Showing papers in "Revista Brasileira De Zootecnia in 2006"

Estudo da curva de crescimento de ovinos Santa Ines

Abstract: Records of 7,271 weights of 952 lambs measured from birth up to 196 days of age between 1983 and 2000, available from the Agricultural Research Corporation of Paraiba database, were used to model the average growth curve of Santa Ines sheep. The influence of environmental effects on the estimated parameters of the Brody, Von Bertalanffy, Logistic, Gompertz and Richards functions was evaluated using the NLIN procedure of SAS. The growth curve was well fitted by all models but larger residual variation was obtained by the Brody and Logistic models. According to the absolute average residual error, the Gompertz model showed a better fit than the models Von Bertalanffy and Richards. Growth curves differed for males and females, born from single and twin lambing. Contemporary group, type of birth and sex significantly affected the estimation of parameters A and K. The correlation between parameters A and K was negative. Improvements in feeding management and forage storage may decrease the indirect effects of climate and contribute to reduce variation in the growth curves.

Efeitos da temperatura e da umidade relativa sobre o desempenho e o rendimento de cortes nobres de frangos de corte de 1 a 49 dias de idade

Abstract: Foram utilizados 180 pintos machos de 1 dia de idade, da linhagem Ross (peso inicial 43,0 ± 0,2 g) para avaliacao dos efeitos de diferentes ambientes sobre o desempenho e as caracteristicas de carcaca. As aves foram criadas no periodo de 1 a 49 dias de idade em um delineamento experimental inteiramente casualizado, com tres ambientes (conforto termico, calor seco e calor umido), seis repeticoes por tratamento e dez aves por unidade experimental. As racoes e a agua foram fornecidas a vontade. O monitoramento da temperatura e da umidade relativa do ar de cada ambiente foi feito por meio de termometros de bulbo seco e de globo negro. Os valores obtidos foram convertidos em valor unico - Indice de Temperatura de Globo e Umidade (ITGU), para caracterizacao do ambiente. As temperaturas que caracterizaram os ambientes de conforto, de calor seco e de calor umido foram, respectivamente, 25,1 ± 2,99; 35,0 ± 0,14 e 31,2 ± 1,82oC e as umidades relativas registradas nos ambientes de calor seco e calor umido foram, respectivamente, de 40 e 75%. Foram avaliados o consumo de racao, o ganho de peso e a conversao alimentar nos periodos de 1 a 21, 1 a 41 e 1 a 49 dias de idade. Ao final do experimento, as aves foram abatidas para avaliacao dos pesos absolutos e do rendimento de carcaca e de cortes nobres (coxa, sobrecoxa e peito). O ambiente de calor influenciou negativamente o consumo de racao e o ganho de peso das aves em todos os periodos estudados, mas esse efeito foi mais acentuado nas aves mantidas em ambiente de calor umido. O calor tambem influenciou negativamente os pesos absolutos de coxa, sobrecoxa e peito. Altas temperaturas prejudicam o desempenho e o rendimento de cortes nobres de frangos de corte de 1 a 49 dias de idade, de modo que esses efeitos sao mais acentuados pelo aumento da umidade relativa do ar.

Características morfogênicas e estruturais do capim-braquiária em pastagem adubada com nitrogênio avaliadas nas quatro estações do ano

Abstract: Este experimento foi realizado com o objetivo de avaliar o efeito da adubacao nitrogenada sobre as caracteristicas morfogenicas e estruturais de Brachiaria decumbens sob pastejo. Os tratamentos consistiram da aplicacao de quatro doses de nitrogenio (75, 150, 225 e 300 kg/ha.ano) antes do inicio das avaliacoes experimentais, realizadas em 2002 durante as estacoes de verao, outono, inverno e primavera. Utilizou-se o delineamento em blocos completos casualizados, com duas repeticoes. A taxa de alongamento de folha, o comprimento final da folha, o indice de area foliar e as porcentagens de colmo e de lâmina foliar aumentaram linearmente, enquanto a porcentagem de material morto decresceu com a adubacao nitrogenada da Brachiaria decumbens sob pastejo. Nao foi constatado efeito da adubacao nitrogenada sobre o numero de folhas vivas, de folhas emergentes e de folhas totais e as taxas de alongamento do colmo e de senescencia foliar. A taxa de alongamento de folha e de colmo, o numero de folhas vivas, o comprimento final da folha, o indice de area foliar e a porcentagem de lâmina foliar e de colmo de Brachiaria decumbens variaram entre estacoes do ano, apresentando valores menores no inverno.

Efeitos de extratos vegetais e antimicrobianos sobre a digestibilidade aparente, o desempenho, a morfometria dos órgãos e a histologia intestinal de leitões recém-desmamados

Abstract: Objetivou-se com este trabalho avaliar o efeito de antimicrobianos e extratos vegetais sobre a digestibilidade, o desempenho, a morfometria e a histologia de leitoes recem-desmamados. Foram realizados tres experimentos de 35 dias (repeticoes no tempo), com um total de 120 leitoes (40 leitoes por experimento). O delineamento foi em blocos casualizados, com cinco tratamentos (controle - racao basal; antimicrobiano - racao basal com bacitracina de zinco, olaquindox e colistina (50 ppm de cada); extrato vegetal A, B e C - racao basal com 700, 1.400 e 2.100 ppm de extrato vegetal, respectivamente), 12 repeticoes por tratamento e dois animais por unidade experimental. O extrato vegetal continha oleo essencial de cravo, tomilho e oregano, acrescido de eugenol e carvacrol. A digestibilidade foi determinada em 40 leitoes (quatro repeticoes por tratamento) utilizando-se o metodo de coleta parcial de fezes e o oxido de cromo como marcador. Ao final do primeiro experimento, foi abatido um animal de cada baia para coleta das amostras. A digestibilidade da MS no tratamento com extratos vegetais foi maior que nos tratamentos controle e com antimicrobianos. O tratamento antimicrobiano promoveu os melhores resultados de desempenho em todos periodos analisados. O maior nivel de inclusao de extratos vegetais foi o que proporcionou os melhores resultados de desempenho e das demais variaveis. O tratamento com antimicrobianos resultou em menor peso relativo do trato gastrintestinal total e do intestino delgado vazio, alem de maior altura de vilosidade e menor relacao altura de vilosidade x profundidade de cripta do ileo que os tratamentos com extratos vegetais. Entretanto, sao necessarios mais estudos sobre os oleos essenciais a serem utilizados, a concentracao de cada oleo, a melhor combinacao e o melhor nivel de inclusao na dieta.

