Abstract This work aims to evaluate the application of ultrasound and marinate with extract of acerola (Malpighia emarginata) residue on the tenderness and lipid oxidation of the meat pork. Samples of loin (Longissimus dorsi) containing approximately 90 g, 10 cm long, 5 cm wide, and 2 cm high were extracted from the pig carcass. The samples were coded and randomly allocated under a factorial scheme 2 (with and without antioxidant extract) x 3 (ultrasonic bath times 0, 5, and 10 minutes); each treatment had four replicates. The final extract volume was adjusted with distilled water, ensuring 200 mg of gallic acid equivalents per kilo of meat. Then, the samples were placed in the ultrasonic bath at a fixed frequency of 170 W, 35 kHz. During the ultrasound application, the bath temperature was maintained at 10 °C with ice/ice water addition when necessary. The acerola´s extract showed a significant effect (P < 0.05) on the meat Cohesiveness and to a lesser extent before rupture. With the modification of the microstructure in the meat, there was a decrease in elasticity. The application of ultrasound to meat (170 W, 35 kHz) in times (5 and 10 minutes) combined with the marinating in a natural antioxidant acerolas residue extract improves the meat's quality characteristics, decreasing the hardness and chewiness.

Abstract This study's objective was to evaluate the physical-chemical, microbiological, and sensory aspects of pork meat with different levels of salting. Pork from the Duroc and Landrace breeds, with an average live weight of 281 ± 15.72 kg, were used. The physicochemical data were analyzed following a completely randomized design with four salt addition levels (30, 50, 70, and 90%). Sensory analysis was performed through a completely randomized design, observing the influence of salt levels in meat. The physical-chemical and sensory variables did not significantly affect (P>0.05) salt addition, except for cooking loss and water retention capacity. It was concluded that the salt introduction levels of 30 and 50% are the most appreciated by consumers. The addition of salt levels in the pork meat does not modify the physical-chemical characteristics and the meat's sensory analysis.

Abstract To evaluate the use of different lipid sources in diets of growing rabbits, 60 New Zealand White rabbits were evaluated on performance, carcass traits, meat composition, fatty acid profile and oxidative stability of refrigerated and frozen meat. The experiment was distributed in a randomized block design, in five treatments, with six replicates and two animals per experimental unit (one male and one female). The treatments consisted of five isonutritive diets, with 2.5% soybean oil (SO), sunflower oil (SFO), cottonseed oil (CO), beef tallow (BT) and poultry fat (PF). There was no effect (P > 0.05) of dietary lipid sources on animal performance, carcass traits and meat composition (P > 0.05). Dietary inclusion of beef tallow resulted in a lower proportion of polyunsaturated fatty acids in meat compared to vegetable oils. The values of thiobarbituric acid-reactive substances (TBARS) indicated higher oxidation in the frozen meat of the animals fed with sunflower oil, cottonseed oil and bovine tallow in their diets. In conclusion, vegetable oils and animal fats can be included in growing rabbit diets without impair performance and meat quality parameters. Dietary inclusion of soybean oil is more advantageous because it promotes the incorporation of polyunsaturated fatty acids and greater lipid stability of refrigerated and frozen rabbit meat.

Avaliou-se o efeito da substituição parcial do milho por sorgo granífero na dieta de suínos castrados sobre as características de desempenho, carcaça e avaliação econômica. Foram utilizados 27 machos híbridos, oriundos de linhagem comercial, com 19,66 ± 2,92kg de peso inicial, distribuídos em três tratamentos com porcentagens crescentes de sorgo granífero - 0%, 25% e 50% - em substituição ao milho, em um delineamento inteiramente casualizado. Foram avaliados: ganho diário de peso, consumo diário de ração, conversão alimentar, espessura de toucinho e parâmetros bioquímicos sanguíneos - ureia, proteínas totais, creatinina, glicose, triglicerídeos e colesterol. Para as características de carcaça foram avaliados: peso nas carcaças quente e fria, rendimento nas carcaças quente e fria, pH e temperatura nas carcaças quente e fria e peso de cortes industriais. Para o desempenho econômico foi calculado o custo da ração, custo do kg suíno e índices de custo médio e de eficiência econômica. Foi utilizada análise de regressão para as variáveis produtivas. Não foram encontrados efeitos para o desempenho e características de carcaça. Nas variáveis bioquímicas, foram encontrados efeitos lineares para a ureia e proteínas totais, com os animais com 0% de sorgo apresentando os maiores valores. Quanto ao desempenho econômico, o grupo com 50% de sorgo apresentou o menor índice de custo e o maior de eficiência econômica. Dessa forma, conclui-se que a substituição do milho pelo sorgo granífero em níveis de até 50% da dieta representa uma alternativa sustentável na suinocultura regional.

