Functional amino acid supplementation postweaning mitigates the response of normal birth weight more than for low birth weight pigs to a subsequent Salmonella challenge.

Previous work has shown that dietary supplementation with key functional amino acids (FAA) improves growth performance and immune status of disease-challenged normal birth weight (NBW) pigs. It is not known whether FAA supplementation attenuates the effects of a subsequent disease challenge or whether this response is similar in low birth weight (LBW) pigs. The objective was to determine the effects of birth weight and FAA supplementation during the postweaning period in Salmonella-challenged pigs. Thirty-two LBW (1.08 ± 0.11 kg) and NBW (1.58 ± 0.11 kg) pigs were assigned to a nursery feeding program at weaning (25 d) for 31 days in a 2 × 2 factorial arrangement. Factors were birth weight category (LBW vs. NBW) and basal (FAA-) or supplemented FAA profile (FAA+; Thr, Met, and Trp at 120% of requirements). At d 31, pigs were placed onto a common grower diet and, after a 7-d adaptation period, were inoculated with Salmonella Typhimurium (ST; 2.2 × 109 colony-forming units/mL) and monitored for 7-d postinoculation. Growth performance, rectal temperature, fecal score, indicators of gut health, ST shedding score in feces, intestinal ST colonization and translocation, and blood parameters of acute-phase response and antioxidant balance were measured pre- and postinoculation. Inoculation with ST increased temperature and fecal score, and the overall rectal temperature was higher in LBW compared to NBW pigs (P < 0.05). Postinoculation (d 7), reduced:oxidized glutathione was increased in NBW compared to LBW pigs (P < 0.05). Salmonella shedding and translocation to spleen were lower in NBW-FAA+ compared to NBW-FAA- pigs (P < 0.05). Postinoculation average daily gain was higher in NBW-FAA+ (P < 0.05) compared to the other groups. Postinoculation haptoglobin, superoxide dismutase, and colonic myeloperoxidase were increased in LBW-FAA- pigs (P < 0.05). Ileal alkaline phosphatase was decreased in LBW compared to NBW (P < 0.05). Overall, FAA supplementation represents a potential strategy to mitigate the effect of enteric disease challenge in NBW, but not LBW pigs.

Effect of strain and nutritional density of the diet on the water-protein ratio, fat and collagen levels in the breast and legs of broilers slaughtered at different ages.

Many requirements are necessary to meet the European Union rules to export poultry, including the amount of physiological water and water-protein ratio (WPR) in carcasses. Therefore, the aim of this study was to identify if strain, nutrition, and age affect the amount of collagen and fat and the WPR in cuts and verify whether the latter meets the international export standards. A total of 3,240 male chicks were housed in a completely randomized design in a 3 × 3 × 5 factorial arrangement, which included 3 nutritional densities (regular, medium, and high), 3 strains (021 Embrapa and 2 commercial strains identified as A and B), and 5 ages. Twelve broilers from each treatment (totaling 540 birds) were slaughtered at 28, 35, 42, 49, and 56 D of age to determine collagen and fat levels and WPR (through the calculation of moisture and protein percentage) in broiler breasts and legs using the near-infrared spectroscopy method. The use of feeds with different nutritional densities presented in this study has no effect on the WPR in the breast and legs of broilers slaughtered between 28 and 56 D of age. However, nutritional density influences liveweight and percentage of fat in the breast and legs. Collagen percentage in the legs decreases with increasing nutritional density. The 021 Embrapa strain cuts present a lower WPR than those of other commercial strains. However, the values found for all strains studied are within the limits of the Europe Union and Brazilian legislations. The liveweight, breast weight, leg weight, and leg fat increases linearly with age. Quite the opposite, water protein ratio, breast fat level, and breast collagen level decrease linearly with age. Leg WPR and leg collagen level are not affected by age. Despite the differences found for strains, nutritional densities and age readers should be aware that these factors may interact with each other depending on the response variable studied.

Effects of feed form and energy levels on growth performance, carcass yield and nutrient digestibility in broilers.

Feed form is well recognized to improve broiler performance, specially by increasing feed intake (FI). However, when different diet energy levels are used, the results differ in the literature. Therefore, this experiment was conducted to evaluate the influence of feed form and dietary metabolizable energy (ME) levels on broiler performance, carcass yield and on the digestibility of DM, CP, starch and gross energy. In total, 1152 male Cobb 500 broilers were evaluated between 35 and 47 days. The birds were distributed according to a completely randomized design in a 2 × 4 factorial arrangement, consisting of two feed forms (mash or pellet) and four ME levels (12.73, 13.06, 13.40 or 13.73 MJ/kg), totaling eight treatments with eight replicates of 18 birds. Broilers fed the lowest ME level presented the lowest weight gain (WG) and worst feed per unit gain (P < 0.01). Metabolizable energy intake increased (P < 0.01) with progressive increments of ME, which, however, did not affect caloric conversion (CC, P > 0.05). Pelleted diets promoted higher FI, WG, ME intake (P < 0.01) and better feed per unit gain and CC (P < 0.05) compared with mash. In mash diets, increasing dietary ME levels promoted a linear increase in WG (P < 0.01) and reduced feed per unit gain (P ≤ 0.05), but did not affect FI (P > 0.05). In pelleted diets, on the other hand, increasing ME levels linearly reduced FI (P < 0.05) and feed per unit gain (P < 0.01). Broilers fed pelleted diets presented higher abdominal fat deposition than those fed mash (P < 0.05). Increasing ME levels reduced the coefficients of ileal apparent digestibility of DM (P < 0.01) and total starch (P < 0.05) but did not affect the digestibility of other evaluated nutrients. The digestibility of all nutrients was lower when pelleted diets were fed compared with mash. Increasing inert material inclusion in the diets at the expense of soybean oil to reduce dietary ME levels promoted higher pellet durability index values (P < 0.05) and the percentage of fines (P < 0.01). Overall, the results suggest that pelleted diets promote better broiler performance because they increase FI, since the digestibility of dietary fractions is reduced. Chickens consuming low-energy pelleted diets may increase FI to compensate for energy deficit. In contrast, broilers fed mash diets may have reached their maximum intake capacity and did not regulate FI by changing feed energy density. When feeding pelleted diets, dietary energy reduction should be considered to reduce feed costs and to improve the carcass quality of broilers.