Dose inseminante para fertilização artificial de ovócitos de jundiá cinza, Rhamdia quelen (Quoy & Gaimardm, 1824)

Abstract: Two females with colored urogenital organ, rounded off abdomen, color egg released, and uniform size and four males with semen released under abdomen pressure were selected to determine the best insemination dose for artificial fertilization of grey jundia, Rhamdia quelen (Quoy & Gaimardm, 1824), oocytes. Females and males received two doses of carp pituitary extract: the first one of 0.5 and 0.25 mg.kg-1 and the second of 5.0 and 2.5 mg.kg-1 for females and males, respectively. Both females produced 169 g of eggs with 1,141 oocytes.oocytes g-1. The males produced a total of 23.6 mL of semen. From all males semen pool sperm concentration (1.97 x 1010 spermatozoa.mL-1), survival sperm index (96%) and sperm morphology were analyzed (66.9% of normal spermatozoa). The fertilization assay was conducted as a complete randomized experimental design with five treatments ((6x103, 6x104, 6x105, 6x106, 2x107 spermatozoa.oocyte-1) and four replications. After eight hours of incubation, the fertilization rates for each treatment were analyzed. The best spermatozoa.oocyte-1 rate was of 89.497 spermatozoa.oocyte-1 that produced a maximum fertilization rate of 86.68%.

Avaliação das características estruturais do capim-braquiária em pastagens adubadas com nitrogênio nas quatro estações do ano

Abstract: This trial was carried out from November 2001 to November 2002, aiming at the evaluation of the effects of nitrogen fertilization upon the tiller demography and forage biomass in Brachiaria decumbens cv. Basilisk pastures fertilized with nitrogen and subjected to the same grazing height. The treatments consisted of four nitrogen rates (75, 150, 225 and 300 kg/ha.yr.) applied before the beginning of the experimental evaluations, which were performed during the Summer, Fall, Winter and Spring, 2002. A completely randomized block experimental design was used with two replications. Seasons and nitrogen rates affected grass tiller population density and forage biomass. The population density of alive and vegetative tillers increased linearly, while that of the dead tillers decreased linearly with the N rates. Forage biomass increased linearly with nitrogen fertilization, whereas the population density of reproductive tillers were not affected by nitrogen fertilization. The alive tiller population density, vegetative and reproductive, leaf biomass, stem and green matter of the Brachiaria decumbens varied among the seasons, with lower values in Winter.

Avaliação da qualidade nutricional da silagem de cana-de-açúcar com aditivos microbianos e enriquecida com resíduo da colheita de soja

Abstract: The objective of this trial was to evaluate the fermentative characteristics and nutritional quality of sugarcane treated with microbial additives and 10% of soybean crop residue based on sugarcane fresh weight. The variety RB855536 harvested at 16 months of age was used in a completely randomized design with tree repetitions. Addition of soybean crop residue reduced 33% of DM losses and 60% of ammonia-N (% total N) although final silage pH increased. Use of inoculants reduced silage pH only in association with soybean crop residue with no significant effects on the remaining variables. For all treatments, silages had higher contents of fiber and lower DM levels than the material before ensiling. In vitro dry matter digestibility (IVDMD) was significantly higher (P<0.05) on treatments with soybean crop residue compared to the other treatments. Moreover, compared with the material used for ensiling, reduction in digestibility was higher for treatments without soybean crop residue (24.3% vs. 9.3%). Combination of soybean crop residue with sugarcane improved nutritional quality and reduced DM and soluble carbohydrates losses, mainly in the form of gases, diluting the proportion of cell wall components and preventing losses in forage IVDMD. The use of the inoculants L. plantarum and L. buchneri during ensiling of sugarcane is not recommended because no improvement was observed on the chemical composition or fermentation profile of silages.

Efeito do genótipo e do sexo sobre a composição química e o perfil de ácidos graxos da carne de cordeiros

Abstract: Este estudo foi realizado com o objetivo de avaliar os efeitos do sexo e do genotipo sobre a composicao centesimal e o perfil de acidos graxos do musculo Semimembranosus (SM) de ovinos submetidos as mesmas condicoes de confinamento. Foram utilizados 12 cordeiros, quatro machos inteiros e quatro femeas da raca Santa Ines (SI) e quatro machos inteiros mesticos ½ Santa Ines x ½ Dorper (SI-D). A raca e o sexo nao influenciaram a composicao centesimal da carne dos cordeiros. No entanto, as concentracoes de fosforo e calcio diferiram significativamente quando considerados estes dois fatores. Os acidos graxos encontrados em maior quantidade na fracao lipidica da carne dos animais foram o oleico, o palmitico e o estearico. Houve efeito do sexo sobre o perfil dos acidos graxos monoinsaturados na carne dos animais Santa Ines. O perfil de acidos graxos de mesticos machos SI-D comprovou melhor valor nutricional da carne, pelo maior percentual de acidos graxos poliinsaturados, pela maior relacao AGPI/AGS e pela menor relacao w6:w3.

