ABSTRACT: This study evaluated chromium and quantitative and qualitative feed restriction as alternative nutritional strategies to ractopamine in finishing barrows. Fifty barrows, genetically similar, with an initial body weight of 99.0 ± 4.3 kg and a final body weight of 117.2 ± 5.8 kg were used. The animals were distributed in a randomized complete block design with five nutritional treatments (Control; Rac = 10ppm ractopamine; Chromium = 0,8mg chromium yeast; Quality = qualitative restriction, 7.5% less net energy in the diet; Quanti = 15% quantitative reduction in feed supply), with five replicates and two animals per replicate. Chromium supplementation and quantitative feed restriction reduced feed, lysine, net energy, and crude protein intakes (P < 0.05). Chromium, ractopamine, and quantitative restriction improved feed conversion (P < 0.05). Supplementation with chromium and ractopamine and feed restriction did not influence the carcass characteristics of the pigs (P < 0.05). Quantitative feed restriction and supplementation of 0.8mg of chromium yeast are presented as potential alternatives to ractopamine in the diet of finishing pigs.

RESUMO: O estudo foi conduzido com o objetivo de avaliar o cromo e restrições alimentares quantitativa e qualitativa como estratégias nutricionais alternativas a ractopamina para suínos machos castrados em terminação. Foram utilizados 50 suínos machos castrados, geneticamente similares, com peso inicial de 99,0 ± 4,3 kg e final de 117,2 ± 5,8 kg. Os animais foram distribuídos em delineamento experimental de blocos ao acaso em cinco tratamentos nutricionais (Controle; Rac = 10ppm de ractopamina; Cromo = 0,8mg de cromo levedura; Qualit = restrição qualitativa com menos 7,5% de energia líquida na dieta e Quanti = redução quantitativa de 15% no fornecimento de ração), com cinco repetições e dois animais por repetição. A suplementação de cromo e a restrição alimentar quantitativa reduziram (P < 0,05) os consumos de ração, lisina digestível, energia líquida e proteína bruta. O cromo, a ractopamina e a restrição quantitativa melhoraram (P < 0,05) a conversão alimentar. A suplementação de cromo, ractopamina e as restrições alimentares não influenciam (P < 0,05) as características de carcaça dos suínos. A restrição alimentar quantitativa e a suplementação de 0,8 mg de cromo levedura se apresentam como potenciais alternativas para a substituição da ractopamina nas dietas.

RESUMO: Realizou-se este estudo com o objetivo de avaliar níveis de energia líquida (EL), mantendo a relação caloria: nutriente, no desempenho e características de carcaça de suínos dos 30 aos 70 kg. Foram utilizados 60 suínos machos castrados, com pesos iniciais de 31,94 ± 3,54 kg e finais de 71,98 ± 5,99 kg. Os animais foram distribuídos em delineamento experimental de blocos casualizados, em cinco níveis de EL (2,40; 2,45; 2,50; 2,55; 2,60 Mcal de EL kg-1 de dieta), com seis repetições e dois animais por unidade experimental. O período experimental foi dividido em fase I: 30 aos 50 kg e fase II: 50 aos 70 kg. As variáveis analisadas foram os consumos de ração diária (CRD), energia líquida (CEL) e lisina digestível (CLdig), ganho de peso diário (GPD), conversão alimentar (CA), peso final (PF), conversão de lisina digestível: ganho (CLdig:G), custo: ganho (C:G), área de olho de lombo (AOL), profundidade de músculo (PM), espessura de toucinho da primeira camada (ET1), espessura de toucinho da segunda camada (ET2), espessura de toucinho total (ETt), percentual de carne magra (CM) e o índice de bonificação de carcaça (IB). Dos 30 aos 50 kg, verificou-se aumento linear (P < 0,05) do PF, GPD e dos CEL e CLdig com o aumento dos níveis de EL na dieta. Dos 50 aos 70 kg, o aumento dos níveis de EL na dieta promoveu melhora linear (P < 0,05) do PF, GPD, CEL, CLdig e da CA dos suínos. No período total, verificou-se aumento linear (P < 0,05) do GPD, CEL, CLdig e melhora linear (P < 0,05) da CA de acordo com o aumento do nível de EL na dieta. As demais variáveis de desempenho não foram afetadas (P > 0,05) pelos níveis de EL. Verificou-se aumento (P < 0,05) da ET2 de acordo com o aumento do nível de EL, porém sem alterar (P > 0,05) as demais características de carcaça. Recomenda-se o nível 2,60 Mcal de EL kg-1 de dieta para suínos machos castrados dos 30 aos 70 kg.

