus intake, which increased linearly. Feed conversion improved in a quadratic way up to the estimated level of 0.330% aP maximum response. Daily weight gain increased and feed conversion improved by adding ractopamine to the diets. Serum alkaline phosphatase activity decreased linearly by increasing the levels of available phosphorus. Bone strength, ash, calcium, and phosphorus contents in the bones also increased quadratically with maximum responses at 0.320, 0.270, 0.277, and 0.295% aP, respectively. The available phosphorus level of 0.330%, corresponding to a daily intake of 8.67 g of aP is suitable for 94 to 125 kg gilts selected for meat deposition fed diets with or without ractopamine.