The objective of this paper was to perform a microclimate evaluation and determine the indexes of thermal comfort indexes, in sun and shade, in integrated crop-livestock-forest systems with different arrangements of eucalyptus and native trees, in the Brazilian Midwest. The experiment was conducted at Embrapa Beef Cattle in Campo Grande, state of Mato Grosso do Sul, Brazil, from July to September 2013. The evaluations were conducted on four consecutive days, from 8:00 a.m. to 5:00 p.m., local time (GMT -4:00), with 1 hour intervals, recording the microclimate parameters: air temperature (°C), black globe temperature (°C), wet bulb temperature (°C), relative humidity (%), and wind speed (m.s), for the subsequent calculation of the Temperature and Humidity Index, the Black Globe Temperature and Humidity Index, and the Radiant Thermal Load. The largest changes in microclimate parameters were found in the full sun, between 12:00 p.m. and 1:00 p.m., in less dense eucalyptus system, followed by the scattered native trees system, resulting in a maximum Temperature and Humidity Index of 81, Black Globe Temperature and Humidity Index of 88 and Radiant Thermal Load of 794 W m. Therefore, it is observed that with the presence of trees in pastures were possible reductions of up to 3.7 % in Temperature and Humidity Index, 10.2 % in the Black Globe Temperature and Humidity Index, and 28.3 % of the Radiant Thermal Load in the shade. Thus, one can conclude that the presence of trees and their arrangement in the systems provide better microclimate conditions and animal thermal comfort in pastures.

Our objective was to evaluate production, nutritive value and carrying capacity of piatã grass (Brachiaria brizantha cv. BRS Piatã), and performance of Nellore heifers in agrosilvopastoral systems (ASPS) with three eucalyptus (Eucalyptus urograndis) tree densities, during winter, spring, summer, and fall. Three integrated systems were evaluated: ASPS-1 (357 trees ha(-1)), ASPS-2 (227 trees ha(-1)), and CON (5 trees ha(-1)). In each system, two sward heights were evaluated: short and tall. A total of 80 11-month-old Nellore heifers were randomly allocated in a randomized split-plot block, 3 × 2 factorial. Greater dry matter availability was observed on CON pastures during the fall season. Greater percentage of leaf lamina was detected on ASPS-1 with short sward height and greater during summer, compared with other seasons. A greater forage production was observed between tree rows and for tall sward height. Spring was the season with less forage nutritive value. Average daily gain was greater during summer and fall. Gain per hectare and stocking rate were greater on CON system and on ASPS-2. Pastures with short sward height had greater gain per hectare and stocking rate. Agrosilvopastoral systems with intermediate tree density seem to be a good choice for producers willing to diversify their revenue sources without decreasing animal production.

O experimento foi conduzido no campus da Universidade Federal de Lavras, objetivando-se comparar o desempenho de minhocas Africanas e Vermelhas produzidas em "minhobox" com esterco de búfalos e de bovinos. O período experimental foi de 40 dias e o delineamento experimental foi o inteiramente casualizado em esquema fatorial 2 x 2, totalizando quatro tratamentos com quatro repetições cada um. As minhocas Vermelhas ganharam peso (P<0,01), enquanto as minhocas Africanas perderam peso. Não houve diferença (P>0,05) para ganho de peso em relação aos tipos de esterco. Para as porcentagens de minerais presentes nas fezes frescas, houve superioridade (P<0,01) dos bovinos em relação aos búfalos para cinzas, nitrogênio, fósforo, cálcio, magnésio, ferro, zinco, ao passo que para enxofre, cobre e manganês, não ocorreu diferença (P>0,05), e os búfalos foram superiores apenas para potássio (P<0,01). Para os porcentuais de minerais presentes no vermicomposto, ocorreram interações de acordo com a origem do esterco e espécie de minhoca para nitrogênio, potássio, zinco e cobre. A maior porcentagem de nitrogênio e cobre foi observada para o vermicomposto procedente de bovino com minhoca Vermelha (P<0,01), de potássio para o vermicomposto derivado de búfalo com minhoca Africana e de bovino com minhoca Vermelha (P<0,05) e para o zinco, as melhores combinações foram de minhocas Africanas com bovinos e de minhocas Vermelhas com búfalos (P<0,01). Considerando a análise dos fatores isolados, houve diferença estatística para o fósforo (P<0,05), a favor do vermicomposto proveniente de bovino, para cálcio e magnésio (P<0,05), a favor de bovino e minhoca Africana e para ferro (P< 0,01), a favor de búfalo e de minhoca Africana. Não houve diferença (P>0,05) para nenhuma das fontes de variação em relação à cinza, enxofre e manganês. Concluiu-se que o minhobox é eficiente para produção de minhocas Vermelhas (P<0,01), uma vez que as minhocas Africanas não se adaptam a esse sistema de criação, as fezes de bovinos são melhores fontes de minerais do que as fezes de búfalos e, para o vermicomposto, ocorrem interações quando são utilizados esterco de búfalos ou bovinos com minhocas Africanas ou Vermelhas.

