With international demand for production systems aimed at thermal comfort and animal welfare, milk producers have become increasingly interested in compost barns. However, doubts about the behavioral aspects of cows in tropical and subtropical climates remain, because the compost barn system offers a larger bed area per animal at a lower stocking rate. The objective of this study was to evaluate whether the diurnal behaviors, hygiene and lameness of crossbred dairy cows are influenced by different number of lactations when housed in a compost-bedded pack barn system under hot and humid conditions. Crossbred cows (Holstein and Jersey), which were divided into two treatments based on number of lactations (primiparous and multiparous cows), were evaluated during lactation (n=12). The study was conducted from September 2015 to February 2016 in a compost barn in the southwest region of the state of Paraná, Brazil. Daytime behavior was observed between milking schedules using focal observations with 0/1 sampling. Cow hygiene and lameness were evaluated using subjective scores ranging from 1 to 4 and 1 to 5, respectively. Animal behavior and welfare was analyzed using Bayesian inference with a mixed effects model. The probabilities of dyspnea and pushing behaviors were higher (P<0.05) in multiparous cows, and the probability increased during the hottest hours of the day. For both multiparous and primiparous cows, the agonistic behaviors of pushing, butting and chasing peaked during the afternoon. Eating behaviors had the highest likelihood values (0.8 at 0800 h). The cows preferred to remain lying down in the morning, while rest and standing rumination were preferred in the afternoon. Primiparous cows were cleaner than multiparous cows, and the hygiene score for this group was significantly lower (P<0.05). The hygiene and lameness scores for all animals were low, and the highest scores were 1 and 2. In conclusion, multiparous cows exhibited more frequent agonistic behaviors during the hottest hours of the day. Regarding hygiene and lameness scores, multiparous cows exhibited a higher degree of dirtiness compared with the primiparous cows.

In this study, we investigated the influence of a silvopastoral system on the thermal environment, behaviour and thermoregulation of dairy heifers in a subtropical climate. The experiment was conducted on a dairy farm in Southwest Paraná, Brazil, during the summer of 2014. Crossbred Holstein × Jersey dairy heifers (n = 10) were used in a split-plot design. The fixed effects in this study include time of day (9:00–10:00, 13:00–14:00, and 17:00–18:00 h) under silvopastoral or open pastures conditions, which were the main-plot and split-plot factors, respectively. To assess the environmental conditions in both systems, air temperature, relative humidity and wind speed were recorded. In addition, the temperature-humidity index was calculated based on the microcli-mate measurements. Respiratory rate and hair coat surface temperature of heifers were measured in both groups during time of day (30 days). Diurnal behaviour using focal observations with 0/1 sampling was observed. Data were analysed using Bayesian inference with a mixed effects model. The air temperature was higher (P<0.05) in open pasture conditions than the silvopasture system. Temperature-humidity index values for the silvopasture system were lower than open pasture during the hottest hours of the day. Regarding thermoregulation responses, there was an interaction between time of day and pasture environment (P<0.05). Heifers showed lower respiratory rates and hair coat surface temperature values (P<0.05) when access to shade was provided, mainly during the hottest periods in the afternoon. In addition, there was also an interaction between rumination and water intake (P<0.05), which indicates a higher rumination frequency for animals in the silvopasture system during the hottest period, as well as a higher water intake frequency for heifers in open pasture during midday. These findings imply that the arrangement of trees in a silvopasture system provides better thermal comfort conditions for dairy heifers raised in a subtropical climate.

No abstract

The silvopastoral system has the potential to alleviate the negative impacts of heat stress on livestock. Through a preliminary study, we assessed the thermal environment experienced by hair coat lambs, as well as the impacts on their bio-thermal and behavioural responses, when either kept in either the silvopastoral system, or exposed to full sun. Twelve hair coat lambs (Dorper × Santa Ines) were randomly assigned to a silvopastoral system or full sun exposure during the summer (from January to February 2017). Parameters, including air temperature, black globe temperature, relative humidity, wind speed, and ground surface temperature, were measured daily for both thermal environments. From 14:00 to 16:00, lambs kept in silvopastoral areas experienced lower levels of air temperature, radiant heat load, and ground surface temperature. Consequently, they had a lower hair coat surface and lower body rectal temperatures. Lambs exposed to a shaded environment spent more time grazing and walking, and less time standing at rest. In conclusion, lambs kept in a silvopastoral system experienced lower levels of radiant heat load and ground surface temperature. In addition, the animals showed a reduced requirement for evaporative cooling and expressed behaviours that indicated a comfortable thermal environment.

The objective of the present study was to verify the efficacy of different anthelmintics in young sheep and the variation between males and females. The work was carried out between March and April 2015 in private property in the municipality of Dom Pedrito - RS. The evaluations were carried out on 180 lambs (90 males and 90 females) crossed Corriedale x Ile de France with mean age of 10 ± 2 months live weight (LW) of 26.00 ± 2.0 kg kept in intermittent grazing with fixed stocking In 20 hectares (ha) of native field. The animals were separated into three groups which received different active principles (Closantel 10% via oral; 30% oral Diophenol and 34% Nitroxinil via injectable). Each group consisted of 60 individuals 30 males and 30 females. The faeces were collected before the application of the active principle (day zero) and after 10 days for the quantification of eggs per gram of faeces (OPG). Also the cultivation of larvae (coproculture) was carried out. The efficacy test was checked according to the following formula Efficacy (E%) = [(OPG control day0 – OPG treatment day10) /OPG day0 ] x 100. All OPG averages were found to be above the maximum dosage limit (OPG> 500). The anthelmintic efficacy in the herd for Closantel dysophenol and Nitroxinil was 64% -7% 60% respectively and efficacy less than 90% is sufficient to presume the resistance of helminths to these drugs. When efficacy was observed between the sexes it was found that all drugs were considered ineffective. However it is worth noting that the efficacy of the active ingredient Nitroxinil was 72% in lambs and 33% in lambs. The population of nematodes identified in the coproculture of the herd referring to day 0 was Haemonchus spp. (45%) followed by Trichostrongylus spp. (53%) and with fewer occurrences Bonostomum spp. (2%). When identification was performed after treatments (day 10) the presence of Haemonchus spp. (43%) Trichostrongylus spp. (56%) and Bonostomum spp. (1%). Efficacy and coproculture tests should be carried out periodically in the herd in order to guide the selection of the most appropriate anthelmintic in the control of verminosis. Comprovou-se que na propriedade há resistência anti-helmíntica aos princípios ativos utilizados. Embora, fosse verificada maior eficácia nas cordeiras fêmeas tratadas com Nitroxinil em comparação aos machos do mesmo grupo, ambos foram considerados ineficazes no combate à parasitose.