Comparative aspects of volatile fatty acid production in the rumen and distal fermentation chamber in Svalbard reindeer

Abstract

Microbial fermentation end products were investigated in Svalbard reindeer at two different locations, on Nordenskioldland (NL) (»=7) and in a marginal area on Nordaustlandet (NA) (n= 11), at different seasons. The pH ranged from 6.51-6.70 in rumen contents and from 6.78-7.17 in the distal fermentation chamber (DFC=caecum and proximal part of the colon) on NL compared to 6.10-6.71 in rumen contents and 6.50-7.35 in DFC contents on NA. The ruminal volatile fatty acid concentration ([VFAJ) was 84.5 ±9.5 mmol/1 compared to 63-9 ± 17.6 mmol/kg in the DFC on NL in winter. In autumn, ruminal and DFC [VFA] was high at 113.5 ± 13.0 mmol/1 and 90.4 ± 10.9 mmol/kg, respectively. On NA ruminal [VFA] was 85.7 ± 12.4 mmol/1 and 59-6 ±1.3 mmol/kg in the DFC in winter, compared to 107.3 ± 18.4 mmol/1 and 102.0 + 12.7 mmol/kg in rumen and DFC, respectively, in summer. Mean acetate/propionate (A/P) ratios in the rumen indicate fermentation in favour of plant fibre digestion in winter (4.8) but not in autumn (3.0) on NL. On NA, the mean A/P ratio was 5.1 in winter, compared to 4.6 in summer. In all DFC investigated the A/P ratio was higher than 8.9-The initial ruminal [VFA] did not reflect the VFA production measured. On NL, the production rate of VFA was low or not detectable in rumen and DFC in winter, while in autumn the total production rate of VFA was 59-3 kJ/kgW 0 75 /d, of which 6.5% originated from the DFC. On NA in winter, a total of 121.3 kJ/kgW 0 7S /d was estimated of which 17% originated from the DFC, compared to a total of 380.4 kj/kgW" 7 '/d in summer where the DFC only contributed 2.7%. Plants (grasses and mosses) with low quality in winter do not seem to contribute significantly to the VFA production in rumen and DFC. VFA production in the DFC seems to be of significant importance in reindeer when pastures have low availability but high quality. The concenttation and the rate of VFA production in the DFC contents were not related to the size of the chamber, but to the diet eaten.

Diet composition, rumen papillation and maintenance of carcass mass in female Norwegian reindeer (Rangifer tarandus tarandus) in winter

“…Svalbard reindeer eat poorly fermentable forage plants and very little lichen in winter. At 25% of OM, the ruminal lignin concentration in these in winter is 66% higher than in Norwegian reindeer in winter (Sùrmo, Haga, Gaare et al, 1999;Table 4) and the ruminal production of VFA is correspondingly low (Sùrmo, Haga, White et al, 1997). They optimize the use of poor quality forage in winter by adapting their ruminal microbial¯ora, increasing the rumen ®ll, and maintaining a large absorptive omasal surface (Orpin et al, 1985;Mathiesen, Vader et al, in press), but they still mobilize substantial amounts of their fat reserves in winter (Reimers, Ringberg & Sùrumgaard, 1982;Tyler, 1987).…”

“…In contrast to the Norwegian reindeer, in the Svalbard reindeer ruminal ammonia declined to only 100 mg/kg wet rumen content weight in late winter (Sùrmo, Haga, White et al, 1997;Sùrmo, Haga, Gaare et al, 1999), which is regarded as too low to support ruminal microbial protein synthesis (érskov, 1992). Likewise, adult female Norwegian reindeer fed mixed lichens ad libitum achieve negative nitrogen balance and lose as much as 150 g LBM per day éksendahl, 1994).…”

Rumen microbial diversity in Svalbard reindeer, with particular emphasis on methanogenic archaea

“…1), where the tundra vegetation is relatively abundant, did not reveal seasonal variations in the ruminal contents of plant cell wall organic dry matter or the mean ruminal pH (Sørmo et al , 1997). However, the ruminal production rate of SCFA was low or not detectable in winter while it was 55 kJ kg −1 BM 0.75 day −1 in autumn in animals on Nordenskiöld Land (Sørmo et al , 1997), reflecting the seasonal changes in their pastures.…”

Where clocks are redundant: weak circadian mechanisms in reindeer living under polar photic conditions

“…1; thick black line; amplitude of the annual cycle of daily activity increased with latitude, reflecting the greater amplitude of the appetite cycle in SR compared with NR (Larsen et al 1985). The quality of the forage on Arctic ranges, moreover, is very high in summer (White and Staaland 1983;Klein 1990;Sørmo et al 1997;Larter and Nagy 2001) and the rates of fermentation of fibre and of passage of digesta increase as a result (Orpin et al 1985;Mathiesen et al 1987; Fig. 5 Average (median, quartiles) duration (hour) of bouts of activity (black bars) and inactivity (white bars) across 1 year in Norwegian (NR, n=6) and Svalbard (SR) reindeer.…”