Data were collected between 2001 and 2003 from Guzerat (G), Criollo (C), Guzerat x Criollo (GC), and Criollo x Guzerat (CG) cows (n=208 records) to estimate heterosis (h i) and direct (g i) and maternal (g m) genetic effects for day of peak milk yield (DMP), maximum milk yield (PML), total milk yield (PTL), daily milk yield (PDL), persistency of lactation (PER), and to estimate relationships between PTL and weaning weight adjusted to 210 d of age (PA210). Lactation curve was estimated by the equation Y(n)=n/ae kn. Variables were analyzed with least squares procedures and mixed models. Final models included effects of genotype of the cow, number, year and season of calving, sex of calf, birth weight as a covariate and two factor interactions. Correlations and regressions were estimated between PA210 and PTL. GC cows had greater production for PML, PTL and PDL (P<0.10) than C and G cows. h i was important (P<0.05) for PML, PTL and PDL. g i were favorable to G (P<0.05) for PML, PTL and PDL. Correlations were important (P<0.05) for all genetic groups. The regression coefficients were 0.044±0.014 (C), 0.037±0.014 (GC), 0.032±0.009 (G) and0.027±0.015 (CG). Calves from C, GC, G and CG cows required 22.5, 27.3, 30.9 and 37.3 kg of milk per each kilogram of weightat weaning. The differences in the efficiency of utilization of milk consumed by calves suggest that different strategies of feeding during lactation should be considered for the production of feedlot calves with C, GC, G and CG cows.

Se analizaron 208 registros obtenidos entre 2001 y 2003 de vacas Guzerat (G), Criollo (C), Guzerat x Criollo (GC) y Criollo x Guzerat (CG) para estimar efectos genéticos directos (g i), maternos (g m) y de heterosis (h i) sobre día de máxima producción (DMP), producción máxima en lactancia (PML), producción total de leche (PTL), producción diaria de leche (PDL), persistencia de la lactancia (PER) y para estimar relaciones entre PTL y peso al destete ajustado a 210 días de edad (PA210). La curva de lactancia se estimó mediante la ecuación Y(n)=n/ae k n. Las variables se analizaron con el método de cuadrados mínimos y modelos mixtos. Los modelos incluyeron grupo genético, número, año y época de parto, sexo, la covariable peso al nacer e interacciones simples. Se estimaron correlaciones y regresiones entre PA210 y PTL. Las vacas GC fueron superiores a vacas C y G para PML, PTL y PDL (P<0.10). La h i influyó (P<0.05) PML, PTL y PDL. Los g i favorecieron a G (P<0.05) en PML, PTL y PDL. Las correlaciones fueron importantes (P<0.05) para todos los grupos genéticos. Los coeficientes de regresión fueron 0.044±0.014 (C), 0.037±0.014 (GC), 0.032±0.009 (G) y 0.027±0.015 (CG). Crías de vacas C, GC, G y CG consumieron 22.5, 27.3, 30.9 y 37.3 kg de leche por cada kilogramo de peso al destete. Las diferencias estimadas en la eficiencia de utilización de la leche consumida por las crías sugieren que la producción de becerros con vacas C, GC, G y CG debe considerar estrategias diferentes de alimentación durante la lactancia.

Adults of Tabanidae may become serious pests wherever they occur due to their attack to humans and others animals. Tabanids were captured near ground, water surface and at 25 m high on primary forests and forest gaps of anthropogenic origin, to understand their abundance, seasonality, diversity and similarity on such environments. Collections were carried out in the Base II of the War Instruction Center in the Jungle (CIGS) located at 54 km from Manaus municipality, Amazonas state. Two Malaise flight interception traps and four attraction traps (two suspended at 25 m high and two above the water surface of igarapé) were installed in forest gap and primary forest, areas for 10 consecutive days, during 15 months. A total of 2,643 specimens of 66 species were captured. Diachlorini (35 species /11 genera) was the most abundant tribe, followed by Tabanini (19 species /three genera), Chrysopsini (seven species /one genus) and Scionini (five species /two genera). Seventeen species were captured only in the primary forest, 11 in the anthropic clearing, and 38 species were common to both environments. The most abundant species were Phorcotabanus cinereus (Wiedemann), Tabanus occidentalis L, Chrysops laetus Fabricius and Tabanus angustifrons Macquart. The greatest richness was found in drier months (September/October) in both areas. Theforest gap showed higher abundance of specimens (1,827) than the primary forest (816). Traps suspended above the water surface were the most efficient (1,723 specimens) probably due to the dispersion of horseflies over small streams.