Efeitos de antimicrobianos, prebióticos, probióticos e extratos vegetais sobre a microbiota intestinal, a freqüência de diarréia e o desempenho de leitões recém-desmamados

Abstract: The purpose of this work was to evaluate the effects of probiotics, prebiotics and herbal extracts as alternatives to antimicrobial agents (as growth promoters) on intestinal microbiology , diarrhea incidence, and on performance of weanling pigs. Two randomized complete block design experiments were carried out during 35 days to compare five treatments: control - basal diet; antimicrobial - basal diet plus Zn bacitracin and olaquindox (50 ppm of each); probiotic - basal diet plus 1,300 ppm of probiotic (Bacillus subtilis and Bacillus licheniformis); prebiotic - basal diet plus 3,000 ppm of mannanoligosaccharide; herbal extract - basal diet plus 500 ppm of herbal extract (garlic, clove, cinnamon, pepper, thyme, cinnamaldehyde, and eugenol). In the Experiment 1, forty 21-d-weaned pigs were alloted to 20 suspended pens, each one with two pigs (one barrow and one gilt) per pen (experimental unit) and four replications per treatment. On 35th day of experimental period, one animal of each experimental unit was slaughtered to collect the content of the jejunum/ileum for microbiological analysis. In the Experiment 2, one hundred and twenty 21-d-weaned pigs composed 12 replications per treatment and two animals (one barrow and one gilt) per experimental unit. Fecal score was daily evaluated to calculate diarrhea incidence. Treatment effect was observed neither on intestinal microbiology nor on diarrhea incidence. The antimicrobial agents improved average daily gain of weanling pigs, during 1-35 (+21.4%) and 15-35 (+22%) days of experimental periods, compared to pigs fed control diet. The probiotic and herbal extract did not improve piglet growth performance. The performance of piglets fed prebiotic was similar to those fed antimicrobials, during 1-14 days of experimental period. However, feed conversion was not improved.

Características morfogênicas e estruturais e produção de forragem do capim-marandu submetido a intensidades e freqüências de desfolhação

Abstract: This trial was carried out to evaluate the influence of defoliation intensities (10 and 20 cm stubble height) and defoliation frequencies (three cut intervals based on the appearance of 5, 7 and 9 leaves/tiller after each defoliation event) on the morphogenetic and structural traits, tillering and herbage production of Brachiaria brizantha cv Marandu swards. Treatments were allocated to experimental units according to a completely randomized design, in a 2 x 3 factorial arrangement, with three replications, in a total of 18 experimental units. Two cuts were performed in the most frequent treatment and one cut for the remaining treatments. Greater defoliation intensity resulted in greater leaf tissue turn over and, when combined to greater defoliation frequencies resulted in younger tillers, which grew up in an environment with lesser light competition. Cutting intensity at 20 cm favored tiller transition from vegetative to reproductive stage, resulting in greater contribution of pseudo stem and dead material to the herbage mass. If frequent defoliation is used, the 10 cm stubble height is the recommended intensity. If less frequent defoliation is used, the 10 cm stubble height may decrease herbage yield, mainly when using the seven leaves frequency. Greater defoliation frequencies showed greater sward renovation, with greater leaf elongation and leaf appearance rates, greater leaf blade length and lesser pseudo-stem accumulation and elongation. Although greater herbage production was obtained at the 20 cm cutting height and 7 leaves frequency, considering all evaluated traits, more frequent cuts promoted greater tissue turn over with high herbage production characterized by its high amount of leaves and less amount of pseudo stem and dead material, allowing for higher herbage production efficiency.

Fatores ambientais que afetam a produção e a composição do leite em rebanhos assistidos por cooperativas no Rio Grande do Sul

Abstract: The effects of some environmental factors on milk yield and milk chemical composition and also on somatic cells count in dairy herds assisted by cooperatives (DHI) in Rio Grande do Sul, Brazil were investigated in this trial. Data were obtained from a 5-year period of dairy control program totalizing 165,311 observations and were used to investigate the effects of year and month of dairy control, age at calving, time of farm on dairy control and stage of lactation on milk yield and composition. Milk yield including all observations averaged 19.36 L/cow/day. Greater milk yield was observed in cows varying from 5 to 6 years of age at calving, at the first 60 days of lactation, in the winter months and in herds with longer time in dairy control. Increased somatic cells count was associated to reduction in milk yield. Lower contents of milk fat and milk protein and greater somatic cells number were observed at the first 60 days of lactation. Concentration of milk lactose decreased with both the increment in somatic cells count and age at calving. Somatic cells count increased as the age of cows advanced and as lactation progressed. Milk contents of protein, fat and lactose all increased during the winter months possibly because of feeding temperate grasses. Results from this study showed that is important taking into account the effects of environmental factors on milk composition.

Caracterização morfométrica de ovinos da raça Santa Inês criados nas microrregiões de Teresina e Campo Maior, Piauí

Abstract: This study aimed to carry out the phenotypic characterization of males and females of Santa Ines hair sheep through body weight measurements and morphmetric and conformation evaluations at different ages. Data consisted of body weights and measurements from 1,113 animals raised in Teresina and Campo Maior regions of Piaui State under pasture regime and 824 animals that participated in Agricultural Fairs in Teresina. Adjusted means for body weight, withers and croup height, corporal and croup length, thoracic perimeter and two indexes of body capacity of the animal were compared by the Student-Newman-Keuls test. The management effect was an important source of variation for the evaluated traits and the sexual dimorphism was more accentuated in the oldest animals. The effects included in the model influenced more the body weights than the morph metric measurements. The index of body capacity (weight and length) indicated a trend for more accumulation of fat in oldest males than in females. The body weight and the morphmetric measurements were positively correlated indicating the possibility of correlated response in breeding programs for the Santa Ines breed.

