ABSTRACT: We evaluated the inclusion of information on genetic relationship into the analysis of crude protein requirement in diets for pigs of Brazilian Piau breed, using Bayesian inference. The animals were assigned to treatments in a completely randomized design in factorial scheme 4 × 2 (crude protein levels × sex) with 12 repetitions per treatment. The evaluations were carried out in the initial, growing and finishing phases, and after slaughter. The traits evaluated were feed conversion (FC), backfat thickness (BF), daily weight gain (DWG), daily feed intake (DFI) and some carcass cuts. Three models were considered to evaluate the inclusion of information on genetic relationship into the analysis: Model I, a simple linear model; Model II, the same effects of Model I with addition of the independent random effect of animal; and Model III, the same effects of Model II, but including the genetic relationship between the animals. Model III presented the best fit and was considered for later inferences. Crude protein (CP) levels did not significantly influence any of the evaluated traits. The effect of sex was significant only for the growing phase, while its interaction with protein levels presented an opposite result for all evaluated traits. Additionally, CP levels of 10.2 %, 9.6 % and 9.0 % can be used in diets for pigs of Brazilian Piau breed in the initial, growing and finishing phases, respectively.

Este estudo foi realizado com o intuito de se determinar as melhores relações de treonina digestível com lisina digestível para leitões dos 28 aos 49 dias de idade. Para isso foram utilizados 120 leitões híbridos comerciais com alto potencial genético para deposição de carne magra na carcaça, desmamados aos 28 dias de idade com peso inicial médio de 7,45kg. Os animais foram distribuídos em delineamento em blocos ao acaso, compostos por cinco tratamentos (relações de treonina digestível e lisina digestível) e controlando o peso inicial, com oito repetições e três animais por unidade experimental. Os tratamentos corresponderam às seguintes relações treonina e lisina digestíveis: 0,50; 0,57; 0,64; 0,71; 0,78. Foram avaliados o desempenho dos leitões e os valores de haptoglobina e escore fecal por períodos: Período I - dos 28 aos 42 dias e Período II - dos 28 aos 49 dias. As relações de treonina e lisina digestíveis não influenciaram o consumo de ração médio diário e o ganho de peso médio diário dos animais. Houve efeito quadrático dos tratamentos em relação à conversão alimentar nos períodos I e II. Não houve efeito dos tratamentos sobre os teores haptoglobina e escore fecal no quinto e décimo dia do período experimental. As melhores relações treonina digestível com lisina digestível encontradas para conversão alimentar foram as de 0, 629 e 0, 648, respectivamente para os períodos I (28 aos 42 dias de idade) e II (28 aos 49 dias de idade).

This study was conducted in order to determine the best relations of threonine with lysine for pigs from 28 to 49 days of age. For this 120 commercial crossbred pigs with high genetic potential for lean meat in the carcase, weaned at 28 days of age with an average initial weight of 7.45kg were used. The animals were allotted to a randomized block design, with five treatments (ratios of threonine and lysine) and controlling the initial weight, with eight replications and three animals per experimental unit. The treatments were the following digestible threonine and lysine: 0.50; 0.57; 0.64; 0.71; 0.78. - From 28 to 42 days and Period II - 28 to 49 days of Period I: piglet performance and values of haptoglobin and faecal score by periods were evaluated. The relations of threonine and lysine did not affect average daily feed intake and average daily weight gain of the animals. Quadratic effect of treatments on the feed conversion in periods I and II. There was no effect of treatments on haptoglobin levels and fecal score in the fifth and tenth day of the trial period. Best digestible threonine to lysine found for feed conversion were 0, 629 and 0 648, respectively for the I (28 to 42 days old) and II (28 to 49 days of age) periods.

