Dietary net energy mainly affects growth performance and pork quality of finishing pigs

The present study was carried out to evaluate the effect of net energy levels in diets for barrows, from 70 to 100 kg, on performance, plasma parameters and carcass characteristics. Two experiments were carried out: in the first (Experiment I), a metabolism assay was carried out to estimate the net energy (NE) of experimental diets. Twelve crossbred barrows, averaging 85.74 ± 6.80 kg initial body weight, were distributed in a randomized block design with two metabolizable energy (ME) levels (3100 and 3500 kcal kg–¹) with six replicates and one animal per experimental unit. In the second (Experiment II), 45 castrated male pigs were used, averaging 70.10 ± 1.26 kg of initial body weight distributed in a randomized block design, with five NE levels (2345, 2425, 2505, 2585, 2665 kcal kg–¹), nine replicates and one animal per experimental unit. The increase in diet NE levels provided a linear reduction (p ≤ 0.00039) in average daily feed intake (ADFI). There was a quadratic effect on NE efficiency (p ≤ 0.0027), average daily gain (ADG), (p ≤ 0.0352) and the feed:gain ratio (F:G), (p ≤ 0.0024), the optimal levels being estimated at 2485, 2493 and 2533 kcal kg–¹, respectively. Drip loss (DL) decreased (p ≤ 0.0001) as NE levels increased. There was also a linear decrease (p ≤ 0.0462) in the Minolta color parameter (+a*), due to the NE levels. Plasma parameters were not affected (p > 0.05) by NE levels. The dietary net energy levels affected the performance and meat quality of finishing pigs and the level of 2493 kcal kg–¹ provided the best ADG.

Dietary net energy mainly affects growth performance and pork quality of finishing pigs

The present study was carried out to evaluate the effect of net energy levels in diets for barrows, from 70 to 100 kg, on performance, plasma parameters and carcass characteristics. Two experiments were carried out: in the first (Experiment I), a metabolism assay was carried out to estimate the net energy (NE) of experimental diets. Twelve crossbred barrows, averaging 85.74 ± 6.80 kg initial body weight, were distributed in a randomized block design with two metabolizable energy (ME) levels (3100 and 3500 kcal kg­1) with six replicates and one animal per experimental unit. In the second (Experiment II), 45 castrated male pigs were used, averaging 70.10 ± 1.26 kg of initial body weight distributed in a randomized block design, with five NE levels (2345, 2425, 2505, 2585, 2665 kcal kg­1), nine replicates and one animal per experimental unit. The increase in diet NE levels provided a linear reduction (p ≤ 0.00039) in average daily feed intake (ADFI). There was a quadratic effect on NE efficiency (p ≤ 0.0027), average daily gain (ADG), (p ≤ 0.0352) and the feed:gain ratio (F:G), (p ≤ 0.0024), the optimal levels being estimated at 2485, 2493 and 2533 kcal kg­1, respectively. Drip loss (DL) decreased (p ≤ 0.0001) as NE levels increased. There was also a linear decrease (p ≤ 0.0462) in the Minolta color parameter (+a*), due to the NE levels. Plasma parameters were not affected (p > 0.05) by NE levels. The dietary net energy levels affected the performance and meat quality of finishing pigs and the level of 2493 kcal kg­1 provided the best ADG.(AU)

Dietary net energy mainly affects growth performance and pork quality of finishing pigs

ABSTRACT The present study was carried out to evaluate the effect of net energy levels in diets for barrows, from 70 to 100 kg, on performance, plasma parameters and carcass characteristics. Two experiments were carried out: in the first (Experiment I), a metabolism assay was carried out to estimate the net energy (NE) of experimental diets. Twelve crossbred barrows, averaging 85.74 ± 6.80 kg initial body weight, were distributed in a randomized block design with two metabolizable energy (ME) levels (3100 and 3500 kcal kg1) with six replicates and one animal per experimental unit. In the second (Experiment II), 45 castrated male pigs were used, averaging 70.10 ± 1.26 kg of initial body weight distributed in a randomized block design, with five NE levels (2345, 2425, 2505, 2585, 2665 kcal kg1), nine replicates and one animal per experimental unit. The increase in diet NE levels provided a linear reduction (p 0.00039) in average daily feed intake (ADFI). There was a quadratic effect on NE efficiency (p 0.0027), average daily gain (ADG), (p 0.0352) and the feed:gain ratio (F:G), (p 0.0024), the optimal levels being estimated at 2485, 2493 and 2533 kcal kg1, respectively. Drip loss (DL) decreased (p 0.0001) as NE levels increased. There was also a linear decrease (p 0.0462) in the Minolta color parameter (+a*), due to the NE levels. Plasma parameters were not affected (p > 0.05) by NE levels. The dietary net energy levels affected the performance and meat quality of finishing pigs and the level of 2493 kcal kg1 provided the best ADG.