Intake, digestibility and urinary excretion of urea and purine derivatives in heifers with different body weights

Abstract: - The objective of this trial was to evaluate the effect of body weight (BW) of heifers on intake, apparentdigestibility of nutrients, microbial protein synthesis, ruminal metabolism, and urinary excretion of nitrogenous compounds.The spot urine sampling and the total collection of urine techniques were used to estimate microbial N flow. Twenty-two heiferswith different body weights (523, 453, 315, 235 and 118 kg) were used in a completely randomized design and assigned tothe following treatments: BW523, BW453, BW315, BW235 or BW118. Animals were fed corn silage ad libitum plus 1.5 kg/dayof concentrate on treatments BW523, BW453, BW315 and BW235 and 2 kg/day on BW118 treatment. Intake of nutrientsincreased linearly from treatment BW118 to BW523. However, the opposite was observed when DMI was expressed aspercentage of BW. Digestibilities of DM and OM and dietary TDN did not differ among treatments but digestibilities of CPand NDF corrected for ash and protein (NDF ap ) were greatest and lowest on BW118 treatment, respectively. The urinaryexcretion of urea (mg/kgBW) was higher on BW118 heifers and varied with BW and dietary contents of CP and RDP. Microbialprotein synthesis was not affected by sampling methodology and was lowest on treatment BW118. Therefore, spot urinesampling can be used to estimate urinary excretion of nitrogenous compounds and microbial protein synthesis.Key Words: Holstein, microbial protein, NDFap, serum urea nitrogen, spot sample

Consumo e tempo diário de pastejo por novilhos Nelore em pastagem de capim-tanzânia sob diferentes ofertas de forragem

Abstract: Os efeitos de diferentes niveis de oferta de forragem, associados a alteracoes no dossel induzidas pelo pastejo, sobre o tempo de pastejo e o consumo de forragem por novilhos mantidos em pastagem de capim-tanzânia foram avaliados neste experimento. Os quatro niveis planejados de oferta de forragem (OF) (kg de MS de lâmina foliar/100 kg de PV animal/dia, %) resultaram em OF de 6,1 ± 0,59; 11,1 ± 0,77; 18,0 ± 1,24; e 23,9 ± 1,15%. Cada piquete foi pastejado por oito animais Nelore, com peso medio de 229,0 e 249,5 kg, para o primeiro e segundo periodos de amostragem, respectivamente. Foi utilizado um delineamento em blocos casualizados com quatro tratamentos, definidos pelos niveis medios de oferta de forragem. O tempo de pastejo, a disponibilidade de materia seca de folhas, a relacao folha/colmo e a altura do dossel apresentaram alta correlacao com o consumo de forragem e podem ser utilizados no desenvolvimento de modelos de predicao de consumo de forragem ou desempenho animal em pastejo. Estudos avaliando consumo e desempenho de animais em pastejo em relacao a ofertas de forragem necessitam de descricoes das disponibilidades e condicoes estruturais da pastagem para interpretacao e comparacao de resultados. Alteracoses nas OF de capim-tanzânia, associadas aquelas nas condicoes estruturais da pastagem induzidas pelo pastejo tiveram efeito quadratico sobre o tempo diario de pastejo e o consumo de forragem de novilhos Nelore. O menor tempo de pastejo e o maior consumo de forragem foram verificados no nivel de OF proximo a 22,5 kg de lâminas foliares/100 kg PV, que corresponde a um residuo pos-pastejo em torno de 4.323,2 kg/ha de MS, 2.887,6 kg/ha de materia verde seca e altura media do dossel de 64 cm.

Demografia de perfilhos basilares em pastagem de Brachiaria decumbens adubada com nitrogênio

Abstract: Em um ensaio de pastejo sob lotacao continua avaliaram-se as taxas de aparecimento, mortalidade e sobrevivencia, a porcentagem de florescimento e a densidade populacional de perfilhos basilares em uma pastagem de Brachiaria decumbens adubada com quatro doses de nitrogenio (75, 150, 225 e 300 kg/ha.ano). Os resultados foram agrupados em tres periodos do ano: fevereiro a abril, maio a agosto e setembro a novembro. O experimento foi conduzido em parcelas subdivididas no tempo segundo delineamento em blocos completos casualizados, com duas repeticoes. A adubacao nitrogenada foi parcelada em tres aplicacoes: a primeira no mes de dezembro de 2002, a segunda em janeiro de 2003 e a terceira em marco de 2003. A avaliacao demografica foi realizada em perfilhos demarcados por um anel de PVC. A partir da populacao inicial, a cada mes os perfilhos foram identificados utilizando-se arames de cores diferenciadas. Para avaliacao da densidade populacional de perfilhos basilares (vegetativos, reprodutivos e mortos), foram colhidas amostras de plantas delimitadas por tres quadrados de 25 x 25 cm por piquete. A adubacao nitrogenada influenciou as taxas de aparecimento e sobrevivencia, o numero de perfilhos vegetativos e a mortalidade de perfilhos na primeira e segunda geracoes apos o inicio das avaliacoes. As maiores taxas de aparecimento ocorreram nos periodos de fevereiro/abril e setembro/novembro, enquanto a maior taxa de mortalidade, em fevereiro/abril. A densidade populacional de perfilhos tambem variou, atingido os maiores valores no periodo de fevereiro/abril. O florescimento do capim-braquiaria se concentrou nos meses de fevereiro a maio.