No abstract

The aim of this study was to evaluate the impact of increased shadow supply in integrated crop-livestock-forest systems on in vitro embryonic development and physiological parameters related to stress response in Nellore heifers (Bos indicus). For the study, animals (n = 16) were randomly divided into two groups and kept in areas with different afforestation systems, the integrated crop-livestock-forest (ICLF) and the integrated crop-livestock (ICL) system. The microclimate of the ICLF system provided better comfort conditions than ICL. No differences of respiratory rate, rectal temperature, cortisol, T3, T4, oocyte quality, and cleavage rate between the systems were verified. A higher blastocyst rate was observed in the ICLF (p < 0.05). The results demonstrate that Nellore heifers managed in ICLF during summer in Midwest of Brazil showed higher production of in vitro embryos, without typical changes in its physiological parameters. The results observed in the present study indicate that zebu females are able to respond satisfactorily to the intense heat conditions; however, we believe that the long period to which these animals are exposed to these conditions interferes in the oocyte competence and embryo development.

Quantitative and qualitative carcass characteristics of feedlot ewes subjected to increasing levels of concentrate in the diet [ ABSTRACTThe aim of this study was to evaluate the effect of increasing levels of concentrate on the quantitative and qualitative carcass characteristics of feedlot ewes. Twenty-four crossbred ewes were randomly distributed in four treatments: (1) diet with 20%; (2) 40%; (3) 60%; and (4) 80% of concentrate. Animals were slaughtered when those receiving the diet with 80% of concentrate reached adult weight, at around 50kg LW. The data were analyzed by means of variance and regression analyses and correlations. The levels of concentrate increased live weight at slaughter linearly. Height at the withers and rump presented medium to high correlation (0.86). The correlation of loin eye area measured on the carcass and by ultrasound examination was 0.81, whereas for back fat thickness it was 0.85. The increase in the use of concentrate in the diets promotes heavier carcasses with better yields and fat cover. Some measures obtained in vivo presented high correlation with those measured on the carcass. The use of ultrasound can be a way to predict the in vivo loin eye area. The use of concentrate improves the meat quality in variables' color and appearance.

No abstract

The objective was to evaluate vaginal temperature as a thermoregulatory response of Nellore heifers under different microclimatic conditions. The study was conducted during one year in an experimental area located at 54°37′W, 20°27′S, and 530 m of altitude in Brazil. Twenty-four Nellore females were reared in integrated crop-livestock-forestry systems with different shading patterns. The randomized complete block experimental design was utilized with a sub subdivided plots scheme, with plot corresponding to the production systems, the subplot to the season of the year, and the sub subplot, the hours of the day. To characterize the microclimate, data regarding air and black globe temperatures, and air relative humidity were collected and from them, temperature-humidity index was calculated. Vaginal temperature was obtained by using a bottom-type temperature logger (i-button) attached to an adapted intravaginal device. The black-globe temperature explained the variation on vaginal temperature. Increases on vaginal temperature were only observed, on average, two hours after the increase of black-globe temperature. The microclimatic conditions found in the systems, resulting from the various tree densities, modify the vaginal temperature in different degrees, demonstrating that the shading effect is not always accompanied by improvements in thermal comfort. The system with intermediate density showed a better microclimatic condition and, consequently, a lower increase in vaginal temperature. The interaction between air temperature, humidity and solar radiation resulted in adverse environmental conditions, however, Nellore heifers showed good adaptation to the environment. In conclusion, vaginal temperature is a good indicator to evaluate the thermoregulatory response in Nellore heifers.