ABSTRACT The objective of this study was to determine the effect of birth weight on growth performance, carcass characteristics, and meat quality of immunocastrated male pigs. Seventy-two boars were assigned to three birth weight categories (BiW): light BiW pigs (LP: 0.98±0.083 kg BW; n = 24), normal BiW pigs (NP: 1.42±0.067 kg BW; n = 24), and heavy BiW pigs (HP: 1.85±0.096 kg BW; n = 24). For treatment design, we considered a weight range of two standard deviations (SD) in relation to the average population body weight (from 0.785 to 2.155 kg BW−1). The animals were housed in six pens with 12 animals per pen, with ad libitum access to water and feed throughout the study. In the growing and finishing phases, pigs were immunocastrated with two doses of vaccine at 112 and 161 days of age. The three BiW categories were different up to departure from the nursery (70 days). After this period, there was no difference between NP and HP in terms of BiW. Measurements showed that a low BiW reduced the loin eye area (9.4%), longissimus thoracis muscle depth (7.6%), and meat:fat ratio (21.6%). Backfat thickness (21.5%) and fat area (11.8%) were higher in LP as compared with the NP and HP categories. Light BiW pigs presented a lower weight steak (7.0%) and belly + rib (8.6%) compared with NP and HP, but did not differ within the LP group. Light BiW pigs required a greater lodging time (14 days), generating higher accumulated feed intake to reach the same slaughter BiW as the other categories. Growth performance and carcass characteristics are influenced by the birth weight (BiW) category. Light BiW pigs require more time and feed intake to reach the same slaughter weight. Birth weight has positive effects on meat quality and weight of commercial cuts.

Resumo: O objetivo deste trabalho foi comparar o desempenho das equações não lineares de Gompertz, logística e a de von Bertalanffy, para descrever a curva de crescimento de suínos machos imunocastrados, desde o nascimento até atingirem 140 kg de massa corporal. O erro-padrão, o número de iterações, o quadrado médio do erro e o coeficiente de determinação foram comparados entre os modelos. A equação logística e a de von Bertalanffy não estimam com precisão as massas inicial e de abate. A equação de Gompertz apresenta maior confiabilidade e é, portanto, a mais adequada para descrever a curva de crescimento de suínos imunocastrados, desde o nascimento até a obtenção de140 kg de massa corporal.

Abstract: The objective of this work was to compare the performance of the nonlinear Gompertz, logistic, and von Bertalanffy equations, to describe the growth curve of immunocastrated male pigs from birth until reaching 140 kg body weight. Standard error, number of iterations, mean square of the error, and coefficient of determination were compared between the models. The logistic and von Bertalanffy equations do not accurately estimate the initial and slaughter weights. The Gompertz equation shows the highest reliability and is, therefore, the most suitable one to describe the growth curve of immunocastrated pigs from birth until 140 kg body weight is reached.

ABSTRACT The objective of this study was to measure the water disappearance in the drinker and the pattern of daily water intake and estimate the amount of water wasted in pig production. The study will also generate information about the daily behaviour of water intake of pigs in the growing and finishing phases. Sixty male pigs with an average initial weight of 44.43 kg subjected to immunocastration were used. Animals received feed and water ad libitum. The animal-performance data, temperature and humidity, and feed and water intake behaviour were collected in real time during the entire experimental period, while water volume consumed was measured daily. The average water disappearance (WD) was 7.98 L, which increased during the studied period, and 29.07% of this corresponds to the estimated water wasted. The daily WD behaviour revealed an increasing pattern throughout the day for growing and finishing periods, with the registered peak at 16:00 and 15:00 h and intake of 6.24 and 9.48 L, respectively. The time spent drinking (TSD) and number of drinker visits (NDV) also showed a peak in the afternoon: 13:00 and 17:00 h for growing and finishing phases, respectively. The TSD was 282.73 and 268.36 s, and the NDV values were 16.13 and 13.84 for growing and finishing phases, respectively. The results demonstrated an increasing pattern during the animal housing period in WD that is proportional to dry matter intake and body weight, and the water wasted represents a significant portion of WD. The daily pattern of WD, TSD, and NDV increase during the total and growing periods, presenting peak activity at 13:00 h. During the finishing phase, TSD and NDV present a pattern similar to the growing phase, but the peak occurs in the last hour of the day.

