Summary ― Some microbiological and biochemical parameters of caecal content were studied in 15-to 49-d-old rabbits that were slaughtered sequentially. The ammonia level did not differ before weaning (11.5 mmol/L on average) (P= 0.41 ) or after weaning (7.4 mmol/L on average) (P= 0.19) but decreased by 40% (P < 0.001) between days 29 and 32. The level of pH decreased linearly (P < 0.001) throughout the period studied. The Escherichia coli counts decreased up to weaning (P < 0.001) and was then not significantly affected by age (P = 0.12). The total volatile fatty acid (VFA) concentration increased between days 15 (8.2 mmol/L) and 25 (33.9 mmol/L) (P< 0.05) and then levelled off below 40 mmol/L. Molar proportions in propionate and in branched-chain fatty acid (BCFA) and valeric acid were high at day 15 but decreased when the animals began to eat solid feed. The C3/C4 ratio reversed at weaning (3.8 on day 15 and 0.5 on day 49) whereas the acetic acid proportion was not affected by age (P= 0.19). High counts of anaerobic microflora were found between 15 and 22 d of age (10 11 bacteria/g of caecal content, on average) and did not change significantly according to the age (at about 10 10 bacteria/g), from day 29 until the end of the experiment (P= 0.29). Amylolytic flora had a similar evolution at a slightly lower level. In contrast, under our breeding conditions cellulolytic microflora slowly colonized the caecum and remained at a low level. The discriminant analysis revealed relationships between ages, intestinal microflora and fermentation parameter; the colibacilli flora was associated with mother-fed animals and amylolytic flora which was linked to BCFA and valeric acid, while the cellulolytic flora was associated with animals older than 4 weeks and linked to the production of C2,

-Thirty-two SPF New Zealand White rabbits of both sexes were used in this experiment. They were sequentially slaughtered at 22, 29, 35 and 42 days of age. The rabbits were only milked by their mother and by foster mothers (no access to solid food) throughout the experiment. They exhibited a caecal fermentation pattern that turned towards a proteolytic metabolic activity (high levels in NH 3 and in branched-chain fatty acids and valeric acid: 17 mmol ' L ' ' and 1 mmol-L-', on average, respectively). The absence of caecal cellulolytic microflora and the low concentration of the total volatile fatty acids (tVFA) could be explained by the lack of substrate that would have been brought by a solid feed. From day 29 onwards, the low tVFA (12.5 mmol-L-1 ) and high NH 3 concentrations (16.5 mmol-L-1 ) explained the high pH value (6.8 on average). This could be considered as a pathological value in weaned rabbits, but in our case no clinical signs of diarrhoea were observed. The evolution of the colibacilli flora according to age was similar to that usually described and thus was not correlated with pH, tVFA or cellulolytic flora. The evolution of the colibacilli population (from 10! bact/g on day 22 to 10 3 on day 42) seemed dependent on ontogenic factors rather than on the composition of the caecal media (pH, etc.

Resumo -O objetivo deste trabalho foi avaliar o efeito de misturas de aditivos fitogênicos na dieta de frangos de corte, sobre seu desempenho zootécnico e rendimento de carcaça. Foram avaliados 660 pintos de sexo misto, entre 1 e 42 dias de idade, em delineamento inteiramente casualizado, com cinco tratamentos e seis repetições de 22 aves (11 machos e 11 fêmeas). Além do controle, foram avaliados tratamentos com antibiótico (10 ppm de virginiamicina) ou com misturas de aditivos fitogênicos: mistura A, 150 ppm de óleos essenciais de alecrim, cravo, gengibre e orégano; mistura B, 150 ppm de óleos essenciais de canela, sálvia, tomilho branco e óleo-resina de copaíba; e mistura A+B, 50% da mistura A e 50% da B. A mistura B proporcionou maior ganho de peso e melhor conversão alimentar das aves, no período de 36 a 42 dias de idade. No período total do experimento, o antibiótico e a mistura B proporcionaram maior ganho de peso das aves. O consumo de ração foi maior com o antibiótico do que com o controle. A mistura A+B e o tratamento controle proporcionaram maior rendimento de coxa+sobrecoxa e maior peso relativo do baço. As mistura B e A+B apresentam potencial como melhoradores de desempenho para frangos de corte.Termos para indexação: Gallus gallus, antibiótico melhorador de desempenho, extratos de plantas, óleos essenciais, óleo-resina de copaíba. Growth performance and carcass yield of broiler chicken feed diets with blends of phytogenic additivesAbstract -The objective of this work was to evaluate the effect of blending phytogenic additives in broiler chicken diets on their growth performance and carcass yield. Six hundred and sixty mixed-sex broiler chicks, from 1 to 42 days of age, were evaluated in a completely randomized design, with five treatments and six replicates of 22 chicks each (11 males and 11 females). Besides the control, treatments with antibiotic (10 ppm virginiamycin) or with blends of phytogenic additives were evaluated: blend A, 150 ppm of a mixture of essential oils from rosemary, clove, ginger, and oregano; blend B, 150 ppm of a mixture of essential oils from cinnamon, sage, white thyme, and copaiba oil-resin; and blend A+B, a mixture of 50% blend A and 50% blend B. Blend B provided the highest weight gain and better feed conversion rate at the period of 36 to 42 days of age. In the total experimental period, the antibiotic and blend B provided higher broiler weight gain. Feed intake was higher with the antibiotic than with the control. Blend A+B and the control treatment provided higher thigh+drumstick yield and higher relative weight of spleen. The blends B and A+B have potential as performance enhancers for broiler chicken.

