Francisco Carlos de Oliveira Silva

Efeito da ractopamina e de métodos de formulação de dietas sobre o desempenho e as características de carcaça de suínos machos castrados em terminação

An experiment was conduced with the objective of evaluating the effects of diet formulation methods and supplementation of ractopamine (RAC) on the performance and carcass characteristics of finishing barrows. Sixty commercial hybrid swines were used, distributed in a randomized experimental block design, in a 2 x 3 factorial arrangment, with two levels of RAC and three methods of diet formulation. Supplementation with RAC improved the final weight, daily weight gain (DWG) and feed conversion (FC) of the finishing barrows. Addition of RAC improved also the carcass characteristics by reducing the backfat thickness in point P1 and increase daily lean meat deposition rate. Diets formulated based in the concept of ideal protein or by the increase of soybean meal provided better results on FC, but did not influence significantly daily feed intake, DWG and carcass characteristics. Finishing barrows supplemented with RAC during 21 or 28 days showed better performance and carcass quality. Diets formulated to attend the levels of digestible lysine by the inclusion of L-lysine HCL with the adjustment of other amino acids for ideal protein relation (ideal protein) or by the greater inclusion of soybean meal (increase of CP) provided better results of feed conversion in finishing borrows supplemented with RAC during 28 days.

Efeito dos níveis de lisina digestível e da ractopamina sobre o desempenho e as características de carcaça de suínos machos castrados em terminação

Foi conduzido um experimento com o objetivo de avaliar o efeito de diferentes niveis de lisina digestivel em racoes suplementadas ou nao com ractopamina (RAC) sobre o desempenho e as caracteristicas de carcaca de suinos machos castrados em terminacao. Quarenta suinos, hibridos comerciais, foram distribuidos em delineamento experimental de blocos ao acaso, em arranjo fatorial 2 x 2 - dois niveis de lisina digestivel (0,67 e 0,87%), com ajuste para os demais aminoacidos para a relacao de proteina ideal, e dois niveis de RAC (0 e 5,0 ppm) - em um periodo de 28 dias. A suplementacao com RAC resultou em maiores ganho de peso diario e taxa de deposicao de carne magra diaria e melhor conversao alimentar. Os niveis de lisina nao influiram no desempenho dos animais, porem reduziram a espessura de toucinho nos pontos P1 e P2 e aumentaram a taxa de deposicao de carne magra diaria na carcaca de suinos alimentados com dietas contendo 0,87% de lisina digestivel quando avaliadas in vivo. Concluiu-se que as caracteristicas de desempenho e de carcaca dos suinos alimentados com racao suplementada com RAC na fase de terminacao melhoraram, porem, o efeito da RAC sobre a profundidade de lombo foi maior no nivel de 0,87% de lisina digestivel.

Níveis de lisina para leitoas selecionadas geneticamente para deposição de carne magra na carcaça, dos 15 aos 30 kg

Foram utilizadas 50 leitoas hibridas, com alto potencial genetico para deposicao de carne magra na carcaca e peso inicial e final de 15,39 ± 0,59 e 30,93 ± 1,72 kg, respectivamente, para avaliar diferentes niveis de lisina. O delineamento experimental foi o de blocos ao acaso, com cinco tratamentos, cinco repeticoes e dois animais por unidade experimental. Os tratamentos corresponderam a uma racao basal com 19% de proteina bruta, suplementada com cinco niveis de L-lisina HCl, resultando em racoes com 0,95; 1,05; 1,15; 1,25; e 1,35% de lisina total. Observou-se que o ganho de peso e o consumo de lisina diario elevaram-se de forma linear com o aumento do nivel de lisina da racao. Houve efeito quadratico dos niveis de lisina sobre o consumo de racao diario e a conversao alimentar, que melhorou ate o nivel de 1,26% de lisina total (0,365%/Mcal de ED) ou 1,13% (0,328%/Mcal de ED) de lisina digestivel, correspondendo a um consumo estimado de lisina total e digestivel de 14,62 g/dia e 13,12 g/dia, respectivamente. Nao se observou efeito dos tratamentos sobre a porcentagem de proteina e de agua na carcaca e os niveis de ureia no soro sanguineo, entretanto, houve efeito quadratico sobre a porcentagem de gordura e a taxa de deposicao de gordura na carcaca, que diminuiram ate o nivel de 1,25 e 1,18% de lisina, respectivamente. Observou-se que a taxa de deposicao de proteina elevou de forma linear com o aumento do nivel de lisina na racao. Os niveis de lisina total que proporcionaram os melhores resultados de desempenho e qualidade de carcaca situaram-se entre 1,18 e 1,35%. Portanto, concluiu-se que a exigencia de lisina total de leitoas dos 15 aos 30 kg e de 1,26% ou de 1,13% de lisina digestivel, correspondendo a consumo estimado de lisina total e digestivel de 14,6 e 13,1 g/dia, respectivamente.

Available phosphorus levels in diets for swine with high genetic potential for meat deposition from 30 to 60 kg.

