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Effects of season and reproductive state on lipid intake and fatty acid composition of gastrointestinal tract contents in the European hare.

Popescu FD, Hackländer K, Arnold W, Ruf T - J. Comp. Physiol. B, Biochem. Syst. Environ. Physiol. (2011)

Bottom Line: GI-tract contents showed significant seasonal changes in their FA composition.Among PUFA, α-linolenic acid peaked in spring while linoleic acid was predominant in late summer and fall, which probably reflected changes in the plant composition of forage.However, independent of seasonal changes, GI-tracts of lactating females showed a significantly (+33%) higher content of linoleic acid, a FA that is known to increase reproductive performance in European hares.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria. francesca.popescu@itpa.unibe.ch

ABSTRACT
We investigated lipid content and fatty acid (FA) composition of gastrointestinal tract contents in free-living, herbivorous European hares (Lepus europaeus). Mean crude fat content in hare stomachs and total gastrointestinal (GI) tracts was higher than expected for typical herbivore forages and peaked in late fall when hares massively deposited body fat reserves. Changes of FA proportions in different parts of the GI-tract indicated a highly preferential absorption of polyunsaturated fatty acids (PUFA). A further reduction of PUFA content in the caecum, along with the appearance of odd-chained FAs in caecum, caecotrophes, and colon content, pointed to a biohydrogenation of PUFA in the hare's hindgut. GI-tract contents showed significant seasonal changes in their FA composition. Among PUFA, α-linolenic acid peaked in spring while linoleic acid was predominant in late summer and fall, which probably reflected changes in the plant composition of forage. However, independent of seasonal changes, GI-tracts of lactating females showed a significantly (+33%) higher content of linoleic acid, a FA that is known to increase reproductive performance in European hares. This finding suggests that lactating females actively selected dietary plants rich in linoleic acid, a PUFA that may represent a limited resource for European hares.

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Linoleic acid and α-linolenic acid proportions in the gastrointestinal tract content of lactating and non-lactating female European hares. Means from all fractions of the gastrointestinal tract ± 95% confidence intervals
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Fig6: Linoleic acid and α-linolenic acid proportions in the gastrointestinal tract content of lactating and non-lactating female European hares. Means from all fractions of the gastrointestinal tract ± 95% confidence intervals

Mentions: The proportions of both linoleic acid (F3,139 = 65.8; P < 0.001) and α-linolenic acid (F3,139 = 67.0; P < 0.001) significantly changed between seasons, with α-linolenic acid reaching a peak in spring (May), and linoleic acid peaking in late summer (August; Fig. 5b). Interestingly, even after statistically adjusting for seasonal differences, mean linoleic acid content was significantly (33%) higher in lactating than in non-lactating females (Fig. 6; F1,80 = 12.1; P < 0.001). In contrast, α-linolenic acid content was not elevated in lactating females (F1,80 = 0.41; P = 0.64). Neither of the two major PUFA was affected by any of the other variables investigated.Fig. 6


Effects of season and reproductive state on lipid intake and fatty acid composition of gastrointestinal tract contents in the European hare.

Popescu FD, Hackländer K, Arnold W, Ruf T - J. Comp. Physiol. B, Biochem. Syst. Environ. Physiol. (2011)

Linoleic acid and α-linolenic acid proportions in the gastrointestinal tract content of lactating and non-lactating female European hares. Means from all fractions of the gastrointestinal tract ± 95% confidence intervals
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3118006&req=5

Fig6: Linoleic acid and α-linolenic acid proportions in the gastrointestinal tract content of lactating and non-lactating female European hares. Means from all fractions of the gastrointestinal tract ± 95% confidence intervals
Mentions: The proportions of both linoleic acid (F3,139 = 65.8; P < 0.001) and α-linolenic acid (F3,139 = 67.0; P < 0.001) significantly changed between seasons, with α-linolenic acid reaching a peak in spring (May), and linoleic acid peaking in late summer (August; Fig. 5b). Interestingly, even after statistically adjusting for seasonal differences, mean linoleic acid content was significantly (33%) higher in lactating than in non-lactating females (Fig. 6; F1,80 = 12.1; P < 0.001). In contrast, α-linolenic acid content was not elevated in lactating females (F1,80 = 0.41; P = 0.64). Neither of the two major PUFA was affected by any of the other variables investigated.Fig. 6

Bottom Line: GI-tract contents showed significant seasonal changes in their FA composition.Among PUFA, α-linolenic acid peaked in spring while linoleic acid was predominant in late summer and fall, which probably reflected changes in the plant composition of forage.However, independent of seasonal changes, GI-tracts of lactating females showed a significantly (+33%) higher content of linoleic acid, a FA that is known to increase reproductive performance in European hares.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria. francesca.popescu@itpa.unibe.ch

ABSTRACT
We investigated lipid content and fatty acid (FA) composition of gastrointestinal tract contents in free-living, herbivorous European hares (Lepus europaeus). Mean crude fat content in hare stomachs and total gastrointestinal (GI) tracts was higher than expected for typical herbivore forages and peaked in late fall when hares massively deposited body fat reserves. Changes of FA proportions in different parts of the GI-tract indicated a highly preferential absorption of polyunsaturated fatty acids (PUFA). A further reduction of PUFA content in the caecum, along with the appearance of odd-chained FAs in caecum, caecotrophes, and colon content, pointed to a biohydrogenation of PUFA in the hare's hindgut. GI-tract contents showed significant seasonal changes in their FA composition. Among PUFA, α-linolenic acid peaked in spring while linoleic acid was predominant in late summer and fall, which probably reflected changes in the plant composition of forage. However, independent of seasonal changes, GI-tracts of lactating females showed a significantly (+33%) higher content of linoleic acid, a FA that is known to increase reproductive performance in European hares. This finding suggests that lactating females actively selected dietary plants rich in linoleic acid, a PUFA that may represent a limited resource for European hares.

Show MeSH
Related in: MedlinePlus