Hebert Silveira

Ractopamine levels on performance, carcass characteristics and quality of pig meat

This study evaluated the effect of ractopamine (RAC) on the performance of finishing pigs and the meat quality of these animals. Seventy crossbred pigs (35 barrows and 35 females) selected for high gain of lean meat, with initial weight of 77.1±0.32 kg were distributed in randomized blocks with five treatments (0, 5, 10, 15, and 20 ppm RAC in the diet) and seven replications during 28 days. The experimental unit was represented by a male and a female pig. Regarding the performance variables, there was a linear increase in final weight with increasing levels of RAC, as well as in average daily weight gain. An improvement in feed conversion was observed for animals fed RAC, and the optimal level - estimated by the LRP model - was ~ 5 ppm. For feed intake, no significant effect on intake of digestible lysine and energy intake was observed. Carcass yield responses increased linearly with the RAC dose. Ash content, color component b* and loss drip linearly decreased with increasing doses of RAC. There was also a significant difference in the percentage of ether extract and crude protein in the loin, and treatment with 20 ppm RAC showed a lower amount of protein and larger amounts of lipids. Moisture content, color component L*, weight loss by cooking and defrosting, shear force and pH were not affected by the treatment. Concerning the lipid oxidation, there was no effect of RAC on the concentration of TBARS (thiobarbituric acid reactive substances) under cooling and under freezing. Thus, all ractopamine levels improve performance compared with control and do not negatively affect the quality of fresh, chilled or frozen pig meat.

Desempenho e características de carcaça de suínos dos 20 aos 50kg recebendo rações com reduzido teor de proteína bruta e diferentes níveis de lisina digestível verdadeira

The objective of this research was to evaluate the different levels of true digestible lysine (TDL) in diets with reduced crude protein (CP) level through to performance and carcass characteristics of pigs from 20 to 50kg. Forty barrows with high performance (initial weight of 22.50±1.4kg and final of 47.8±3.4kg), distributed in randomized block design with five treatments (four levels of TDL - 0.7, 0.9, 1.1 and 1.3% - in 14% CP diets - and a control treatment, formulated in accordance to Brazilian Tables, with 1.03% of TDL and 18% CP) and four replications during 31 days were utilized. There were no differences (P>0.05) between levels of TDL in diets with 14% CP for average daily gain; however, just the level of 0.7% of TDL was different of control treatment. There was no difference (P>0.05) on feed intake, but there was crescent linear effect (P 0.05) to backfat thickness. It was conclude that the level of 1.1% TDL in diets with reduced CP increase carcass yield without to modify the performance.

Effects of dietary supplementation of red pepper (Schinus terebinthifolius Raddi) essential oil on performance, small intestinal morphology and microbial counts of weanling pigs

BACKGROUND Many strategies, such as the antibiotic growth promoters, have been developed to improve intestinal health and performance of newly weaned piglets. Natural products such as essential oils have been scientifically recognized as growth enhancer feed additives for weanling pigs, replacing the antibiotics. Therefore, it has been hypothesized that Brazilian red pepper could replace performance-enhancing antibiotics also in weanling pig diets. However, one experiment was conducted to determine the effects of dietary Brazilian red pepper essential oil or antimicrobial growth promoter on intestinal health and growth performance of weanling pigs. RESULTS No effects of treatments were observed on performance and organ weights (P > 0.05). Overall, both additives [red pepper essential oil (RPEO) or antibiotic (ANT)] increased gut Lactobacillus counts compared to negative control, as well as reduced villi density (P < 0.05). Animals fed diets containing 1.5 g kg-1 RPEO presented the lowest incidence of diarrhea (P < 0.05). CONCLUSION Our findings suggested that essential oil from Brazilian red pepper or chlorohydroxyquinoline added in weanling pig diets affect gut microbiota and histology without affecting performance and organ weights. In addition, there was an indication that high doses of essential oil could reduce the incidence of diarrhea.