Exigências de lisina digestível para juvenis de tilápia-do-nilo

Abstract: Este estudo foi realizado com o objetivo de determinar a exigencia de lisina digestivel para juvenis de tilapia-do-nilo. Noventa e seis peixes revertidos sexualmente e com peso vivo inicial de 5,72 ± 0,10 g foram alimentados por 42 dias com quatro racoes (29.51% de PB e 3.235 kcal de energia digestivel/kg) contendo diferentes niveis de L-lisina HCl (0,1; 0,3; 0,5 e 0,7%, correspondendo a racoes com 1,04; 1,27; 1,51 e 1,741% de lisina digestivel, respectivamente). Os peixes foram distribuidos em 16 tanques com capacidade de 1.000 L cada um, em um delineamento inteiramente casualizado, com quatro tratamentos, tres repeticoes e seis peixes por unidade experimental. Nao foi observado efeito dos niveis de lisina sobre o indice hepato-somatico, a gordura visceral, a sobrevivencia e os teores de agua e extrato etereo na carcaca. A analise de Linear Response Plateau do ganho de peso e da conversao alimentar versus niveis de lisina digestivel demonstrou estimativa de exigencia de 1,56 e 1,44% de lisina digestivel, respectivamente. Foi observado efeito quadratico sobre o rendimento de carcaca, que aumentou ate o nivel de 1,61% de lisina digestivel. Considerando o desempenho, recomenda-se que dietas para juvenis de tilapia-do-nilo devem conter 1,44% de lisina digestivel (5,23% da proteina da dieta).

Comportamento ingestivo de cabras Alpinas em lactacao alimentadas com dietas contendo diferentes niveis de fibra em detergente neutro proveniente da forragem

Abstract: Avaliou-se o efeito de diferentes niveis de fibra em detergente neutro proveniente da forragem (FDNF) na dieta sobre o comportamento ingestivo de cabras em lactacao. Cinquenta cabras da raca Alpina foram distribuidas em um delineamento inteiramente casualizado, com cinco tratamentos e dez repeticoes, sendo alimentadas a vontade com dietas contendo 20, 27, 34, 41 ou 48% de FDNF. Foi utilizada uma racao completa com feno de tifton-85 (Cynodon sp.) + mistura concentrada constituida de fuba de milho (Zea mays L.), farelo de soja (Glycine max L.) e mistura mineral. As dietas foram fornecidas duas vezes ao dia, as 8h30 e 16h30. O comportamento ingestivo foi determinado mediante observacao visual individual dos animais, durante 24 horas, a intervalos de 10 minutos para se determinar o tempo despendido em alimentacao, ruminacao e ocio. O tempo com alimentacao e ruminacao e o tempo de mastigacao total aumentaram linearmente, enquanto o tempo de ocio diminuiu linearmente com o aumento do nivel de FDNF nas dietas. Observaram-se efeitos linear decrescente na eficiencia de alimentacao e ruminacao (g MS/h) e linear crescente no numero diario de refeicoes, conforme amumentaram os niveis de FDNF.

Características quantitativas da carcaça de cordeiros deslanados Morada Nova em função da relação volumoso:concentrado na dieta

Abstract: Eighteen lambs averaging initial body weight (BW) of 15 kg were allotted to six groups of three animals (one lamb per diet) and were fed diets with following forage:concentrate ratios (F:C): 1) 40F:60C; 2) 55F:45C; or 3) 70F:30C Lambs of each group were slaughtered when the animal fed the diet with the highest concentrate level reached 25 kg of BW Animals were slaughtered after 16 h of fasting (feed and water) After obtaining the slaughter body weight (SBW), animals were anesthetized by electric discharge and killed by bleeding of the carotid arteries and jugular veins Blood was then collected and weigthed Soon after evisceration, skin, head and extremities of the fore and rear members were removed The gastrointestinal tract (GIT) was emptied, weighted and the value added to that of blood to obtain the empty body weight (EBW), which was calculated by subtracting SBW from GIT + blood weights The carcasses were weighted and stored at 4°C within a 24-hours period The empty body (EBW), hot carcass (HCW) and cold carcass weights (CCW) were all used to calculate the biological (BY), hot carcass (HCY) and cold carcass yields (CCY) as well as the weight loss by cooling process (CWL) The carcass was divided in five cuts (leg, loin, ribs, shoulder clod and neck) that were weighted for calculation of cut yields The leg was dissected in muscle, bone and fat, and weights of these tissues were expressed in absolute weight and in percentage of leg weight The muscle:bone and muscle:fat ratios, index of leg muscularity (ILM) and the loin eye area (LEA) were also calculated Increasing dietary concentrate from 30 to 60% increased not only hot and cold carcass yields but also biological yield The increasing levels of concentrate in the diet showed no effect on the percentage of leg muscle However, it was observed an increase in both fat deposition and rib eye area

Estimação de parâmetros genéticos para peso do nascimento aos 550 dias de idade para animais da raça Tabapuã utilizando-se modelos de regressão aleatória

Abstract: Data provided by the Brazilian Zebu Breeders Association (ABCZ), consisting of 21,762 records from 4,221 animals of Tabapua cattle, weighted from birth to 550 days of age, were used to estimate covariance functions by random regression models using Legendre polynomials of order two to five. Models included the direct and maternal genetic, animal and maternal permanent environmental random effects and compared by Schwarz´s Bayesian information criteria (BIC) and Akaike´s information criteria (AIC). Both criterions suggested the model including direct genetic, maternal genetic, animal permanent and maternal permanent environmental effects respectively adjusted by cubic, quadratic, fourth order and linear polynomials, and residual variances adjusted by fifth order variance function as the best one to describe the covariance structure of the used database. Direct heritability estimates were higher at the beginning and at the end of the growth trajectory. Maternal heritability estimates increased from birth to 160 days of age and decreased thereafter. In general, genetic correlation estimates decreased as age between weights increased. Efficiency of selection may be improved by using weights of the post weaning period because of their higher genetic variance and heritability estimates.

