Two experiments were carried out to evaluate, respectively, nitrogen balance (NB) and the productive performance of 31-to-50-day-old rabbits subjected to different levels of lysine and methionine+cystine (met+cys). Seventy-five animals were randomly distributed in 5 × 3 blocks (five levels of lysine: 5.5, 6.5, 7.5, 8.5 and 9.5 g/kg combined with three levels of met+cys: 5.0, 6.0 and 7.0 g/kg), with 15 treatments and five replications for the NB assay. The assay lasted 14 days: 10 days for acclimatization and four days for feces and urine collection. Increasing met+cys levels had a quadratic effect on the nitrogen excreted in urine (NU): the lowest excretion was found at the dietary level of 5.9 g/kg met+cys. Increasing lysine levels also affected NU and nitrogen retained daily (NR): the lowest NU was obtained at the dietary level of 7.28 g/kg lysine, and maximum NR was found at 7.24 g/kg lysine. Increases in met+cys levels in the diets affected neither performance nor carcass characteristics of rabbits up to 50 days of age. On the other hand, body weight at 50 days, daily weight gain and feed conversion of rabbits slaughtered at 50 days had a quadratic effect as the lysine levels increased. The best results were found at 7.5, 7.38 and 7.36 g/kg lysine. Lysine and met+cys levels of 7.4 and 5.0 g/kg in the diet are recommended for 31-to-50-day-old rabbits.

Conduziram-se experimentos para determinar a digestibilidade da polpa cítrica desidratada (PCD) e avaliá-la na alimentação de coelhos. Para o ensaio de digestibilidade utilizaram-se 30 coelhos recebendo duas dietas: uma referência e outra com substituição de 20% da primeira por PCD. O ensaio teve duração de dez dias para adaptação mais quatro para coleta de fezes. Os coeficientes de digestibilidade e os nutrientes digestíveis para MS, PB, FDN, FDA e EB da PCD foram respectivamente: 83,75 e 76,04%; 70,12 e 5,03%; 40,14 e 9,52%; 68,98 e 15,09%; e 81,48% e 3394 kcalED kg-1 MS. Para o desempenho utilizaram-se 120 coelhos recebendo dietas com diferentes níveis de PCD (0, 20, 40, 60, 80 e 100%) substituindo o milho. Observou-se redução linear (p < 0,01) para o consumo de ração e ganho de peso diário, peso vivo aos 50 e 70 dias e rendimento de carcaça com o aumento gradativo de PCD. Efeitos quadráticos (p < 0,01) sobre a conversão alimentar dos 32 aos 50 e 32 aos 70 dias de idade provocaram melhores valores com 42,74 e 44,40% de PCD, respectivamente. PCD a 20% não afetou (p > 0,05) nenhuma característica de desempenho quando comparada à dieta controle. Conclui-se: a PCD pode substituir o milho até 20% nas dietas de coelhos.

Several experiments were conducted to determine the digestibility of dehydrated citrus pulp (DCP) and evaluate its effect on rabbit feed. Digestibility assay comprised 30 rabbits fed on two diets: a reference diet and a diet in which 20% consisted of DCP. The digestibility assay comprised 10 days for adaptation and four days for feces collection. The digestibility coefficient and digestible nutrient rates for DM, CP, NDF, ADF, and CE of DCP were respectively 83.75 and 76.04%; 70.12 and 5.03%; 40.14 and 9.52%; 68.98 and 15.09%; and 81.48% and 3394 kcalDE kg-1 DM. Performance assay consisted of 120 growing rabbits receiving diets with six DCP levels (0, 20, 40, 60, 80 and 100%) to replace corn. Linear decrease (p < 0.01) in daily feed intake and weight gain, live weight after 50 and 70 days and carcass yield with gradual DCP increase, were reported. Quadratic effect (p < 0.01) on the feed conversion from 32 to 50 and from 32 to 70 days old produced better DCP rates, respectively 42.74% and 44.40%. DCP 20% failed to affect (p > 0.05) any performance characteristic when compared to that in control. Results show that DCP in the rabbit's diet may replace up to 20% of corn.