Objetivou-se nesta pesquisa determinar as faixas de conforto térmico, avaliadas em termos de temperatura e Índices de Temperatura de Globo Negro e Umidade (ITGU), adequadas à criação de codornas de corte na fase final de criação. Foram alojadas 300 codornas de corte, em diferentes ambientes térmicos. Cada grupo de 60 aves foi distribuído, aleatoriamente, em 03 câmaras climáticas, sendo 10 aves por unidade experimental (gaiola), totalizando 15 tratamentos. Os tratamentos foram: CP - Conforto Preconizado (temperaturas de 26 e 25 oC, respectivamente, para quarta e quinta semana de criação); QM - Calor Moderado (30 oC para a quarta e quinta semana de criação) e QS - Calor Severo (33 oC para a quarta e quinta semana de criação). Durante a quarta semana de criação das codornas (22 a 28 dias), o melhor valor de ITGU foi de 75,8 ± 0,9 e para a quinta semana de criação (29 a 35 dias) ITGU de 75,3 ± 0,7 (indicativos de conforto térmico para esta idade). Verificou-se que: codornas mantidas em estresse térmico (seja por frio ou calor) durante a fase inicial de criação não se recuperam ao final do ciclo de vida; mesmo quando criadas em condições de conforto térmico na fase inicial, após este período, quando mantidas em temperaturas de estresse seja por calor moderado ou severo crônicos, não conseguem se manter com a performance normal, demonstrando a necessidade de se garantir que o ambiente térmico dos aviários seja mantido adequado de acordo com as exigências para cada idade das codornas.

The objective of this research was to determine the temperature comfort, evaluated in terms of temperature and indices Black Globe Temperature and Humidity (BGTH), appropriate to the creation of quails in the final phase. Were housed 300 quails in different thermal environments. Each group of 60 birds were distributed randomly into 03 chambers, with 10 birds per pen (cage), totaling 15 treatments. The treatments were: CP - Comfort Pressed (temperatures of 26 and 25 oC, respectively, for fourth and fifth week of creation); MH - Moderate heat (30 ºC for the fourth and fifth week of creation) and HS - Heat Severus (33 oC for the fourth and fifth week of creation). During the fourth week of creation quail (22-28 days), the best value of BGTH was 75.8 ± 0.9 and for the fifth week of creation (29-35 days) BGTH 75.3 ± 0, 7 (indicative of thermal comfort for this age). It was found that: quail maintained in thermal stress (either hot or cold) during the initial phase can not recover the end of the life cycle, even when reared under conditions of thermal comfort in the initial stage after this period, while kept at temperatures of heat stress is moderate or severe chronic, can not keep up with the normal performance, demonstrating the need to ensure that the thermal environment of poultry is kept in accordance with the appropriate requirements for each age of the quail.

Visando-se determinar se o plasma sangüíneo tem efeitos sobre o crescimento, o desenvolvimento bacteriano e a estrutura intestinal de leitões desmamados aos 28 dias de idade consumindo quantidades iguais de dietas, 24 leitões desmamados aos 28 dias de idade foram utilizados em um experimento com delineamento em blocos ao acaso com quatro tratamentos (dietas com 0,0; 2,5; 5,0 e 7,5% de plasma sangüíneo), seis repetições e um animal por unidade experimental. Foram constatadas diferenças significativas entre os tratamentos em relação aos ganhos de peso, às conversões alimentares e às quantidades de colônias de E. coli. Os animais que consumiram as dietas com plasma sangüíneo apresentaram maiores ganhos de peso, melhores conversões alimentares e menores quantidades de E. coli no intestino delgado do que os animais que receberam dietas sem plasma. Não se observou efeitos significativos das quantidades de plasma sangüíneo consumido sobre a estrutura intestinal dos leitões doze dias após o desmame. Concluiu-se que a inclusão de plasma sangüíneo na proporção mínima de 2,5% aumenta ganho de peso, melhora conversão alimentar e reduz a incidência de colônias de E. coli no intestino de leitões desmamados aos 28 dias de idade criados em condições de desafio, mas não afeta a estrutura intestinal.

In order to evaluate the effects of spray-dried plasma on performance (weight gain, feed intake, and feed conversion), growth, intestinal health (microflora colonization and intestinal wall morphology) of piglets fed equal amounts per day of feed, 24 piglets weaned at 28 days old were used in an experiment performed as a randomised block design with four treatments (diets with 0.0, 2.5, 5.0 and 7.5% inclusion of spray-dried plasma), six replicates and one animal per experimental unit. Significant differences were observed among treatments weight gain, feed conversion and numbers of E. coli colony forming-units (CFU). Pigletsfed diets with different levels of spray-dried plasma had higher weight gain, better feed conversion and lower amounts of E. coli CFU in the small intestine than animals fed diets without spray-dried plasma in the diets. No significant effect of the treatments on the intestinal wall morphology at day twelve after weaning was observed. In conclusion, the inclusion of 2.5% spray-dried plasma in the diets in creases weight gain, improves feed conversion and reduces the incidence of E. coli CFU in the small intestine of piglets weaned at 28 days of age reared under challenging conditions, however, no beneficial effect on the intestinal wall morphology was observed with the inclusion of spray dried plasma in the diets.

