Antonio Ilson Gomes de Oliveira

Parâmetros genéticos de longevidade e produtividade de fêmeas da raça Nelore

In order to estimate the (co)variance components, heritabilities and genetic correlations of longevity and herd life in females, informations of 56,413 births of females from a Nellore cattle herd, from 1950 to 2000, under different rearing and management conditions, were used. It was studied from calf: weaning weight (W205C), yearling weight (W365C), weight in 550 days (W550C), from cows: weaning weight (W205), yearling weight (W365) and weight in 550 days (W550), age at first calving (AFC), calving interval (CI), herd life (RL), longevity (LONG), reproductive efficiency (RE), index production (IP), index of metabolic production (IMP), sum of index production (SIP), sum of index metabolic production (SIMP). The analysis were performed using the MTDFREML software, estimating (co)variance components, assuming animal model. Direct genetic, maternal and permanent environmental effects were analyzed. Fixed effects of farm, feeding program, rearing condition, birth calf year, birth calf season and calf sex, were also analyzed. Heritability estimates showed similar results among the different analyses, higher (0.24 to 0.75) for W205, W365, W550, W205C, W365C, W550C, IP, IMP, AFC, RL, LONG and lower (0 to 0.10) for RE, CI, SIP and SIMP. Some correlations between maternal genetic effect and the growth traits were negative. In general, estimates of genetic and phenotypic correlations among LONG and growth traits were negative, suggesting genetic antagonism between LONG and early maturity, between the LONG and reproductive and productive traits were positive, suggesting the significant effect of reproductive and productive traits on LONG.

Curvas de crescimento e influência de fatores não-genéticos sobre as taxas de crescimento de bovinos da raça Nelore

Non-genetic effects were evaluated on growth rate of Nelore cattle from birth to 205 days (TX1), 205 to 365 days (TX2), and 365 to 550 days (TX3) of age. The data came from nine bimonthly weight-age records, from birth to two years of age, of 1.138 animals, 508 males and 630 females, collected between 1978 and 1993. Brody, Gompertz, Richards, Bertalanffy and Logistic nonlinear models were fitted for each animal, generating weight estimates at different ages. Gompertz model showed the best fitting and was chosen for growth rates computations. Effects (P<0,01) of sex on TX2 and TX3, year of birth on all growth rates, and season of birth on TX2 and TX3 (P<0,01), were observed. The optimization of management techniques in specialized herds is possible with the informations of the non-genetic factors that influence growth rates at distinct ages.Avaliou-se a influencia de efeitos nao-geneticos sobre as taxas de crescimento de bovinos da raca Nelore nas seguintes fases: do nascimento a desmama, 205 dias, (TX1); da desmama a um ano, 365 dias, (TX2); e de um ano ao sobreano, 550 dias, (TX3). Os dados constam de nove pesagens bimestrais do nascimento aos dois anos de idade, observadas entre 1978 e 1993, em 1.138 animais da raca Nelore, sendo 508 machos e 630 femeas. Os modelos nao-lineares de Brody, Gompertz, Richards, Bertalanffy e Logistico foram ajustados aos dados de peso-idade de cada animal, para a obtencao de pesos em idades de interesse. O modelo de Gompertz foi o que melhor se ajustou aos dados e, a partir dele, foram calculadas as taxas de crescimento. Foram observadas influencias (P<0,01) de sexo sobre TX2 e TX3, de ano sobre todas as taxas e de epoca de nascimento sobre TX2 e TX3. Com a identificacao dos fatores nao-geneticos que influenciam a eficiencia do crescimento dos animais em diferentes fases de sua vida, torna-se possivel otimizar as tecnicas de manejo empregadas em rebanhos especializados.

Source of variation and genetic parameters of days open and days dry in Holstein dairy cattle in Minas Gerais State

The objective of this work was to evaluate the effect of some environmental factors on days open (DO) and days dry (DD), as well as to estimate genetic parameters for these traits in Holstein breed cows. A total of 6,485 records of DO and DD were used. The database were analyzed using a model that included the fixed effects of dairy group farmers, calving year, calving season, production level (PL), genetic group (GG), calving age class (CA) and the first order interactions between PL, GG and CA, and the random effect of bulls. The means, standard error and coefficients of variation for DO and DD were 121.21 (0.69) days, 46.10% and 92.27(0.59) days, 51.71%, respectively. For DO, effects of bull, dairy group farmers, calving year, calving season , PL were significant and was observed interaction between PL and GG. For DD, the effects of dairy group farmers, calving year, calving season, PL, CA and the interaction between PL and GG and for bull were significant. Genetic group did not affected the studied variables and a reduction in DO and DD with year was observed. The heritability estimate in univariate and bivariate analyses were 0.052 and 0.027 for DO, and 0.004 and 0.0001 for DD, respectively. The repeatabilities for DO and DD were 0.06 and 0.03, respectively. It was observed that the environmental effects are the most important on these traits. The genetic, phenotypic and environmental correlations between DO and DD (0.55, 0.72 and 0.73, respectively) show that cows with higher DO had greater days dry.

