Characterization of a model to induce hyperlipidemia in feed-restricted dairy cows

Hepatic lipidosis is a prevalent metabolic disorder, and in vivo models to study intermediary lipid metabolism are needed dairy cows. Objectives were apply method induce hyperlipidemia characterize the responses safety of intervention feed-restricted dry Holstein cows at 8 mo gestation. It was hypothesized that infusion tyloxapol would without deleterious effects on health Pregnant, nonlactating parous (n = 33) mean (± standard deviation) 234 ± 2.2 d gestation fed for ad libitum intake 1 5 restricted 41% required NEL from 6 13. On 14, when 247 gestation, kept off feed, received i.v. 10% solution 120 mg/kg body weight block hydrolysis triacylglycerols very-low-density lipoprotein (VLDL) particles. Blood sampled 720 min analyzed concentrations triacylglycerol, VLDL cholesterol, total cholesterol serum reflect hepatic secretion or reduced clearance such metabolites blood. Rectal temperature, respiration heart rates, clinical signs related potential anaphylaxis monitored first 30 relative infusion, any abnormal behavior subsequent 24 h. Infusion progressively increased serum. Tyloxapol rectal temperature by 0.19°C after rates 10 29% 40%, respectively. induced tachycardia (heart rate >80 beats/min) 66.7% 22), frothy salivation 39.4% 13), muzzle twitching 15.2% 5), eyes 12.1% 4), muscle 48.5% 16), nystagmus 6.1% 2), hyperexcitement 18.2% 6), staggering gait 4) cows; however, all these transient, returned normal 20 infusion. No other observed past None aborted length, calf birth weight, risk diseases 21 postpartum did not differ between receiving companion group receive tyloxapol. with some animals showing transient reactions treatment, but complications cow offspring. Application this model can be useful