With the objective of evaluating levels of available phosphorus (AP) in diets for swine with high genetic potential for meat deposition,sixty female commercial hybrid swine were used, with initial weight of 30 ± 0.618 kg, distributed in a completely randomized experimental design, with five treatments, six replications and two animals per experimental unit. The treatments consisted of a basal diet without phosphorus supplementation and another four diets obtained by supplementing the basal diet with dicalcium phosphate to obtain five available phosphorus levels (0.115, 0.195, 0.275, 0.355 and 0.435%). No effect of the available phosphorus levels was observed on the feed daily intake. The available phosphorus levels influenced linearly the daily weight gain (DWG) and the feed conversion (FC), and the daily weight gain increased up to the level of 0.349% available phosphorus, and remained on a plateau. The feed conversion decreased to 0.345% of available phosphorous and remained on a plateau. The bone strength, phosphorus levels and ash percentage in the bones linearly increased as available phosphorous levels increased in the rations. There was no effect of the available phosphorous levels of the diets on the amount of calcium in the bones. The available phosphorous levels that showed the best results for daily weight gain and feed conversion in female swine with high genetic potential for meat deposition, from 30 to 60 kg, are, respectively, 0.349 e 0.345%, corresponding to the estimated daily intakes of 7.45 and 7.36 g.

Available phosphorus levels in diets for swine from 15 to 30 kg genetically selected for meat deposition

Com o objetivo de avaliar niveis de fosforo disponivel (PD) em racoes para suinos selecionados geneticamente para deposicao de carne, utilizaram-se 60 leitoes hibridos comerciais (30 machos castrados e 30 femeas) com peso inicial de 15,00 ± 0,41 kg, distribuidos em delineamento experimental inteiramente casualizado, com seis racoes, cinco repeticoes e dois animais (um macho e uma femea) por unidade experimental. Avaliaram-se uma racao basal e outras cinco racoes, obtidas pela suplementacao da racao basal com fosfato bicalcico, totalizando seis niveis de fosforo disponivel (0,114; 0,221; 0,328; 0,435; 0,542 e 0,649%). Os niveis de fosforo disponivel promoveram aumento linear no consumo diario da racao. O ganho de peso diario e a conversao alimentar variou de forma quadratica de acordo com os niveis de PD, com valores maximos de 0,509 e 0,477% de PD na racao, respectivamente. A resistencia ossea e os teores de calcio e fosforo no osso tambem aumentaram de forma quadratica de acordo com os niveis de PD, com valores maximos de 0,529; 0,619 e 0,596% de PD na racao, respectivamente. Nao houve efeito dos niveis de PD nas racoes sobre o teor de cinza ossea. Os melhores resultados de ganho de peso e conversao alimentar de suinos, machos castrados e femeas, na fase dos 15 aos 30 kg, selecionados geneticamente para deposicao de carne, sao proporcionados pelos niveis de fosforo disponivel de 0,509 e 0,477%, respectivamente, correspondentes a consumos diarios de 6,39 e 5,93 g de fosforo disponivel.

Níveis de energia metabolizável mantendo a relação lisina digestível: caloria em rações para suínos machos castrados em terminação

Forty barrows from commercial hybrids averaging initial weight of 60.1 ± 1.3 kg were used in a trial to evaluate different ME levels, maintaining the digestible lysine:calorie ratio, on the performance and carcass characteristics. A randomized block experimental design with four treatments, five replicate and two animals per experimental unit was used. The treatments consisted of four ME levels (3,100, 3,230, 3,370, and 3,500 kcal/kg) with 2.41 g of digestible lysine/Mcal of EM ratio. Animals were fed until the end of the experimental period, when the animals reached 95.46 ± 2.89 kg. It was observed linear effect of treatments on feed intake. Feed:gain ratio increased linearly as the ME levels increased. There was no treatment effect on energy efficiency, weight gain, carcass yield, backfat thickness and lean meat yield. It was concluded that increasing ME levels (3,100 to 3,500 kcal/kg, maintaining the dietary digestible lysine:calorie ratio of barrows, increase feed:gain ratio and decrease feed intake with no effect on weight gain and carcass characteristics.

Planos de nutrição para leitoas com alto potencial genético para deposição de carne magra dos 65 aos 105 kg

Ninety and six crossbred gilts with high genetic potential for lean meat gain, with average initial weight of 65.93 ± 2.78 kg and final weight of 105.50 ± 2.18 kg, were used to evaluate the effect of nutrition plans, based on the effects of lysine levels on the carcass traits of gilts in the finishing phase. A randomized block design, with four treatments, 12 replicates and two animals per box, used as experimental unit, was used. The treatments were constituted of nutritional plans (established by sequential lysine levels) for two different weights, from 65 to 95 kg and from 95 to 105 kg. The isoenergy diets and the lysine levels were obtained by changes on dietary corn and soybean proportion. There was no effect of treatments on daily weight gain and daily feed intake. There was effect of nutrition plans on feed:gain ratio, and the nutrition plan 3 showed an increase of 7.86% in relation to nutrition plan 1 and did not differ from the others. Lysine intake increased as the lysine levels of nutrition plans increased. In the nutrition plan 4, lysine intake was 25.43% higher than the other plans. There was no significant difference of nutrition plans on muscle growth ratio, muscle feed:gain ratio, carcass length, backfat thickness in the region between the last and last but one lumbar vertebra, backfat thickness at 6.5 cm from the midline carcass, carcass yield, lean meat yield, fat yield and ham yield. By economic analysis, the nutrition plan 2 showed the best economic return on feed intake. It can be concluded that the nutrition plan 3 (1.00-0.90% lysine) showed the best results of performance and carcass characteristics.

