Nikolas de Oliveira Amaral

Características da carcaça e viabilidade econômica do uso de cloridrato de ractopamina para suínos em terminação com alimentação à vontade ou restrita

The objective of this research was to evaluate the supplementation of 5ppm of ractopamine (RAC), associated or not with feed restriction, on carcass characteristics on finishing pigs and the economic viability of its use. Thirty hybrid barrows (life weight of 107.2±6.2kg), receiving the experimental diets during 28 days before the slaughter. A randomized blocks design in factorial scheme 2 x 2 + 1 (with or without RAC in diets with 1.04% of total lysine; ad libitum or feed restriction of 15% and an additional treatment - control - ad libitum, without RAC containing 0.8% of lysine - standard diet), totalizing five treatments and six replicates. The addiction of RAC per se increased the loin eye area, the meat percentage, the carcass meat:fat ratio, the allowance index, the gross earnings and the production net earnings and decreased the animals backfat thickness. When associated with feed restriction, the RAC decreased the carcass fat percentage. Compared to standard diet, the RAC increased the carcass yield, the carcass meat percentage and the allowance index paid to the producer and decreased the backfat thickness. The RAC associated at the feed restriction decreased the fat carcass percentage and increased the carcass meat:fat ratio and the gross earnings. Thus, the supplementation with 5ppm of RAC, associated or no at the feed restriction, improves the carcass characteristics and the economic viability of production.

Ractopamine hydrochloride in formulated rations for barrows or gilts from 94 to 130 kg

Foi realizado um experimento com o objetivo de avaliar o desempenho, a composicao de carcaca e a viabilidade economica do uso de 5 e 10 ppm de cloridrato de ractopamina (RAC) em racoes formuladas para suinos machos castrados ou para femeas dos 94 aos 130 kg. Utilizaram-se 60 suinos, distribuidos em delineamento de blocos ao acaso, em arranjo fatorial 3 × 2, composto de tres niveis de ractopamina e dois sexos. Nao houve interacao significativa entre a ractopamina e o sexo para as variaveis analisadas. Observou-se, nos animais que receberam ractopamina, maior peso final, ganho de peso medio diario e conversao alimentar. As femeas apresentaram menor peso final, consumo medio diario de racao e conversao alimentar. Para rendimento de carcaca, area de olho-de-lombo e rendimento de carne na carcaca, o nivel de 10 ppm foi superior ao controle. A ractopamina, independentemente do nivel utilizado, reduziu a espessura de toucinho e melhorou o rendimento de filezinho, pernil e carne no pernil. As femeas apresentaram maior rendimento de carne na carcaca, menor espessura de toucinho, maior flexibilidade da barriga e menor espessura de toucinho da barriga. As carcacas de suinos sob suplementacao com ractopamina apresentaram melhor indice de bonificacao, receita bruta e receita liquida. Houve reducao no custo total e aumento no indice de bonificacao das carcacas das femeas, o que melhorou a receita liquida. Dessa forma, a suplementacao com 5 ppm de ractopamina e suficiente para melhorar o desempenho, a composicao de carcaca e o rendimento de cortes da carcaca de suinos machos castrados e femeas. Alem disso, a suplementacao com 5 ou 10 ppm de ractopamina, nas condicoes estudadas, e economicamente viavel, e o abate de femeas aos 130 kg, mais rentavel que o de machos castrados.

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.

Probiotics and antibiotics as additives for sows and piglets during nursery phase

O objetivo neste trabalho foi avaliar os efeitos do uso de probioticos em dietas para matrizes e leitoes, sobre o desempenho, os parâmetros morfofisiologicos e a indicencia de diarreia nos leitoes durante 28 dias apos o desmame. Foram utilizados 120 leitoes desmamados aos 21 dias, provenientes de 24 leitegadas cujas matrizes (primiparas) receberam probioticos ou antibioticos a partir do 94o dia de gestacao ate o desmame. Foi utilizado um delineamento inteiramente casualizado em esquema fatorial 2 × 3 (probioticos ou antibioticos para matrizes e tres dietas para leitoes - antibioticos, probioticos ou associacao antibiotico-probiotico) com quatro repeticoes de cinco animais para avaliacao do desempenho e da incidencia de diarreia. Aos 28 dias de experimento, dois animais de cada parcela foram sacrificados para mensuracao de parâmetros histologicos do jejuno e pH do estomago e ceco. A associacao probioticos + antibioticos na dieta dos leitoes resultou em maior ganho de peso e consumo de racao nos animais filhos das matrizes que receberam probioticos durante as fases de gestacao e lactacao. Quando as femeas receberam antibioticos, os leitoes que receberam apenas probioticos apresentaram maior consumo, porem nao foram observadas diferencas na conversao alimentar. O uso de antibioticos + probioticos na dieta de leitoes reduziu o pH do ceco e, quando associado ao uso de probioticos para matrizes, aumentou a relacao vilosidade:cripta do jejuno. O uso de promotores de crescimento nao influenciou o pH estomacal nem a incidencia de diarreia. O fornecimento de probioticos na dieta das matrizes durante as fases de gestacao e lactacao em assossiacao ao uso na dieta dos leitoes apos o desmame e eficaz em manter o desempenho dos animais, as condicoes histofisiologicas do trato gastrintestinal e o controle de diarreia durante a fase de creche.

Corporal composition of swine feed fron 10 to 20 kg with diet containing different levels of lysine and crude protein.

