-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.

The objective of this study was to evaluate the effects of spray‐dried porcine plasma (SDPP) on performance, measurement of thyroid hormones triiodothyronine (T3) and thyroxine (T4), body temperature and relative organ weights of weaned piglets exposed to a heat stress or a thermoneutral environment. One hundred and forty‐four piglets with initial BW of 5.82 ± 0.33 kg (28 d old) were used. The experimental design was a 4 x 2 factorial arrangement, four plasma levels (0.0, 2.5, 5.0 and 7.5%) and two environments (34º [heat stress (HS)] and 24°C [thermoneutral (TN)]). SDPP was fed from weaning (28 d of age) to the end of the trial (piglets were weighed at the beginning, 7, 21 and 35 days of trial). Rectal, neck, shoulder and leg temperatures were measured every seven days. At 21 days of trial, one piglet per pen was slaughtered to determine the weight of the carcass and organs. Blood samples were collected at 18 and 35 days of trial to determine levels T3 and T4. The rectal, neck, shoulder and leg temperatures were increased (p < 0.05) 0.4, 1.5, 1.0 and 1.3ºC, respectively, and relative weight of the lungs (p < 0.05) and total T3 (p < 0.05) were decreased 0.001 kg/kg and 0.19 ng/dl, respectively, for pigs in the HS environment. The estimated inclusion of 5.1% of SDPP had the greatest (p < 0.05) weight gain during the first week, and throughout the nursery phase, the 5% of inclusion had a tendency of improvement (p = 0.075), regardless of ambient temperature. For the entire period, pigs reared in the HS environment had the greatest (p < 0.05) estimated feed intake by the quadratic regression with the inclusion of 4.3% of SDPP.

-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.

The aim of this study was to determine the values of apparent digestible energy (DE) and metabolizable energy (ME) for crude glycerin derived of biodiesel based on pork fat for finishing pigs. The diets consisted of a basal diet and four levels of crude glycerin (0, 5, 10 and 15%). Twelve pigs were housed individually in metabolic cages and after seven days of adaptation, total collections of urine and feces for four consecutive days were performed. Gross energy (GE) of crude glycerin, diets, urine and fecal samples from each animal was determined. The crude glycerin used in this experiment presented 74.74% glycerin and 6,500 kcal kg -1 gross energy. The values of digestible energy (DE) and metabolizable energy (ME) were estimated by difference in the DE, and content of the basal diet was subtracted from the test diets containing the ingredient. The amount of GE, DE and ME for finishing pigs was 6,500, 5,839 and 5,509 kcal kg -1 , respectively, with a coefficient of 91.0% of DE and 94.0% of ME. The energy of crude glycerin is based on the levels of fatty acids and GE depends on the concentration of fatty acids and glycerin, ME being a percentage of GE averaging is 84.75%.Energia digestível e metabolizável de glicerina bruta para suínos em terminação RESUMO. O objetivo do estudo foi determinar os valores de energia digestível (ED) e metabolizável (EM) aparente da glicerina bruta de biodiesel à base de gordura suína para suínos em terminação. Os tratamentos experimentais consistiram de quatro níveis de glicerina bruta (0, 5, 10 e 15%) a partir de uma dieta basal. Doze suínos foram alojados individualmente em gaiolas metabólicas e foram realizadas coletas de urina e fezes durante quatro dias. Foi determinada a energia bruta (EB) da glicerina bruta, das dietas, da urina e das amostras de fezes de cada animal. A glicerina bruta apresentou 74,74% de glicerina e 6.500 kcal de energia bruta kg -1 . Os valores de energia digestível (ED) e metabolizável (EM) foram estimados por diferença, em que o conteúdo ED e EM da dieta basal foram subtraídos das dietas contendo o ingrediente teste. A quantidade de EB, ED e EM para suínos em terminação foi de 6.500, 5.839 e 5.509 kcal kg -1 , respectivamente, com um coeficiente de 91,0% de ED e 94,0% de EM. A energia da glicerina bruta é baseada nos níveis de ácidos graxos e a EB depende da concentração de ácidos graxos e glicerina, sendo a EM um percentual da EB variando na média de 84,75%.Palavras-chave: biodiesel, coproduto, banha suína, suíno. 42Silveira et al.