Com o objetivo de avaliar diferentes níveis de lisina digestível 35 suínos machos castrados com peso inicial de 95,6 ± 1,1kg e mantidos em salas bioclimáticas reguladas à 32ºC foram distribuídos em um experimento com delineamento inteiramente casualizado dentro de cinco níveis de lisina digestível (0,66; 0,78; 0,90; 1,02 e 1,14%) sete repetições e um animal por unidade experimental. O fornecimento de ração foi realizado duas vezes ao dia e restrito pelo menor consumo dentro de cada repetição. O peso final, o consumo de ração médio diário, a espessura de toucinho, a profundidade de músculo, a área de olho de lombo e o percentual de carne na carcaça não foram afetados pelos níveis de lisina digestível. Houve tendência quadrática sobre o ganho de peso (P=0,08), deste modo, a conversão alimentar apresentou efeito quadrático (P=0,05), os quais estimaram níveis de 0,99 e 0,98% de lisina digestível, correspondentes aos consumos estimados de 23,04 e 26,21g/dia de lisina digestível, respectivamente. Os níveis de lisina digestível também afetaram de forma quadrática o peso e o rendimento de carcaça; os quais foram estimados em 0,95% e em 0,86% de lisina digestível, respectivamente. Houve redução linear no peso relativo do intestino delgado. Conclui-se que o nível de lisina digestível para suínos machos castrados em fase de terminação e mantidos sob estresse por calor é de 0,98 %.

With the objective of evaluated different digestible lysine levels 35 castrated male pigs with initial weight of 95.6 ± 1.1kg and housed in bioclimatic rooms regulated at 32ºC were distributed in experimental design of randomized blocks into of five digestible lysine levels (0.66; 0.78; 0.90; 1.02 and 1.14%), seven replications and one pig per experimental unit. The supply of feed was realized twice per day and restricted by lesser feed intake within each repetition. The final body weight, average daily feed intake, backfat thickness, muscle depth rate, longissimus dorsi muscle area and carcass meat percentage were not affecteed by digestible lysine levels. There was quadratic trend on average weight gain (P=0.08) and this way, the feed conversion showed a quadratic effect (P=0.05), which estimated digestible lysine levels of 0.98 and 0.99%, corresponding at estimated intake of 23.04 and 26.21g/day of digestible lysine, respectively. The digestible lysine levels also showed quadratic effect on the weight and yield of carcass, which were estimated in 0.95 and 0.86% of digestible lysine, respectively. There was linear decrease in small intestine relative weight. The digestible lysine level for finishing phase barrows and housed under heat stress is 0.98%.

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%.

Com o objetivo de determinar os efeitos do plasma sanguíneo sobre as vilosidades intestinais e o desenvolvimento bacteriano no intestino delgado, bem como, sobre o desempenho de leitões desmamados aos 35 dias de idade foram distribuídos ao acaso 24 leitões em um experimento com delineamento em blocos, com quatro tratamentos (0,0; 2,5; 5,0 e 7,5% de plasma sanguíneo), seis repetições e um animal por unidade experimental. Foram constatadas diferenças entre tratamentos com relação ao ganho de peso, conversão alimentar, unidades formadoras de colônias de E. coli e altura de vilosidades. Os leitões alimentados com as dietas que continham plasma ganharam mais peso e tiveram menos E. coli no intestino delgado que os leitões alimentados com a dieta controle. Os leitões que receberam as dietas que continham 5,0 ou 7,5% de plasma apresentaram melhor conversão alimentar em comparação aos animais do controle, e os que foram alimentados com as dietas que continham 2,5; 5,0 ou 7,5% de plasma receberam, respectivamente, 45,0; 75,0 e 70,0% menos doses de antibiótico em relação aos leitões do tratamento controle. Os níveis de 2,5% e 7,5% de plasma na dieta proporcionaram aumentos nas alturas das vilosidades do duodeno e do jejuno dos leitões. A inclusão de plasma sanguíneo em dietas para leitões desmamados aos 35 dias de idade em condições de desafio sanitário tem efeito direto na formação de colônias de E. coli e na altura das vilosidades do intestino delgado, bem como, aumenta o ganho de peso e melhora conversão alimentar dos leitões.