Polpa de caju em rações para frangos de corte na fase final: desempenho e características de carcaça

Abstract: A pesquisa foi desenvolvida com os objetivos de avaliar o desempenho e as caracteristicas de carcaca de frangos de corte alimentados com dietas contendo diferentes niveis de polpa de caju desidratada e analisar a viabilidade economica desse sistema de producao. Foram utilizados 320 frangos com 22 dias de idade, da linhagem Ross, de ambos os sexos, distribuidos em delineamento em blocos casualisados, com quatro tratamentos - niveis de inclusao (0, 5, 10 e 15%) de polpa de caju desidratada (PCD) - e cinco repeticoes com 16 aves. Aos 42 dias de idade, foram selecionadas, por peso e sexo, quatro aves (dois machos e duas femeas) por unidade experimental, as quais foram abatidas para avaliacao do rendimento de carcaca e de seus cortes. A inclusao de ate 15% de polpa de caju desidratada em racoes para a fase de crescimento nao influenciou o consumo, o ganho de peso e as principais caracteristicas de carcaca dos frangos de corte. A conversao alimentar piorou e a viabilidade economica (renda bruta e margem bruta media) foi menor com o incremento da polpa de caju desidratada nas racoes. O uso de polpa de caju desidratada para frangos de corte depende do preco da polpa em relacao ao preco do ingrediente convencional (milho) e do oleo vegetal utilizado na formulacao da dieta.

Avaliação econômica da terminação em confinamento de novilhos jovens e superjovens de diferentes grupos genéticos

Abstract: The objective of this study was to economically evaluate feedlot finished steers and young steers from two genetic groups: 5/8Charolais (CH) 3/8Nellore (NE) and 5/8NE 3/8CH. The average age of animals at the end of the experimental period was 22.8 and 15.2 months for steers and young steers, respectively. Animals were maintained in the feedlot until reach the previously established slaughter weight of 430 kg. Animals were fed a diet containing a forage:concentrate ratio of 60:40 with the following chemical composition: 10.25% crude protein and 3.18 Mcal of digestible energy/kg of dry matter. Economical evaluation was performed as follows: FW - period spent for young steers to reach final body weight similar to steers and FBCS - period spent for young steers to reach final body condition score (FBCS) similar to steers. Variables responsible for most of the total production cost of one hectare of corn silage were: crop fertilizer (23.27%), nitrogen fertilizer (16.05%), seeds (11.56%), insecticide (9.97%), post-emergent herbicide (9.40%), and canvas (6.85%). Of the total estimated cost of the diet, forage represented 23.75% and concentrate 76.25%. The cost per kg of weight gain was similar between steers and young steers FW (R$ 1.29/kg) and greater than young steers FBCS (R$ 1.18/kg). Total and monthly profitabilities were, respectively, 25.79 and 4.19% for steers and 26.19 and 2.68% for young steers (FW) and 28.11 and 3.60% for young steers (FBCS) showing that reduction of the feeding period of feedlot beef steers increases profitability. Among genetic groups, 5/8CH 3/8NE animals showed higher total net income as well as total and monthly profitabilities compared to 5/8NE 3/8CH.

Características de carcaça e dos componentes não-carcaça de cabritos Moxotó e Canindé submetidos a dois níveis de alimentação

Abstract: Foram utilizados 22 cabritos nao-castrados (10 Moxoto e 12 Caninde com peso medio inicial de 15 kg) confinados em baias individuais. Os animais foram distribuidos em um delineamento inteiramente casualizado, em arranjo fatorial 2 x 2 (duas racas e dois niveis de alimentacao: AV = a vontade e AR = 30% de restricao). Foram avaliados os rendimentos de carcaca quente (RCQ), verdadeiro (RV) e comercial (RC), os cortes da carcaca e o rendimento dos componentes nao-carcaca em relacao ao peso do corpo vazio (PCV). Cabritos alimentados a vontade apresentaram maiores RCQ e RC e porcoes comestiveis da carcaca. O rendimento verdadeiro nao foi influenciado pelo maior nivel de alimentacao. Apos o abate e resfriamento da carcaca, foram feitos os seguintes cortes: pescoco, paleta, costelas (1a-5a), costelas (6a-13a), lombo, perna e baixo. Apesar do maior peso (kg) dos cortes dos animais alimentados AV, nao foi observada diferenca entre seus rendimentos em relacao ao peso da carcaca fria. O rendimento da perna foi afetado pelo nivel de alimentacao, sendo menor para os grupos com nivel de alimentacao AV. Os rendimentos do figado, da cabeca e do trato gastrintestinal foram influenciados pelo nivel de alimentacao. A raca nao foi determinante de diferencas nas caracteristicas de carcaca e dos componentes nao-carcaca, assim como no rendimento dos cortes quando o peso e o tamanho a maturidade foram semelhantes. A restricao alimentar afetou o desenvolvimento e a deposicao de tecidos nos animais, resultando em menores rendimentos e quilogramas de carcaca fria a ser comercializada.