ABSTRACT: This study evaluated the effect of dietary net energy (NE) levels on growth performance and carcass characteristics of barrows from 30 to 70 kg of body weight (BW). Sixty barrows with initial body weight (IBW) of 31.94 ± 3.54 kg and final body weight (FBW) of 71.98 ± 5.99 kg were allotted to one of five dietary NE levels (2.40, 2.45, 2.50, 2.55, and 2.60 Mcal kg-1), using a completely randomized block design with six replicates and two barrows per replicate. The experimental period was divided into phase I: 30 to 50 kg and phase II: 50 to 70 kg. The variables analyzed were average daily feed intake (ADFI), net energy intake (NEI), digestible lysine intake (LysI), average daily gain (ADG), feed conversion (FC), FBW, digestible lysine conversion:gain (LysI:G), Cost:Gain (C:G), loin eye area (LEA), muscle depth (MD), first backfat layer (BF1), second backfat layer (BF2), total backfat (BFt), lean meat percentage, and carcass bonus index (BI). In phase I, there was a linear increase (P < 0.05) in FBW, ADG, NEI, and LysI with increasing NE levels in the diet. In phase II, increasing dietary NE levels also increased (P < 0.05) FBW, ADG, NEI, LysI, and FC linearly. Overall, there was a linear increase (P < 0.05) in ADG, NEI, LysI, and FC with increasing NE levels in the diet. The other performance variables were not affected (P > 0.05) by the NE levels. There was an increase (P < 0.05) in BF2 with increasing NE levels, but the other carcass characteristics were not altered (P > 0.05). We recommended 2.60 Mcal of NE kg-1 in the diet for growing barrows from 30 to 70 kg.

RESUMO: Realizou-se este estudo com o objetivo de avaliar os efeitos de níveis de cromo levedura e lisina digestível, desempenho e características de carcaça de suínos em terminação. Foram utilizados 64 machos castrados com peso inicial de 72,77 ± 7,20 kg e final de 119,44 ± 9,47 kg, distribuídos em esquema fatorial 2 x 2, sendo dois níveis (Cr0: 0 ppb e Cr800: 800 ppb) e dois níveis de lisina digestível (L0: nível recomendado e L+10%: 10%). A temperatura do ar registrada de 30,9 ± 3,7 ºC durante o período experimental foi considerada como de estresse por calor. As variáveis de desempenho não foram influenciadas (P>0,05), contudo L+10% aumentou (P<0,05) o consumo de lisina digestível diário. As características de carcaça dos animais não foram influenciadas (P>0,05) pelos níveis de cromo levedura e lisina digestível. A suplementação de 800 ppb de cromo levedura, e o aumento em 10% do nível de lisina digestível, isolados ou associados, não melhoram o desempenho e as características de carcaça de suínos em terminação submetidos a temperaturas ambientais elevadas.