With the objective to determine the effects of spray-dried plasma on intestinal villi and bacterial growth in the small intestine, as well as on performance of piglets weaned at 35 days old, 24 piglets were randomly assigned in an experimental block design with four treatments (0.0; 2.5; 5.0, and 7.5% spray dried plasma), six replicates and one piglet per experimental unit. Differences were observed among treatments with respect to weight gain, feed conversion, E. coli colony-forming units, and villus height. Pigs fed diets containing spray dried plasma gained more weight and had less E. coli in the small intestine than piglets fed the control diet. The piglets fed the diets containing 5.0 or 7.5% plasma showed better feed conversion compared to those receiving the control diet. Piglets fed the diets containing 2.5; 5.0 or 7.5% plasma received 45.0; 75.0, and 70.0% lesser doses of antibiotics compared to piglets in the control treatment. The levels of 2.5% and 7.5% plasma in the diet resulted in increases in villus height in the duodenum and jejunum. The inclusion of spray-dried plasma in diets for health challenged piglets weaned at 35 days of age has a direct effect on the formation of E. coli colony-forming units and villus height in the small intestine and improves weight gain and feed conversion.

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.

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.

Para avaliar o efeito de níveis de lisina digestível sobre o desempenho e as características de carcaça de suínos machos castrados dos 60 aos 100 dias de idade, foram utilizados 300 animais com peso médio de 25±0,52 kg, distribuídos em delineamento experimental de blocos ao acaso, com 5 tratamentos (0,65; 0,75; 0,85; 0,95 e 1,05% de lisina digestível), 5 repetições e 12 animais por unidade experimental. Não houve efeito dos níveis de lisina digestível sobre o consumo médio diário de ração. O consumo de lisina digestível aumentou de forma linear com o aumento desse aminoácido na ração. O ganho de peso médio diário aumentou e a conversão alimentar melhorou de forma quadrática com o aumento dos níveis de lisina digestível da ração. Não foi observado efeito dos níveis de lisina digestível sobre a espessura de toucinho dos animais, entretanto, o rendimento de carcaça e a quantidade de carne aumentaram de forma quadrática com o aumento dos níveis de lisina digestível. Os níveis de 0,96 e 0,92% de lisina digestível, correspondentes aos consumos estimados de 18,69 e 17,69 g/dia, proporcionam os melhores resultados de ganho de peso e conversão alimentar, enquanto os níveis de 0,89 e 0,90%, correspondentes aos consumos estimados de 17,28 e 17,52 g/dia, propiciam os melhores resultados de rendimento e quantidade de carne na carcaça de suínos machos castrados dos 60 aos 100 dias de idade.

In order to evaluate digestible lysine levels on the performance and carcass traits of castrated male pigs from 60 to 100 days of age, 300 barrows with initial weight of 25.0±0.52 kg were allotted in a completely randomized block design with five treatments (0.65, 0.75, 0.85, 0.95, and 1.05% digestible lysine levels), five replicates, and 12 pigs per experimental unit. There was no effect of digestible lysine levels on average daily feed intake. The average daily gain increased and feed conversion improved quadratically with increasing dietary digestible lysine levels. There was no effect of the digestible lysine levels on pig backfat thickness; however the carcass yield and quantity of meat increased quadratically with increasing digestible lysine levels in the diets. The levels of 0.96 and 0.92% digestible lysine, corresponding to the estimated intakes of 18.69 and 17.69 g/day provide the best results of weight gain and feed conversion, while levels of 0.89 and 0.90%, corresponding to the estimated intakes of 17.28 and 17.52 g/day, provide the best results of yield and quantity of meat in the carcass of barrows from 60 to 100 days of age.

