ABSTRACT This study aimed to evaluate the use of decision trees to select sows based on the production parameters of parity order (PO) 1 sows from a commercial herd. Data were collected at a piglet production unit with a capacity of housing 5,500 sows in collective pens. Piglet production and sow culling information was collected from PO1 and PO2 sows. The period from January 2017 to March 2020 was analyzed. The correlation analysis was used to identify the influence of the production parameters on sow culling after exploring the database using the graphical analysis and descriptive statistics. The ANOVA was applied to evaluate differences in the response variables between culled and unculled sows. Two models were proposed using the decision tree method: model 1 referred to sow culling, and model 2 comprised the total number of liveborn piglets (TBA). The calculated value was close to 0, although the correlations of the production parameters with culling were statistically significant. The mean number of weaned piglets was higher for unculled sows in PO1 (p < 0.05). The number of weaned piglets, total number of liveborn piglets, and weaning-service interval did not differ in the unculled and culled sows in PO2 (p > 0.05). Using a confusion matrix as a metric tool, the decision tree method used in this study provided consistent results for this database, indicating its possible use for decision-making in sow selection.

RESUMO: O desempenho e as características de carcaça de suínos em terminação alimentados com dietas contendo diferentes níveis de fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA) foram avaliados por meio de meta-análise. O banco de dados foi construído com informações de 24 artigos, 113 tratamentos e 2.507 animais. Análises de correlação e variância foram realizadas. O ganho de peso dos suínos apresentou correlação negativa (P < 0,01) com o teor de FDN da dieta e com o consumo de FDN. A taxa de conversão alimentar apresentou correlação positiva (P < 0,01) com a inclusão de FDA presente nos ingredientes testados e com o consumo de FDN e FDA. A espessura do toucinho apresentou correlação negativa (P < 0,05) com o teor de FDN das dietas. A análise de variância mostrou que o desempenho dos suínos em terminação não foi influenciado (P > 0,05) pela inclusão de ingredientes com alto teor de FDN. Da mesma forma, a inclusão de ingredientes com alto teor de FDA não alterou (P > 0,05) o consumo de ração e a conversão alimentar. Porém, o uso de ingredientes com alto teor de FDA reduziu (P < 0,05) em 4% o ganho de peso dos suínos. O uso de ingredientes com altas concentrações de FDN e FDA afetam negativamente o ganho de peso e conversão alimentar de suínos em terminação, porém fração relacionada a FDA tem relação positiva com a redução da espessura de toucinho.

ABSTRACT: Performance and carcass traits of finishing pigs fed diets containing different levels of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were evaluated through meta-analysis. The database was constructed using information from 24 papers, 113 treatments, and 2507 animals. Correlation and variance analyze were performed. The weight gain of the pigs showed a negative correlation (P < 0.01) with the dietary NDF content and with NDF consumption. The feed conversion ratio showed a positive correlation (P < 0.01) with the inclusion of ADF in the test ingredient and with the consumption of NDF and ADF. The backfat thickness showed a negative correlation (P < 0.05) with the NDF content in the diets. The analysis of variance showed that the performance of finishing pigs was not influenced (P > 0.05) by the inclusion of ingredients with high NDF content. Likewise, the inclusion of ingredients with high ADF content did not alter (P > 0.05) feed intake and feed conversion ratio. However, the use of ingredients with a high ADF content reduced (P < 0.05) by 4% the weight gain of the pigs. The use of ingredients with high concentrations of NDF and ADF negatively affect the weight gain and feed conversion of finishing pigs; however, the ADF-related fraction has a positive relationship with the reduction of the backfat thickness.