Curvas de crescimento e de deposição dos componentes corporais em aves de postura de diferentes linhagens

Abstract: The growth curves of egg pullets of semi heavy: Hy Line Brown (HLB) and Hisex Brown (HSB) and light strains: Hy Line W36 (HLW36) and Hisex White (HSW) were evaluated. Three hundred birds of each strain were assigned to a completely randomized design with four replicates of 75 birds. Body weight (BW), feather weight (FW) and body depositions of protein, fat, ash and water were weekly measured. The growth curves were determined by Gompertz function with data collections. The semi heavy birds were later than the light ones for BW, with greater body growth rates and weights at maturity. The HLW36 were 64.23 g lighter at maturity than the HSW. Data obtained for feather growth and protein deposition were similar, but the semi heavy birds showed greater weight at maturity (WM) than the light ones. However, for these components, the birds Hy Line had larger depositions than Hisex. HLW36 strain had smaller feather rate at maturity, making it three days later than HSW. The lowest protein deposition in the end of growth period caused the deviation of energy ingested for fat deposition in HSB birds and overestimated the WM in relation to HLB birds. Hy Line birds had later body ash composition and showed greater WM than Hisex. Among the studied variables, Hy Line birds had always heavier WM, however, the body water content of Hisex birds was greater and the maximum rates at maturity were later. This fact explains the similarity in the weight gain among the studied strains, once other body components were greater for Hy Line birds.

Desempenho e características de carcaça de bovinos Nelore em confinamento alimentados com bagaço de cana-de-açúcar e diferentes fontes energéticas

Abstract: Avaliaram-se o ganho de peso e as caracteristicas da carcaca de bovinos Nelore alimentados com bagaco de cana-de-acucar (in natura ou hidrolisado) como volumoso e concentrado contendo farelo de germen de milho, casca do grao de soja ou polpa de citrus em substituicao parcial (50%) ao milho. Quarenta bovinos Nelore (peso medio inicial de 340 kg e idade inicial de 32 meses) foram alimentados com quatro dietas fornecidas na proporcao volumoso:concentrado 39:61. As fontes substitutivas do milho nao afetaram o peso final (470,8; 478,6; 476,4 e 475,3 kg) e o ganho medio diario (1,1; 1,1; 1,1 e 1,2 kg/animal/dia). Nao houve efeito sobre o rendimento de carcaca (55,3; 55,3; 54,0 e 54,8%), a area de Longissimus (24,2; 23,0; 25,0 e 23,2 cm2/100 kg de carcaca) e a espessura de gordura (4,4; 5,6; 4,7 e 4,4 mm). O menor custo por arroba foi observado no tratamento com polpa de citrus (R$ 44,20), seguido do farelo de germen de milho (R$ 48,80) e da casca de soja (R$ 50,80), porem, quando utilizado somente o milho, o custo da arroba foi de R$ 51,80. O milho moido pode ser parcialmente substituido pelo farelo de germen de milho, pela casca de soja ou pela polpa de citrus em dietas para bovinos em confinamento alimentados com bagaco de cana-de-acucar (in natura ou hidrolisado) como volumoso, pois a substituicao nao alterou o ganho de peso e as caracteristicas de carcaca.

Nitrogênio e enxofre em características produtivas do capim-braquiária proveniente de área de pastagem em degradação

Abstract: Objetivou-se avaliar os efeitos de combinacoes de doses de N com as de S para as caracteristicas produtivas do capim-braquiaria (Brachiaria decumbens), coletado em cilindros com plantas + solo em uma pastagem em degradacao em area de Neossolo Quartzarenico. O experimento foi conduzido em casa-de-vegetacao, no periodo de novembro de 2003 a marco de 2004. Foram utilizadas cinco doses de N (0; 100; 200; 300 e 400 mg/dm3) e cinco doses de S (0; 10; 20; 30 e 40 mg/dm3), combinadas em estudo de superficie de resposta baseado em desenho experimental composto central modificado de um fatorial 52 fracionado. Realizaram-se tres cortes nas plantas, em intervalos de 30 dias. As doses de N e de S foram determinantes para o numero de perfilhos, producao de massa seca das lâminas foliares e dos colmos mais bainhas no primeiro crescimento da graminea e para a relacao folha:colmo no segundo crescimento. A adubacao com N teve efeito isolado no numero de perfilhos e na producao de massa seca das lâminas foliares e dos colmos mais bainhas no segundo e no terceiro crescimentos. O numero de folhas foi influenciado pelas doses de N e de S de forma isolada, no primeiro crescimento, e pelas doses de N no segundo e no terceiro crescimentos. As relacoes entre as doses de N e as de S para obtencao das maximas producoes de massa seca foram, de maneira geral, em torno de 10:1. A aplicacao, principalmente de N mas tambem de S, influenciou as caracteristicas produtivas do capim-braquiaria e consequentemente a sua recuperacao.

Cana-de-açúcar em substituição à silagem de milho em dietas para vacas em lactação: parâmetros digestivos e ruminais

Abstract: This trial was conducted to evaluate the effects of replacing corn silage with sugarcane on intake, apparent digestibility of nutrients, ruminal pH and ammonia nitrogen, and ruminal passage rate of digesta in lactating dairy cows. Proportion sugarcane increased as follows: 0, 33.3, 66.6 and 100% of the forage portion of the diet. Twelve Holstein and crossbred Holstein/Zebu cows with potential yield varying from 5,000 to 7,000 kg of milk per lactation were randomly assigned to three 4x4 Latin squares. Cows were maintained in individual stalls and were fed ad libitum twice a day a diet containing a forage:concentrate ratio of 60:40 during the 84-days experimental period. Replacing corn silage with sugarcane linearly reduced the intakes of all nutrients with the exception of lignin and nonfiber carbohydrates. No significant effects on apparent digestibilities of dry matter, organic matter and crude protein were observed by replacing corn silage with sugarcane in this trial. However, neutral detergent fiber digestibility decreased and that of nonfiber carbohydrates increased when sugarcane replaced corn silage in the diet. Although ruminal pH did not differ among treatments, a significant quadratic response was found according to time after feeding. Significant quadratic responses were also observed for concentration of ruminal ammonia by increasing the proportion of sugarcane in the diet as well as time past the morning feeding. Ruminal passage rate of digesta decreased and average total retention time increased as sugarcane replaced corn silage, which possibly explains the observed reduction in dry matter intake. Therefore, it is recommended to include up to 33% of sugarcane in the diet of lactating dairy cows yielding 24 kg of milk per day.