This experiment was conducted to determine the requirement of available phosphorus (aP) for pigs kept in hot environment. Seventy-two pigs (36 castrated males and 36 females) with initial weight of 15.10±0.31 kg were allotted in a completely randomized block design with six treatments (0.107, 0.214, 0.321, 0.428, 0.535, and 0.642% of aP), six replicates and two pigs (1 castrated male and 1 female) per experimental unit. Pigs were kept in a hot environment with temperature of 34.1±0.8 ºC. The levels of aP influenced the daily weight gain, which increased quadratically up to the estimated level of 0.477%, and feed conversion, which improved quadratically up to the estimated level of 0.457%. The levels of aP also influenced the content of phosphorus in the bone, which increased quadratically up to the estimated level of 0.529%. The available phosphorus requirement of 15- to 30-kg pigs kept in a hot environment, for the best results of daily weight gain, feed conversion and bone parameters are 0.477, 0.457, and 0.529%, corresponding to the estimated daily available phosphorus intakes of 4.75; 4.55 and 5.27 g, respectively.

The objective of this study was to evaluate the effects of increasing dietary digestible tryptophan levels on performance and carcass traits of growing pigs. Fifty crossbred castrated male pigs, with average initial and final body weight of 29.0 ± 1.20 kg and 60.4 ± 1.95 kg were allotted in a completely randomized block design, with five treatments (0.125, 0.133, 0.141, 0.149, and 0.157% of digestible tryptophan, corresponding to digestible tryptophan:lysine relations of 15.0, 16.0, 17.0, 18.0, and 19.0%, respectively) and five replicates, with two pigs per experimental unit, which was represented by the pen. Experimental diets and water were supplied ad libitum throughout the experimental period. Averages of minimum and maximum temperatures inside the facility were of 24.3 ± 0.87 ºC and 28.0 ± 1.82 ºC, respectively. Feed intake and body weight gain increased linearly with increasing dietary tryptophan levels. However, there was no effect of digestible tryptophan on feed conversion or protein deposition of pigs. The highest tryptophan level evaluated (0,157%), corresponding to a digestible tryptophan:lysine relation of 19.0%, provided the greatest weight gain of 30 to 60 kg castrated male pigs.

In order to evaluate the effects of increasing dietary tryptophan levels on performance and carcass characteristics of growing pigs, a total of 60 crossbred castrated male pigs, with average initial and final body weights of 15.50 ± 1.15 and 30.60 ± 1.35 kg were used. Pigs were allotted in a completely randomized block design, with five dietary treatments (0.149, 0.158, 0.168, 0.177, and 0.187% digestible tryptophan, corresponding to digestible tryptophan:lysine relations of 16.0, 17.0, 18.0, 19.0, and 20.0%), six replicates, and two animals per experimental unit, which was represented by the pen. Experimental diets and water were supplied ad libitum throughout the experimental period. The average maximum and minimum temperatures inside the rooms were of 21.5 ± 1.12°C and 26.4 ± 1.91°C, respectively. There was no effect of digestible tryptophan on daily feed intake or protein deposition of pigs. Body weight gain increased quadratically with increasing digestible tryptophan in the diets up to 0.175% maximum response. Increasing digestible tryptophan in the diets linearly improved feed conversion of pigs. The greatest weight gain of 15 to 30 kg castrated male pigs is obtained at 0.175% digestible tryptophan, corresponding to a digestible tryptophan:lysine relation of 18.82% and an estimated daily intake of 2.32 grams of digestible tryptophan.

Com o objetivo de avaliar níveis de lactose em rações para leitões desmamados aos 21 dias de idade, foi realizado um experimento com 72 animais com peso inicial médio de 6,10 kg, distribuídos em delineamento de blocos ao acaso com quatro rações (0, 4, 8 e 12% de lactose), seis repetições e três animais por unidade experimental. Os animais foram alimentados com as rações experimentais no período de 21 a 35 dias de idade e, no período de 36 a 49 dias, receberam uma ração basal isenta de lactose. Os níveis de lactose não afetaram o ganho diário de peso, o consumo diário de ração e a conversão alimentar dos leitões de 21 a 35 dias. O uso de lactose nas rações também não afetou o desempenho dos leitões avaliados dos 21 aos 49 dias de idade. As rações também não influenciaram a altura das vilosidades, a profundidade de criptas e a relação vilosidade:cripta. A lactose proporcionou maior diversidade e equilíbrio da comunidade microbiana intestinal. A riqueza microbiana de Lactobacillus spp. aumenta com a adição de lactose na ração até o nível de 8% em relação ao número total de microrganismos intestinais, o que indica possível melhora da saúde intestinal.