ABSTRACT: Effects of plasticizer types and whey protein concentrate (WPC) as coatings were evaluated on internal quality and shelf life of eggs stored for 42 days. Eggs were coated with WPC at 8 % solution combined with the plasticizers glycerol (GLY), sorbitol (SOR), and propylene glycol (PRO). The eggs were stored at 20 °C. Weight loss, Haugh Unit (HU), albumen and yolk pH, and yolk index (YI) were evaluated weekly from day 0 to 42 days. After, electron microscopy of the eggshell structure was performed. The data was submitted to the analysis of variance and the effects of treatment, storage time, and the interaction between these factors were evaluated. There was significant interaction between factors (treatment and periods) for weight loss (p < 0.0001), HU (p < 0.0001), albumen (p < 0.0001), and yolk pH (p < 0.0001), and YI (p < 0.0001). After 42 days, uncoated eggs showed greater weight loss (5.4 %), compared to WPC+GLY, (3.8 %), WPC+SOR (3.3 %) and WPC+PRO (3.9 %). Similar results were verified for HU at 42 days of storage. Uncoated eggs showed HU of 58.46 (B), while coated eggs showed higher values: WPC+GLY – 66.58 (A), WPC+SOR – 68.79 (A), and WPC + PRO – 71.53 (A). The plasticizers GLY, SOR and PRO, associated with WPC, demonstrated effectiveness in maintaining the quality of eggs throughout the 42 days of storage. However, WPC+SOR showed superiority in preserving quality integrity of eggs. This result can be related to the chemical structure of SOR, making the combination more efficient for storage.

ABSTRACT: This study was designed to simulate productive and economic losses due to the withdrawal of antibiotic growth promoters (AGP) from pig diets. Articles that compared diets with AGP (AGP+) or without AGP (AGP–) for pigs were collected from electronic databases and the performance results were entered in a database. A meta-analysis was performed following the sequence: graphical analysis, correlation, and variance-covariance. The performance results observed in the meta-analysis, feed cost, and AGP costs were used to build equations to estimate the economic effect of withdrawing AGP. The database comprised 81 scientific articles containing 103 experiments totalizing 42,923 pigs. Avilamycin (24.7 %) was the most frequent AGP in the database, followed by Colistin (15.4 %), Tiamulin (11.7 %), Tylosin (8.0 %), Lincomycin (9.4 %), and Bacitracin (5.4 %). Weight gain (p < 0.05) increased in AGP+ diets during post-weaning (6.5 %). However, there was no effect of AGP on weight gain of growing-finishing pigs. There was better (p < 0.05) feed conversion in pigs fed AGP+ diets in all rearing phases. Weight gain and feed conversion improved (p < 0.05) with the addition of Avilamycin, Bacitracin, and Tylosin. AGP withdrawal in the post-weaning phase increased feed costs by US$ 0.86 per animal and in growing-finishing phase the increase was US$ 3.11. Thus, pigs fed AGP+ diets have a better performance than pigs fed AGP- diets and the withdrawal of AGP increases feed costs.

ABSTRACT This study was developed using meta-analysis to evaluate the effect of β-mannanase on both poultry and pig performance. Two databases were constructed using information from previous studies that evaluated the β-mannanase supplementation in diets for broilers (30 papers; 19,643 birds) and pigs (20 papers; 5,319 animals). The meta-analysis followed three sequential analyses: graphical, correlation, and variance-covariance. The effect of β-mannanase supplementation on performance considerably varied in both databases. Data analysis considering the study effect showed that β-mannanase supplementation did not influence feed intake. Diets supplemented with β-mannanase did not influence weight gain, but improved feed conversion (−1%) of broilers compared with the control group. Feeding pigs diets supplemented with β-mannanase improved weight gain (+5%) and feed conversion (−6%) compared with pigs fed non-supplemented diets. β-mannanase supplementation increased the digestibility coefficient of dry matter, crude protein, and energy in both species. The inclusion of β-mannanase also improved the metabolizable energy content in broiler diets and enhanced the digestibility of energy in pig feeds. Current results indicate that β-mannanase can be considered as an important tool for nutritionists who search for improved feed conversions and nutrient digestibility coefficients.