ABSTRACT: This study evaluated the effects of chromium yeast and digestible lysine levels on the performance and carcass characteristics of finishing pigs. Sixty-four barrows with an initial weight of 72.77 ± 7.20 kg and final weight of 119.44 ± 9.47 kg were used, distributed in a 2 x 2 factorial scheme, with two levels of chromium yeast (Cr0: 0 ppb and Cr800: 800 ppb) and two levels of digestible lysine (L0: recommended level and L+10%: 10%). The recorded air temperature of 30.9 ± 3.7 ºC during the experimental period was considered as heat stress. Performance variables were not influenced (P>0.05); however, L+10% showed an increase (P<0.05) in daily digestible lysine intake. Carcass characteristics of the animals were not influenced (P>0.05) by the chromium or digestible lysine levels. Supplementation with 800 ppb of yeast chromium and a 10% increase in the level of digestible lysine, isolated or associated, did not improve the performance and carcass characteristics of finishing pigs, subjected to high ambient temperatures.

ABSTRACT 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.

ABSTRACT This study was conducted to evaluate different nutritional plans of net energy (NE) with a constant calorie:nutrient ratio on the performance of piglets from 7 to 30 kg. Sixty barrows with an initial weight of 7.11±0.89 kg were distributed among five nutritional plans: two NE-decreasing plans (A and B, starting from NE concentrations of 2.47 and 2.52 Mcal kg−1, respectively, and ending both at 2.37 Mcal kg−1) and three NE-constant plans (C, 2.37 Mcal kg−1; D, 2.42 Mcal kg−1; and E, 2.47 Mcal kg−1). The nutritional plans were composed of two decreasing plans: A, 2.47-2.42-2.37-2.37-2.37 Mcal of NE kg−1 of feed; B, 2.52-2.47-2.42-2.37-2.37 Mcal of NE kg−1 of feed; and three constant plans: C, 2.37 Mcal of NE kg−1 of feed; D, 2.42 Mcal of NE kg−1 of feed; E, 2.47 Mcal of NE kg−1 of feed, from 7 to 10, 10 to 15, 15 to 20, 20 to 25, and 25 to 30 kg, respectively, with six replicates per treatment and two animals per experimental unit. Animal performance was evaluated through the following measurements: average daily feed intake (ADFI), NE intake, standardized ileal digestible lysine intake (SID Lys intake), average daily gain (ADG), feed:gain ratio (F:G), final weight (FW), feed cost per kg of weight gain (CWG), economic efficiency index (EEI), and fecal score. Piglets’ final weight was 32.95±3.30 kg. Considering the total experimental period, there was no effect of the nutritional plan on ADG, F:G, CWG, and EEI. The final weight of piglets under plan D was higher than that recorded for those allocated to plan C, not differing from the other nutritional plans. Piglets fed under nutritional plans A and D presented higher ADFI compared with those subjected to other plans. Net energy and SID Lys intakes were significantly higher in piglets subjected to plans A, D, and E compared with those under plans B and C. Net energy nutritional plans did not influence the fecal score and the occurrence of diarrhea of the piglets. Based on our analysis, a nutritional plan containing a constant NE level of 2.42 Mcal kg−1 of feed may be recommended for piglets from 7 to 30 kg.

RESUMO: Realizou-se a meta-análise com o objetivo de determinar o nível recomendado de lisina digestível e sua influência sobre o desempenho produtivo de porcas primíparas lactantes. A base de dados composta por 26 publicações, 138 dietas e 3.820 fêmeas foi desenvolvida a partir de artigos sobre a associação entre, lisina, proteína bruta e porcas primíparas lactantes. Os níveis de lisina digestível dos estudos variaram de 0,22 a 1,43% com valores médios de 0,85% de lisina digestível nas dietas, com consumo de 41,25 g dia-1. O consumo de lisina digestível das porcas apresentou correlação positiva (P<0,05) com o consumo de ração, aminoácidos essenciais, proteína bruta, energia metabolizável, perda de peso corporal da porca, produção de leite, número e peso de leitões ao desmame. O consumo de lisina indicou correlação negativa (P<0,05) para espessura de toucinho ao desmame e intervalo desmame-cio. Observou-se efeito quadrático (P<0,01) da perda de peso corporal da porca e ganho de peso diário dos leitões e efeito quadrático (P<0,01) do peso dos leitões ao desmame em função do aumento do nível de lisina da dieta. O nível de 1,04% de lisina digestível indica a menor perda de peso da porca. O maior peso dos leitões ao desmame e maior ganho de peso diário dos leitões é verificado com a inclusão de 1,30 e 1,07% de lisina digestível na dieta, respectivamente.

