Milk output and composition in mice divergently selected for BMR
| Autor: | Andrzej K. Gębczyński, Julita Sadowska, Katarzyna Paszko, Marek Konarzewski |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
medicine.medical_specialty
Physiology Aquatic Science Carbohydrate Biology Genetic correlation chemistry.chemical_compound medicine.anatomical_structure Animal science Endocrinology chemistry Insect Science Lactation Internal medicine Basal metabolic rate medicine Homeothermy Animal Science and Zoology Composition (visual arts) Lactose Molecular Biology Paternal care Ecology Evolution Behavior and Systematics |
| Zdroj: | Journal of Experimental Biology. |
| ISSN: | 1477-9145 0022-0949 |
| DOI: | 10.1242/jeb.111245 |
| Popis: | From an evolutionary perspective, the high basal metabolic rate (BMR) of homeotherms is hypothesised to be a by-product of natural selection for effective parental care. We estimated the daily milk output during two consecutive lactation bouts in mice divergently selected for high/low BMR and applied a cross-fostered design to control for potential differences in the between-line suckling abilities of nursed juveniles. Additionally, to remedy the potential limitation imposed by the ability of mother mice to dissipate excess heat, we exposed them to an ambient temperature of 17°C during the most energetically demanding second week of lactation. We found that the mice selected for high BMR produced significantly more milk in a 24 hour period in both reproductive bouts. The milk samples obtained from the high BMR females had lower protein concentration and did not differ with respect to fat. On the other hand, the concentration of the primary milk carbohydrate - lactose, was higher. Although all the above between-line differences were statistically significant, their magnitude was too small to unambiguously ascribe them as stemming from a positive genetic correlation between the physiological traits underlying BMR and lactation performance. Nevertheless, our study lends such support at least at the level of phenotypic variation. |
| Databáze: | OpenAIRE |
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