RESUMODentre as principais zoonoses de origem bacteriana, transmitidas pelas aves, pode-se assinalar as salmoneloses causadas por salmonelas patogênicas, que causam toxinfecções alimentares e podem estar presentes em produtos e subprodutos de origem animal contaminados. Com o objetivo de buscar subsídios no sentido de aperfeiçoar os sistemas de prevenção e controle alternativos para esta zoonose, foi realizado um experimento com 780 frangos de corte, da linhagem Ross, abatidos aos 31 dias de idade, submetidos a três tratamentos, com 4 repetições de 65 aves cada. Os animais do tratamento um receberam o probiótico Mucosal starter culture e foram inoculados com Salmonella enteritidis (SPRING et al., 2000), na dose de 10 5 unidades formadoras de colônias, por mililitro. No tratamento dois-controle positivo-os animais somente foram inoculados com S. enteritidis, na mesma dose que no tratamento um. Os animais do tratamento três-controle negativo-não receberam inoculação de salmonelas e nem probiótico. Avaliou-se o peso vivo, o consumo de ração e foram estimadas a conversão alimentar, o fator de produção e a percentagem de contaminação por salmonela. Não foram detectadas diferenças significativas, entre os tratamentos, para os parâmetros zootécnicos e microbiológicos analisados. Os animais que receberam o probiótico não se mostraram mais eficientes quando inoculados com salmonelas patogênicas, mas apresentaram um melhor desempenho em relação ao padrão da linhagem Ross utilizada. Termos para indexação:Saúde pública, salmonela, zoonose, avicultura, aditivo. ABSTRACTSalmoneloses are zoonoses cause by pathogenic salmonellas very common in products of infected birds. A experiment was made with the main aim to consider the need to search subsidy and perfectly for control and prevention systems in the growth of disease in public health. 780 chickens from Ross line are used, they were 31-day-old, and three treatments have been applied to 4 repetitions of 65 birds each. The animals of treatment one received the probiotic Mucosal starter culture and were inoculated with Salmonella enteritidis in 10 5 units group colony forms/ militer. The treatment two was considered positive control and the animal were inoculated with S. enteritidis the same way that treatment one. The animals of treatment three did not receive probiotics and nor inoculated with salmonella. Some parameters were analyzed such as weight, food conversion , production factor and the percent of the contamination by salmonellas. There were not differences to the zootechnical and microbiological parameters for everyone treatments analysed. The animals that received probiotic did not show more efficient when inoculated with S. enteritidis, but they presented best performance that status from Ross line used.

ResumoCom o objetivo de avaliar o desempenho e o custo de produção de frangos de corte, foram testados probióticos e prebióticos como promotores de crescimento alternativos aos antimicrobianos (colistina/ avilamicina), na ração de 6.450 pintos de corte, machos, da linhagem Cobb, criados de 1 a 42 dias de idade, distribuídos em um delineamento inteiramente casualisado, formado por oito tratamentos de rações experimentais, com 13 -17 repetições de 50 aves cada por tratamento. Os probióticos foram o Bacillus subtilis em diferentes concentrações e/ou recomendação de uso, uma mistura de Saccharomyces cerevisiae mais Aspergillus oryzae ou um prebiótico composto de mananoligossacarídeos (MOS) adicionados em uma ração inicial e outra de crescimento comum a todos os tratamentos. Não se verificou diferenças significativas na conversão alimentar entre tratamentos. Entretanto, o peso médio dos animais que receberam Bacillus subtilis (1,6 x 10 9 CFU/g) ou uma mistura de probióticos foi maior ou semelhante ao peso das aves alimentadas com os antimicrobianos. Conclui-se que é possível substituir os antimicrobianos utilizados, pelos probióticos avaliados como promotores de crescimento sem prejuízos no desempenho e no custo de produção de frangos de corte. Unitermos: frangos de corte, antimicrobianos, probióticos, prebióticos, desempenho AbstractEffects of alternative promoters of growth on the performance and cost of production of broilers. Probiotics and prebiotics were compared to antimicrobials as alternative growth promoters in male broilers grown from 1 to 42 days of age. Eight treatments were evaluated: a control feed without antimicrobials or alternative growth promoters, a control feed with antimicrobials, a control feed with the antimicrobials colistine and avilamicine, three rations with probiotic Bacillus subtilis in different concentrations and/or under recommended usage, one ration with probiotic Saccharomyces cerevisiae in addition to a mixture of probiotic Biotemas, 22 (3): 157-163, setembro de 2009