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 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 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.

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.