Leucine levels in low protein diets for pigs in the initial phase / Níveis de leucina em dietas com baixa proteína bruta para suínos na fase inicial

The objective of this study was to evaluate the standardized ileal digestible (SID) leucine levels in low crude protein diets on Performance, backfat thickness, longissimus dorsi depth and biochemical blood parameters of starting pigs. A total of 50 pigs, with initial weight of 11.14±0.24 kg; were distributed in a randomized blocks design with five treatments (1.10; 1.25; 1.40; 1.55 and 1.70% SID leucine), five replicates and two animals per experimental unit, comprised for a barrow and a gilt. The feed conversion ratio (FCR) reduced (P=0.018) due to the increasing SID leucine levels, without affecting other growth performance parameters (final weight, average daily feed intake, average daily gain, backfat thickness, longissimus dorsi depth and lean meat percentage). There was a quadratic effect for plasma triglyceride (P=0.049) and plasma urea (P=0.001). The optimal SID leucine levels obtained for triglycerides and urea were 1.16% and 1.24%, respectively, by associating the quadratic model with the Linear Response Plateu. Low crude protein diets with SID leucine levels up to 1.70% improved the feed conversion with desired urea and triglycerides concentration in blood plasmas achieved at 1.16% and 1.24%, respectively.

O objetivo do presente trabalho foi o de avaliar níveis de leucina digestível em dietas com baixa proteína bruta sobre o desempenho, espessura de toucinho, profundidade do músculo longissimus dorsi parâmetros sanguíneos de suínos na fase inicial. Foram utilizados 50 suínos mestiços (Landrace x Large white x Pietrain), com peso inicial de 11,14 ± 0,24 kg; distribuídos em um delineamento experimental de blocos casualizados, com cinco tratamentos (1,10; 1,25; 1,40; 1,55 e 1,70% de leucina digestível), cinco repetições e dois animais por unidade experimental, sendo um macho castrado e uma fêmea. A conversão alimentar reduziu (P=0,018) em função do aumento dos níveis de leucina digestível, sem influenciar os demais parâmetros de desempenho (peso final, consumo diário de ração, ganho de peso diário, espessura de toucinho, profundidade de lombo e porcentagem de carne magra). Com relação às variáveis plasmáticas foi observado efeito quadrático para a concentração de triglicerídeos (P=0,049) e ureia (P=0,001) em que associado ao platô do modelo Linear Response Platô (LRP) observou-se que o nível ótimo de leucina digestível para triglicerídeos e ureia foi de 1,16% e 1,24%, respectivamente. A menor concentração de ureia plasmática foi obtida ao nível de 1,24% de leucina digestível. Dietas com baixa proteína bruta e níveis de até 1,70% de leucina digestível melhoram a conversão alimentar dos suínos na fase inicial com a melhor concentração de ureia e triglicerídeos no plasma sanguíneo de 1,16% e 1,24%, respectivamente.

Leucine levels in low protein diets for pigs in the initial phase / Níveis de leucina em dietas com baixa proteína bruta para suínos na fase inicial

The objective of this study was to evaluate the standardized ileal digestible (SID) leucine levels in low crude protein diets on Performance, backfat thickness, longissimus dorsi depth and biochemical blood parameters of starting pigs. A total of 50 pigs, with initial weight of 11.14±0.24 kg; were distributed in a randomized blocks design with five treatments (1.10; 1.25; 1.40; 1.55 and 1.70% SID leucine), five replicates and two animals per experimental unit, comprised for a barrow and a gilt. The feed conversion ratio (FCR) reduced (P=0.018) due to the increasing SID leucine levels, without affecting other growth performance parameters (final weight, average daily feed intake, average daily gain, backfat thickness, longissimus dorsi depth and lean meat percentage). There was a quadratic effect for plasma triglyceride (P=0.049) and plasma urea (P=0.001). The optimal SID leucine levels obtained for triglycerides and urea were 1.16% and 1.24%, respectively, by associating the quadratic model with the Linear Response Plateu. Low crude protein diets with SID leucine levels up to 1.70% improved the feed conversion with desired urea and triglycerides concentration in blood plasmas achieved at 1.16% and 1.24%, respectively.(AU)

O objetivo do presente trabalho foi o de avaliar níveis de leucina digestível em dietas com baixa proteína bruta sobre o desempenho, espessura de toucinho, profundidade do músculo longissimus dorsi parâmetros sanguíneos de suínos na fase inicial. Foram utilizados 50 suínos mestiços (Landrace x Large white x Pietrain), com peso inicial de 11,14 ± 0,24 kg; distribuídos em um delineamento experimental de blocos casualizados, com cinco tratamentos (1,10; 1,25; 1,40; 1,55 e 1,70% de leucina digestível), cinco repetições e dois animais por unidade experimental, sendo um macho castrado e uma fêmea. A conversão alimentar reduziu (P=0,018) em função do aumento dos níveis de leucina digestível, sem influenciar os demais parâmetros de desempenho (peso final, consumo diário de ração, ganho de peso diário, espessura de toucinho, profundidade de lombo e porcentagem de carne magra). Com relação às variáveis plasmáticas foi observado efeito quadrático para a concentração de triglicerídeos (P=0,049) e ureia (P=0,001) em que associado ao platô do modelo Linear Response Platô (LRP) observou-se que o nível ótimo de leucina digestível para triglicerídeos e ureia foi de 1,16% e 1,24%, respectivamente. A menor concentração de ureia plasmática foi obtida ao nível de 1,24% de leucina digestível. Dietas com baixa proteína bruta e níveis de até 1,70% de leucina digestível melhoram a conversão alimentar dos suínos na fase inicial com a melhor concentração de ureia e triglicerídeos no plasma sanguíneo de 1,16% e 1,24%, respectivamente.(AU)