Inclusão de fontes de óleo na dieta de cabras em lactação: produção, composição e perfil dos ácidos graxos do leite

Abstract: The objectives of this trial were to evaluate the effect of dietary oil supplementation on milk yield, milk composition and milk fatty acids profile of lactating Saanen goats. Four ruminally cannulated multiparous goats averaging 54±1.02 kg BW and 80 days in milking were used. Goats were fed a control diet or a diet supplemented with one the following oil sources: canola, rice or soybean. The statistical design was a 4 x 4 Latin square and data were analyzed using the MIXED procedure of SAS (2001). Mean comparisons were done by orthogonal contrasts with significance level at 10%. Except for content of milk total solids, no significant differences were observed for milk yield and milk composition by feeding different oil sources to lactating goats. Oil supplementation increased milk fat concentration of 18:0, 18:1n-9 and 18:2 (CLA) and decreased that of saturated fatty acids (SFA), short chain fatty acids (SCFA) and medium chain fatty acids (MCFA). Oil supplementation also increased milk concentration of monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA), long chain fatty acids (LCFA), n-3, n-6 and the PUFA/SFA ratio. Feeding soybean oil to lactating goats increased milk content of PUFA, n-6, and the ratios of n-6/n-3 and PUFA/SFA and decreased concentration of 22:6n-4 compared to canola oil. Inclusion of vegetable oils in diet of lactating goats improved milk nutritional quality due to increased concentration of desirable fatty acids.

Uso de prebióticos à base de mananoligossacarídeo em rações para frangos de corte

Abstract: O experimento foi realizado com objetivo de estudar o uso de mananoligossacarideos (standard e concentrado) em racoes para frangos de corte. Foram utilizados 1.080 pintos de corte machos da marca Ross, com peso medio inicial de 42 g, distribuidos em um delineamento inteiramente ao acaso, com seis tratamentos e nove repeticoes de 20 aves por unidade experimental. As aves foram criadas em cama de maravalha reaproveitada, utilizada anteriormente por outro lote. Foram testados os tratamentos: testemunha, antibiotico (avilamicina), mananoligossacarideo alta concentracao (MOS AT), mananoligossacarideo standard (MOS ST), MOS AT + avilamicina e MOS ST + avilamicina para avaliacao do ganho de peso, do consumo de racao, da conversao alimentar, da viabilidade e do rendimento de cortes. No periodo de 1 a 21 dias de idade, nao foram encontradas diferencas significativas entre os tratamentos para as variaveis consumo de racao, conversao alimentar e viabilidade economica. Os resultados de desempenho das aves alimentadas com racao contendo MOS ST ou MOS AT, combinados ou nao com o antibiotico, nao diferiram dos obtidos nos tratamentos com avilamicina e da racao basal. No periodo de 1 a 42 dias de idade, a adicao de MOS ST, combinado ou nao com avilamicina, melhorou o ganho de peso das aves, enquanto o MOS AT afetou de forma negativa o ganho de peso. A conversao alimentar, o consumo de racao e a viabilidade economica nao foram influenciados pelos tratamentos. No entanto, o uso de aditivos em racoes para frango de corte melhorou o rendimento de cortes e reduziu a gordura abdominal.

Influência de fatores de ambiente sobre a contagem de células somáticas e sua relação com perdas na produção de leite de vacas da raça Holandesa

Abstract: Cumulative milk yield at 305 days (MY-305) and somatic cell count (SCC) from the first to the fifth lactation of Holstein cows were analyzed in this study. Somatic cell count was logarithmically transformed to somatic cell score (SCS) that was then included in the model not only as a dependent but also as an independent variable. Year, season, and parity order all significantly affected the average SCS in this study. Data of the effect of SCS on milk yield showed significant losses on MY-305 because of the observed negative linear relationship between these two variables. Somatic cell score affected differently MY-305 from different parity orders with greater effect after the 3rd parity. Although clinical mastitis seems to cause greater economic losses, prevention and control of sub-clinical mastitis deserve more attention due to its greater prevalence leading to significant reduction on herd productivity.

Utilização de Saccharomyces cerevisiae como probiótico para tilápias-do-nilo durante o período de reversão sexual submetidas a um desafio sanitário

Abstract: A 29-d experiment was carried out to evaluate the Saccharomyces cerevisiae (SC) as probiotic in diets for Nile tilapia (Oreochromis niloticus) during the sexual reversion phase, under a sanitary challenge. Three hundred 2-d larvae averaging 8.9 ± 1.02 mg and 0.71 ± 0.09 cm were allotted to a completely randomized design with two treatments and six replicates in twelve 50 L-aquaria. Sanitary challenge consisted of a daily supply of 0.5 mL of fresh swine manure. Treatments consisted of a commercial diet for the sexual reversion of tilapia, with (TP) or without (TT) 0.1% of S. cerevisiae. The larvae were fed ad libitum five times a day. At the end of experiment, the fries were counted, measured and weighed. Two fries of each treatment were randomly chosen for gu removal and counting of the number of bacteria and total coliforms. No treatment effect on performance and survival was observed. Only the intestine of TP fries was colonized by SC. No significant differences were observed for bacteria and total coliforms per g of intestinal content and aquarium water. The use of Saccharomyces cerevisiae as probiotic in diets for Nile tilapia (Oreochromis niloticus) during the sexual reversion period resulted in intestine settling with no effect on performance and survival, in a system of culture with sanitary challenge.