Associations between annual and seasonal variations in body mass and reproductive success and blood biochemical parameters in semi-domesticated reindeer

• Published in: Rangifer
• Main Authors: Ingrid H. Holmøy, Øystein Holand, Stein I. Thoresen, Ellen Dahl, Erik Ropstad
• Format: Article in Journal/Newspaper
• Language: English
• Published: Septentrio Academic Publishing 2009
• Subjects: body condition; calf survival; luteal function; nutritional status; pasture condition; Rangifer; Animal culture; SF1-1100; Rangifer tarandus
• Online Access: https://doi.org/10.7557/2.29.1.210; https://doaj.org/article/622e831fa48f4dbf8043b13d9eecdf87

The main objective of the study was to follow reproductive performance and blood biochemical parameters associated with fat and carbohydrate metabolism in a herd of free-ranging, semi-domesticated reindeer (Rangifer tarandus tarandus) over a two-year period, with extreme between-year variation in forage availability. The effects of climatic factors on reindeer reproductive performance were investigated by analysing whether time of onset of luteal function in autumn and calf survival were associated with changes in body mass and weather conditions, such as snow depth, precipitation, and temperature. Considerable between-year variation in the onset of luteal activity was found. In 1997, 4.2% of the female reindeer were either cycling or pregnant in the second week of October, whilst in 1998, in the same week, 100% were cycling or pregnant. Although energy balance was important for timing of the onset of luteal activity, delayed conception had no apparent effect on calf survival. The results indicated that maternal body mass (BM) in spring was of primary importance for calf survival, and the productivity of the herd. Since climatic factors influence the availability of forage, and hence female BM, it also has an indirect impact on calf survival. Females with low BM demonstrated greater seasonal variation in BM than heavier females. Plasma concentrations of free fatty acids and β-hydroxy butyric acid responded to changes in forage availability, but the initial condition of the reindeer and their fat reserves also seemed to have a major influence on these parameters. Abstract in Norwegian / Sammendrag: Sammenheng mellom års- og sesongvariasjon i kroppsvekt og henholdsvis reproduksjonssuksess og biokjemiske blodparametre hos tamrein Hovedformålet med studien var å følge reproduksjonen og blodparametre knyttet til fett og karbohydratmetabolismen hos en tamreinflokk (Rangifer tarandus tarandus) gjennom en toårs periode med stor årlig variasjon i næringstilgang. Effekten av klima på reinens reproduksjonssuksess ble ...