Allowing dairy cattle to access pasture or outdoor areas is known to be beneficial for cows' welfare and is considered important by the general public. However, in confinement-based operations with ...high-yielding cows, pasture access may be difficult to implement, especially for lactating animals. Providing pasture access to heifers and dry cows seems a more feasible option for most farms. The objective of this study was to investigate the effects of providing high yielding dairy cows with free-choice pasture access during the dry period on their health, behavior and milk production. Over the study period, a total of 78 Holstein cows were assigned to 1 of 2 treatments during the dry period (51 ± 8 d): housing with free-choice access to the pasture (PAST) or housing continuously without any access to the outdoors (CTRL). After calving, all cows from both treatments were mixed and housed continuously. To assess the effects of the treatment on cows' performance, all animals enrolled were monitored both before calving and during the first 100 d in milk (DIM) of the following lactation. The behavior of all cows involved was monitored continuously during the whole observation period using collar-based sensors. All cows were inspected monthly to assess lameness, hock lesions, cleanliness, and body condition score (BCS). During the period after calving (0-100 DIM), milk production and composition were also monitored. Results showed that free-choice pasture access affected cows' feeding behavior. Before calving, the animals in PAST spent more time feeding than in CTRL and, interestingly, this difference tended to persist for several weeks after calving. During the dry period, cows in PAST were cleaner than in CTRL but no differences in locomotion and BCS were found between the 2 groups. Free-choice pasture access during the dry period also affected milk production during the following lactation. The cows that spent the dry period in PAST produced more milk than CTRL counterparts, particularly for the animals that calved during summer. In the current study we have found that providing free-choice pasture access during the dry period can positively affect the performance of dairy cattle and represents a desirable practice in confinement-based dairy production systems.
Abstract The aim of this research was to evaluate the spatial distribution of bedding variables in a climate-controlled compost bedded pack barn (CBP) equipped with an evaporative cooling system ...associated with a tunnel ventilation mode. The study was conducted on a farm in the West Mesoregion of Minas, MG, Brazil. The interior of the animal facility was divided into a mesh of 120 equidistant points, where the bedding surface temperature (tb-sur), the bedding temperature at 0.20 m depth (tb-20) and the bedding penetration resistance (PRb) of layer 0 to 0.20 m depth were measured. Bedding samples were collected to obtain the moisture (Mb) and pH in the surface and at 0.20 m depth. Geostatistics technique was used to evaluate the dependence and spatial distribution. Through the bedding area, the tb-sur presented low variability, with 6 ºC of amplitude, and tb-20 presented highest values (up to 55 °C). The spatial distribution of Mb-20 was similar to that observed on the surface and its highest levels occurred in the region near the feed alley (> 40%). The distribution of pH was similar in both layers. The tendency of high PRb occurred in the layer between 0.15 and 0.20 m (0 and 1500 kPa).
Abstract In this study, we aimed to assess the spatial variability of microclimate inside a closed compost-bedded pack barn (CBP) with a negative ventilation system during summer and winter. The ...research was carried out in a CBP located in the Zona da Mata region, Minas Gerais, Brazil. For each of the stations analyzed, the following environmental mean variables observed inside a CBP were measured: air dry-bulb temperature (tdb), air relative humidity (RH), and windspeed, Temperature-Humidity index, and specific enthalpy. The kriging maps showed that the most critical housing conditions in the thermal environment were found, mainly, from the central part of the CBP, close to the exhaust fans. The analyses also pointed out that the system presented temperature gradients along the length, up to 3°C. During the summer afternoon, the entire region of the CBP was in a discomfort situation (tdb>26°C; RH>75%). During the winter, the measured environmental data remained within the comfort zone throughout the facility. However, probably due to the lack of thermal insulation of the material used to close the sides of the CBP, it did not allow spatial thermal uniformity for both seasons. It was also inefficient to keep the animals within the comfort zone for lactating cattle during the critical summer period.