ABSTRACT: The effects of mycotoxins on the productive performance of growing pigs and broilers were evaluated using meta-analytical approach. Two databases were constructed: (1) Broilers, with information collected from 51,497 birds and published in 158 scientific papers from 1980 to 2016; and (2) Pigs, with information collected from 7,743 animals and published in 72 scientific papers from 1980 to 2015. The meta-analyses were performed independently for each specie, following three sequential analyses: graphical, correlation, and variance-covariance. Broilers and pigs challenged by mycotoxins reduced (p < 0.05) feed intake by 9 and 6 %, weight gain by 15 and 11 %, and feed efficiency by 6 and 4 % compared with non-challenged animals, respectively. Aflatoxins were the most studied mycotoxins in both databases. Birds and pigs challenged by aflatoxins reduced (p < 0.05) feed intake by 10 and 8 %, growth by 15 and 11 %, and feed efficiency by 6 and 7 % compared to non-challenged animals, respectively. In both databases, variation on growth performance due to mycotoxins showed a linear relationship (p < 0.05) with the feed intake variation caused by the challenge. The intercepts of the regression-based equations were different from zero and negative, which may indicate that mycotoxins altered the maintenance requirements in challenged animals. In conclusion, both broilers and growing pigs show losses in performance responses and worse nutritional efficiency when challenged by mycotoxins.

ABSTRACT We evaluated the effects of a protease supplementation on the growth performance and intestinal health of broilers. Cobb chicks (392; 1-42 d) were divided into four treatments (seven replicates of 14 birds each). There were two feed formulations: a standard diet (SD) and a low crude protein and digestible amino acids diet (Low CP&AA). The two diets were either supplemented (+P) or not (−P) with a protease (Jefo Protease; 1.25 g kg−1). Performance was evaluated by feeding phases (1-7, 8-21, 21-35, and 35-42 d). On day 28, ileum samples were analyzed by a morphometric index for histological alterations (I See Inside Scoring System – ISI). Broilers fed the Low CP&AA had a poor feed conversion ratio (FCR); however, the addition of the protease to the Low CP&AA positively affected FCR and body weight gain and promoted a performance similar to the group fed SD−P. Birds fed diets supplemented with the protease presented the best ISI morphological index, mainly as a result of the low number of alterations regarding the lamina propria, epithelial thickness, and enterocyte proliferation. It is possible to conclude that the enzyme improves feed conversion and lamina propria, epithelial thickness, and proliferation of enterocytes index of broiler chickens when added to a standard diet or with a low crude protein and digestible amino acids diet.

ABSTRACT Several empirical models were proposed to predict feed intake (FI) of growingfinishing pigs reared under high environmental temperatures. However, these models have not been evaluated under conditions different from those in which they were developed. Twelve empirical models were evaluated using a database built after systematic literature review (observed data: 28 studies in which the FI was evaluated in pigs under high environmental temperatures). Model accuracy was assessed using the mean squared of prediction error (MSPE). Analyses were performed considering two scenarios: (1) general population, where all observed data were used in the simulation; (2) reference population, where data were filtered in order to simulate only scenarios with environment (temperature range) and animals (body weight and sex) similar to that used in the model development. Six models estimated FI values similar (p > 0.05) to those observed in the general population, while four models produced estimates similar to the observed values in the reference populations. Most models were more accurate when they were simulated using the reference population than when the simulation considered the general database. Moving the simulation from the general database to the reference population reduced up to 98 % of the MSPE, depending on the equation. Empirical models allow to accurately predict FI of growing-finishing pigs exposed to high environmental temperatures, especially in scenarios similar to the ones used for model development. Thus, population characteristics (body weight and sex) and environment (temperature range) must be considered in the model assessment.

