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ABSTRACT The aim of this study was to identify differences in morphogenesis, structure, and forage accumulation rate of Urochloa brizantha cv. MG13 Braúna, from Urochloa cv. Cayana and Urochloa cv. Convert 330 (sabiá grass) during the deferment period. The experimental design was completely randomized, with four replications in experimental plots of 12.25m2. The evaluations took place for two years, 2021 and 2022. The deferment period was 90 days. Phyllochron (PHY) and leaf senescence rate (LSR) were lower at the beginning of deferred, contrary to leaf elongation rate (LER) and population density tillers (PDT). Stem growth rate (SGR) was higher in 2021 and at the beginning of deferment. Leaf growth rate (LGR) and total growth rate (TGR) were higher at the beginning of deferment. The braúna grass presented higher PDT. The SGR and the TGR of cayana grass are superior to those of braúna grass. The braúna grass produces a canopy consisting of lighter and denser byts, compared to other weeds. In Uberlândia, MG, braúna grass with an initial height of 30cm produces less stem, while cayana grass produces more forage during deferral.

ABSTRACT The objective was to investigate the feeding behavior of sheep in marandu grass (Brachiaria brizantha cv. Marandu) pastures under continuous stocking with the same average height and different horizontal structures. The treatments were composed of less heterogeneous pastures (P-H, 24% coefficient of variation of plant heights and more heterogeneous pastures (P+H, 46% coefficient of variation of plant heights) and the locations of the picket, front and back, were also evaluated. A randomized block design was used, with split plots in space and four replications in two years. Crossbred lambs were used, managed under continuous stocking and variable stocking rate, to maintain average height of pastures at 30 cm. Greater masses of total forage, live leaf, live stem and dead material, and greater time of sheep in rumination, occurred in the front, in relation to the paddock background. In P-H, grazing time (GT) did not vary between regions. In P+H, GT was lower at the front than at the background. Idle time (IT) was similar between P-H and P+H. However, the animals remained more IT in the front than in the background. The feeding behavior of grazing sheep is modified in marandu grass pastures under continuous stocking with the same average height, but with different spatial variability of the vegetation.

ABSTRACT To verify if strategies to reduce the height of Marandu grass pasture at beginning of the deferral period change intake and metabolic parameters in sheep during the dry season, 18 crossbred females, ½ Dorper + ½ Santa Inês were used, distributed in 9 Marandu grass paddock handles to 3 drawdown strategies at the beginning of deferral period: 1) maintenance of grass with 15cm for 5 months before deferral start (15/15cm); 2) maintenance of marandu grass with 25 cm for 5 months, but at the beginning of deferral it was reduced to 15cm (25/15cm); 3) maintenance of 35 cm grass for 5 months, but at the beginning of deferral it was reduced to 15cm (35/15cm). The experiment was conducted in a completely randomized design (CRD), with 6 repetitions and repeated measures over time. Strategies to reduce the height of Marandu grass pasture, at the beginning of the deferral period, do not change nutrient intake and energy and protein metabolism. However, changes occurring in the pasture during the dry season alter these variables, and deferral is an interesting strategy to be used for forage production in winter, however, to optimize its use, it is necessary to use supplementation with concentrated rich in fermentable carbohydrates.

ABSTRACT This work was conducted to evaluate the effect of deferred pasture condition of Brachiaria brizantha cv. Marandu in the late winter on tillering during the growing season. The treatments were three pasture conditions at late winter: short pasture, tall pasture and tall/mown pasture. In September and October, tiller appearance rate (TApR) and tiller mortality rate (TMoR) were greater in the tall/mown pasture. In November and December, tall pasture presented greater TApR. From November to January the TMoR was greater in the tall pasture. The tiller stability index of short and tall/mown pastures were greater in October. The short pasture presented a greater tiller number than the tall and tall/mown pastures during the entire experimental period. Deferred and short pasture of marandu palisade grass at late winter presents in general lower tiller mortality and higher population density of tillers from the early spring onwards, in comparison to tall pasture. The mowing of marandu palisade grass with high forage mass at the late winter, although it only temporarily compromises the population stability of tillers, also stimulates its fast tillering from spring on.

