O objetivo deste trabalho foi avaliar a substituição do milho pela casca, farinha de varredura ou raspa de mandioca sobre ganho médio diário, consumo e conversão alimentar e rendimento de carcaça de novilhas confinadas. Foram utilizadas 28 novilhas mestiças, com aproximadamente 24 meses de idade e peso médio inicial de 365 kg, distribuídas em um delineamento em blocos casualizados, em um experimento de 56 dias, com quatro tratamentos e sete repetições. Não houve efeito da substituição do milho pelos produtos da mandioca sobre ganho médio diário, conversão alimentar e rendimento de carcaça. No entanto, o consumo foi inferior nas rações contendo raiz e resíduos da mandioca.

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RESUMO -Avaliaram-se os efeitos dos níveis de substituição do milho (MI) pela farinha de varredura de mandioca (FV) (25, 50, 75 e 100%) em rações para ovinos, sobre consumo voluntário, digestibilidade total dos nutrientes, balanços de nitrogênio (BN) e de energia (BE), pH e concentração de nitrogênio amoniacal (N-NH 3 ) do líquido ruminal. Foram utilizados quatro carneiros machos, castrados, sem raça definida, com peso médio de 41,4 kg de peso vivo em um ensaio de digestibilidade utilizando o método de coleta total de fezes e urina. Os animais foram mantidos em gaiolas metabólicas, distribuídos em delineamento experimental quadrado latino 4x4. O líquido ruminal foi obtido por meio de sonda esofágica, nos tempos de zero, 2, 4, 6 e 8 horas após à alimentação da manhã. Não houve efeito dos níveis de substituição para os consumos de matéria seca (MS), matéria orgânica (MO), fibra em detergente neutro (FDN ABSTRACT -This work was carried-out to study the effect of substitution levels of corn (COR) by cassava by-product flour (CPF) (25, 50, 75 and 100%) in the ration for sheep on voluntary intake, nutrients apparent digestibility and nitrogen (NB) and energy (EB) balance, pH and ammonia concentration (N-NH 3 ) in ruminal liquid. Four male, castrated sheep, without defined race, with medium weight of 41.4 AW, in trial of digestibility were used, using the method of total collect feces and urine. The animals were kept in cages of metabolism in 4x4 latin square design. The ruminal liquid was obtained by means of probe esofagic in the times 0, 2, 4, 6 and 8 hours (after feeding). There was no effect of substitution levels on intake of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), energy and nitrogen (N) and for apparent digestibility of DM, OM, CP, NDF, starch and gross energy (GE) and for NB and TDN levels. The intake of starch and GE presented quadratic increase until the level of 75% CPM in the ration. The concentration of the ammonia nitrogen and the pH of ruminal liquid did not differ in function of the substitution levels of the COR to CPM. It was concluded that CPM can totally substitute COR in the sheep ration.Key Words: cassava by-product flour, corn, digestibility, intake, nitrogen balance, sheep IntroduçãoA alimentação dos animais representa um dos maiores custos na produção animal, principalmente quando se utilizam fontes alimentares como o milho, que apesar das elevadas qualidades nutricionais apresentam em geral um custo elevado. Alguns subprodutos de indústria, como aqueles da produção de farinha de mandioca (casca de mandioca, farinha de varredura) possuem potencial e disponibilidade para serem utilizados como alimento energético e podem ser usados na alimentação de ruminantes (Pereira, 1987).A mandioca (Manihot esculenta, Crantz), uma fonte rica em energia para as rações animais, é um

The experiment was carried out to evaluate performance, carcass characteristics, chemical composition and fatty acid composition of bulls and steers (1/2 Nellore vs 1/2 Simmental) fi nished in feedlot. From 8 to 20 months the animals were raised conventionally. At 20 month of age 16 bulls were randomly selected of which 8 were surgically castrated. At 32 months of age the animals were transferred into a feedlot system with individual pens of 10 m 2 . Both groups of animals were slaughtered at 35 months of age. The bulls were heavier initially and displayed higher fi nal weight, higher average daily gain and hot carcass weight than steers, bulls also had higher moisture content, crude protein and cholesterol and lower total fat content than steers. The ratios of PUFA to SFA and of n-6 to n-3 in bulls were higher than in steers.

