The objective of this experiment was to evaluate the effects of metabolizable energy (ME) levels in diets with high digestible lysine concentration on performance, carcass traits, and meat quality of barrows from 95 to 158 days of age. Eighty commercial hybrid barrows (50 ± 1.82 kg) selected for lean meat deposition, were assigned to four dietary treatments (3,150, 3,235, 3,320, and 3,400 kcal EM kg -1 ) in a randomized design with 10 replicate pens per treatment and two pigs per pen. From 95 to 116 days of age, we observed no effects of ME on final body weight (FBW), average daily gain (ADG), metabolizable energy intake (MEI), and feed conversion (F: G). Average daily feed intake (ADFI) decreased linearly with increasing ME levels (Ŷ = 5.79961 -0.00096790X -r 2 = 0.89). From 95 to 137 days of age, no effects of ME were observed on final body weight (FBW), average daily gain (ADG), metabolizable energy intake (MEI), and feed conversion (F: G). Average daily feed intake (ADFI) decreased linearly with increasing ME (Ŷ= 6.1176 -0.001X -r 2 = 0.97). From 95 to 158 days, of age no effects of ME were observed on FBW and ADG. Dietary ME influenced the ADFI and F: G, which decreased linearly with increasing ME concentrations (Ŷ= 8.12951 -0.00149X -r 2 = 0.99; Ŷ= 6.0914 -0.001X -r² = 0.75, respectively). There was a linear increase in loin eye area (LEA) with increasing ME (Ŷ = -29.851 + 0.0207 X -r² = 0.87). Backfat thickness, pH, and temperature, measured at different times after slaughter (0 min, 45 min, 3 h, and 24 h), were not affected by dietary ME. The level of ME also did not affect the meat quality parameters Color L*, Color a*, Color b*, Warner-Bratzler shear force, thaw water losses, cooking water losses, sum of water losses, intramuscular fat content, and TBARS. Diets with 3,400 kcal kg -1 ME, corresponding to 2.75, 2.57, and 2.31 g digestible lysine/Mcal of ME for pigs from 95 to 116, 116 to 137, and 95 to 158 days of age, respectively, resulted in best performance and carcass traits, without negative effects on meat quality.Objetivou-se com este experimento avaliar os efeitos de níveis de energia metabolizável (EM) em rações com alta lisina no desempenho, nas características de carcaça e na qualidade de carne de suínos machos castrados, dos 95 aos 158 dias de idade. Foram utilizados 80 suínos (Agroceres PIC), machos castrados, com peso inicial de 50 ± 1,82 kg. Os animais foram distribuídos em delineamento inteiramente casualizado, com quatro tratamentos (3150 kcal EM kg -1 , 3235 kcal EM kg -1 , 3320 kcal EM kg -1 , 3400 kcal EM kg -1 ), dez repetições e dois animais por unidade experimental, representada pela baia. No período de 95 a 116 dias de idade, não foram observados efeitos dos níveis de EM sobre os parâmetros de desempenho: peso médio final (PMF), ganho de peso médio diário (GPD), consumo de energia metabolizável (CEM) e conversão alimentar (CA). O consumo de ração médio diário (CDR) reduziu de forma linear com o aumento dos níveis de EM da ração (Ŷ= 5,79961 -0,00096790 X -r 2 = 0,89). No período de...

The objective of the study was to evaluate the effects of glutamine and glutamate (Gln/Glu) on the growth performance and immune response of nursery pigs fed different digestible lysine content. Two hundred and sixteen piglets, weaned at 21 days old, were assigned to a randomized block design according to their initial body weight (BW), in a 2 × 2 factorial arrangement with two levels of lysine (control-lys and low-lys) and two levels of Gln/Glu (0 and 12 g kg-1), with nine replicates. At 26 d, piglets consuming the low-lys diet not supplemented with Gln/Glu presented a higher (P < 0.01) incidence of diarrhea than the other treatments. From 21 to 32 d of age, the piglets fed the control-lys diets performed better than those fed low-lys diets (P < 0.01). From 21 to 42 d of age, there was a correlation (P < 0.01) between lysine level and Gln/Glu supplementation for average daily feed intake (ADFI) and feed conversion (FC). Gln/Glu supplementation improved (P < 0.05) the ADFI of pigs fed the low-lys diets, resulting in a higher (P < 0.01) average daily weight gain (ADG) and BW; however, worse (P < 0.05) FC. Piglets consuming control-lys diets had higher (P < 0.05) serum urea nitrogen concentration (SUN) and IgG than low-lys piglets. In addition, Gln/Glu supplementation correlated with higher (P < 0.01) SUN. Dietary supplementation of glutamine and glutamate improved the growth performance of weaned piglets from 21 to 42 days of age, regardless of the diets’ lysine levels. In addition, reducing lysine levels 10% below the requirement negatively affects the growth performance and the immune response of nursery piglets.

