Spatiotemporal variations on infrared temperature as a thermal comfort indicator for cattle under agroforestry systems.

With the expanding use of thermal assessment techniques in beef cattle, infrared thermography has become a promising tool for assessing the environment for animal thermal comfort. Goals of this study were: (1) to evaluate cattle thermal comfort in agroforestry systems with different shade availability (2) to verify the spatiotemporal variations of infrared temperature inside agroforestry systems, and; (3) to test infrared thermography as a potential tool to assess animal thermal comfort indices in agroforestry systems. A trial was carried out between June 2015 and February 2016, covering Central-Brazil's dry winter and rainy summer seasons, respectively. The experimental area of Embrapa Beef Cattle is located in Campo Grande (Mato Grosso do Sul), coordinates 20°24'53″ S, 54°42'26″ W and 558 m altitude. The 12 ha plot has two agroforestry systems varying shade availability. Traditional Black Globe Temperature and Humidity Index, Heat Load Index and Radiation Thermal Load were determined, from measurements using digital thermo-hygrometers, with datalogger. Surface temperature and humidity of tree canopies and pasture were determined using an infrared thermographic camera. Results show spatiotemporal variations in infrared temperature. This means that the environment inside agroforestry systems is not homogeneously comfortable for cattle, and the system with the lowest shade availability has the greatest heat accumulation area. Weak to strong associations were identified between infrared variables and thermal comfort indices (0.08 = r ≤ 0.75). Positive relationships were also obtained and equally well explained by the Black Globe Temperature and Humidity Index and Heat Load Index (0.55 = R2 ≤ 0.94). We conclude that infrared thermography can be used as a tool to assess thermal comfort indices in agroforestry systems and to determine onset of animal thermal stress from environment and heat body accumulation.

Environmental variables responsible for Zebu cattle thermal comfort acquisition.

The aim of this study was to estimate, using data mining, which microclimate and behavioral variables affect the behavior of animals to seek shaded or sunny areas. The experiment was carried out between January and May 2016 in an integrated crop-livestock-forest system. In this system, we defined two different areas: shaded and sunny. Microclimatic variables (At, BGt, RH, and WS) were measured in each area on 4 consecutive days per month. With these variables, we determined the bioclimatic indicators (THI, BGHI, HLI, MRT, RTL, and ETI). In addition, we calculated the absolute difference (Δ) by subtracting the value recorded in shaded areas from the value recorded in sunny areas for all microclimatic variables and bioclimatic indicators, except for WS. The behaviors (grazing, ruminating, and other activities), posture (standing or lying), and use of areas (shaded or sunny) of 38 Zebu cattle were recorded on 2 consecutive days per month. The data mining technique was applied for analysis in a classification task. The model correctly classified 76% of the instances with a Kappa statistic of 0.51 after features selection from the database. The ΔBGt was the most important feature in the model to classify the decision of Zebu cattle to seek another area or remain in a determined area. The model was built with seven classification rules, being one simple rule, composed of the interaction between ΔBGt and rumination; and other more complex rules, composed of the interactions among the ΔBGt, WS, and rumination. The preference of Zebu cattle to seek or remain in shaded or sunny areas was influenced by eight features: rumination, drinking water, WS, ΔBGt, MRT in shade, BGHI in sun, ΔBGHI, and HLI in sun.

Infrared thermography for microclimate assessment in agroforestry systems.

In agroforestry systems, trees modify climatic parameters over a given area and create a complex microclimate through interactions between topography, plant composition and organizational structure of trees. In this way, indicators such as surface temperature of tree canopy and pasture, monitored by infrared thermography, are important to monitor the thermal environment of animal production and pasture establishment. Goals of this study were (1) to evaluate temporal and local variations of temperature and humidity leaf surface of tree canopy and pasture in agroforestry systems by infrared remote sensing and, (2) to validate infrared thermography as a potential tool for assessment microclimate in agroforestry systems. The study was carried out between June 2015 and February 2016 in an experimental area located at 54°370'W, 20°270'S and 530 m altitude, in Brazil. Surface temperatures and humidity of tree canopy and pasture in two agroforestry systems with different densities and tree spatial arrangements were determined using infrared thermography. Air, black globe and dew point temperatures, relative humidity and wind speed were measured using digital thermo-hygrometers with datalogger. Moderate to strong associations have been identified between microclimate parameters and those monitored by means of thermography measurements (0.45 ≥ r ≤ 0.78), suggesting positive relationships and equally well explained by air temperature, black globe temperature and relative air humidity (R2 = 0.68 ≥ R2 ≤ 0.98). Variations in hourly averages of temperatures and humidity of pasture and tree canopy show similar patterns between seasons, with consistently higheraverages during summer and under full sun, indicating the existence of a thermal band with leaf temperatures above air temperature. Therefore, this work's findings support use of infrared thermography as a tool for microclimate assessment in agroforestry systems.

Infrared thermography for evaluation of the environmental thermal comfort for livestock.