Objetivou-se verificar o efeito dos niveis de lisina digestivel verdadeira (LDV) e proteina bruta (PB) nas racoes sobre a composicao de carcaca de suinos na fase inicial. Foram utilizados 80 suinos Landrace x Large White, machos castrados e femeas, com peso inicial de 9,1±1,2 kg e final de 21,5±4,8 kg, desmamados aos 28 dias, alojados em grupos de dois, durante 35 dias na creche. Foi utilizado um delineamento em blocos casualizados em esquema fatorial 2x4 (dois niveis de PB - 16 e 18% e quatro de LDV - 0,7; 0,9; 1,1 e 1,3%) com cinco repeticoes. Apos a pesagem, um animal de cada baia foi abatido e as carcacas utilizadas para determinacao da porcentagem de agua (%A), proteina (%P) e lipidios (%L) e taxa de deposicao de proteina (TDP) e lipidios (TDL). Nao houve diferencas para %A na carcaca. Houve efeito quadratico dos niveis de lisina na %P e TDP na carcaca apenas em racoes com 18% PB, sendo 1,02% de LDV o nivel que proporcionou melhor resultado. Nao houve diferenca em racoes com 16% PB. Para %L, nao houve diferenca quando 18% PB foi utilizado, porem houve efeito quadratico com 16% PB, sendo 0,99% o nivel de LDV que proporcionou a maior deposicao. Para TDL, os niveis de 1,08 e 1,00% de LDV resultaram em maiores valores em racoes com 18 e 16% PB, respectivamente. Conclui-se que 18% PB na racao e o ideal e que 1,02% de LDV deve ser mantido para uma melhor composicao de carcaca de suinos na fase inicial.

Ractopamine in diets for finishing pigs of different sexual categories

Performance and carcass and cut yield of finishing pigs of three sexual categories fed diets with different levels of ractopamine were studied. Forty-eight hybrid animals (initial weight of 92.1±2.4 kg) were distributed in a completely randomised design in 3 × 2 factorial arrangement (three sexual categories: surgically castrated males, two females and immunologically castrated males - with or without 10 ppm of ractopamine), totalling six treatments and eight repetitions with one animal per experimental plot during 28 days. Ractopamine improved weight gain and feed conversion of all sexual categories. The best results were obtained with immunologically castrated males, which, in turn, had lower carcass yield and backfat thickness in the belly. In the absence of ractopamine, depth and loin eye area were higher in females but no differences in these variables were observed between categories when this additive was used. Ractopamine increased the sirloin yield in all sexual categories. There was no difference in bonus index. Ractopamine improves the performance of pigs of 92 to 125 kg. Immunologically castrated males have the best performance responses to ractopamine, but with losses in carcass yield, loin characteristics and backfat thickness of the belly.

Nutrient reduction in rations with phytase for growing pigs

Two experiments were conducted to evaluate the performance, the energy and nutrient balance and economic viability of production of growing pigs fed diets with reduced levels and phytase. In experiment 1, 60 barrows and gilts (initial weight 25 ± 1.72 kg) were housed in a randomized block design with three diets, ten replicates and two animals per experimental unit (one male and one female). One of the diets was formulated with a reduced level with phytase and evaluated in comparison to a positive-control diet that was formulated according to the nutritional recommendations for animals of this breed, and a negative-control diet without phytase. The different diets did not affect feed intake, but the diet with phytase promoted better final weight, daily weight gain and feed conversion, although it did not differ from the positive control diet. In experiment 2, 27 barrows (initial weight 49 ± 3.67 kg) were housed in random blocks with three diets and nine replicates with experimental plot represented by one animal. The diets did not affect the balance of energy and nutrients but had a significant effect on the efficiency of utilization of calcium and phosphorus, which was the lowest in animals that received the positive-control diet. Economic viability improved when nutrients were reduced and phytase was added in the ration. The addition of phytase (500 ftu/kg) in rations formulated with nutritional levels reduced for growing swines improves rearing productivity and it is economical viable.

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.

Evaluation of different corn textures in dry grain or silage forms for piglets from 7 to 15 kg

Objetivou-se com este estudo avaliar os efeitos do tipo de milho (duro e dentado) e da forma de armazenamento (graos secos ou silagem de graos umidos) no valor nutricional das racoes e no desempenho de leitoes dos 7 aos 15 kg. No ensaio de digestibilidade, utilizaram-se 24 leitoes machos castrados (peso inicial de 18,7 ± 1,5 kg), mesticos Landrace X Large White, mantidos em gaiolas de metabolismo em delineamento de blocos casualisados em esquema fatorial 2 X 2, com seis repeticoes, considerando um animal por parcela experimental. Os valores de energia metabolizavel (EM) obtidos foram: 3.841 kcal de EM/kg de materia seca (MS) para o milho seco; 3.912 kcal de EM/kg de MS para o milho umido; 4.022 kcal de EM/kg de MS para o milho ensilado seco; e 3.928 kcal de EM/kg de MS para o milho ensilado umido. O processo de ensilagem do milho melhorou os coeficientes de digestibilidade da materia seca e da proteina bruta e a energia digestivel das racoes, independentemente da forma de armazenamento, ao passo que os tipos de milho nao influenciaram essas variaveis. No ensaio de desempenho, foram utilizados 60 leitoes (peso inicial de 7,3 ± 1,2 kg) machos castrados, tambem mesticos Landrace X Large White, mantidos durante 28 dias na creche, em mesmo delineamento, porem com cinco repeticoes e tres animais por unidade experimental. O tipo de milho e a forma de armazenamento nao influenciaram o ganho de peso e o consumo de racao. O milho dentado e o processo de ensilagem melhoraram a conversao alimentar de forma independente (interacao nao-significativa). A substituicao do milho seco pela silagem de graos umidos melhora a digestibilidade dos nutrientes das racoes e a conversao alimentar de leitoes dos 7 aos 15 kg; alem disso, o milho dentado promove melhor conversao alimentar nesse periodo.

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.