The study evaluated the effect of partial substitution of corn by sorghum in diet of castrated pigs and the effects on performance, carcass traits and economic feasibility. It were used 27 crossbred barrows from commercial line with 19.66 ± 2,92kg of initial live weight, divided in three groups with increasing rates of sorghum - 0%, 25% and 50% - replacing corn, distributed in a completely randomized design. The trial evaluated: daily weight gain, daily feed intake and feed:gain ratio, backfat thickness and blood biochemical parameters - urea, total proteins, creatinine, glucose, triglycerides and cholesterol. For carcass traits it was evaluated: hot and cold carcass weight, hot and cold carcass yield, pH and temperature in hot and cold carcasses and industrial weight cuts. For economy feasibility was calculated the cost of feed consumed, cost of pig kg, average cost index and economy efficiency rate. It was used regression analysis to evaluate the productive variables. No effects were found for performance data and carcass traits. For the biochemical variables, the effects were linear for urea and total protein, with animals in control group (0% of sorghum) showing higher rates. The bioeconomical performance showed that 50% sorghum had the lowest cost and the highest rate of economic efficiency. Thus, it was concluded that substitution of corn by sorghum at levels up to 50% of the diet represents an alternative to sustainability of regional swine production.

The objective of this study was to evaluate the physicochemical and microbiological parameters of pork meat submitted to dry salting. Sodium chloride (NaCl) was added at levels of 0%, 2.5%, 5%, 7.5% or 10% by the meat weight. Dry salting technique was used, which consists of rubbing the sodium chloride manually, followed by a rest period. The data were submitted to analysis of variance using a completely randomized experimental design. The means were compared by Duncan test at 5%. The salting process reduced (P < 0.05) humidity and water activity, and it increased (P < 0.05) ash, chloride, palmitic acid, and water holding capacity levels compared to those of the control. Luminosity (L*) was lower (P < 0.05) in the control, and a* color was more intense in samples with 2.5% NaCl. Cooking loss was lower (P < 0.05) in the samples salted with 5% and 10% NaCl, and similarity was observed between the levels 0 and 7.5% salt. The treatments with levels 0% and 2.5% NaCl had higher mesophilic counts. The other microbiological parameters were within limits established by law. Therefore, salting with 5% NaCl can be used in pork meat in order to maintain the physicochemical and microbiological characteristics of the final product.

Objetivou-se avaliar o desempenho de suínos na fase inicial e de crescimento alimentados com diferentes tipos de óleos essenciais de plantas adaptadas ao semiárido Nordestino. Foram utilizados 40 suínos da linhagem comercial Agroceres®, (20 machos castrados e 20 fêmeas) com peso vivo médio inicial de 13,5 ± 3kg, distribuídos em um delineamento em blocos casualizados, com cinco tratamentos e quatro repetições. Os tratamentos consistiram na ração controle e outras quatro rações que continham 0,01% de óleos essenciais de erva-doce, marmeleiro, alfavaca e erva-cidreira. As variáveis avaliadas foram: desempenho, incidência de diarréia e perfil microbiológico. Não houve efeito da adição dos óleos essenciais para as variáveis de consumo de ração, ganho de peso, conversão alimentar e contagem de bactérias para os animais na fase inicial, apresentando influência da adição dos óleos para consumo de ração, conversão alimentar na fase de crescimento I e para consumo de ração na fase total. Os óleos essenciais de marmeleiro, erva-cidreira e alfavaca apresentaram um efeito positivo no controle da diarréia. Concluiuse que os óleos essenciais de marmeleiro, erva-cidreira e alfavaca, podem ser utilizados como antimicrobiano para combater a diarréia dos leitões, sem acarretar prejuízo no desempenho.