Two experiments were carried out in order to estimate the nutritional value and the performance of growing rabbits fed different levels of pearl millet (ADR 7010). In the digestibility trial, nutritional values of pearl millet were determined in 22 45-day-old New Zealand White rabbits, allotted in a completely randomized design, subjected to two treatments - a reference diet and a test diet with 70% of its volume composed of reference diet and 30% of pearl millet - and 11 replications. The apparent digestibility values of dry matter, crude protein, neutral detergent fiber and gross energy of the pearl millet were 88.7, 85.4, 24.4 and 75.0%, respectively. In the performance trial, 120 32-day-old New Zealand White rabbits were used. Rabbits were allotted in a completely randomized design and subjected to six treatments, with 10 replications and two animals for each experimental unit. The diets were formulated with increasing levels of pearl millet (20, 40, 60, 80 and 100%), substituting the corn in the reference diet, according to the digestible energy. No differences were observed in daily feed intake, daily weight gain, feed conversion, carcass traits and feed cost per kilogram of rabbit. Regardless of the amount of corn substituted, pearl can replace corn in diets for growing rabbits.

The objectives of this study were to determine the chemical composition of vegetable and mixed crude glycerin and digestible energy to and evaluate different inclusion levels in rabbit feeding. A total of 108 rabbits were used in the digestibility assay, assigned in a completely randomized design into nine treatments, one reference diet plus eight test diets, where the glycerin types were included at levels of 4, 8, 12 and 16%, replacing the reference diet roughage. In the performance assay, 180 rabbits were assigned to a completely randomized design into a 2 × 4 factorial arrangement (two types of glycerin and four levels of inclusion: 3, 6, 9 and 12%) plus a reference diet and ten replications. The vegetable and mixed crude glycerin showed digestible energy of 5,099 and 4,953 kcal/kg of dry matter, respectively. Although feed intake decreased linearly with the growing inclusion of both kinds of glycerin during both evaluated periods (from 32 to 50 and 32 to 70 days), performance losses occurred only with the inclusion of vegetable crude glycerin. The inclusion of mixed crude glycerin up to 12% allowed similar animal performance to the reference diet up to 50 days, unlike vegetable crude glycerin, for which inclusions over 6% in the diet resulted in poorer performance compared with that obtained with the reference diet. In the total period, differences were not observed for live weight or weight gain of the animals fed both glycerin types. Carcass weight decreased linearly with the inclusion of both glycerin types, with lower values compared with the reference diet only for the two highest levels of glycerin inclusion. Mixed crude glycerin can be included up to the maximum level studied (12%), while vegetable glycerin can be added up to 6% in the diet of growing rabbits.

A total of 70 five-month-old female New Zealand White rabbits were assigned in a completely randomized design, over three reproductive cycles, with two treatments: a reference diet and a half-simplified diet containing 79.83% cassava byproduct. The study evaluated body weight and feed intake of does, feed cost, number and total body weight of kits at kindling and weaning per female during three cycles, number and percentage of mortality/female/cycle, and weight gain of kits from birth to weaning. No interaction was observed between the diets and among the reproductive cycles for any evaluated characteristics. The body weight of does at the moment of weaning was similar in both groups for all three reproductive cycles. However, does fed the half-simplified diet had lower feed intake during the three reproductive cycles and, consequently, more reproductive flaws. The number of kits at weaning, body weight of kits at kindling and weaning, weight gain of kits from birth to weaning, and total body weight of kits at weaning were lower for the group of does fed the half-simplified diet and, consequently, there was a higher number and percentage of dead kits in this group. The total numbers of kits at kindling and weaning and total body weight of kits at birth during all three reproductive cycles were similar between the groups; however, total body weight of weaning rabbits was higher for the animals receiving the reference diet. It is possible to conclude that although the use of the half-simplified diet decreases the reproductive performance of does, it reduces feed cost per kg of body weight by 23.63% compared with the reference diet, proving to be a viable nutritional option for rabbit production.

Dois experimentos foram realizados para determinar o valor nutritivo da silagem de grãos úmidos de milho (SGUM) e avaliar os efeitos da substituição gradativa do milho seco das rações pela SGUM sobre o desempenho e características quantitativas de carcaça de coelhos, no período de 36 a 70 dias de idade. No ensaio de digestibilidade, foram utilizados 22 coelhos da raça Nova Zelândia Branco, com 50 dias de idade, alojados individualmente em gaiolas de metabolismo, em delineamento inteiramente ao acaso, com dois tratamentos e 11 repetições. Os valores da matéria seca digestível, proteína bruta digestível, energia bruta digestível, fibra em detergente neutro digestível, fibra em detergente ácido digestível e amido digestível da SGUM foram, respectivamente, 94,42%; 7,94%; 3973kcal kg-1, 6,74%; 2,61% e 68,73%. No experimento de desempenho, foram utilizados 110 coelhos, distribuídos em um delineamento inteiramente casualizado, com cinco tratamentos, 11 repetições e dois animais por unidade experimental. Os tratamentos consistiram de uma dieta referência e outras quatro com 25, 50, 75 e 100% de substituição do milho pela SGUM, com base na matéria seca do milho incluído na dieta referência. Não foram observadas diferenças entre os tratamentos no desempenho, tanto no período de 36 a 50 dias como no período total do experimento, de 36 a 70 dias de idade. Nenhuma diferença foi observada no peso e rendimento de carcaça entre os tratamentos. Diante dos resultados, a SGUM substitui eficientemente o milho seco em dietas para coelhos.