No abstract

We aimed to evaluate the performance, carcass and pork quality traits, as well as the mRNA expression of genes related to intramuscular fat deposition in female pigs from different genetic lines. A total of eighteen female pigs (Large White × Landrace × Duroc × Pietrain) × (Large White × Landrace) (Hybrid) averaging 88.96 ± 3.44 kg in body weight and twelve female pigs (Duroc) × (Large White × Landrace) (Duroc) averaging 85.63 ± 1.55 kg in body weight were assigned to a completely randomized design experimental trial that lasted 45 days. Pigs from both genetic lines received the same diet, which was initially adjusted for their nutritional requirements from 0 to 17 days of age and subsequently adjusted for nutritional requirements from 17 to 45 days of age. The performance of pigs did not differ among groups (p > 0.05). Duroc pigs showed a lower backfat thickness (p < 0.03) and greater intramuscular fat content (p < 0.1). A greater mRNA expression of the peroxisome proliferator-activated receptor gamma gene (PPARγ, p = 0.008) and fatty acid protein translocase/cluster differentiation (FAT/CD36, p = 0.002) was observed in the Longissimus dorsi muscle of Duroc pigs. Similarly, a greater expression of PPARγ (p = 0.009) and FAT/CD36 (p = 0.02) was observed in the Soleus muscle of Duroc pigs. Overall, we observed that despite the lack of differences in performance between the genetic groups, Duroc pigs had greater intramuscular fat content than hybrid pigs. The increased intramuscular fat content was associated with an increase in the mRNA expression of key transcriptional factors and genes encoding enzymes involved in adipogenesis and lipogenesis in glycolytic and oxidative skeletal muscle tissues.

We evaluated the effects of L-arginine supplementation during the last third of gestation on molecular mechanisms related to skeletal muscle development of piglets and litter traits at birth. Twenty-three nulliparous sows averaging 205.37 ± 11.50 kg of body weight were randomly assigned to the following experimental treatments: control (CON), where pregnant sows were fed diets to meet their nutritional requirements; arginine (ARG), where sows where fed CON + 1.0% L-arginine. Skeletal muscle from piglets born from sows from ARG group had greater mRNA expression of MYOD (p = 0.043) and MYOG (p ≤ 0.01), and tended to present greater mRNA expression (p = 0.06) of IGF-2 gene compared to those born from CON sows. However, there were no differences (p > 0.05) in the histomorphometric variables of fetuses’ skeletal muscle. The total weight of born piglets, total weight of born alive piglets, piglet weight at birth, coefficient of variation of birth weight, and the incidence of intrauterine growth restriction (IUGR) piglets did not differ between groups. No stillborn piglets (p < 0.01) were verified in the ARG sows compared to CON group. The blood levels of estradiol (p = 0.035) and urea (p = 0.03) were higher in ARG sows compared to those from the CON group. In summary, our data show that arginine supplementation of nulliparous sows at late gestation enhance mRNA expression of key myogenic regulatory factors, which likely contribute to improve animal growth rates in later stages of development.

Resumo. O aumento na deposição de gordura e da conversão alimentar durante a fase de terminação são fatores que implicam diretamente na qualidade da carne e também na rentabilidade da cadeia produtiva. Apesar disso, o abate tardio dos suínos pode resultar em benefícios para o frigorífico, pela redução dos custos operacionais por suíno abatido e melhor utilização dos equipamentos, bem como vantagens econômicas para o produtor resultantes da diluição dos custos de produção. Portanto, a suplementação de betaína na ração de suínos de linhagens com maior potencial para deposição de músculo, é uma estratégia para aumentar a deposição de tecido magro e minimizar a deposição de gordura. Em vista disso, objetivou-se com este trabalho, apresentar e discutir os mecanismos de ação, finalidades e resultados recentes de estudos na literatura sobre a suplementação desse modificador de carcaça na ração de suínos em terminação. A betaína atua principalmente como doadora de grupos metil, que aumentam a disponibilidade de metionina para a deposição proteica. Em relação ao seu efeito osmoprotetor, a betaína se acumula no interior das organelas celulares, protegendo-as contra estresses osmóticos e iônicos, o que reduz os gastos de energia para manter a homeostase, se tornando ainda mais importante durante os períodos quentes do ano.

Two experiments were conducted to determine the effects of dietary net energy content (NE) on performance and carcass traits of fi nishing barrows fed low-crude protein (CP)diets. Pigs (60.0±1.05kg, Exp. 1, 93.0±1.56kg, Exp. 2) RESUMO Dois experimentos foram conduzidos para determinar os efeitos da energia líquida (EL) da ração no desempenho e nas características de carcaça de suínos, recebendo dietas com proteína bruta reduzida (PB

The aim of this study was to evaluate the visceral composition, cuts, and meat quality of two strains of free-range chickens fed diets containing crushed sugar cane. 448 chickens were distributed at 35 days of age, in two randomized blocks design, in 4x2 factorial, with four levels of replacement in the feed (0; 15; 30 and 45%) by sugarcane and two strains (Pesadão and Label Rouge), in two repetitions per block of fourteen birds per experimental unit. In 30 minutes after slaughter, the parameter a* was higher for animals of the Pesadão strain relation to the Label Rouge lineage. A quadratic effect was observed with increasing levels of sugarcane on the L* parameter of breast meat; and linear effect on parameter b* of the breast skin. Within 24 hours after slaughter, a quadratic effect of sugarcane levels was observed on the b* parameter of the breast meat. The increase in sugarcane levels linearly reduced the weight of heart, liver, chest, thigh plus drumstick, wing, carcass yield and relative heart weight of the animals. A quadratic effect was observed with increase in sugarcane levels over the relative weight of abdominal fat, the lowest fat content was observed in animals that consumed up to 30% of sugarcane in the feed. The use of sugarcane as an alternative feedstuff in up to 45% in the diet maintains the quality of meat and reduces the abdominal fat content, however, decreases the carcass yield.