The objective was to evaluate the performance of starter pigs and growth fed with different types of essential oils from plants adapted to semiarid Northeast. A total of 40 pigs from commercial line Agroceres ®, (20 castrated males and 20 females) with average weight of 13.5 ± 3kg, distributed in a randomized block design with five treatments and four replicates, the treatments in the control diet and four diets containing diets 0.01% essential oils of fennel, quince, lemon grass and basil. The variables were: performance, incidence of diarrhea and microbiological perfil. No effect of addition of essential oils for the variables feed intake, weight gain, feed conversion and bacteria count for the animals in the initial stage, showing the influence of the addition of oil for feed intake, feed conversion during the growth phase I and phase feed intake in total. The essential oils of quince, lemon grass and basil had a positive effect on control of diarrhea. It was concluded that the essential oils of quince, lemon grass and basil, can be used as an antimicrobial agent to combat diarrhea of piglets without causing performance losses.

Dois experimentos foram realizados para determinar o valor nutricional do ovo desidratado (OD), o efeito do tempo de jejum pós-eclosão (TJPe) e a inclusão do ovo desidratado em rações para frangos de corte. No primeiro experimento, 120 pintos de corte machos, linhagem Ross-308, foram alojados em delineamento inteiramente casualizado, com três tratamentos e cinco repetições de oito aves. As coletas de excretas foram realizadas no período de 24 a 29 dias de idade, pela manhã e à tarde. No segundo experimento, um lote misto de 810 pintos da linhagem Cobb-500, com peso vivo inicial 33,41 ± 0,53, foi alojado em boxes de 1,0 × 1,5 m. O delineamento experimental utilizado foi o inteiramente casualizado com 9 tratamentos e 6 repetições de 15 aves, em esquema fatorial 3 × 3, com três níveis de ovo desdratado (0, 2 e 4%) e três tempos de jejum pós-eclosão (28, 40 e 52 horas), correpondentes a 0, 12 e 24 horas de jejum pós-alojamento, respectivamente. O ovo desidratado apresentou 51,54% de PB e 4.278 kcal EMAn. Na fase de 1 a 7 dias, o peso vivo, o ganho de peso e o consumo de ração entre as aves submetidas a jejum de 40 e 52 horas foram inferiores aos daquelas alimentadas mais cedo (às 28 horas do tempo de jejum pós-eclosão), enquanto as aves submetidas a 52 horas de jejum pós-eclosão (24 horas de jejum pós alojamento) apresentaram os piores resultados. O nível de 4% de ovo desidratado na ração pré-inicial melhorou o peso vivo no segundo e terceiro dia de idade dos pintinhos. No período de 1 a 21 dias, o ovo desidratado pode ser utlizado na alimentação de frangos, pois não prejudica o desempenho das aves.

Two experiments were carried out to determine the nutritional value of the dried egg (DEGG), and the effect of the post-starvation hatching time (PSHT) and the inclusion of dried egg powder in the diet of broiler chicks. In experiment 1, 120 male Ross-308 broiler chicks were housed according to a completely randomized design into three treatments and five repetitions of eight birds each. Excreta collection was daily performed from 24 to 29 days of age in the morning and afternoon. In experiment 2, a sex-mixed batch of 810 Cobb-500 chicks was used. Initial weight was 33.41 ± 0.53 g, and the chicks were housed in pens measuring 1.0 × 1.5 m. A completely randomized experimental design was used with nine treatments and six repetitions of 15 birds each, according to a 3 × 3 factorial of three DEGG levels (0, 2 and 4%) and three PSHT (28, 40 and 52 hours), corresponding to: 0, 12 and 24 hours of starvation after housing, respectively. DEGG showed 51.54% of CP and 4,278 kcal AMEn/kg. From 1 to 7 days of age, the birds submitted to starvation for 40 and 52 hours showed lower live weight, weight gain and feed intake when compared to birds fed sooner (at 28 hours PSHT). The poorest performance was shown by birds fasted for 52 hours (24 hours of starvation after being housed). DEGG levels of 4% in the pre-initial diet improved the live weight in the second and third days of age. In conclusion, DEGG might be used from 1 to 21 days of age in broiler diets without impairing the bird performance.