This experiment was carried out to evaluate performance and carcass characteristics of 40 crossbred young bulls (Zebu×European) finished in a feedlot under two roughage sources (Bermuda grass hay or sorghum silage) with or without the addition of yeast (Saccharomyces cerevisae). The bulls were 20 months old, their initial average weight was 356 kg and they were allocated into four groups of ten animals. The experimental diets were Bermuda grass, Bermuda grass+yeast, sorghum silage and sorghum silage +yeast. Animal performance and carcass characteristics were not influenced by roughage source or yeast addition. The average daily weight gain was 1.50 kg, dry matter intake (DMI) was 11.1 kg/d, DMI as percentage of liveweight was 2.60% and feed dry matter conversion was 7.70. The mean dressing percentage was 52.0% and hot carcass weight was 268 kg. Carcass conformation was classified between good-minus to good. Carcass length (137 cm), leg length (72.9 cm) and cushion thickness (26.6 cm) were not influenced by treatments. The average fat thickness was 3.80 mm and the Longissimus muscle area was 66.9 cm 2 . The classification of color, texture and marbling were slightly dark red to red, fine and slight-minus to light-typical, respectively. The mean percentage of bone, muscle and fat in the carcass was 15.5%, 62.3% and 22.5%, respectively. Yeast addition increased γ-linolenic fatty acid (0.15 vs. 0.11%) deposition. Bermuda grass hay increased deposition of α-linolenic (0.49 vs. 0.41%), arachidonic (2.30 vs. 1.57%), eicosapentaenoic (0.41 vs. 0.29%), docosapentaenoic (0.80 vs. 0.62%), docosahexaenoic (0.11 vs. 0.06%) and n-3 fatty acids, and reduced n-6: n-3 ratio in meat, when compared to sorghum silage treatments. The treatments had no effect on saturated fatty acids (49.5%), polyunsaturated fatty acids (11.8%), n-6 fatty acids (9.87%), n-3 (1.61%) and PUFA:SFA ratio (0.24). Monounsaturated fatty acid levels were higher on sorghum silage (40.7 vs. 37.7%). The addition of yeast caused higher n-6: n-3 ratio (7.28 vs. 5.70) than treatments without yeast.

This work was carried out to evaluate animal performance and carcass characteristics of 45 young bulls of three genetic groups: Nellore, 1/2 Nellore × 1/2 European and 1/4 Nellore × 3/4 European finished in feedlot. At the beginning of feedlot, the average bull was 20 (±2) months old, and average weight body was 356.0 (±7.9) kg. The 1/2 Nellore × 1/2 European young bulls had greater (P b 0.05) initial weight (381.7 kg), final weight (531.6 kg) and hot carcass weight (279.2 kg) than 1/4 Nellore × 3/4 European animals (334.6; 498.3 and 256.8 kg, respectively) and Nellore bulls (336.4; 446.4 and 234.3 kg, respectively). The crossbred bulls had greater daily weight gain (1.5 kg) as compared to the Nellore group (1.1 kg). However, carcass dressing was similar (52.3%) among groups. The superiority of crossbred animals over Nellore was observed when considering carcass conformation (good vs. regular), carcass length (136.6 vs. 130.1 cm), cushion thickness (26.6 vs. 25.0 cm), fat thickness (3.38 vs. 1.92 mm) and marbling (light vs. trace). The Nellore group had greater leg length (77.9 vs. 72.9 cm), better meat color (red vs. slightly dark red) and greater bone percentage (16.6 vs. 15.6%) than crossbred specimens. The 1/2 Nellore × 1/2 European groups had greater Longissimus muscle area (68.8 cm 2 ) and greater fat percentage (23.9%) than 1/4 Nellore × 3/4 European and Nellore animals. There was no difference in regards to texture (fine) and muscle percentage (62.9%). There was no difference among crossbreds for moisture (73.2%), ash (1.03%) and fat (1.81%) levels. Nellore animals had greater percentage of protein (25.3 vs. 23.8%), total cholesterol (27.5 vs. 23.0 mg/100 g muscle), stearic acid (25.0 vs. 21.6%), transvaccenic acid (1.6 vs. 1.3%) and γ-linolenic acid (0.2 vs. 0.1%) than crossbred specimens. Total saturated fatty acids (49.9%), monounsaturated fatty acids (38.1%), polyunsaturated fatty acids (12.1%), n-6 (10.0%), n-3 (1.7%), PUFA/SFA ratio (0.2) and n-6/n-3 ratio (6.27) in the Longissimus muscle were similar among genetics groups.