With the objective of evaluating levels of lactose in diets for piglets weaned at 21 days of age, it was carried out an experiment with 72 animals, with average weight of 6.12 kg, distributed in a completely randomized block design with four diets (0, 4, 8, and 12% lactose), six replicates, and 3 animals per experimental unit. Animals were fed the experimental diets from 21 to 35 days of age and they were fed a lactose-free basal diet from 36 to 49 days of age. The lactose levels did not affect daily weight gain, feed intake and feed conversion of piglets from 21 to 35 days of age. The use of lactose levels in the diets also did not affect performance of the piglets assessed from 21 to 49 days old. Diets also did not influence villous height, crypt depth and villous:crypt ratio. Lactose resulted in greater diversity and balance of the intestinal microbial community. The Lactobalillus spp. richness increases with the addition of lactose in diet up to the level of 8% in relation to the total number of intestinal microorganisms, which may a possible improvement of intestinal health.

Foram utilizados 72 leitões, 36 machos castrados e 36 fêmeas, com peso inicial de 14,97 ± 0,36 kg para avaliar níveis de fósforo disponível (Pd). Os animais foram distribuídos em delineamento experimental de blocos ao acaso, com seis níveis de Pd (0,107; 0,214; 0,321; 0,428; 0,535 e 0,642%), seis repetições e dois animais (um macho castrado e uma fêmea) por unidade experimental. A temperatura interna da sala foi mantida em 24,5 ± 1,2ºC e a umidade relativa do ar em 76,3 ± 8,5%. Os níveis de Pd influenciaram o consumo de ração diário e o ganho de peso diário, que aumentaram de forma quadrática até os níveis estimados de 0,420 e 0,443%, respectivamente, e a conversão alimentar, que melhorou de forma quadrática até o nível estimado de 0,461%. Verificou-se efeito dos níveis de Pd sobre a quantidade de fósforo e cinzas no osso, que aumentou de forma quadrática até os níveis estimados, respectivos, de 0,525 e 0,520%. Os níveis de Pd melhoraram a deposição diária de proteína na carcaça, que aumentou de forma quadrática até o nível estimado de 0,394%, e não afetaram a deposição diária de gordura na carcaça. Os níveis de Pd que proporcionam os melhores resultados de ganho de peso, conversão alimentar e mineralização óssea de suínos de alto potencial genético para deposição de carne magra mantidos em ambiente termoneutro na fase dos 15 aos 30 kg são respectivamente 0,443; 0,461 e 0,525%, que correspondem a consumos diários estimados de 5,25; 5,45 e 6,14 g de fósforo disponível.

It was used 72 pigs, 36 castrated males and 36 females, with initial weight of 14.97 ± 0.36 kg to evaluate levels of dietary available phosphorus (aP). The animals were distributed in a completely randomized block design, with six levels of aP (0.107; 0.214; 0.321; 0.428; 0.535 and 0.642%), six replicates and two animals (one castrated male and one female) per experimental unit. Air temperature and relative humidity in the room were kept at 24.5 ± 1.2°C and 76.3 ± 8.5%, respectively. The levels of aP influenced both daily feed intake and daily weight gain, which increased in a quadratic way up to the estimated levels of 0.420% and 0.443%, respectively and feed conversion, which improved in a quadratic manner up to the estimated level of 0.461%. It was observed the effects of levels of aP on quantity of phosphorus and ash in the bone, which increased in a quadratic manner up to the estimated levels of 0.525% and 0.520%, respectively. Levels of Ap affected daily protein deposition in the carcass, which increased in a quadratic way up to the estimated level of 0.394%. There was no effect of levels of aP on daily fat carcass deposition. Levels of aP that provided the best results for daily weight gain, feed conversion and bone mineralization in swines with high genetic potential for lean meat kept in thermoneutral environment, from 15 to 30 kg are 0.443, 0.461 and 0.525%, respectively, corresponding to estimated daily intakes of 5.25, 5.45 and 6.14 g of aP.