Effects of abomasal infusion of tallow or camelina oil on responses to glucose and insulin in dairy cows during late pregnancy
| Autor: | Siru Salin, Tuomo Kokkonen, Aila Vanhatalo, Ilkka Simpura, Raymond C. Boston, Kari Elo, Juhani Taponen |
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| Rok vydání: | 2011 |
| Předmět: |
Blood Glucose
medicine.medical_specialty medicine.medical_treatment Adipose tissue Fatty Acids Nonesterified Catheterization Fats 03 medical and health sciences NEFA Insulin resistance Latin square Tallow Pregnancy Internal medicine Genetics medicine Lipolysis Animals Plant Oils 030304 developmental biology 2. Zero hunger 0303 health sciences Chemistry Insulin Abomasum 0402 animal and dairy science 04 agricultural and veterinary sciences Glucose Tolerance Test medicine.disease 040201 dairy & animal science Endocrinology Glucose Basal (medicine) Brassicaceae Animal Science and Zoology Cattle Female Insulin Resistance Food Science |
| Zdroj: | Journal of dairy science. 95(7) |
| ISSN: | 1525-3198 |
| Popis: | Late pregnancy is associated with moderate insulin resistance in ruminants. Reduced suppression of lipolysis by insulin facilitates mobilization of nonesterified fatty acids (NEFA) from adipose tissue, resulting in elevated plasma NEFA concentrations. Decrease in dry matter intake (DMI) before parturition leads to accelerated lipomobilization and increases plasma NEFA, which may further impair insulin sensitivity. The aim of the study was to evaluate the effects of elevation of plasma NEFA concentration by abomasal infusions tallow (TAL) or camelina oil (CAM) on whole-body responses to exogenous glucose and insulin. We further assessed whether CAM, rich in C18:3n-3, enhances whole-body insulin sensitivity compared with TAL. Six late-pregnant, second-parity, rumen-cannulated dry Ayrshire dairy cows fed grass silage to meet 95% of metabolizable energy requirements were used in a replicated 3 × 3 Latin square with 5-d periods and 5 recovery days between each period. Treatments consisted of abomasal infusion of 500 mL/d (430 g of lipids/d) of water (control), TAL, or CAM administered in 10 equal doses daily. Intravenous glucose tolerance test (IVGTT) and i.v. insulin challenge (IC) were performed on d 5 after 98 and 108 h of treatment infusions, respectively. Infusion of lipids increased basal plasma NEFA concentrations on d 5 (CAM: 0.25; TAL: 0.28; control: 0.17 mmol/L). Following glucose injection, the rate of glucose clearance (CR) was lower in lipid-treated cows (CAM: 1.34; TAL: 1.48; control: 1.74%/min) and time to reach half-maximal glucose concentration (T(1/2)) was longer (CAM: 54; TAL: 47; control: 42 min). Similar responses were observed after insulin injection. Increased plasma NEFA concentration tended to decrease insulin secretion in IVGTT. Infusion of CAM increased plasma C18:3n-3 content (CAM: 26.4; TAL: 16.1; control: 20.9 g/100g of fatty acids). Data suggest that CAM had an insulin-sensitizing effect, because the disposition index and insulin sensitivity index, derived from minimal model analysis, were higher in CAM than in TAL during IVGTT, and lower insulin concentrations during IC led to similar glucose clearance in CAM as in TAL. These results indicate that elevated plasma NEFA concentration per se induces whole-body insulin resistance in late-pregnant dry cows. |
| Databáze: | OpenAIRE |
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