Temperature and Temperature Humidity Index Changes during Summer to Autumn in a Temperate Zone May Affect Liveweight Gain and Feed Efficiency in Sheep

Lamb finishing during summer in southern Australia faces the challenges of dry paddock feed low nutrient value and energy concentration, combined with periods high temperature that reduce appetite. One potential forage to overcome these is camelina, a brassica lipid concentration. Liveweight gain (LWG) efficiency (FE) pelleted diet containing 15% camelina hay (CAM) were compared an equivalent based on oaten (STD), commonly used seasons. The experiment was conducted under autumn conditions using 56 maternal Composite (Composite) wether lambs (4 months, 28–38 kg liveweight) Merino yearlings (15 37–43 liveweight). Animals maintained group pens (8/pen) weekly average intakes per pen liveweights determined shaded well-ventilated animal house. LWG FE for both types significantly lower weeks 5–8 1–4. These changes coincided higher proportion daytime maxima exceeding 28 °C (50% vs. 21%) night-time hours 22 (15% 9%). indicated sheep fed CAM less affected by elevated temperatures than STD 5–8. However, further research controlled environmental required validate results.