ABSTRACT: A meta-analysis was carried out to evaluate the recommended levels of digestible lysine and its influence on the productive performance of primiparous lactating sows. The database consisted of 26 publications, 138 diets and 3,820 sows was developed from articles on the association between, lysine, crude protein and lactating primiparous sows. The digestible lysine levels of the studies ranged from 0.22 to 1.43% with average values of 0.85% digestible lysine in the diet, with consumption of 41.25 g day-1. The digestible lysine intake of sows was positively correlated (P<0.05) with feed intake, essential amino acids, crude protein, metabolizable energy, body weight loss sows, milk production, number and weight of piglets at weaning. Digestible lysine intake showed negative correlation (P<0.05) with backfat thickness at weaning and weaning to oestrus interval. It was observed a quadratic effect (P<0.01) of body weight loss sow and daily weight gain of piglets and a quadratic effect (P<0.01) in the weight of piglets at weaning due to increased dietary lysine level. The level of 1.04% of digestible lysine indicates less weight loss sows. The greater weight of piglets at weaning and increased daily weight gain of piglets was verified with the addition of 1.30 and 1.07% digestible lysine in the diet, respectively.

RESUMO: Realizou-se este estudo com o objetivo de avaliar a associação de cromo-levedura e selênio-levedura como aditivos nutricionais melhoradores de desempenho e das características quantitativas de carcaça de suínos machos castrados em terminação. Foram utilizados 48 suínos machos castrados, híbridos comerciais, com peso inicial de 68,3±3,5 kg e peso final de 99,6±3,6 kg. Os animais foram distribuídos em delineamento experimental de blocos casualizados, composto por três níveis de cromo-levedura e selênio-levedura (controle sem suplementação de cromo-levedura e selênio-levedura; suplementação de 0,4 mg kg-1 de cromo-levedura e 0,3 mg kg-1 de selênio-levedura; e 0,8 mg kg-1 de cromo-levedura e 0,6 mg kg-1 de selênio-levedura), com oito repetições e dois animais por unidade experimental. A suplementação de cromo-levedura e selênio-levedura não influenciou (P>0,05) o consumo de ração diário, os consumos de lisina digestível, de proteína bruta e de energia metabolizável, o ganho de peso diário, a conversão alimentar, o peso e comprimento de carcaça, espessura de toucinho, profundidade de músculo, percentagem e quantidade de carne magra e índice de bonificação. A suplementação associada de cromo e selênio-levedura não influencia o desempenho e as características quantitativas de carcaça de suínos machos castrados em terminação.

ABSTRACT: The present study was performed to evaluate the association of chromium-yeast and selenium-yeast as nutritional additives to enhance performance and quantitative characteristics in the carcass of finishing barrows. A total of 48 barrows, commercial hybrid, with initial weight of 68.3±3.5 kg and final weight of 99.6±3.6 kg, were utilized for the study. The animals were distributed in a randomized complete block design, consisting of three levels of chromium-yeast and selenium-yeast (i.e., without supplementation of chromium-yeast and selenium-yeast, supplementation of 0.4 mg kg-1 chromium-yeast and 0.3 mg kg-1 selenium-yeast, and supplementation of 0.8 mg kg-1 chromium-yeast and 0.6 mg kg-1 selenium-yeast) with eight replicates and two animals per experimental unit. The supplementation of chromium and selenium-yeast did not significantly affect (P>0.05) the average daily feed intake, digestible lysine, crude protein and metabolizable energy intake, average daily weight gain, feed conversion, weight and carcass length, back fat thickness, muscle depth, percentage and amount of lean meat, and carcass allowance. These findings suggest that supplementation of chromium and selenium-yeast does not affect the performance or quantitative characteristics in the carcass of finishing barrows.