From fifteen female dogs with clinical diagnoses of pyometra, hematological exams were performed at three times: M0 (prior to the surgery), M24 (24h after ovarysalpingohisterectomy-OSH) and M48 (48h after OSH). Anemia was seen in 80% of the cases, characterized as mild normocytic normochromic type. The means of total leukocyte counts were 27.043, 57.940 and 40.139 céls/µL in M0, M24 and M48. A total of80% of the animals presented neutrophilic left shift in all moments. During medullar exams, the cellular, iron reserve and megakaryocytic concentration were raised as well as the ME ratio, showing a value of 26,3:1,0, probably due to the elevation of granular proliferation and maturation compartment, as the mean of the reserve compartment was within normal range. As 83% of the animals with neutrophilic left shift showed a melullary reserve compartment raised, it can be concluded that female dogs with piometra had left shift of neutrophils with disproportionally between compartments, without segmented medullar saturation.

Compararam-se duas diferentes metodologias na avaliação genética de curvas de crescimento de animais Nelore: o algoritmo SAEM e o método Two-step. Para a implementação dessas metodologias, foram utilizados o modelo de crescimento de Brody modificado e o modelo touro. A diferença entre o SAEM e o Two-step é que o algoritmo SAEM estima simultaneamente parâmetros do modelo e efeitos genéticos e ambientais, e o método Two-step faz esse processo de estimação em duas etapas distintas. Mais ainda, o algoritmo SAEM utiliza o método de máxima verossimilhança, e o do Two-step o de máxima verossimilhança restrita. Foram obtidos, com base nas metodologias testadas, além das estimativas de efeitos fixos e parâmetros genéticos, os valores genéticos preditos para os touros avaliados. A partir dos valores genéticos preditos, foram obtidas as curvas genéticas para os touros. O algoritmo SAEM mostrou-se consistente na estimação dos efeitos fixos e na predição dos efeitos aleatórios, apresentando-se como uma alternativa viável para avaliação genética de animais Nelore.

Utilizou-se análise de agrupamento para classificar e selecionar modelos não lineares de crescimento de bovinos Nelore, tendo em vista os resultados de diferentes avaliadores de qualidade de ajuste. Ajustaram-se 12 modelos não lineares. A qualidade de ajuste dos modelos foi medida pelo coeficiente de determinação (R²), quadrado médio do erro (QME), critério de informação de Akaike (AIC), critério de informação Bayesiano (BIC), erro quadrático médio de predição (MEP) e coeficiente de determinação de predição (R²p). O modelo Brody foi o que apresentou o melhor ajuste para o conjunto de dados.

A estimação dos componentes de (co)variância dos parâmetros de modelos de crescimento pode ser feita por vários métodos. A metodologia bayesiana se apresenta como uma forma alternativa de estimação. Foi realizado um estudo, por meio de dados simulados e de dados reais de animais Nelore, para a estimação dos componentes de (co)variância dos parâmetros do modelo de crescimento de Von Bertalanffy, por meio da metodologia hierárquica bayesiana. Com base nos componentes estimados, foram encontradas as herdabilidades para cada parâmetro do modelo e as correlações genéticas e ambientais entre esses parâmetros. As distribuições marginais a posteriori dos parâmetros a, R, μ, u, G e σ2e foram obtidas por meio do algoritmo Gibbs Sampler e as dos parâmetros b e k por meio do algoritmo Metropolis-Hastings. A metodologia se mostrou eficiente, proporcionando estimativas para os parâmetros próximas aos valores simulados. Os parâmetros a e k dos dados reais apresentaram valores de herdabilidades compatíveis com a realidade, indicando que esses parâmetros poderiam ser usados para fins de seleção.The estimation of the (co)variance components for the parameters of the growth models can be evaluated by many methods. The Bayesian approach is an alternative method of the estimation. A study was performed using simulated and real data from Nelore cattle for estimation of the (co)variance components for the parameters of Von Bertalanffy growth curve, using a bayesian hierarchical model. From the estimated components, the heritabilities for each parameter and genetic and environmental correlations between these parameters were determined. The samples of posterior marginal distributions for the parameters a, R, μ , u, G, and σ2e were obtained by using Gibbs Sampler algorithm and for the parameters b e k by using the Metropolis-Hastings algorithm. The efficiency of the bayesian inference methodology was verified since estimated parameters were quite close to the simulated ones. The parameters a and k from real data showed heritabilities compatible with the reality indicating they could be used in selection programs.