Níveis de lisina digestível em rações, utilizando-se o conceito de proteína ideal, para suínos machos castrados de alto potencial genético dos 15 aos 30 kg

Fourty barrows with high genetic potential for lean gain averaging initial and final body weights of 15.76 + 0.93 kg and 30.23 + 1.56 kg, respectively, were used to evaluate the effect of digestible lysine levels, using the ideal protein concept, on the performance and carcass composition. The treatments were composed of a basal diet containing 19.46% crude protein and 3,280 kcal of ME/kg, that were supplemented with different levels of HCl-L-Lysine, resulting in diets with 0.90, 1.00, 1,10, and 1.20% of digestible lysine. The diets were supplemented with increasing levels of synthetic amino acids, resulting in diets with ratios of methionine + cystine, threonine, tryptophan and valine:lysine constant in 60, 60, 19 e 69%, respectively, based on the true digestibility. No treatment effects on feed intake, concentration of plasma urea and percentages of water, protein and fat in the carcass were observed in this trial. However, significant quadratic effects on weight gain and feed:gain ratio with quadractic maximum and minimum of 1.10 and 1.12% of lysine, respectively, were detected. Intake of digestible lysine increased linearly among treatments. The depositions of protein and fat in the carcass answered quadractily with quadratic maxima at 1.12 and 1.08%, respectively. The level of digestible lysine that provided the best results of performance and carcass characteristics of barrows with high genetic potential from 15 to 30 kg was of 1.12% of true digestible lysine, corresponding to a digestible lysine intake of 12.03 g/day (3.42 g of Lys/Mcal of ME).

Levels of lysine for gilts with high genetic potential for lean gain from 30 to 60 kg

Fifty hybrid gilts, with high genetic potential for lean gain and initial and final average weight of 30.0 ± 0.45 and 59.9 ± 2.53 kg, respectively, were used in an experiment to evaluate diet with different levels of lysine. An experimental desi gn of randomized blocks, with five treatments, five replicates and two animals per experimental unit, was used. The treatments corresponded to a basal diet with 17.5% crude protein, supplemented with five levels of HCl-L-lysine, resulting in diets with 0.80, 0.90, 1.00, 1.10, and 1. 20% of total lysine. There were no effects of treatments on daily weight gain and serum urea concentration, however, daily feed intake and d aily lysi e intake increased linearly with the dietary lysine level. There was a quadratic effect of lysine levels on feed:gain ratio, that increased up to the total lysine level of 1.16% (0.347%/Mcal of DE) or 1.05% (0.315%/Mcal of DE) of digestible lysine, corresponding to the tot al and digestible lysine intake of 21.8 and 19.7 g/day, respectively. There was no effect of treatments on protein percentage, however , the ater percentage in carcass linearly decreased. There was quadratic effect of treatments on fat percentage and fat deposition rate in carcass, that decreased up to the lysine level of 1.09 and 1.12%, respectively. The protein deposition rate improved quadraticly up to the le vel f lysine of 1.04%. It was concluded that gilts with high genetic potential for lean gain, from 30 to 60 kg require 1.16% of total lysine or 1.05% (0.315%/ Mcal of DE) of true digestible lysine, corresponding to total and digestible lysine intake of 21.8 and 19.72 g/day, respectivel y, for maximal performance. The level of total lysine of 1.04% or 0,93% of digestible lysine proportioned the best protein deposition rate.

Digestible methionine plus cystine to digestible lysine ratio in diets supplemented with ractopamine for finishing pigs

The experiment was carried out to determine digestible methionine + cystine: digestible lysine (Met + Cys/Lys) ratio for barrows selected for deposition of lean meat in the carcass supplemented with ractopamine (RAC) in the finishing phase. Sixty-four barrows with 84.68 ± 1.34 kg BW was allotted to an experimental randomized block design, fed diets containing four Met + Cys/Lys ratio (0.54, 0.58, 0.62 and 0.66) supplemented with ractopamine, eight replications, during a period of 28 days. Met + Cys/Lys did not affect feed intake, average daily gain, feed conversion, fat thickness, lean meat amount, carcass weight, lean meat percentage and carcass yield of pigs. Met + Cys/Lys ratio influence quadraticaly the concentrations of total cholesterol in the loin and linearly the cholesterol concentrations in the subcutaneous fat. The lowest levels of total cholesterol were observed in pigs fed diet with 0.66 Met + Cys/Lys ratio. In pigs from 85 to 109 kg supplemented with ractopamine, the 0.54 Met + Cys/Lys ratio meets the requirement for better performance and better carcass traits, while to lower the cholesterol levels in the loin and subcutaneous fat the requirement is 0.66 Met + Cys/Lys ratio.