ABSTRACT A nitrogen balance test was performed to evaluate the individual responses of growing pigs to threonine intake. Eight commercial barrows were used (body weight ranging from 15 to 20 kg). A dose-response study was performed, in which the threonine supply increased in seven equidistant steps (the seven dietary threonine levels ranged from 50 to 120% of the requirements) every three days for each pig. The levels of all other amino acids were 20% higher than the tested amino acid. Nitrogen retention as a function of threonine intake was calculated per individual and per group (NLIN and NLMixed, respectively) using a linear plateau model. The highest break point value was 42.42 g of threonine intake (the most demanding individual), whereas the lowest value was 34.16 g (the least demanding individual), corresponding to a difference of 19%. In terms of N retention, the highest plateau value was 66.71 g and the lowest was 49.48 g, with a difference of 25%. There was no significant correlation between slope and plateau values or between slope and break point values. When using the model in which all parameters were random effects, the variations in threonine intake and nitrogen retention were 1.68±1.30 and 0.01±0.10 g, respectively, and no variance in the slope of the curve was detected. The average daily threonine intake values for the maximum response obtained in the group, as calculated by the NLIN and NLMixed procedures, were 13.96 and 14.02 g/day, respectively. The threonine intake for the maximum N retention between individuals ranged from 34.16 to 42.42 g, corresponding to a difference of 19%. The current recommended intake to optimize N retention is 14.02 g/day. The group responses obtained by the NLMixed procedures are very similar to those estimated by the NLIN procedure (all individuals).

ABSTRACT Little is known about the toxicity of concomitantly occurring mycotoxins in pig diets. This study was conducted to evaluate, through meta-analysis, the individual and the combined effects of mycotoxins on pig performance. The meta-analysis followed three sequential analyses (graphical, correlation, and variance-covariance) based on a database composed of 85 published papers, 1,012 treatments and 13,196 animals. Contamination of diets with individual mycotoxins reduced (p < 0.05) feed intake by 14 % and weight gain by 17 %, while combined mycotoxins reduced the same responses by 42 % and 45 %, respectively, in comparison with the non-challenged group. The correlation (p < 0.05) between reduction in weight gain (ΔG) and reduction in feed intake (ΔFI) was 0.67 in individual challenges and 0.93 in combined challenges. The estimated ΔG was –6 % in individual challenges and –7 % in combined challenges when ΔFI was zero, suggesting an increase in the maintenance requirements of challenged animals. Most of ΔG (58 % in individual challenges and 84 % in combined challenges) was attributed to the changes in feed efficiency. The association of mycotoxins enhances individual toxic effects and the ΔFI is important in explaining the deleterious effects on the growth of challenged pigs.

<p>Uma meta-análise foi desenvolvida para estudar o desempenho, características de carcaça e interações com variáveis nutricionais em suínos machos castrados, inteiros e imunocastrados. Para a base de dados, foram utilizados 27 artigos totalizando 2.917 animais. A meta-análise foi realizada através de análises gráficas, de correlação e de variância-covariância. Suínos machos inteiros apresentaram consumo de ração 9% inferior (P<0,05) aos castrados e 11% inferior (P<0,05) em relação aos imunocastrados. O ganho de peso foi maior (P<0,05) nos suínos imunocastrados em relação aos machos inteiros (9%) e castrados (12%) e apresentou correlação positiva (P<0,05) com a ingestão de proteína bruta em todas as categorias estudadas. Interceptos das equações que estimavam o consumo de lisina total em função do ganho de peso dos animais foram 15,3; 20,4 e 22,3g para suínos machos castrados, imunocastrados e inteiros, respectivamente, indicando empiricamente que animais inteiros apresentam maior exigência de lisina para mantença em relação aos animais castrados. O peso de carcaça quente e rendimento de carcaça não diferiram (P>0,05) entre as categorias sexuais estudadas. Porém, suínos machos castrados apresentaram conteúdo de carne magra 5% inferior (P<0,05) aos imunocastrados e 7% inferior (P<0,05) em relação aos inteiros. A espessura de toucinho dos suínos castrados foi 21% superior (P<0,05) em relação aos imunocastrados e 27% superior (P<0,05) aos inteiros. As respostas de desempenho diferem em suínos machos castrados, inteiros e imunocastrados. Esta meta-análise indicou que as variáveis nutricionais e exigências de mantença nas diferentes categorias sexuais dos suínos devem ser consideradas em pesquisas futuras.</p>

