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.

This study aimed to evaluate the effect of supplementing arginine (Arg) + glutamine (Gln) replacing antibiotics on performance, immune response, and antioxidant capacity of pigs in the growing phase. One hundred and fifty 63-d-old pigs with initial body weight (BW) of 25.0 ± 1.46 kg were distributed in a randomized block design, with three treatments and ten replicates. The three diets were control; antibiotic, control + 100 mg/kg tiamulin and 506 mg/kg oxytetracycline; amino acid, control + 10 g/kg Arg and 2 g/kg Gln. Dietary treatments were fed from 63 to 77 d. Following the treatment period, all pigs were fed the control diet from 77 to 90 d. Data were analyzed using GLIMMIX and UNIVARIATE in SAS 9.4. From 63 to 70 d, pigs fed diets with antibiotics had improved (P &lt; 0.05) average daily feed intake (ADFI), average daily weight gain (ADG), gain to feed ratio (G:F), and 70 d BW compared to those fed control or amino acid diets. From 70 to 77 d, including antibiotics in the diet increased (P &lt; 0.05) ADG and 77 d BW. From 77 to 90 d, pigs fed the amino acid diet had greater (P &lt; 0.05) ADG and ADFI than those fed an antibiotic diet. From 63 to 90 d, although pig performance was not affected (P &gt; 0.05), growth curve of pigs fed the antibiotic diets was different (P &lt; 0.05) from those fed the control and amino acids diets. At 70 d, serum tumor necrosis factor-α and diamine oxidase (DAO) were lower (P &lt; 0.05) in pigs fed the antibiotic diet than the control diet, and pigs fed the amino acid diet had intermediate results. Ferric reducing antioxidant power (FRAP) was lower (P &lt; 0.05) in pigs fed the amino acid diet than the antibiotic diet, and pigs fed the control diet had intermediate results. At 70 and 77 d, serum urea nitrogen was higher (P &lt; 0.05) in pigs fed the amino acid diet. At 77 d, DAO and serum immunoglobulin G was lower (P &lt; 0.05) in pigs fed the antibiotic diet. FRAP was lower (P &lt; 0.05) in pigs fed the amino acid and control diets. Serum malondialdehyde was higher (P &lt; 0.05) in pigs fed the amino acid diet than those fed the control diet, and pigs fed the antibiotic diet had intermediate results. At 90 d, antibiotics or amino acids did not affect (P &gt; 0.05) serum parameters. Amino acid blend supplementation at the selected doses in this study did not positively affect growing pigs. Although from 63 to 77 d, antibiotics improved performance, when considering the overall study period, growing pigs did not benefit from a diet containing antibiotics.

Increasing fat deposition and feed conversion ratio over the days in finishing phase directly influence pork quality and productive profitability. Nonetheless, the slaughter of heavier pigs can result in benefits for the slaughterhouse due to dilution of production and processing costs, as well as economic benefits for the pig producer resulting from the dilution of production costs. Therefore, dietary supplementation of chromium for finishing pigs of high lean-genotypes is a strategy to increase lean tissue accretion and minimize fat deposition, reflecting positively on growth performance. This review discussed recent studies results and mechanisms of action of this modifier of performance and carcass a traits in finishing pigs. Chromium increases the insulin action, facilitating insulin binding to the receptors on cell membrane. As a result, insulin-sensitive cells uptake more glucose, which will be later converted into energy. This additional energy is use to increase protein synthesis, thereby increasing the amount of lean tissue and reducing fat content in the carcass, without altering protein intake by pigs. Chromium also reduces lipid oxidation rate maintaining meat quality for longer period. In conclusion, dietary Cr supplementation for finishing pigs have shown that 0.2 mg/kg of organic Cr sources for pigs from ~60 kg until the slaughter can improve growth performance, lean gain and reduce fat content in carcass. However, the development of nanotechnology has allowed the use of inorganic Cr source at 0.2 mg/kg of inclusion, leading to improve the growth performance and carcass traits of finishing pigs.

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.

The objective of the present study was to evaluate the effects of cooling systems by negative pressure versus directed ducts on the performance of lactating sows and their litter. The experiment was conducted in a tropical climatic region in Brazil. Ninety-four lactating sows during 26.2±1.7 days of lactation were included with their 1,236 piglets. Sows were distributed using a completely randomized block design into two treatments: a negative pressure cooling (NPC) system and a directed duct cooling (DDC) system. We adopted sow parity as blocking criterion. During the experimental period, environmental temperatures inside the farrowing rooms were 22.9±1.5 and 25.4±2.5 °C, respectively, using the NPC and DDC systems. Sow daily feed intake, litter weight at weaning, piglet weight at weaning, litter daily weight gain, piglet daily gain, and daily milk production per sow were greater in the NPC system than in the DDC system. The type of cooling system did not affect piglet weight after standardization, mortality, number of piglets weaned per sow, and estrus return. The use of an NPC system can reduce the effects of higher environmental temperatures better than the DDC system. The NPC system allowed for greater feed intake, piglet and litter weight gain, weight of piglets and litter at weaning, and milk production compared with the DDC system.