RESUMO: Realizou-se este estudo com o objetivo de avaliar planos sequenciais de energia metabolizável (EM), mantendo a relação lisina: caloria, para leitões dos 7 ao 30 kg. Foram utilizados 48 leitões, fêmeas, com peso inicial de 6,9 ± 1,2 kg e final de 30,5 ± 3,8 kg, distribuídos em delineamento de blocos ao acaso em três planos nutricionais, sendo: 1- 3.300-3.250-3.200-3.150 Kcal de EM kg-1 de ração; 2- 3.400-3.350-3.300-3.250 Kcal de EM kg-1 de ração; e 3- 3.500-3.450-3.400-3.350 Kcal de EM kg-1 de ração, dos 7 aos 10 kg, dos 10 aos 15 kg, dos 15 aos 20 kg e dos 20 aos 30 kg, respectivamente, com oito repetições e dois animais por unidade experimental. Dos 7 aos 10 kg, não houve efeito (P>0,05) dos planos nutricionais nas variáveis avaliadas. Observou-se, dos 7 aos 15 kg, maiores (P<0,05) consumos de energia e ganho de peso e melhor (P < 0,05) conversão alimentar nos animais alimentados com os planos nutricionais 2 e 3. Os leitões alimentados com os planos nutricionais 2 e 3 apresentaram maior (P<0,05) peso final, consumos de ração, de energia, de lisina digestível, ganho de peso e melhor conversão alimentar nos períodos dos 7 aos 20 kg, dos 7 aos 25 kg e dos 7 aos 30 kg. Recomenda-se o plano sequencial contendo 3.400-3.350-3.300-3.250 Kcal de EM kg-1 de ração dos 7 aos 10 kg, dos 10 aos 15 kg, 15 aos 20 kg e dos 20 aos 30 kg, respectivamente, equivalentes aos níveis de 2.546-2.513-2.501-2.475 Kcal de energia líquida kg-1 de ração.

ABSTRACT: The objective of this study was to evaluate sequential metabolizable energy (ME) plans, maintaining the lysine: calorie ratio for piglets from 7 to 30 kg. Forty eight female piglets with initial weight of 6.9 ± 1.2 kg and final weight of 30.5 ± 3.8 kg were randomly allocated in a randomized complete blocks design to three nutritional plans with eight replicates and two animals per experimental unit. Sequential plans provided four ME levels: plan 1: 3,300-3,250-3,200-3,150 kcal ME kg-1, plan 2: 3,400-3,350-3,300-3,250 kcal ME kg-1, and plan 3: 3,500-3,450-3,400-3,350 kcal ME kg-1 of feed, from 7 to 10 kg, 10 to 15 kg, 15 to 20 kg and 20 to 30 kg, respectively. From 7 to 10 kg, there was no effect (P>0.05) of the nutritional plans in the evaluated variables. From 7 to 15 kg, a higher (P<0.05) energy intake and weight gain and a better (P < 0.05) feed conversion was observed in animals fed with nutritional plans 2 and 3. Nutritional plans 2 and 3 resulted in higher (P<0.05) final weight, feed intake, energy intake, digestible lysine intake, weight gain, and better feed conversion in the 7 to 20 kg, 7 to 25 kg and 7 to 30 kg. It is recommended the sequential plan containing 3,400-3,350-3,300-3,250 kcal ME kg-1 of feed from 7 to 10 kg, from 10 to 15 kg, 15 to 20 kg, and from 20 to 30 kg; respectively, equivalent to levels of 2,546-2,513-2,501-2,475 kcal net energy (NE) kg-1 of feed for piglets.

