Catch-up growth of yearling wapiti stags (cervus elaphus)

Ten yearling wapiti stags were used to investigate effects of winter nutrition on subsequent growth on summer pasture. One group of five (LOW) was wintered on medium-quality hay, and the other group of five (HIGH) was wintered on hay and alfalfa–barley pellets (16% crude protein). By the time they grazed spring pasture in mid-April, HIGH wapiti had larger frame dimensions and were 20 kg heavier than those wintered on hay alone, despite their lower pre-winter weights. However, subsequent catch-up growth rapidly narrowed these differences, and both groups attained similar weights and frame measurements by late July. Liveweight gains on summer pasture were 0.30 and 0.15 kg d−1 for LOW and HIGH wapiti, respectively. Although LOW wapiti tended to have higher gut fill (3.3 vs. 2.5 kg dry matter), the difference (corrected for assumed dry-matter content) was insufficient to explain compensatory weight gain. Digestibilities and mean retention times did not differ consistently between the treatment groups but were...