Dois experimentos foram realizados para investigar a relação cálcio (Ca):fósforo disponível (Pd) e o nível de fitase (UF) no primeiro e segundo ciclos de postura. No primeiro ciclo de postura, 128 aves foram distribuídas em arranjo fatorial 3 × 2 + 1, composto de três relações Ca:Pd (14:1 = 4,2% Ca e 0,30% Pd; 12:1 = 3,5% Ca e 0,30% Pd; e 9:1 = 3,5% Ca e 0,38% Pd), dois níveis de fitase (0 e 600 UF) e uma relação Ca:Pd controle (11:1 - 4,2% Ca e 0,38% Pd). No segundo ciclo de postura, 240 aves foram distribuídas em arranjo fatorial 2 × 2 × 2, composto de dois níveis de cálcio (3,5 e 4,2%), dois de fósforo disponível (0,30 e 0,38%) e dois de fitase (0 e 600 UF). No primeiro ciclo, entre as aves alimentadas com as rações sem fitase, o maior peso dos ovos (PO) foi obtido com a relação 9:1 (3,5% Ca e 0,38% Pd) e o menor, com a relação 12:1 (3,5% Ca e 0,30% Pd). A melhor massa de ovos (MO) e conversão alimentar por massa de ovos (CAMO) foram observadas nas aves alimentadas com a ração com relação Ca:Pd 14:1 e a pior, com a ração formulada com relação 12:1. Nas aves alimentadas com a ração com fitase, a melhor conversão alimentar por massa de ovos foi obtida com a relação 12:1 (3,5% Ca e 0,30% Pd) e a pior, com a relação 9:1 (3,5% Ca e 0,38% Pd). No segundo ciclo, o consumo de ração (CR) reduziu com o aumento dos níveis de cálcio (3,5 para 4,2%), fósforo disponível (0,30 para 0,38%) e fitase (0 para 600). As conversões alimentares por massa de ovos e por dúzia de ovos melhoraram, respectivamente, com o aumento dos níveis de fósforo disponível e de fitase, enquanto a gravidade específica melhorou com o aumento do nível de cálcio da ração. Para poedeiras no primeiro ciclo de postura, recomendam-se as relações 14:1 (4,2% Ca:0,30% Pd) sem fitase e 12:1 (3,5% Ca:0,30% Pd) com 600 UF e, para aves no segundo ciclo de postura, recomenda-se relação correspondente a 4,2% Ca e 0,38% Pd. A suplementação de rações deficientes em fósforo disponível com 600 UF melhora o peso dos ovos no segundo ciclo de postura.

Two experiments were carried out to investigate the calcium (Ca):available phosphorus (aP) ratio and the level of phytase in the first and second posture cycle. In the first posture cycle, 128 birds were distributed to a 3 × 2 + 1 factorial arrangement, composed of three Ca:aP ratio [14:1 (4.2% Ca and 0.30% aP), 12:1 (3.5% Ca and 0.30% aP), and 9:1 (3.5% Ca and 0.38% aP)], two levels of phytase (0 and 600 Phytase Units - PU) and a Ca:aP control [11:1 (4.2% Ca and 0.38% aP)]. In the second posture cycle, 240 birds were distributed to a 2 × 2 × 2 factorial arrangement, composed of two Ca (3.5 and 4.2%), two aP (0.30 and 0.38%) levels and two phytase levels (0 and 600 PU). In the first posture cycle, among birds fed diets without phytase, the greater eggs weight was obtained with 9:1 Ca:aP ratio and the smaller, with 12:1 Ca:aP ratio. The best eggs mass and feed conversion by eggs mass (FCEM) were observed in birds fed a diet with 14:1 Ca:Pd ratio and worse, with the ration with 12:1 Ca:aP ratio. In birds fed diet with phytase, the best FCEM was obtained with 12:1 Ca:aP ratio and worse, with 9:1 Ca:aP ratio. In the second posture cycle, the diet consumption decreased with increasing levels of calcium (3.5 to 4.2%), available phosphorus (0.30 to 0.38%) and phytase (0 to 600 PU). Feed conversion by eggs mass or per dozen eggs improved, respectively, with increasing levels of available phosphorus and phytase, while specific gravity improved with the increase of dietary calcium level. For laying hens in the first posture cycle, it is recommended 14:1 (4.2% Ca:0.30% Pd) ratio without phytase and 12:1 (3.5% Ca:0.30% Pd) ratio with 600 PU and, for birds in the second posture cycle, it is recommended 14:1 (4.2% Ca and 0.38% Pd) ratio. The supplementation of diets deficient in available phosphorus with 600 PU improves egg weight in the second posture cycle.