In Compost-Bedded Pack Barn (CBP) systems, air velocity is linked with the thermal comfort of housed dairy cattle and bedding quality and, therefore, assessing ventilation efficiency is essential. In ...this context, the objective of this study was to evaluate and characterize dependence and spatial distribution of air velocity at the 1.5 m height (vair,M) and at bedding level (vair,B) in an open CBP system with positive pressure ventilation. The study was conducted in 2021, in a facility located in the Zona da Mata region, Minas Gerais, Brazil. The facility area was divided into a mesh composed of 55 equidistant points, where vair,M and vair,B data were collected in the morning (09:00 a.m.) and afternoon (03:00 p.m.) periods, during three weeks in Brazilian winter. Geostatistics techniques were used to assess dependence and spatial distribution. In both periods evaluated, there were a strong occurrence of spatial dependence and non-uniform vair,M and vair,B distributions. The vair,M and vair,B values were lower than recommended (1.8 m∙s-1) in more than 65.0% of the area. Adequate ventilation levels were observed only in the first 20.0 m of the facility, from Southeast to Northwest, because of the fan lines present.
Among animal facilities, compost-bedded pack (CBP) barns have attracted a lot of attention from milk producers and the scientific community. Systematic investigation of the main thermal properties ...utilizing sawdust in CBP barns is of environmental and economic relevance. In this paper, the aim was to (a) develop predictive equations for the thermal conductivity (k) of compost bedding as a function of moisture content (MC), the degree of compaction (DCo), and particle size (PS); and (b) investigate the links between k and depth within bedding material. Samples of compost bedding materials were collected from 42 commercial CBP barns distributed throughout Kentucky (USA). From these predictive equations, it was possible to understand how the MC, DCo, and PS of the bedding materials may influence the behavior of k. These results are very useful for solving obstacles to simulate and predict the variable outcomes of the compost bedding materials process in CBP barns, allowing for its optimization, consequently reducing the time and energy spent on their optimization and allowing for simulation and assessment of compost bedding process modifications. The results of the current study may have important implications in the design and management of bedded pack barns.
ABSTRACT For drip irrigation design and management, it is necessary to know the relation between flow and pressure acting on emitters. In the case of subsurface drip irrigation, the backpressure ...phenomenon may change the hydraulic characteristics of emitters. Thus, this study aimed at determining such relationship between flow and pressure of different driplines in surface and subsurface conditions; aiming to find possible differences in hydraulic behavior. We tested four emitter types; two pressure compensating (D5000 and Hydro PCND) and two non-pressure compensating (TalDrip and Jardiline). Emitter flow rates were attained in atmospheric conditions and submerged in water, in which submergence levels represented backpressure. Assays were performed using inlet pressures of 80, 100, 120, and 150 kPa for the Hydro PCND dripline and 25, 50, 100, and 150 kPa for the other ones; the backpressures were of 0.49, 1.47, 2.45, 4.41 and 6.37 kPa with four replications. The emitters had their proportionality constants and discharge exponents changed in submerged applications, representing backpressure effect. Non-pressure compensating emitters had their discharge exponent decreased, while in pressure compensating ones, it was increased. Backpressure reduced emitter flow rates at all evaluated pressures.
ABSTRACT This study was conducted with the aim of assessing the effects of different ambient temperature values on the performance of laying birds from one to 42 days of age in order to obtain ...optimal comfort temperatures. A total of 864 laying hens were distributed in four climatic chambers with different temperature ranges. One of the chambers was maintained within the thermal range recommended by the literature and the others were maintained under temperatures that consisted of mild and moderate cold stress and moderate heat stress. The experiment was conducted according to a completely randomized design in a split-plot arrangement and six replications. The data were analyzed by means of the analysis of variance and regression. The final performance of birds with temperatures of 33, 28, 26, 23, 19, and 19 °C (for the first, second, third, fourth, fifth, and sixth week of age, respectively) presented better productive results, confirming the assertiveness regarding the best thermal comfort and welfare of laying birds during the rearing stage. The results showed that under conditions of cold thermal stress, birds presented a worse performance, thus affecting their development and productive efficiency.