Effect of ractopamine and conjugated linoleic acid on performance of late finishing pigs.

The dietary inclusion of feed additives to improve the carcass characteristics of the final product is of great importance for the pork production chain. The aim of our study was to evaluate the effects of the association of ractopamine (RAC) and conjugated linoleic acid (CLA) on the performance traits of finishing pigs during the last 26 days prior to slaughter. In total, 810 commercial hybrid barrows were used. Animals were distributed among treatments according to a randomised block design in a 3 × 3 factorial arrangement, with three RAC levels (0, 5 or 10 ppm) and three CLA levels (0, 0.3 or 0.6%). Pigs fed the diet with 5 ppm RAC had higher average daily feed intake (ADFI) (2.83 kg; P < 0.05) when compared with those fed 10 ppm RAC and the control diet (2.75 and 2.74 kg, respectively). Lower ADFI values (P < 0.01) were observed with the diets containing CLA compared with the control diet with no CLA (2.73 and 2.75 v. 2.85 kg/day, respectively). The average daily weight gain of pigs fed 5 and 10 ppm RAC was +148 and +173 g/dayhigher (P < 0.001), respectively, than those fed the control diet. Dietary RAC levels influenced (P < 0.001) feed conversion ratio (FCR), which was reduced as RAC levels increased, with the pigs fed 10, 5 and 0 ppm RAC presenting FCR values of 2.57, 2.71 and 3.05, respectively. FCR also improved (P < 0.05) with the inclusion of 0.6% CLA relative to the control diet (2.70 v. 2.84, respectively). There was a significant interaction between CLA × RAC levels (P < 0.01) for final BW, loin eye area (LEA) (P < 0.05) and backfat thickness (BT) (P < 0.05). The treatments containing 10 ppm RAC + 0.6% or 0.3% CLA increased LEA and reduced BT. In conclusion, the level of 10 ppm inclusion of RAC increased the overall performance parameters of pigs and therefore improved production efficiency. The combined use of RAC and CLA promoted a lower feed conversion ratio as well as better quantitative carcass traits, as demonstrated by the higher LEA and lower BT. The dietary inclusion of CLA at 0.3% improved feed efficiency, however, without affecting LEA or BT yields.

Impact of birth weight and daily weight gain during suckling on the weight gain of weaning piglets / Impacto do peso ao nascimento e ganho de peso na maternidade sobre o ganho de peso dos leitões na creche

This study evaluated the effect of birth weight and weight gain during the suckling phase on the piglet daily weight gain during the nursery phase (21-61 days of age). Piglets (n= 534) derived from 55 first-parity sows were weighed at birth, weaning, and end of the nursery phase. The data were analyzed according to a completely randomized experimental design, with three classes of birth weight (BW) and two classes of weight gain during the suckling phase (SDWG). High BW and low SDWG piglets were 0.2kg lighter at weaning than low BW and high SDWG animals (P< 0.05). However, at the end of the nursery phase, this situation was inverted, with high BW and low SDWG piglets 2.20kg heavier (P< 0.05). Low BW and high SDWG piglets were heavier at weaning and at the end of the nursery phase than low BW and low SDWG piglets (P< 0.05). At the same time, intermediate and high BW and low and high SDWG piglets presented body weight differences at weaning (P< 0.05), but not at the end of the nursery phase (P< 0.05). Piglets with 1.25 to 2.30kg BW and low weight gain during suckling presented a partial compensatory growth during the nursery phase.(AU)

Objetivou-se avaliar o efeito do peso dos leitões ao nascimento e do seu ganho de peso na maternidade sobre seu desempenho na fase de creche (21-61 dias de idade). Quinhentos e trinta e quatro leitões, provenientes de 55 primíparas, foram pesados ao nascimento, no desmame e na saída da creche. Os animais foram distribuídos em um delineamento inteiramente ao acaso, em três classes de peso ao nascimento (PN) e duas classes de ganho de peso diário (GPD) na maternidade. Os animais com alto PN e baixo GPD na maternidade desmamaram 0,2kg mais leves que os animais com baixo PN e alto GPD na maternidade (P<0,05). Porém, os animais com alto PN e baixo GPD na maternidade saíram da creche 2,10kg mais pesados (P<0,05). A diferença aos 21 dias entre os dois tratamentos (alto e baixo GPD) com animais de baixo PN foi de 1,18kg e passou para 2,20kg ao final da creche (P<0,05). No caso dos animais com médio e alto PN, a diferença ao desmame era de 1,14 e 1,26kg e passou para 0,90 e 0,70kg na saída da creche (P<0,05), respectivamente. Leitões com peso ao nascimento entre 1,25 e 2,30kg, com baixo ganho de peso diário na maternidade, apresentaram efeito compensatório parcial no ganho de peso diário durante a creche.(AU)