RESUMO: O objetivo deste estudo foi medir o balanço de nitrogênio (N) de suínos alimentados com dietas limitantes em lisina contendo níveis práticos de inclusão de farelo de trigo (FT) ou casca de soja (CS). Foram utilizados 24 suínos machos castrados com peso médio inicial de 57,36±2,01 kg e 72,68±3,24 kg nos experimentos 1 e 2, respectivamente. No experimento 1 os tratamentos foram CT1 - dieta controle, e FT - dieta com inclusão de 15% de FT. No experimento 2 CT2 - dieta controle, e CS - dieta com inclusão de 6% CS. As dietas fibrosas aumentaram (P<0,05) o N fecal em 64,54 e 60,55% em relação a CT1 e CT2, respectivamente. O N urinário foi maior (P<0,05) nos suínos que receberam a dieta FT, mas não foi afetado no experimento com CS. A retenção de N (NRET) foi maior (P<0,05) nos suínos alimentados com a dieta FT, entretanto quando a proporção do NRET foi expressa em relação ao N ingerido (NING) não houve diferença entre os tratamentos (P<0,05). A inclusão de CS não afetou (P<0,05) a NRET quando os resultados foram expressos em termos absolutos ou proporcionais. Em conclusão, a inclusão de níveis práticos de FT ou CS não afeta significativamente o custo metabólico envolvido no metabolismo de N. Entretanto, apenas o FT foi capaz de contribuir para o balanço de N dos suínos, enquanto a quantidade N relativa a adição de CS foi totalmente recuperada nas fezes.

ABSTRACT: The aim of this study was to measure the nitrogen (N) balance of pigs fed with lysine-limiting diets containing practical levels of wheat bran (WB) or soybean hulls (SH). Twelve pigs with average weights of 57.36±2.01 and 72.68±3.24 kg were used in trials 1 and 2, respectively. In trial 1, treatments were CT1 - control diet and WB - diet with inclusion of 15% WB. In trial 2, CT2 - control diet and SH - diet with inclusion of 6% SH. Fibrous diets increased (P<0.05) the fecal N in 63.54 and 60.55% in relation to CT1 and CT2, respectively. The urinary N was higher (P<0.05) in pigs receiving the WB diet, but was not influenced in the trial with SH. The N retention (NRET) was higher (P>0.05) in pigs ingesting the WB diet; although, when the proportion of NRET was expressed relative to N ingested (NING) there was no difference (P>0.05) between treatments. Inclusion of SH did not affect (P>0.05) the NRET when the result was expressed in absolute or proportional terms. In conclusion, inclusion of practical levels of WB and SH does not significantly affect the metabolic costs involved with nitrogen metabolism. However, only WB was able to contribute to the N balance of pigs, while the relative amount of N added by SH was fully recovered in feces.

O objetivo deste trabalho foi determinar a exigência de manutenção e a eficiência de deposição de lisina em suínos em crescimento. Utilizou-se o delineamento experimental permutável, com repetições ao longo do tempo. Doze suínos castrados com peso vivo (PV) médio de 52±2 kg foram alojados em gaiolas metabólicas, com temperatura controlada de 22ºC. As dietas foram formuladas para fornecer 30, 50, 60 e 70% das exigências esperadas de lisina estandardizada e fornecidas para atender 2,6 vezes a exigência de energia para manutenção. O experimento teve duração de 24 dias e foi dividido em dois períodos de 12 dias: sete para adaptação dos animais à dieta e cinco para coleta de amostras. O teor crescente de lisina na dieta não influenciou a ingestão de matéria seca pelos suínos. A quantidade de nitrogênio excretado foi de 47% do ingerido, dos quais 35% foram excretados pelas fezes e 65% pela urina. As perdas endógenas de lisina estimadas foram de 36,4 mg kg-1 PV0,75. A exigência de manutenção de lisina em suínos com aproximadamente 50 kg é de 40,4 mg kg-1 PV0,75, e a eficiência de deposição de lisina é de 90%.

The objective of this work was to determine the maintenance requirement and the deposition efficiency of lysine in growing pigs. It was used the incomplete changeover experimental design, with replicates over time. Twelve castrated pigs with average body weight (BW) of 52±2 kg were kept in metabolism crates with a controlled temperature of 22ºC. The diets were formulated to supply 30, 50, 60, and 70% of the expected requirements of standardized lysine, and provided at 2.6 times the energy requirements for maintenance. The trial lasted 24 days and was divided into two periods of 12 days: seven days for animal adaptation to the diet and five days for sample collection. The increasing content of lysine in the diet did not affect dry matter intake of the pigs. The amount of nitrogen excreted was 47% of the nitrogen intake, of which 35% was excreted through feces and 65% through urine. The estimated endogenous losses of lysine were 36.4 mg kg-1 BW0.75. The maintenance requirement of lysine for pigs weighing around 50 kg is 40.4 mg kg-1 BW0.75, and the deposition efficiency of lysine is 90%.