<p>A meta-analysis was carried out in order to study performance, carcass characteristics and nutritional interactions in castrated, entire and immunocastrated males. A total of 27 studies were used in the database, totaling 2917 animals. The meta-analysis followed three sequential analyses: graphical, correlation and variance–covariance. Entire males showed feed intake 9% lower (P<0.05) than surgically castrated males and 11% lower (P<0.05) than immunocastrated pigs. Weight gain was higher (P<0.05) in immunocastrated pigs in comparison to entire (9%) and castrated (12%) males. Daily weight gain showed positive correlation (P<0.05) with crude protein intake in all sex categories. The intercepts in the equations estimating the total lysine intake depending on the weight gain were 15.3; 20.4 and 22.3g for surgically castrated, immunocastrated and entire males, respectively, indicating empirically that the entire males have higher lysine requirement for maintenance in comparison to surgically castrated pigs. Hot carcass weight and carcass yield did not differ (P>0.05) between treatments. However, castrated males showed lower lean meat content (P<0.05) in comparison to immunocastrated (5%) and entire (7%) males. The backfat thickness of surgically castrated pigs was 21% higher (P<0.05) relative to immunocastrated and 27% higher (P<0.05) in comparison to entire pigs. Performance responses differ in surgically castrated, entire and immunocastrated male pigs. The meta-analysis indicated that the nutritional variables and maintenance requirements in different sexual categories of pigs should be considered in future research studies.</p>

Uma meta-análise foi realizada para avaliar o desempenho e a qualidade de carcaça e carne de suínos em função do sistema de alojamento nas fases de crescimento/terminação. Foram selecionadas publicações indexadas com resultados de experimentos comparando variáveis de desempenho e de pós-abate de suínos alojados em sistemas intensivos convencionais ou ao ar livre. A base de dados contemplou 27 artigos publicados entre 1997 e 2009. Ao total, foram considerados 2.985 animais e 701 médias na análise de dados. A meta-análise foi realizada através de duas análises sequenciais: gráfica e de variância-covariância. O sistema de criação de suínos ao ar livre aumentou em 9% (P<0,05) o consumo de ração, reduziu em 2% (P<0,01) o ganho de peso diário e piorou em 3% (P<0,05) a conversão alimentar dos animais em relação ao sistema confinado. As características de carcaça (peso de carcaça quente, rendimento, espessura de toucinho e percentual de carne magra) e de carne no Longissimus dorsi (perda por gotejamento e cozimento, pH, temperatura inicial, força de cisalhamento, marmoreio dureza, maciez e suculência) não foram influenciadas (P>0,05) pelo sistema de alojamento dos suínos. Concluiu-se que o sistema de criação influencia no desempenho dos suínos, mas não interfere nas características de carcaça e carne estudadas.

A meta-analysis was carried out to study performance and characteristics of carcass and meat in pigs in function of housing system during the growing/finishing period. Indexed publications with results of experiments comparing performance and post-slaughter variables of pigs housed in outdoor or conventional intensive systems were selected. In total, 2.985 animals and 701 averages were considered in the data analysis. Meta-analysis followed two sequential analyses: graphic and variance. The outdoor productive system increased in 9% (P<0.05) feed intake, reduced in 2% (P<0.01) daily weight gain and worsened in 3% (P<0.05) feed conversion ratio of pigs in comparison to animals in the confined system. Characteristics of carcass (hot carcass weight, yield, backfat thickness and lean meat percentage) and Longissimus dorsi meat (drip and cooking loss, pH, the initial temperature, shear force, marbling, hardness, juiciness and tenderness) were not affected (P>0.05) by the housing system. It is concluded that the housing system influences the pig performance, but does not interfere in characteristics of carcass and meat.