RESUMO -Foi determinada a recuperação fecal de quatro indicadores internos: cinza insolúvel em ácido (CIA), cinza insolúvel em detergente ácido (CIDA), fibra em detergente ácido indigestível (FDAI) e fibra em detergente neutro indigestível (FDNI) e a digestibilidade aparente da matéria seca (MS) e da matéria orgânica (MO). Foram utilizados quatro ovinos castrados, alimentados com quatro níveis de substituição do milho pela farinha de varredura. As amostras dos alimentos, sobras e fezes foram incubadas in situ, durante 192 horas, em três vacas Holandesas, portadoras de cânula de rúmen para determinar as fibras em detergente neutro e ácido indigestíveis. As recuperações fecais da CIA e da FDNI não diferiram de 100% e apresentaram para os coeficientes de digestibilidade de MS e MO valores semelhantes àqueles obtidos pelo método de coleta total. A recuperação fecal da CIDA e FDAI diferiu de 100%.Palavras-chave: cinza insolúvel em ácido, cinza insolúvel em detergente ácido, fibra em detergente ácido indigestível, fibra em detergente neutro indigestível Fecal Recuperation of Internal Markers in Assay with RuminantsABSTRACT -This experiment was carried out to assess the fecal recuperation of the following internal markers: acid insoluble ash (AIA), acid detergent insoluble ash (ADIA), indigestible acid detergent fiber (IADF), indigestible neutral detergent fiber (INDF), and the apparent digestibility of dry matter (DM) and organic matter (OM). Four castrated sheep were used, fed with four levels of substitution of corn by cassava by-product meal. The feed samples, orts and feces were incubated in situ for 192 hours in three Holstein cows with ruminal cannula to determine the indigestible neutral detergent fiber and indigestible acid detergent fiber. The fecal recuperation of AIA and INDF were not different from 100% and had values for the digestibility coefficient of DM and OM similar to those obtained by the total feces collection method. The fecal recuperation of ADIA and IADF differed from 100%. Zootec., v.31, n.4, p.1865-1874, 2002 IntroduçãoOs indicadores têm sido utilizados como ferramenta experimental por muitos anos (Merchen, 1993) e um amplo número de substâncias tem sido avaliado como indicador para estudar a função digestiva em ruminantes. O indicador pode ser interno, aquele que ocorre naturalmente no alimento ou externo que é adicionado na ração ou administrado oral ou intraruminalmente.Tem-se discutido muito sobre o assunto, mas os pesquisadores não encontraram ainda, uma substân-cia com características de indicador perfeito ou definir qual componente químico que se assemelha mais com aquelas desejadas. Segundo Merchen (1993), nenhuma das substâncias usadas como indicador preenchem todas as características, mas várias são suficientemente adequadas para fornecer dados significativos. Por esta razão, a procura de indicadores ideais constitui um dos assuntos de grande interesse na pesquisa de técnicas que facilitem estudos de nutrição animal. Nos últimos anos têm sido proposto várias substâncias ou novos m...

This study evaluates the effects of three diets: a control (CON), containing sodium monensin (MON) and containing propolis extract (PRO). The performance of 33 feedlot-finished bulls, 11 for each diet, and carcass characteristics were examined. The 27 months old bulls, with initial liveweight 400±2.33 kg, were kept in a feedlot for 84 days, till 484±6.76 kg at slaughter. The roughage and concentrate ratio of the diets was 52:48 on DM basis. Maize silage was used as roughage and maize, soyabean meal, urea, mineral salt and limestone were used as concentrate. The average final weight (501 kg), hot carcass weight (275 kg) and average daily gain (1.17 kg) were higher (P<0.05) for bulls fed with PRO than for those on the CON (472, 259 and 0.87 kg, respectively), or MON (480, 259 and 0.94 kg, respectively) diets. Dry matter conversion was better (P<0.05) for bulls fed with PRO (8.04) than those on the CON (10.9) or MON (9.72) diets. Carcass characteristics such as conformation, carcass length, leg length, cushion thickness, Longissimus muscle area, Longissimus muscle area/100 kg of liveweight, fat thickness, colour, texture and marbling were not influenced (P>0.05) by the treatments.