O objetivo deste trabalho foi avaliar o desempenho animal, as características de carcaça e os custos para suínos alimentados com dietas ajustadas, para condições brasileiras, através do modelo InraPorc®. Foram utilizados 36 suínos castrados e 36 fêmeas, nas fases de crescimento e terminação, em um delineamento inteiramente casualizado. Os tratamentos foram dietas controles e dietas ajustadas para machos e fêmeas. O programa alimentar e o perfil animal foram adicionados ao modelo para parametrização e definição das estratégias nutricionais e alimentares nas dietas ajustadas. O desempenho e as características de carcaça não foram influenciados pelos tratamentos. O custo médio de alimentação para os animais que receberam a dieta controle foi 3,4% e 2,4% superior para os machos e para as fêmeas, respectivamente. Na comparação entre as dietas, o custo médio de alimentação para os animais que receberam a dieta controle foi 2,9% superior. A receita líquida foi R$0,19 e R$0,66 superior para os machos e fêmeas que receberam a dieta ajustada, respectivamente. As dietas ajustadas através do InraPorc® para suínos em crescimento e terminação não influenciam no desempenho e nas características de carcaça, contudo reduzem os custos de alimentação, o que gera aumento da receita líquida de produção.

The objective of this study was to evaluate animal performance, carcass characteristics and costs for pigs fed diets adjusted to Brazilian conditions, through the model InraPorc®. We used 36 barrows and 36 females, during the growing and finishing in a completely randomized design. The treatments were control diets and diets adjusted for both males and females. The feeding program and the animal profile were added to the model parameterization and define strategies and nutritional feed in the diets adjusted. The performance and carcass traits were not affected by treatments. The average cost to feed the animals that received the control diet was higher in 3.4% and 2.4% for the males and females respectively. Comparing the diets, the average cost to feed the animals that received the control diet was 2.9% higher. Net income was R$0.19 and R$0.66 higher for males and females which received the diet adjusted, respectively. Diets adjusted through InraPorc® for the growing and finishing pigs did not influence the performance and carcass traits, however reduced feed costs which generates higher net production.

Um experimento avaliou a adição de ractopamina e extratos cítricos a dietas de suínos em terminação. Foram utilizados 108 suínos (54 machos e 54 fêmeas) em um delineamento de blocos completos ao acaso, sendo o sexo o fator de bloqueamento e nove os tratamentos: T1. controle (C) (0ppm de ractopamina e 0ppm de extratos cítricos), T2. C+10RAC (ractopamina, em ppm), T3. C+20RAC, T4. C+250EC (extratos cítricos, em ppm), T5. C+500EC, T6. C+250EC+10RAC, T7. C+250EC+20RAC, T8. C+500EC+10RAC e T9. C+500EC+20RAC. O peso vivo final (109,9±3,6kg), consumo de ração (2,6±0,2kgd-1), ganho de peso (1,0±0,1kgd-1), conversão alimentar (2,7±0,2), comprimento de carcaça (97,0±2,7cm), profundidade de músculo (56,1±5,6mm) e pH (5,9±0,3) não foram influenciados pelos tratamentos. Sobre o peso de carcaça, o efeito foi somente do tratamento com 20ppm de ractopamina em relação a 10ppm de ractopamina, sendo 5,7% superior. A espessura de toucinho do grupo controle foi 35% superior aos níveis de ractopamina, e a interação foi 500ppm de extratos cítricos e 10ppm de ractopamina. A carne magra do controle foi 5,3% inferior em relação aos níveis de ractopamina. A alimentação de suínos em terminação com dietas contendo ractopamina, extratos cítricos e suas interações não altera o desempenho, mas influencia algumas características de carcaça.

