Shade Modifies Behavioral and Physiological Responses of Low to Medium Production Dairy Cows at Pasture in an Integrated Crop-Livestock-Forest System

Abstract

Under conditions of high temperature, humidity, and incidence of solar radiation, dairy cows use behavioral changes as a strategy to decrease the metabolic heat production at pasture. The objective of this study was to evaluate the behavioral and physiological responses of Gyr and Girolando (5/8 Holstein 3/8 Gyr, and ½ Holstein ½ Gyr) dairy cows submitted to environments with and without shade. The experiment was conducted at Embrapa Cerrados (Technology Center for Dairy Zebu breeds—CTZL), Brasilia, Distrito Federal—Brazil, with 48 Gyr and Girolando cows total in the lactation group, with low to medium milk production, in full sun or shade with Eucalyptus urograndis (267 plants/ha−1). The physiological and behavioral characteristics evaluated were panting score, superficial temperature, and time spent grazing, ruminating, and lying down. Other traits included skin and coat thickness, hair diameter, density and length, and predominant coat color. In addition, body measurements, such as body length, the height of withers, chest circumference, and shin circumference, were measured. Shaded cows had 34% longer rumination times than cows in full sun (p = 0.01). With a temperature-humidity index ranging from 79 to 83, the rumination time was 1.7 times higher in cows under shade (p = 0.01) during a 24-h period of observation. There were no significant differences in the grazing time between the environments, but lying time was 23% longer in cows under the sun (p = 0.01). The panting score was not influenced by the environment (p = 0.17). Girolando cows had a 35% higher panting score than Gyr cows (p = 0.01) regardless of the environment. The panting score increased two and a half times during the afternoon compared with the morning (p = 0.01). The surface and rectal core temperatures had significant differences between treatments and time of the day. Body measurements were not different between cows in both environments, but there was a difference between breeds. The use of trees in pastures with a silvopastoral system for dairy zebu cows is indicated to improve grazing behavior, as well as time spent ruminating and lying down.

Relationship among thermal environment, stage of lactation, body characteristics, yield and milk constituents of dairy Gyr cows managed on pasture

“…It is known that milk yield of high-producing dairy cows will reduce when the minimum THI of a day exceeds 65 units (Zimbelman et al, 2009). In this study, we used the value of 74 of THI as a threshold to determine the thermal comfort (Reis et al, 2021), due to the cows`features (primiparous Zebu) of this study, and we did not find an effect of THI on milk yield. The cows in this study showed a lactation peak in the third month, then maintained their milk yield until the 6th month and reduced from the 7th month onwards.…”

Feed intake, emission of enteric methane and estimates, feed efficiency, and ingestive behavior in buffaloes supplemented with palm kernel cake in the Amazon biome

“…Possibly, this is due to the supply of supplementation and the strategies adopted by the animals to overcome situations of intense heat or rain ( 45 ). Immediately after the offer, the animals start feed intake, and, in reflex, the rumination activity is also influenced since it occurs soon after ingestion.…”

Understanding the impacts of intensity and harvest frequency on Tithonia diversifolia for use in tropical silvopastoral systems

“…Several advantages have been documented concerning the adoption of SPS in comparison to extensive grazing systems based on forage monocultures, emerging as a promising strategy to mitigate the environmental impact of livestock farming and enhance the resilience of tropical pasture systems towards climate uctuations. These bene ts include improvements in soil physical, chemical, and biological properties (Santos et al 2022), soil organic carbon storage (Resende et al 2020; Filho et al 2024), as well as similar total forage accumulation and greater nutritive value (Gomes et al 2022;Brunetti et al 2022), protein supply during the dry season (Ovani et al 2023), weed reduction (Munaro et al 2023), shaded pasture for animals (Reis et al 2021), promotion of animal welfare (Cândido et al 2023), improved animal performance (Oliveira et al 2022), greenhouse gas emission mitigation (Monteiro et al 2024) and, consequently, provision of ecosystem services (Schmitt Filho et al 2023). These bene ts depend on the characteristics or application of each chosen tree or shrub resource.…”