Honor Scale: evidence on construct validity Guerra, Valeschka M.; Gouveia, Valdiney V.; de C. R. Araújo, Rafaella ...
Journal of applied social psychology,
06/2013, Volume:
43, Issue:
6
Journal Article
Peer reviewed
Honor is an important construct, mainly emphasized in collectivist cultures, such as Brazil. However, there is a lack of studies regarding honor in this cultural context. Therefore, the current ...research aims at proposing a short version of the Honor Scale (HS‐16) to the Brazilian context. Construct validity (i.e., factorial, convergent, and discriminant validity, as well as internal consistency and composite reliability) is reported in Studies 1 (n = 220) and 2 (n = 222), with participants from general population. In both studies, participants answered the Honor Scale and demographic questions. The authors find the HS‐16 to be a reliable and valid scale, thereby enabling its use in quantitative studies regarding the correlates of honor concerns.
ABSTRACT This study aimed to evaluate gas levels and the acoustic environment (noise) of growing-finishing swine in different facilities, one composed of shallow pool (SP) and another of partially ...slatted floor (PSF). Sensors and a sound level meter were used to measure gas concentrations (CO2 and NH3) and noise at 1.50 meters above the ground and at animal height. Data on gas concentrations and noise levels were measured at 9am, 12pm, and 3 pm. Results showed differences (P<0.05) between noise levels at animal height and gas concentrations measured in relation to stall type and data collection time. The highest noise values were found in the shallow pool stall, measured at animal level. The highest NH3 (13 ppm) and CO2 (1174.5 ppm) values were observed in the shallow pool stall at 3pm. The stall floor with shallow pool seems to provide greater welfare in relation to noise level for growing-finishing swine.
Quantification of hydraulic processes that occur in small plastic containers used for seedlings, during and between irrigations, is essential for effective management of irrigation and fertilization ...on substrates. Tests were carried at the Hydraulics Laboratory of the Federal University of Lavras, with the objective of determining the hydraulic conductivity of partially saturated substrates, using the method proposed by Bruce & Klute (1956), on six substrates (S1, S2, S3, S4, S5 e S6) with four replications. Flow tests were conducted to estimate the horizontal diffusivity and, through this, the unsaturated hydraulic conductivity (K(θ)). The rate at which the moisture expands in space and time occurs differently among substrates, especially substrates S5 (pine bark, vermiculite and peat) and S2 (ash, peat and other materials), which had lower and higher diffusivity, respectively. There is a sharp decrease in K(θ) after increasing tension, especially on the substrate S3 (pine bark and topsoil), while for the substrate S5 values were so small that they do not stand out among others. The unsaturated hydraulic conductivity increases exponentially with increasing in water content. Key words: hydraulic processes flow water movement A quantificacao dos processos hidraulicos que ocorrem dentro do recipiente durante e entre irrigacoes, e essencial para a gestao eficaz da irrigacao e adubacao em substratos. Os testes foram feitos no laboratorio de hidraulica da Universidade Federal de Lavras com o objetivo de determinar a condutividade hidraulica nao saturada de substratos usando-se o metodo proposto por Bruce & Klute (1956) em seis substratos (S1, S2, S3, S4, S5 e S6) com quatro repeticoes. Foram realizados ensaios de fluxo horizontal visando estimar a difusividade e, por seu meio, a condutividade hidraulica nao saturada (K(θ)). A taxa com que a umidade avanca no espaco e no tempo ocorre de maneira diferenciada entre os substratos avaliados destacando-se os substratos S5 (casca de pinus, vermiculita e turfa) e S2 (cinza, turfa e outros materiais), que tiveram menor e maior difusividade, respectivamente. Apos o aumento da tensao ocorre uma nitida diminuicao da K(θ), especialmente no substrato S3 (casca de pinus e terra vegetal) enquanto para o substrato S5 os valores foram tao pequenos que nao se destacam dentre os demais. A condutividade hidraulica nao saturada aumenta com o aumento da umidade, de forma exponencial. Palavras-chave: processos hidraulicos fluxo movimento de agua
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