Do alfalfa grazing and lactation length affect the digestive tract fill of light lambs?

摘要

This experiment tested the hypothesis that alfalfa-raised light lambs suckling their mothers until slaughter (22-24 kg) and having concentrate ad libitum may consume forage to achieve a similar performance to their weaned concentrate-fed counterparts. Thirty-two single Rasa Aragonesa lambs were assigned to one of four treatments in a 2x2 factorial design. The factors were the inclusion of forage in the diet (alfalfa grazing vs. concentrate-fed indoors) and lactation length (weaning at a target body-weight (BW) of 13 kg vs. suckling until slaughter). After slaughter, the digestive contents of each gastrointestinal compartment were weighed individually and the pH of the rumen and caecum contents was recorded. Samples of the reticulo-rumen, caecum and colon-rectum contents were collected for neutral-detergent fibre (NDF), acid-detergent fibre (ADF) and lignin analysis. The empty BW was not affected by forage inclusion or suckling (P