Efeitos de programas de iluminação na produção de ovos de codornas (Coturnix coturnix)

Com o objetivo de avaliar o efeito de programas de iluminacao continuo e intermitentes sobre a producao de codornas-japonesas (Coturnix japonica) criadas em galpao aberto, neste trabalho, realizado no Departamento de Zootecnia da Universidade Federal de Lavras MG, utilizaram-se 720 codornas de 36 semanas de idade, durante 5 periodos de 28 dias submetidas a 3 programas de luz em delineamento inteiramente ao acaso com restricoes nos tratamentos e 12 repeticoes. O programa continuo contou com fotoperiodo medio de 15h30 (natural + artificial) e noite principal (escotoperiodo) de 8h30 (± 12 min); o programa intermitente 1 contou com iluminacao intermitente com duas fotofases fracionadas em 15h30 e com uma noite principal de 8h30 (± 12 min); o programa intermitente 2 teve iluminacao intermitente com 3 fotofases em um periodo estimulatorio de 15h30 (duas fotofases e duas escotofases equidistantes entre a luz natural) e escotoperiodo de 8h30. Avaliaram-se o consumo de racao (g/ave/dia), producao de ovos (ovos/ave/dia x 100), peso e massa dos ovos (g), conversao alimentar expressa por peso de ovo (g/g) e por duzia de ovos e as medias foram comparadas pelo teste SNK (5%). Os resultados das aves nos diferentes programas apresentaram-se semelhante (P>0,05) para postura, peso, massa dos conversao/duzia de ovos. As codornas no programa intermitente 1 apresentaram menor (P<0,05) consumo de racao e melhor (P<0,05) conversao alimentar/peso de ovos em relacao as aves dos demais programas. O uso de programas de iluminacao intermitente em codornas criadas em galpao aberto, a partir da 36a semana de idade, reduz o tempo de iluminacao artificial, sem afetar a producao de ovos, o peso, massa de ovos e conversao alimentar/duzia de ovos; no entanto, o consumo de racao e reduzida e a conversao alimentar/peso de ovos e melhorada com o regime intermitente 1.

Avaliação de carcaças de suínos da raça Large White utilizando medidas convencionais

To establish the measures that best define the quality of the carcass of swine, data of lean meat yield (MY), fat yield (FY), dressing percentage (DP), carcass length for the Brazilian Method of Carcass Classification (CLBM), carcass length for the American Method of Carcass Classification (CLAM), average backfat thickness (ABT), backfat thickness 4 cm from the dorsal mid-line (P1), backfat thickness 6.5 cm from the dorsal mid-line (P2), backfat thickness 8 cm from the dorsal mid-line (P3), loin eye area (LEA), lean:fat ratio (LFR) and ham yield (HY) were used, obtained in 664 Large White swine. Initially, in order to make clear the importance and possible relations structures among variables, the cluster analysis was used. Afterwards, the multiple regression linear model was used, using the SAS package. Firstly, it was estimated the partial correlation (Type II) of each trait to evaluate the importance of the quality variables of the carcass. Secondly, a procedure of adjusting equation selection named Backward was used. It was verified that, except for DP, all the measures of carcass classification evaluated presented correlation with MY and FY. The measures ABT, P1, P2, P3 and LFT were inversely correlated with MY and directly correlated with FY. The opposite was observed for the measures CLBM, CLAM, LEA and HY. ABT, AOL, RCG and RP are just enough to evaluate the quality of the carcass in terms of lean meat yield, and, in terms of FY, besides these measured previous its necessary the evaluation of P1. The measures of loin eye area and average backfat thickness, as proposed by MBCC, shown as being what best evaluates the amount of meat and fat in the carcass.

Curvas de Lactação em Rebanhos da Raça Holandesa no Estado de Minas Gerais: Escolha do Modelo de Melhor Ajuste

Para selecionar o modelo de curva de lactacao de melhor ajuste aos dados de producao de leite no dia de controle de animais da raca Holandesa no Estado de Minas Gerais, utilizaram-se 157.932 controles de 17.150 lactacoes, de 1990 a 1996, do arquivo inicial com 305.506 controles de 56.422 lactacoes, do Servico de Controle Leiteiro da ACGHMG. Ajustaram-se os dados para os fatores: regiao, nivel de producao, ano-estacao de parto, classes de ordem e idade ao parto (COPI), grupo genetico, numero de controles e interacoes, alem dos efeitos linear e quadratico da duracao da lactacao. Para verificar o melhor ajuste aos modelos Quadratico logaritmico, Gamma Incompleta, Regressao Multipla e Multifasico (Monofasico e difasico), foram usados menor desvio padrao residual, R2 ajustado ao numero de parâmetros das equacoes, autocorrelacao de primeira ordem e teste de Durbin-Watson. O uso de uma funcao difasica para predizer a producao de leite em programas de selecao e recomendado, sendo tambem possivel estimar, com base nessa funcao, a producao de leite em 305 dias.

Sires genetic evaluations using complete or partial projected lactation records. 1. Genetic parameters estimates.