ABSTRACT The objective of this study was to evaluate sequential digestible phosphorus levels for gilts from 30 to 100 kg. Sixty gilts were used, with an initial weight of 29.98±3.37 kg and final weight of 100.66±8.82 kg, distributed in a randomized block design, with five nutritional digestible phosphorus levels: 2.19-1.88-1.68, 2.69-2.38-2.18, 3.19-2.88-2.68, 3.69-3.38-3.18, and 4.19-3.88-3.68 g kg−1, respectively, for the growth phases 30 to 50 kg, 50 to 70 kg, and 70 to 100 kg, with six replicates and two animals per pen. The nutritional plans did not influence the final weight, days to reach 100 kg, total and daily weight gain, total and daily feed intake, crude protein intake, digestible lysine intake, or metabolizable energy intake. An increase in digestible phosphorus and calcium intake was observed according to the increase in the digestible phosphorus level in the diet. There was a significant effect on feed conversion. No effect of nutritional plans was observed for backfat thickness, muscle depth, loin eye area, lean meat percentage, or carcass bonus index. There was no difference in the production of dry and natural matter or the residue coefficient. The effect of the nutritional digestible phosphorus levels in the contents of total solids and volatile solids was verified. There was a difference in the concentration of total nitrogen and total phosphorus in the manure. The nutritional plan with 3.19-2.88-2.68 and 3.69-3.38-3.18 g kg−1 of digestible phosphorus results in better feed conversion than the basal diet. For a lower excretion of phosphorus in the manure, the recommended nutritional plan is 2.19-1.88-1.68 g kg−1 of digestible phosphorus.

ABSTRACT This experiment was conducted to evaluate the growth performance and carcass characteristics of gilts from 25 to 100 kg body weight (BW) fed diets with increased net energy (NE) levels. Seventy-two gilts with initial BW of 23.24±2.47 kg were allotted to one of six dietary treatments (2300, 2380, 2460, 2540, 2620, and 2700 kcal NE kg−1) using a completely randomized block design, with two pigs per replicate, and six replicates per treatment. Corn-soybean meal-based diets were formulated to be fed in three phases (25 to 50, 50 to 70, and 70 to 100 kg BW). Soybean oil was added to replace the inert ingredient kaolin to meet the NE level of each diet. Increasing dietary NE decreased the average daily feed intake (ADFI) and improved the feed:gain ratio (F:G) and standardized ileal digestible (SID) lysine:gain ratio in all the phases evaluated. In the second phase, average daily gain increased with increasing dietary NE level, although SID lysine intake decreased. At the end of the first phase, increasing dietary NE increased backfat and decreased lean percentage. In the last phase, lean percentage linearly decreased as dietary NE increased. Increasing dietary NE for gilts from 25 to 100 kg BW decreases ADFI and improves F:G. However, as dietary NE increases, lean percentage decreases without affecting growth performance.

ABSTRACT This experiment was conducted to evaluate growth performance and carcass characteristics of barrows from 25 to 100 kg fed diets with different dietary net energy (NE) levels. Seventy-two barrows with initial body weight (BW) of 25.19±2.13 kg were allotted using a completely randomized block design to one of six dietary NE treatments (2300, 2380, 2460, 2540, 2620, and 2700 kcal kg−1), which had two pigs per replicate and six replicates per treatment. Diets were formulated to be fed in three phases (25 to 60, 60 to 70, and 70 to 100 kg BW). The six different dietary NE densities were met by adding soybean oil in place of the inert ingredient (kaolin) to a corn-soybean meal-based diet. Increasing dietary NE decreased average daily feed intake and average daily standardized ileal digestible (SID) lysine intake in all of the three phases evaluated and improved the feed:gain ratio and SID lysine:gain ratio in the first and third phases. In the first and second phases, average daily NE intake and NE:gain ratio were similar among treatments, but NE increased and NE:gain worsened during the last phase as dietary NE increased. Average daily gain was not affected by dietary NE in the first and second phases; however, it improved in the last phase. Backfat was thicker, and lean percentage was reduced by increasing the dietary NE in all three phases of this study. Thus, barrows consume less feed, but carcass fat increases if dietary NE is increased from 2300 to 2700 kcal kg−1.