Dois experimentos foram realizados para estimar as exigências de sódio para poedeiras semipesadas no final do primeiro e durante o segundo ciclo de postura. O delineamento experimental foi o inteiramente casualizado, com sete níveis de sódio (0,08; 0,13; 0,18; 0,23; 0,28; 0,33 e 0,38%), cada um com seis repetições de seis aves no final do primeiro ciclo de postura e cinco repetições de seis aves no segundo ciclo de postura. No final do primeiro ciclo, não houve efeito dos níveis de sódio sobre o consumo de ração (CR), o peso dos ovos (PO), a conversão por dúzia de ovos (CDZ) e a gravidade específica (GE), mas a produção de ovos (PR), a massa de ovos (MO) e a conversão por massa de ovos (CMO) foram afetadas de forma quadrática. As exigências de sódio foram estimadas em 0,21; 0,22 e 0,21%, respectivamente. No segundo ciclo, os níveis de sódio não tiveram efeito sobre o peso e a gravidade específica dos ovos, entretanto, influenciaram de forma quadrática a PR, MO, CMO e CDZ. Nesse ciclo, as exigências de sódio foram estimadas em 0,20; 0,19; 0,18 e 0,19%, respectivamente. Considerando as estimativas de exigências de sódio pela produção de ovos e pela conversão por massa de ovos, sugerem-se 0,22 e 0,20% como níveis máximos de sódio, respectivamente, para o final do primeiro ciclo e para o segundo ciclo de postura.

Two experiments were carried out to estimate sodium requirements for brown-eggs laying hens in the late first and during second egg-production cycle. A completely randomized design was used, with seven sodium levels (0.08, 0.13, 0.18, 0.23, 0.28, 0.33 and 0.38%), six replications of six birds in the late first egg-production cycle and five replications of six birds in the second egg-production cycle. In the late first egg-production cycle, sodium levels (SL) had no effect on feed intake (FI), egg weight (EW), egg dozen feed conversion (EDC) and egg-shell specific gravity (SG). The SL showed quadratic effect on egg production (EP), egg mass (EM) and egg mass feed conversion (EMC), that resulting in sodium requirements (SR) of 0.21, 0.22 and 0.21%, respectively. In the second egg-production cycle, SL had no effect on EW and SG. However, EP, EM, EMC and EDC improved when the levels of sodium were 0.20, 0.19, 0.18 and 0.19%, respectively. Considering the estimates of sodium requirements to egg production and egg mass feed conversion, could be suggests 0.22% e 0.20% as maximum sodium levels, respectively, to late first and second egg-production cycle.

Objetivou-se avaliar a adaptabilidade fisiológica de 73 matrizes suínas híbridas em lactação ao ambiente quente. As fêmeas foram distribuídas em delineamento inteiramente casualizado, num esquema fatorial de 5 x 4 x 4, sendo, cinco ordens de parto - OP (1ª, 2ª, 3ª, 4ª e 5ª), quatro momentos em relação ao parto (quatro dias antes e 3, 10 e 17º dia depois) e quatro horas do dia (8, 12, 16 e 20 h). A temperatura retal (TR) oscilou com a hora do dia, a OP, e o momento de avaliação, sendo maior às 16 h, em primíparas e na fase inicial da lactação. A freqüência respiratória permaneceu elevada, principalmente entre as 12 e 16 h do dia em fêmeas jovens. Conclui-se que o calor intenso entre 12 e 16 h conduz aos animais ao desconforto térmico, sendo as primíparas a categoria de menor adaptabilidade.