Records of 4,595 lactations from 2,254 cows, daughters of 145 sires and 1,618 dams of Gyr breed from 18 herds, with observed calving time from 1980 to 1997, were used to estimate the genetic and phenotypic parameters of milk yield up to 305 days and projected partial lactations. From 91, 151, 211 or 241 days in milk, 10, 30, 50 or 70% of the milk yield were projected for the observed and 305 days of lactation. The genetic parameters were obtained using MTDFREML system. Independent of the trait, as fixed effects the herd-year, calving season and calving age of the cow were included in the animal model, with linear and quadratic effects and it was considered as random effects of animal, the permanent environment and error. Heritability estimates for milk yield up to 305 days (P305d) was 0.17 (0.047), and for the estimated projected production (PE) of one percentage of lactations, ranged from 0.17 (0.048) to 0.27 (0.056). Genetic and phenotypic correlations estimates between P305d and PE ranged from 0.94 (0.466) to 1 (0.589) and from 0.73 (0.236) to 1 (0.194), respectively. The production estimated by projecting the milk productions of 10% of the lactations from 91, 151 and 211 days or by the projection of 10, 30, 50 or 70% of the lactations from the 241 days were similar to that obtained for the milk production up to 305 days, and that the milk productions estimated by the projections of the milk productions were highly correlated with the milk productions up to 305 days.

Determinação de fatores multiplicativos para estimar a produção de leite no dia do controle leiteiro, a partir da produção de leite da manhã ou da tarde

The objective of this work was to determine the multiplicative factors to estimate the milk production (DP) based on the morning (MM) or afternoon (AP) milk yield and their were obtained of 3,632 lactations from 2,143 cows of the Gir breed, daughters of 335 sires, from 1993 to 1996 records. The calving year (Y) lactation length - linear (LL), calving age - linear and quadratic (A) and a factor K (the possible double, triple and quadruple interactions among management level (low-high), class of parity (primiparous-multiparous), calving season (rainy-dry) and nine classes of calving to milk control interval were included in the model to fit these effects on the multiplicative morning (MF) and afternoon factors (AF). Significant effects of Y, I, LL and K on the factors, except effect of LL upon the AF were observed, suggesting the use of factors which simultaneously consider the effects contained in K, besides Y, A and LL, to obtain more precise estimates of milk yield on the day of the milk control. The multiplicative factors of the morning decrease over the lactation, in both seasons, for multiparous and primiparous, and animals raised in herds of high management level. However, AF for multiparous and primiparous, in both seasons, in both level of management, trend to increase over the lactation, except for cows in herds of low management level and in the rainy season, which did not show stable behavior.

Curvas de crescimento de fêmeas da raça nelore e seus cruzamentos

Selecao para caracteristicas do crescimento pode ser feita apos ajustadas funcoes de crescimento para todos os animais sob selecao. Porem, a curva de crescimento de femeas e influenciada pelas gestacoes e lactacoes subsequentes. Neste trabalho, metodos sao descritos para selecionar uma funcao que ajuste a curva de crescimento de femeas bovinas considerando-se os efeitos de variacao de peso corporal devido a gestacao e a lactacao. Foram utilizados dados provenientes do Instituto Agronomico do Parana, constituindo-se de 15.271 observacoes de pesos de 103 femeas, sendo 43 Nelore, 10 F1 Guzera x Nelore, 29 F1 Red Angus x Nelore, 5 F1 Marchigiana x Nelore e 16 F1 Simental x Nelore. Comparou-se o ajuste das funcoes de Brody, Gompertz, Logistica, Von Bertalanffy e Michaelis-Menten reparametrizada (MMr) aos efeitos do ganho de peso em funcao da idade, sendo adicionado a todas as funcoes o ganho de peso durante a gestacao e a perda de peso na lactacao de femeas da raca Nelore e Cruzadas. Ao ajustar as funcoes, observou-se um Coeficiente de Determinacao Multiplo Ajustado variando entre 0,7552 e 0,9267. Observou-se o menor Quadrado Medio do Residuo e o Desvio Medio Absoluto para a funcao de MMr. Para descricao da curva de crescimento em funcao da idade das femeas, deve ser ajustada a funcao de MMr.

Palatabilizantes em dietas para leitões de 6 a 18 kg

A total of 192 weaning crossbred Landrace x Large White piglets weighing 6.9 kg and 23 days old was used to determine the effect of addition of flavours in simple or complex diet on the performance, blood parameters and the organs weight of piglets. A randomized block design, in a 2 x 3 factorial scheme, with two diets (simple or complex) and addition or not of two flavours (F1 and F2), was used. It was observed that the flavour addition did not affect weight gain, feed intake and feed conversion. The complex diet showed better feed conversion than the simple diet. The blood glucose concentration was higher in the pos-prandial period. The simple diet showed higher effect on the glucose levels. The blood glucose concentration was not influenced by the tested flavours. The insulin showed higher levels in the pos-prandial period, although it was also not influenced by both diets, as well as the tested flavours. The weight of liver, pancreas and kidneys was not affected by the addition of flavours, therefore, simple diet showed higher weight, when compared to the complex diet. It was concluded that the used flavours showed no effects on the piglet performance, blood parameters and organs weight.