This study was carried out to evaluate the effect of the addition of the citrus extracts and ractopamine in finishing pig diets. A Hundred eight pigs were used (54 males and 54 females) in a completely randomized design, blocked by sex and distributed in nine treatments: T1. control (C) (0ppm of the ractopamine e 0ppm of the citrus extracts), T2. C+10RAC (ractopamine, ppm), T3. C+20RAC, T4. C+250EC (citrus extracts, ppm), T5. C+500EC, T6. C+250EC+10RAC, T7. C+250EC+20RAC, T8. C+500EC+10RAC and T9. C+500EC+20RAC. The final body weight (109.9±3.60kg), feed intake (2.6±0.24kg d-1), body weight gain (1.01±0.09kg d-1), feed conversion ratio (2.7±0.25), carcass length (97±2.71cm), depth muscle (56.1±5.63mm), and pH (5.9±0.33) were not affected by treatments. There was a significant effect for the treatment with 20ppm of ractopamine, which was 5.7 higher, in relation to the treatment with 10ppm of ractopamine. The backfat thickness of control group was 35% higher than the ractopamine levels and the interaction was of 10ppm of ractopamine and 500ppm of citrus extracts. The lean meat in the control group was on average, 5.3% lower in relation to the ractopamine levels. Feeding of finishing pigs with diets containing ractopamine, citrus extracts and their interactions didn't affect performance, however affected some carcass characteristics.

Uma metanálise foi realizada para avaliar a relação entre a espessura de toicinho e as variáveis nutricionais de porcas gestantes e lactantes. A base de dados contemplou 14 artigos publicados de 2000 a 2006 em revistas indexadas. A metanálise foi realizada através de análises gráfica, de correlação e de variância. A correlação entre espessura de toicinho na gestação (ETg) com consumo de alimento na gestação (CAl G) foi de -0,09 (P=0,04), com CAl na lactação (CAl L) baseado na tabela NRC (1998) foi de -0,09 (P=0,06), com CAl na lactação baseado na tabela Rostagno (2000) foi de -0,08 (P=0,06) e com consumo de proteína bruta na lactação (CAl L PB) foi de -0,08 (P=0,06). A correlação entre espessura de toicinho na lactação (ETl) com CAl na gestação foi de 0,29 (P<0,01), com CAl na gestação NRC (1998) foi de 0,20 (P<0,01), com CAl na gestação Rostagno (2000) foi de 0,20 (P<0,01), com CAl na lactação foi de -0,21 (P<0,01), com consumo na lactação NRC (1998) foi de -0,24 (P<0,01) e com consumo na lactação Rostagno (2000) foi de 0,24 (P<0,01). O CAl de PB na gestação foi de 0,20 (P<0,01) e o CAl de PB na lactação foi de -0,26 (P<0,01). A variação da espessura de toicinho durante a lactação é influenciada pelos níveis de proteína e lisina da dieta e pela gordura e proteína no leite. A variação da espessura de toicinho na gestação e na lactação foi semelhante para as tabelas do NRC (1998) e de Rostagno (2000). Há relação significativa entre espessura de toicinho e variáveis nutricionais em porcas gestantes e lactantes.

A meta-analysis was undertaken to evaluate the relationship between backfat thickness and nutritional variables of sows during gestation and lactation. The database was developed from 14 studies published between 2000 and 2006. The meta-analysis was carried out trough by graphical analysis, correlation and variance. The correlation between backfat thickness at gestation (BTg) and feed intake (FI) at this phase was -0.09 (P=0.04). The correlation between backfat thickness at gestation (BTg) and lactation FI NRC (1998) was -0.09 (P=0.06); BTg and FI at lactation Rostagno (2000) presented a correlation of-0.08 (P=0.06). In the same way the correlation between BTg and crude protein (CP) intake at lactation was -0.08 (P=0.06). The correlation between backfat thickness at lactation (BTl) and FI at gestation was 0.29 (P<0.01). BTl and FI at gestation NRC (1998) presented a correlation of 0.20 (P<0.01). For BTl and gestation feed intake Rostagno (2000) a correlation of 0.20 (P<0.01) was reported. The correlation between BTl and lactation FI was -0.21 (P<0.01), the correlations between BTl and lactation FI NRC (1998) were -0.24 (P<0.01) and lactation FI Rostagno (2000) 0.24 (P<0.01). Correlations of 0.20 (P<0.01) and -0.26 (P<0.01) were observed between BTl and CP intake at gestation and CP intake at lactation respectively. The backfat thickness variation at lactation is influenced by protein and lysine levels in the diet and fat and protein of the milk. Gestation and lactation backfat thickness variation was similar to NRC (1998) and Rostagno (2000). There is a significant relationship between backfat thickness and nutritional variables in pregnant and farrowing sows.