The objective of this study was to assess the use of infrared thermography as a microclimate-evaluating tool and an estimate of the thermal comfort provided by four types of tree to cattle under grazing conditions in the central region of Brazil. The experiment was conducted at the Embrapa Beef Cattle Company, in Campo Grande, MS, Brazil, from June to August 2015. Evaluations were carried out over four consecutive days, at 1-hour intervals, from 8:00 a.m. to 4:00 p.m. (local time; GMT - 4:00). Infrared thermography images of tree crowns and soil surface underneath them from the shadow projection of four tree species native to the Brazilian cerrado (savannah-like) biome were obtained. The microclimate was assessed by estimation of thermal indices: temperature and humidity index, black globe, and radiation thermal load. The previous was calculated based on records of air temperature, dew point temperature, black globe temperature, air relative humidity, wind speed, and solar radiation. The geometrical settings of the trees were assessed for each tree component. Five thematic groups were formed based on multiple factor analysis that summarizes three synthetic analytical dimensions to explain the total variance among the studied elements and the existing correlations between groups. Positive linear correlations were found between thermography and the temperature measurements, thermal comfort indices, and radiation, suggesting that infrared thermography can be used as a tool for estimating and monitoring the microclimate and thermal comfort, presenting a potential use of measurement in agroforestry systems.

Shading effect on physiological parameters and in vitro embryo production of tropical adapted Nellore heifers in integrated crop-livestock-forest systems.

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.

Vaginal temperature as indicative of thermoregulatory response in Nellore heifers under different microclimatic conditions.

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.

Shading effect on microclimate and thermal comfort indexes in integrated crop-livestock-forest systems in the Brazilian Midwest.

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-1), 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-2. 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.

Milheto em dietas de suínos em crescimento e terminação / Millet in diets of growing and finishing pigs

Realizou-se este estudo com o objetivo de avaliar níveis de milheto híbrido ADR 8010(r) nas dietas de suínos em crescimento e terminação sobre o desempenho e características quantitativas de carcaça. Foram utilizados 48 animais, machos castrados, geneticamente similares, com peso inicial de 30,0±2,9kg. Os animais foram distribuídos em delineamento experimental de blocos casualizados, com quatro níveis de inclusão de milheto na dieta (0; 25; 50; e 75%), seis repetições, sendo cada unidade experimental constituída por dois animais. Foram analisados os parâmetros de desempenho (consumo de ração, ganho de peso e conversão alimentar) e as características de carcaça (peso e comprimento de carcaça, espessura de toucinho, profundidade de músculo, percentual e quantidade de carne magra). Os níveis de milheto não influenciaram (P>0,05) nos parâmetros de desempenho e características de carcaça dos suínos. O milheto ADR 8010(r) pode substituir o milho em até 75% nas dietas de suínos em crescimento e terminação, sem prejudicar o desempenho e características de carcaça dos animais.

The aim of this study was to evaluate levels of millet hybrid ADR 8010(r) in the diets of pigs in growing and finishing on performance and carcass quantitative characteristics. It was used 48 barrows, genetically similar c, with initial weight around 30.0±2.9kg. The animals were distributed in a randomized block design, with four levels of inclusion of millet in the diet (0; 25; 50 and 75%), six replicate of two animals each. It was analyzed the parameters of performance (feed intake, weight gain and feed conversion) and carcass traits (weight and height of carcass, back fat thickness, depth of muscle, percentage and amount of lean meat). The level of inclusion of millet do not influence (P>0.05) the parameters of performance and characteristics of carcass of pigs. The millet ADRR 8010(r) can replace the corn up to 75% on diets of pigs in growth and finishing without impacting performance and carcass characteristics of animals.

Perfil lipídico da carne e gordura de suínos alimentados com milheto / Lipid profile of meat and fat of pigs fed with pearl millet

O objetivo deste trabalho foi avaliar níveis de milheto na alimentação de suínos na composição lipídica e de colesterol da gordura subcutânea e da carne. Foram utilizados 48 animais, machos castrados, distribuídos em um delineamento experimental de blocos casualizados, com quatro níveis de milheto na dieta (0; 25; 50 e 75%), seis repetições, sendo cada unidade experimental constituída por dois animais. Foram analisados os perfis lipídicos da gordura e da carne através de cromatografia gasosa e a quantidade de colesterol nas amostras de carne foi determinada seguindo a metodologia de extração. O aumento do nível de milheto na dieta dos suínos reduziu (P<0,05) a concentração dos ácidos mirístico, palmítico, palmitoleico, heptadecanoico e aumentou a concentração do ácido linoleico na gordura subcutânea. O nível de inclusão de 50,82% de milheto na dieta possibilita máxima deposição do ácido linolênico na gordura. Os níveis de milheto não modificam o perfil de ácidos graxos e o teor de colesterol na carne suína. O nível de 42,09% de inclusão de milheto na dieta resulta no maior índice trombogênico da carne.

The aim of this study was to evaluate the replacement of corn by millet in the diets of pigs on the lipid composition and cholesterol from subcutaneous fat and meat. It was used 48 castrated males, distributed on randomized experimental blocks design, with four levels of millet in the diet (0; 25; 50 and 75%), six replicate of two animals each. It was analyzed the lipid profiles of fat and meat by gas chromatography and the amount of cholesterol in the meat samples was determined following the extraction methodology. The increased level of millet in the diet of pigs reduced (P<0.05) the concentration of myristic, palmitic, palmitoleic and heptadecanoic acids and increased the concentration of linoleic acid in subcutaneous fat. The inclusion level of 50.82% of millet in the diet allowed maximum deposition of linolenic acid in fat. Levels of millet did not change the fatty acid profile and cholesterol content in pork. The level of 42.09% inclusion of millet in the diet results in the highest rate thrombogenic meat.

Performance of Nellore heifers, forage mass, and structural and nutritional characteristics of Brachiaria brizantha grass in integrated production systems.

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.