Lamb performance in hardwood silvopastures, II: animal behavior in summer1

Abstract

Integrating trees into pastures, a practice known as silvopasture, may benefit livestock in the summertime through the provision of shade. The purpose of this project was to compare the behavioral patterns of sheep grazing in silvopastures and open pastures. Black walnut (Juglans nigra L.) and honeylocust (Gleditisia triacanothose L.) based silvopasture systems were compared with open pastures in a randomized complete block design with three blocks over two summers. Behavior measures were recorded within a replicate within a week, and these measures were taken sequentially within three experimental periods. Ewe lambs (n = 3) within each experimental unit were equipped with a wideband audio-recording device to detect prehension events. Time-lapse cameras documented sheep behavior every 60 s. In the silvopastures, the lambs spent over 90% of daylight hours within shade from trees. Lambs in silvopastures spent more time lying down than animals in the open pastures (P ≤ 0.01), while lambs in the open pastures spent more than 2 h longer each day standing (P < 0.0001). Lambs in the black walnut silvopastures spent more time grazing (488 ± 14 min · d−1) than lambs in the honeylocust silvopastures (438 ± 14 min · d−1; P = 0.0493) and lambs in the open pastures (417 ± 14 min · d−1; P = 0.0026). There was no difference in grazing time for lambs in the latter two systems (P = 0.5597). Spectral analysis of the imagery revealed that the lambs in the black walnut silvopastures grazed more frequently than the lambs in the other systems for both years. The acoustic analysis, though limited by recorder durability to 47 complete recordings, revealed no difference in total bites taken per day (P ≥ 0.7222) or in the morning (P ≥ 0.2069), afternoon (P ≥ 0.5816), and evening periods (P ≥ 0.9337). Silvopastures provide an opportunity to improve lamb comfort in the summer.

Herbage Yield, Lamb Growth and Foraging Behavior in Agrivoltaic Production System

“…In the current study, the lambs in solar pastures spent their ruminating and idling activities predominantly under shade (<96%), while 45% of their grazing activity took place in shade directly under the solar panels. Similarly, in a recent silvopastoral study, Pent et al (2020) noted that lambs spent over 90% of daylight hours within the boundaries of the shade. Cloete et al (2000) recorded that lambs born in shaded paddocks were 3.8% heavier at weaning than those were born and raised in paddocks without shade.…”

Effect of the Silvopastoral System on the Thermal Comfort of Lambs in a Subtropical Climate: A Preliminary Study

“…However, sheep experiencing a high radiant heat load when fully exposed to the sun will narrow their prescriptive zone, particularly the superior limit [41]. According to Pent et al [19], a sensitive change by conduction will only be effective if the surface temperature is lower than the body temperature of lambs. The authors also stated that the SP promotes a more effective loss of heat by conduction than open pastures.…”

“…Although animals in the extensive system performed grazing activity more than half of the time and at different times of the day [47], lambs needs to have a thermal environment that stimulates it to seek food. Pent et al [19] evaluated the behavioural repertoire of lambs in a SP system with black walnut (Juglans nigra L.) and honeylocust (Gleditisia triacanothose L.) in the USA and concluded that lambs in the shaded system spent more time grazing. The same authors stated that the activity is performed depending on the comfort conditions when food is not limited.…”

“…In addition, a severe or long period under thermal stress may lead to compromised immune function in lambs [18]. Moreover, when exposed to shade, lambs are more comfortable, have more lying behaviour, and spend more time grazing than animals in open pasture systems in a temperate climate [19]. This evidence shows that if lambs are exposed to a harsh environment in an earlier phase, both productivity and welfare are compromised, resulting in economic loss [16,20].…”

Thinning forests or planting fields? Producer preferences for establishing silvopasture

“…Silvopasture is an agroforestry practice defined as the intentional integration and co-management of trees, forages, and livestock (Orefice and Carroll 2017). Benefits include shade for animals, reduced wind speed, nutritious forages, timber and non-timber tree products, and ecosystem services such as increased biodiversity and carbon sequestration (Kurtz 2000;Workman et al 2003;Montagnini and Nair 2004;Buergler et al 2005;Moorhead and Dickens 2012;Pent et al 2020a). There are two general silvopasture establishment methods.…”