Herbal extracts and symbiotic mixture replacing antibiotics in piglets at the initial phase

The objective of this work was to evaluate the use of vegetable extract based addictives associated or not to symbiotics as an alternative for antibiotic as growth promoters for piglets at initial phase. It was used 125 pigs of commercial genetic line with initial weight of 7.4 ± 1.1 kg, weaned at 20 days of age, during 50 days. The experimental design used was randomized blocks (initial weight), with five treatments and five replicates with five animals per experimental unit. The experimental diets were a basal diet, without additive, and other four diets, one diet containing antibiotic (colistin + zinc oxide); diet with 0.3% of a symbiotic mixture; diet with 0.3% of a symbiotic mixture plus 0.05% of herbal mix (plant extracts and microencapsulated essential oils); and another diet with 0.3% of symbiotic mixture plus 0.1% of herbal mixture. It was observed that the use of the symbiotic mixture associated to 0.05% of herbal mixture showed positive results, similar to the ones obtained with diets containing antibiotics for the final weight, average weight gain, average daily feed intake and pH of stomach and diarrhea incidence. The use of symbiotics promoted smaller vilous:depth crypt ratio, except when associated to 0.1% of herbal mixture, which was similar to the diet without addictives. There was no differences in the feed conversion, coliform and lactobacillus count in the jejune and in the cecum and in the pH of cecum. The use of herbal mixture associated to symbiotic is a viable alternative for replacing the use of antibiotics as growth promoters for piglets in the initial phase. However, the concentration of the herbal mixture is an important factor to be considered.

Performance and carcass characteristics of swine at 50 kg fed diets with different energy levels and reduced levels of crude protein

The aim of this work was to evaluate the effects of different levels of metabolic energy (ME) in diets with a reduced level of crude protein (CP) on the performance and carcass characteristics of growing swine. Thirty-two high-performance barrows (initial weight of 22.5 ± 1.43 kg and final weight of 50.81 ± 2.54 kg) were distributed in a randomized block design with four treatments (three levels of ME - 3,060, 3,230 and 3,400 kcal/kg - in diets with 14% CP, and one control treatment with 3,230 kcal ME/kg and 18% CP) and four replicates. The diets were formulated with a true digestible basis of amino acids present in the feed, with methionine and threonine concentrations corrected as a function of lysine levels. The animals were slaughtered and their carcasses were studied. The ME levels did not affect the average weight gain, the feed:gain ratio, the backfat thickness or the loin eye area. A higher carcass yield and a higher carcass meat:fat ratio were observed in the animals that received the 3,230 and 3,060 kcal/kg ME levels. Compared to the control treatment, only the 3,400 kcal/kg ME level had a lower average daily feed intake. It is concluded that the CP level in diet should be reduced from 18% to 14% and the metabolizable energy level should be increased, thus reducing the feed intake and increasing the carcass meat:fat ratio without affecting the animal weight gain.

Metabolizable energy for piglets in the nursery phase submitted at activation of immune system

The objective of this work was to evaluate the performance of piglets in the nursery phase submitted to activation of immune system with vaccine against Haemophilus parasuis and to different levels of metabolizable energy in the diets. It was used 160 barrows and females at 30 days of age, weaned at 23 days of age, with initial weight of 7.97 ± 0.54 kg, distributed in 2 × 4 factorial arrangement (with vaccination and without vaccination with four levels of metabolizable energy - 3,200; 3,300; 3,400 and 3,500 kcal/kg). Each combination was evaluated with five repetitions of four animals per experimental plot (two males and two females). Energy levels reduced linearly the intake, feed conversion and the total number of leukocytes in blood in the experimental period, regardless of the use of vaccine which in turn reduced daily average weight gain only in the first week after second application and it increased the number of limonocytes and spleen weight after three weeks. There was no difference in the C-reactive protein quantity in the blood in the periods when it was evaluated. The use of vaccine reduces performance immediatelly after its application but after it occurs recovery of performance with changes in the number of monocytes and spleen weight. Dietary energy levels do not smooth this reduction in the performance, but they influence intake, feed conversion and blood parameters in the total period of use.