RESUMO: Este estudo foi conduzido para avaliar o efeito das concentrações de ractopamina no perfil lipídico da gordura e carne suína. Utilizou-se 90 machos castrados, pesando inicialmente 71,9±4,4kg, foram distribuídos em delineamento de blocos ao acaso em três concentrações de ractopamina (0, 10 e 20ppm), com quinze repetições e dois animais por unidade experimental. Foi utilizada cromatografia gasosa para analisar os perfis lipídicos da gordura subcutânea e da carne. A inclusão de ractopamina na dieta alterou (P<0,05) os níveis dos ácidos graxos α-linolênico e eicosatrienoico na gordura subcutânea e não afetou (P>0,05) nenhum dos outros ácidos graxos ou índices avaliados. Em relação à gordura da carne, houve efeito (P<0,05) sobre nove ácidos graxos avaliados, com redução (P<0,05) dos ácidos graxos láurico, mirístico e palmítico, e aumento (P<0,05) do linoleico, γ-linolênico, dihomo-γ-linolênico e eicosapentaenoico. A ractopamina também afetou (P<0,05) a concentração do linolênico e araquidônico na carne. Os índices avaliados também foram afetados (P<0,05). A inclusão de 10ppm diminuiu a concentração dos ácidos graxos saturados, índice aterogênico, índice trombogênico e ômega 6: ômega 3, e aumentou a concentração dos ácidos graxos insaturados e poli-insaturados. A inclusão de ractopamina teve menor efeito na gordura subcutânea do que na carne, sendo que o nível de 10ppm melhorou o perfil lipídico da carne.

ABSTRACT: This study was conducted to evaluate the effect of ractopamine concentrations on swine fat and meat lipid profiles. Ninety finishing barrows, initially weighing 71.9±4.4kg, were distributed in a randomized block design in three ractopamine concentrations (0, 10 and 20ppm) with fifteen replicates of two animals in each. Gas chromatography was used to analyze the lipid profiles of backfat and meat. The inclusion of ractopamine in the diet changed (P<0.05) α-linolenic acid and eicosatrienoic acid concentrations in the backfat but did not affect (P>0.05) any of the other fatty acids or indexes evaluated. In the meat, a significant effect (P<0.05) was observed on nine fatty acids evaluated, with a decrease (P<0.05) in lauric, myristic, and palmitic fatty acids, and an increase (P<0.05) in linoleic, γ-linolenic, dihomo-γ-linolenic, and eicosapentaenoic acid. Ractopamine also affected (P<0.05) the concentration of α-linolenic and arachidonic acid in the meat (P<0.05). The indexes evaluated were also affected (P<0.05). Addition of 10ppm decreased the saturated fatty acid concentration, atherogenic index, thrombogenic index and omega 6: omega 3, while it increased unsaturated and polyunsaturated fatty acids concentrations. Ractopamine addition had less effect on the backfat than on the meat, and the 10ppm level improved the meat lipid profile.

ABSTRACT This study was conducted to evaluate nutritional plans of digestible phosphorus for barrows weighing between 30 and 100 kg. Eighty animals were distributed in a randomized block design with five nutritional plans containing 2.19-1.86-1.71, 2.57-2.23-2.09, 2.94-2.61-2.46, 3.32-2.99-2.84, and 3.70-3.36-3.32 g of digestible phosphorus kg−1 of diet, respectively, for the phases of 30 to 50 kg, 50 to 70 kg, and 70 to 100 kg, with eight replications and two barrows per experimental unit. The nutritional plans of digestible phosphorus had no effect on the final body weight, feed intake, daily weight gain, or feed conversion of barrows. The daily intake of digestible phosphorus increased with the dietary concentrations of digestible phosphorus. Of the carcass characteristics assessed, only muscle depth responded significantly to the highest concentration of digestible phosphorus, as assessed in barrows sequentially fed the 3.70-3.36-3.32 g kg−1 diet. The nutritional plans had no effect on backfat, rib eye area, or carcass lean tissue mass, percentage, and deposition. The nutritional plan containing 2.19-1.86-1.71 g kg−1 of digestible phosphorus meet the nutrient requirements for performance and carcass characteristics of barrows weighing from 30 to 100 kg.