Um experimento foi realizado para avaliar o desempenho e o custo do alimento de suínos machos castrados e inteiros suplementados ou não com aminoácidos. Foram utilizados 48 animais com peso vivo inicial de 38,8±0,2kg, distribuídos num delineamento de blocos ao acaso em três tratamentos, sendo machos castrados (MC), machos inteiros (MI) e MI suplementados com 5% de aminoácidos (MI+5%AA). Não houve efeito (P>0,05) dos tratamentos sobre o peso vivo e o ganho de peso dos suínos. O consumo de ração, a conversão alimentar e o custo do alimento diferiram (P<0,05) entre os tratamentos. O consumo médio de ração foi de 2,43kg, sendo que os MC apresentaram consumo superior (P<0,05) em 5,5 e 5,2% em relação aos MI e aos MI+5%AA, respectivamente. A conversão alimentar média foi 2,28; sendo que os MC apresentaram pior conversão (P<0,05) em 6,2 e 11,6% em relação aos MI e aos MI+5%AA, respectivamente. O custo médio do alimento foi de R$ 1,82 kg-1, sendo superior (P<0,05) para os MC em relação aos MI e MI +5%AA. O tipo sexual do macho (castrado ou inteiro) e a suplementação aminoacídica não afetam o peso vivo e o ganho de peso, mas alteram o consumo de ração, a conversão alimentar e o custo de alimento.

An experiment was carried out to evaluate the performance and feed cost of barrows and boars fed or not with amino acid supplemented diets. Forty-eight animals were used with initial weight of 38.8±0.2kg distributed in a randomized block design with three treatments, being barrows males (CM), boars males (IM) and IM supplemented with 5% of amino acids (IM+5% AA). The treatment had no effect on body weight and weight gain. Feed intake, feed conversion ratio and feed cost were different (P<0.05) among treatments. Average feed intake was of 2.43kg, and the intake observed on CM (P<0.05) was higher at 5.5 and 5.2% in relation to IM and IM+5%AA, respectively. Feed conversion ratio was of 2.28, and the CM showed the worse conversion (P<0.05) at 6.2 and 11.6% in relation to IM and IM+5%AA, respectively. Average feed cost was of R$ 1,82kg-1, being higher (P<0.05) for the CM in relation to IM and IM+5%AA. The sex category (barrows or boars) and amino acid supplementation did not affect body weight and weight gain, but alter feed intake, feed conversion ratio and feed cost.

Foi realizado um experimento para avaliar a digestibilidade aparente de dietas e o metabolismo de suínos alimentados com dietas contendo bentonita sódica submetidos a diferentes programas alimentares. Foram utilizados 24 suínos machos castrados, meio irmãos paternos, com peso vivo médio inicial de 42,2kg, alojados em gaiolas metabólicas. O delineamento experimental foi o inteiramente casualizado com três níveis de bentonita sódica (0,0; 0,3 e 0,5%) e dois programas alimentares (restrito e à vontade), com oito repetições cada. A adição de bentonita sódica não alterou (P>0,05) o consumo de ração e os balanços da energia e do nitrogênio. O consumo de ração diferiu (P<0,01) entre a alimentação restrita e à vontade (1,17 vs. 2,19kg d-1). O programa alimentar alterou (P<0,05) o balanço do N, mas não afetou (P>0,05) a retenção de N pelos animais. A alimentação à vontade alterou (P<0,05) o balanço da energia, sobretudo a energia retida (3.825 vs. 3.013kcal d-1). A adição de 0,5% de bentonita sódica nas dietas reduziu em 9% (P<0,01) a excreção fecal de fósforo. A adição de bentonita sódica nas dietas de suínos não altera os balanços da energia e do N nem as digestibilidades aparentes do Ca, Mg, Zn, Cu e Mn. A adição de bentonita sódica reduz a excreção fecal de fósforo. Não há interação entre o programa alimentar e a adição de bentonita sódica nas dietas.