The aim was to assess the physiological adaptability of 73 hybrid female swine in lactation in the hot climate. The females of 1st, 2nd, 3rd, 4th, and 5th parturition orders (PO) were used, distributed in a completely randomized outline, in a factorial arrangement of 5 x 4 x 4, being five PO (1st, 2nd, 3rd, 4th, and 5th), four moments in relation to the delivery (four days before, and on the 3rd, 10th and 17th day after), and four hours a day (8, 12, 16 and 20 h). The rectal temperature oscillated according to the hour of day, the PO, and the moment of evaluation, being greater at 16 h, in primiparous, and in the initial phase of lactation. The breathing frequency remained elevated, mainly between 12 and 16 h, in young females. One concluded that the intense heat between 12 and 16 h leads the animals to the thermal discomfort, mainly the category of smaller adaptability.

Foram avaliados os efeitos da ordem de parto e do estágio de lactação sobre a produção e composição do leite de matrizes suínas híbridas mantidas em ambiente quente (± 28,5°C). Foram utilizadas 36 fêmeas de 1, 2, 3 e <FONT FACE=Symbol>³</FONT>4a ordem de parição, avaliadas em quatro estágios (equalização, 7, 14 e 22,3° dias de lactação). A ordem de parto influenciou (P<0,05) a estimativa de energia e produção do leite e o ganho em peso dos leitões entre as porcas de 1° e 3° partos, não havendo diferença (P<0,05) entre as demais ordens de parição. A composição do leite não foi influenciada (P<0,05) pela ordem de parto. O estágio de lactação influenciou (P<0,05) a produção e a composição do leite das porcas, não havendo diferenças (P>0,05) para a estimativa da energia do leite e o ganho em peso dos leitões. Matrizes suínas mantidas em ambiente quente têm a produção e a composição química do leite modificadas de acordo com o estágio de lactação. A produção de leite varia de acordo com a ordem do parto, tendo as primíparas uma produção de leite menor do que as porcas de 3a parição.

Effects of parity order and stage of lactation were evaluated on production and milk composition of hybrid female pigs in a hot environment (±28.5°C). Thirty-six females of 1st, 2nd, 3rd and <FONT FACE=Symbol>³</FONT>4th parity order were used and evaluated on four stages (equalization of the litter, 7, 14 and 22.3 days of lactation). Parity order influenced (P<0.05) the estimation of energy, milk production and weight gain of piglets between sows of first and third parturition, but there wasn't a difference (P<0.05) among the other ones. Parity order did influence (P<0.05) the composition of milk. The stage of lactation influenced (P<0.05) the production and composition of milk of the sows, however, there were no differences (P<0.05) for the estimate of milk energy and the weight gain of the piglets. It was concluded that female pigs maintained in hot environment had the production and chemical composition of milk modified according to the stage of lactation, while the variation of milk production was according to parity order, being the milk production of primiparous smaller than the third parity sows.

O experimento foi realizado com a finalidade de determinar as exigências nutricionais de metionina+cistina (M+C) de poedeiras semipesadas. Foram utilizadas 360 aves distribuídas em delineamento inteiramente casualizado, com cinco tratamentos e 12 repetições de seis aves. As rações experimentais com 17,2% PB (isoprotéicas) e 2.800 kcal EM/kg (isocalóricas) foram formuladas à base de milho e farelo de soja para atender às exigências de todos os nutrientes, exceto M+C, sendo suplementadas com DL-metionina (99%) em substituição ao amido de milho para proporcionar cinco níveis (0,61; 0,68; 0,75; 0,82 e 0,89%) de M+C total. As características de desempenho foram avaliadas no período de 20 a 44 semanas de idade das aves. Os níveis de M+C afetaram o desempenho das aves, com efeito quadrático sobre o peso dos ovos, a massa de ovos e a conversão por massa de ovos. As estimativas encontradas foram de 0,73; 0,69 e 0,69% de M+C total ou 0,66; 0,63 e 0,63% de M+C digestível respectivamente. Portanto, recomenda-se 0,70 e 0,64%, ou consumo de 762 e 697 mg, respectivamente, de M+C total e digestível/ave/dia para poedeiras semipesadas do início de produção até o pico de postura.