Digestibility and performance experiments were carried out to evaluate the nutrients digestibility coefficients of high moisture corn silage (HMCS) and the gradative replacing (0, 25, 50, 75 and 100%) of dry grain corn by HMCS on performance and carcass yield of growing rabbits from 36 to 70 days old. In the digestibility experiment 22 rabbits were used allocated on a completely randomized design, with two treatments and 11 replicates. The values of digestible dry matter, digestible crude protein, digestible crude energy, digestible neutral fiber detergent, digestible acid fiber detergent and digestible starch were, respectively, 94.42%; 7.94%; 3973kcal kg-1; 6.74%; 2.61% and 68.73%. In the performance experiment, 110 rabbits were allocated on a completely randomized design, with five treatments, 11 replications and two rabbits per experimental unit. The HMCS replaced the dry grain corn in levels of 0, 25, 50, 75 and 100%, on dry matter basis. No differences were observed on performance in the period from 36 to 50 and the period from 36 to 70 days old. No difference was observed also on weight and carcass yield. The results showed that the HMCS replaces efficiently the dry grain corn in rabbit diets.

O objetivo neste trabalho foi avaliar o desempenho e os parâmetros ósseos de frangos de corte alimentados com rações contendo diferentes níveis de óleo de linhaça no período de 1 a 42 dias de idade. Nas fases inicial e de crescimento (1 a 21 dias e 22 a 42 dias, respectivamente), foi adotado delineamento inteiramente casualizado com 4 níveis de óleo de linhaça (2,0; 3,5; 5,0 ou 6,5%), 6 repetições e 50 aves/unidade experimental. Os níveis de óleo de linhaça tiveram efeito linear crescente sobre o diâmetro e o peso absoluto da tíbia, mas não influenciaram o peso do fêmur. Os dados revelaram interação idade e nível de óleo de linhaça para o índice de Seedor, comprovando que os efeitos positivos e negativos dos maiores níveis de óleo de linhaça observados para o fêmur e a tíbia, respectivamente, aumentaram no final da fase de crescimento. Os parâmetros de crescimento e qualidade do fêmur e da tíbia apresentaram comportamento cúbico, decorrente da idade. Os níveis de óleo de linhaça e a idade tiveram efeito quadrático sobre o peso das cinzas do fêmur. A concentração de cinzas foi positivamente influenciada pelos níveis de óleo de linhaça nas rações, contudo, os melhores resultados foram evidenciados a partir dos 28 dias. A resistência óssea não foi influenciada pela ingestão de óleo de linhaça, mas sofreu efeito cúbico da idade. Verificou-se interação significativa idade × nível de óleo de linhaça para a densidade mineral óssea, e que os melhores efeitos do óleo ocorrem na fase inicial de criação das aves. Rações contendo 6,5% de óleo de linhaça são benéficas para o crescimento e a mineralização dos ossos longos de frangos de corte.

This study aimed to evaluate the performance and bone parameters of broiler chickens fed on diets with different linseed oil (LO) levels from 1 to 42 days of age. At the initial and growing phases (1 to 21 days and 22 to 42 days of age, respectively) a completely randomized design was used with four linseed oil levels (2.0, 3.5, 5.0 or 6.5%), six replicates and 50 birds per experimental unit. The birds were fed diets with different linseed oil levels (2.0; 3.5; 5.0 and 6.5%). A linear effect of linseed oil was observed on tibia absolute diameter and weight but the femur was not influenced by linseed oil inclusion in the diet. Data revealed significant interaction between age and linseed oil levels for the Seedor index, demonstrating that the positive and negative effects of the highest linseed oil levels observed for femur and tibia, respectively, increased at the end of the growth phase. The femur and tibia growth and quality parameters presented cubic performance in function of age. The inclusion of linseed oil and age showed a quadratic effect on the femur ash weight. The ash concentration was positively influenced by the levels of linseed oil in the diets but the best results were shown after 28 days. The bone strength was not influenced by the different linseed oil levels, but showed cubic performance in function of age. However, there was significant age × linseed oil level interaction for bone mineral density, so that the best results with linseed oil addition were observed at the initial rearing stage of the birds. It was concluded that diets with 6.5% linseed oil are beneficial to growth and mineralization of long bones in broiler chickens.