Rumen function in reindeer ( Rangifer tarandus tarandus ) after sub-maintenance feed intake and subsequent feeding

• Published in: Rangifer
• Main Authors: Anna Nilsson, Birgitta Åhman, Michael Murphy, Timo Soveri
• Format: Article in Journal/Newspaper
• Language: English
• Published: Septentrio Academic Publishing 2009
• Subjects: bacteria; ciliate protozoa; diet; forage; lichen; papillae; Animal culture; SF1-1100; Rangifer; Rangifer tarandus
• Online Access: https://doi.org/10.7557/2.26.2.189; https://doaj.org/article/3cfcaca184344852a10127c918b33346

The aim of this experiment was to ascertain how different feeding strategies affect the rumen function of reindeer after nutritional deprivation. Rumen adaptation to various diets, after restricted feeding, was studied in 44 eight-month-old semi-domesticated female reindeer (Rangifer tarandus tarandus). All animals were initially fed a simulated winter diet based on lichens (lichen diet). A control group, continuously offered the lichen diet ad libitum, was compared to four groups of reindeer that were first restrictively fed (half the ad libitum ration) for eight days followed by one day without feed. The rumen content of restrictively fed animals had higher pH, lower dry matter content and volatile fatty acid (VFA) concentration, a changed composition of VFAs, and lower counts of bacteria compared to that of the control group. The effect was less dramatic than previously reported for reindeer starved for several days. On day 10, the four restrictively fed groups were introduced to different diets. One group was re-fed the lichen diet ad libitum and did not differ from the control group when the experiment ended after five weeks of feeding. Two groups were fed grain-based reindeer feed (pellets) combined with either lichens or grass silage, and one group was fed silage with a gradually increased addition of pellets. Diarrhoea and so called “wet belly” occurred initially in the three latter groups. After five weeks of feeding, the reindeer in the three pellet-fed groups had an altered composition of VFAs and higher counts of protozoa, and also tended to have higher total VFA concentration in the rumen, compared to the control animals and those re-fed the lichen diet. Only small changes were observed in the size of rumen papillae and these could be associated with energy intake. Protozoa decreased over time on the lichen diet. This study confirmed that rumen function was significantly affected by a relatively short period of restricted feed intake. The experiment also revealed a clear difference in rumen function ...