A trial was carried out to determine the nutritional requeriments of methionine + cystine (M+C). A total of 360 laying hens was allotted to a completely randomized design with five treatments and 12 replicates of six birds. The corn-soybean meal based diets were formulated to be isonitrogenous (17.2% CP) and isoenergy (2,800 kcal ME/kg) to meet the bird requeriment in all nutrients, except for M+C, that was supplemented with DL-methionine (99%) in replacement with corn starch. The following total M+C levels were obtained: 0.61, 0.68, 0.75, 0.82, and 0.89%. All variables were evaluated from 20 to 44 weeks old. Egg weight, egg mass and egg mass:feed ratio were all affected quadratically by the M+C levels. The estimates obtained were: 0.73, 0.69, and 0.69% of total lysine and 0.66, 0.63, and 0.63% of digestible M+C, respectively. Therefore, it is recommended levels of 0.70 and 0.64% or intake of 762 and 697 mg total and digestible M+C/bird/day, respectively, for semi-heavy laying hens from the starter to peak of egg production.

O experimento foi realizado com o objetivo de avaliar o efeito da redução da PB e da suplementação de rações com aminoácidos industriais sobre o desempenho de poedeiras. Duzentas e setenta poedeiras Lohmann LSL com 26 semanas de idade foram alojadas em densidade de 562 cm²/ave e distribuídas em delineamento inteiramente ao acaso. Foram avaliados os seguintes tratamentos: T1 = dieta controle (DC) com 16,5% PB, 0,80% de lisina (L) e 0,70% de metionina+cistina (MC); T2 = 15,25% PB, 0,73% de L e 0,64% de MC; T3= 14%PB, 0,66% de L e 0,58% de MC; T4 = 15,25% PB com 0,80% de L e 0,64% de MC; T5 = 14% PB com 0,80% de L e 0,58% de MC; T6 = 15,25% PB com 0,73% de L e 0,70% de MC; T7 = 14% PB com 0,66% de L e 0,70 de MC; T8 = 15,25% PB com 0,80% de L e 0,70 de MC; e T9 = 14% PB com 0,80% de L e 0,70% de MC. Cada tratamento foi constituído de cinco repetições de seis aves. As rações continham 2.800 kcal de EM. As suplementações aminoacídicas com 15,25 e 14,00% PB foram realizadas para proporcionar níveis de L, MC ou L+MC semelhantes aos da dieta controle. As aves foram alimentadas com 110 g de ração/dia, receberam água à vontade e foram submetidas a um programa de luz de 17 horas por dia. As características de desempenho foram avaliadas em quatro períodos de 28 dias. A redução da proteína da ração de 16,5 para 14% não alterou o desempenho das aves, mas a suplementação com lisina nas dietas com baixo teor de proteína diminuiu a produção e a massa de ovos e as conversões por massa e por dúzia de ovos em relação à dieta controle.

The effect of decreasing dietary CP and supplementation of lysine and methionine+cystine on the performance of 270 laying hens Lohmann LSL strain was evaluated in this trial. The birds averaging 26 weeks of age were allotted to a stocking rate of 562 cm²/bird as a completely randomized design with five replicate of six birds. The treatments were as follows: T1 = control diet (CD) with 16.5% CP, 0.80% of lysine (L) and 0.70% of methionine+cystine (MC); T2 = 15.25% CP, 0.73% of L and 0.64% of MC; T3 = 14%CP, 0.66% of L and 0.58% of MC; T4 = 15,25% CP with 0.80% of L and 0.64% of MC; T5 = 14% CP with 0.80% of L and 0.58% of MC; T6 = 15,25% CP with 0.73% of L and 0.70% of MC; T7 = 14% CP with 0.66% of L and 0.70 of MC; T8 = 15,25% CP with 0.80% of L and 0.70% of MC and, T9 = 14% CP with 0.80% of L and 0.70% of MC. The diets contained 2,800 kcal of ME. Diets were suppplemented with amino acids at 15.25 and 14.0% of crude protein to show levels of Lys, MC or L+MC similar to control. The birds were fed 110 g of diet/day and water ad libitum and were submitted at a program of light of 17 hours. The variables were evaluated during four periods of 28 days. The decreasing dietary CP from 16.5 to 14% did not affect bird performance, whereas the lysine supplementation of lower protein diet decreased egg production and egg mass and feed:egg mass ratio and feed:egg dozen ratio in relation to control.