An experiment was carried out to evaluate the digestibility of diets and metabolism of pigs fed diets containing sodium bentonite subjected to different feeding programs. Twenty-four barrows were used, littermates, 42.2kg initial live weight, housed in metabolic cages. Experimental design was completely randomized with three sodium bentonite levels (0.0; 0.3 and 0.5%) and two feeding programs (restricted and ad libitum), with eight replications each. Addition of sodium bentonite didn't affect (P>0.05) the feed intake, the energy and N balance. The feed intake differ (P<0.01) between restricted and ad libitum feeding (1.17 vs. 2.19kg d-1). The feeding program alter (P<0.05) the N balance, but don't affected (P>0.05) the N retention in pigs. Ad libitum feeding alter (P<0.05) the energy balance, mainly the retained energy (3,825 vs. 3,013kcal d-1). Addition of 0.5% of sodium bentonite in diets reduced in 9% (P<0.01) the fecal phosphorus excretion. Sodium bentonite in diets doesn't alter the energy and N balance neither apparent digestibility of Ca, Mg, Zn, Cu and Mn. Sodium bentonite in diets reduce the fecal phosphorus excretion. There is no interaction between the feeding program and the addition of sodium bentonite in diets.

O objetivo deste trabalho foi avaliar, por meio da meta-análise, o efeito da fitase e da xilanase sobre a digestibilidade ileal aparente (DIa) de aminoácidos, cálcio e fósforo, em suínos em fase de crescimento. A base de dados consistiu de 21 artigos publicados entre 1998 e 2009, no total de 82 tratamentos e 644 suínos. A meta-análise foi realizada por análise gráfica, de correlação, de variância-covariância. As concentrações de fósforo fítico e as frações fibra em detergente neutro, fibra em detergente ácido e lignina em detergente ácido, nas dietas, apresentaram correlações baixas e negativas com a DIa do cálcio, fósforo e aminoácidos. A adição de fitase às dietas aumentou em 2% a DIa da arginina, em 14% a do cálcio e em 34% a do fósforo. A DIa da arginina, fenilalanina, isoleucina e lisina foi 3,3% superior em suínos alimentados com dietas com xilanase, em relação às dietas sem a enzima. O fósforo fítico e as fibras, nas dietas, reduzem a DIa do cálcio, do fósforo e dos aminoácidos essenciais. O uso de fitase e xilanase, nas dietas, melhora o aproveitamento de cálcio, fósforo e alguns aminoácidos. No entanto, o excesso de cálcio e fósforo nas dietas reduz a ação da fitase sobre a digestibilidade ileal dos nutrientes.

The objective of this study was to evaluate the effect of phytase and xylanase on the apparent ileal digestibility (aID) of amino acids, calcium and phosphorus in growing pigs through meta-analysis.The database consisted of 21 articles published between 1998 and 2009, with a total of 82 treatments and 644 pigs. A meta-analysis was performed by graphical, correlation, variance and covariance analyses. Concentrations of phytic phosphorus and the fractions neutral detergent fiber, acid detergent fiber and acid detergent lignin, in the diet, showed a low and negative correlation with aID of calcium, phosphorus and amino acids. The addition of phytase in the diets increased the aID of arginine in 2%, calcium in 14% and phosphorus in 34%. The aID of arginine, phenylalanine, isoleucine and lysine was 3.3% higher in pigs fed diets containing xylanase, in comparison to the diets without the enzyme. Phytic phosphorus and fiber in the diets reduce the aID of calcium, phosphorus and essential amino acids. The use of phytase and xylanase in the diets improves the utilization of calcium, phosphorus and some amino acids. However, excessive calcium and phosphorus in the diets reduces the phytase action on the ileal digestibility of the nutrients.