ABSTRACT The purpose of this study was to evaluate the effect of glutamine supplementation plans on performance, carcass yield, and cut yield of broilers reared in a high-temperature environment. A fully randomized design was adopted for the experiment, comprising 900 male Hubbard broiler chicks assigned to five treatment groups (0% glutamine from one to 42 days of age; 0.5% glutamine from 1 to 7 days of age, followed by 0% from 8 to 42 days; 1.0% glutamine from 1 to 7 days of age, followed by 0.5% from 8 to 14 days and 0% from 15 to 42 days; 1.5% glutamine from 1 to 7 days of age, followed by 1.0% from 8 to 14 days, 0.5% from 15 to 21 days, and 0% from 22 to 42 days; 2.0% glutamine from 1 to 7 days of age, followed by 1.5% from 8 to 14 days, 1.0% from 15 to 21 days, and 0% from 22 to 42 days), consisting of six replicates of 30 animals each. The experiment was composed of four periods: pre-starter (1-7 days), starter (8-21 days), grower (22-33 days), and finisher (34-42 days). Glutamine supplementation plans up to 21 days do not improve the performance of broilers in the periods from 1 to 21 and from 1 to 42 days of age reared in a high-temperature environment. Carcass yields and cuts of broilers at 42 days of age are not changed by glutamine supplementation for up to 21 days.

RESUMO: Este estudo foi conduzido com o objetivo de avaliar o efeito dos níveis de energia líquida no perfil lipídico da gordura e carne suína. Foram utilizados 90 animais, com peso inicial de 71,94±4,43kg, distribuídos em delineamento de blocos ao acaso em cinco níveis de energia líquida (2.300, 2.425, 2.550, 2.675 e 2.800Kcal kg-1 de ração), com nove repetições e dois animais por unidade experimental. Foram analisados os perfis lipídicos da gordura subcutânea e da carne por cromatografia gasosa. O aumento do nível de energia líquida usando óleo de soja melhorou o perfil lipídico da gordura subcutânea e da carne, aumentando linearmente (P<0,05) a concentração dos ácidos graxos poli-insaturados, especialmente ácido linoleico e α-linolênico, reduzindo linearmente (P<0,05) os ácidos graxos monoinsaturados e saturados e ômega 6: ômega 3. No tecido adiposo foi observado redução linear (P<0,05) dos índices aterogênico e trombogênico. Em conclusão, o aumento do nível de energia líquida da dieta, com a utilização do óleo de soja, melhora o perfil lipídico da gordura subcutânea e da carne suína.

ABSTRACT: This study was conducted to evaluate the effects of net energy levels on the lipid profile of adipose tissue and muscle of swines. A total of 90 animals, with initial weight of 71.94±4.43kg, were used, and distributed in a randomized block design in five net energy levels (2,300, 2,425, 2,550, 2,675, and 2,800Kcal kg-1 feed), with nine replicates and two animals per experimental unit. Lipid profiles of adipose tissue and muscle were analyzed using gas chromatography. Increasing the levels of net energy using soybean oil, improved the lipid profile of adipose tissue and muscle, increased linearly (P<0.05) the concentrations of polyunsaturated fatty acids, especially linoleic and α-linolenic acid, reduced linearly (P<0.05) the monounsaturated and saturated fatty acids and omega 6: omega 3. In adipose tissue was observed linear reduction (P<0.05) of atherogenic and thrombogenic indexes. In conclusion, increasing the level of net energy of the diet using soybean oil improved the lipid profile of adipose tissue and muscle.