Effect of canola oil inclusion in diets of lactating dairy cows

Author(s)

Katiéli Caroline Welter

• Document type: Master's Dissertation
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2015-02-09

Examining board members

Arlindo Saran Netto; Ives Cláudio da Silva Bueno; Marcia Saladini Vieira Salles

• Advisor: Arlindo Saran Netto

Abstract

The aim of this study was to evaluate the effect of canola oil inclusion in the diet of dairy cows on milk yield and composition, total apparent digestibility, blood and ruminal variables. Were used 18 Holstein cows averaging 22 (± 4) kg/day of milk yield in the middle stage of lactation. The cows were distributed in a Latin square design, with 6 contemporary square, 3 periods and 3 treatments: T1 = control diet (without inclusion of oil); T2 = inclusion of 3% canola oil in the diet and T3 = inclusion of 6% canola oil in the diet (dry matter bases). The inclusion of canola oil in the diet of lactating cows linearly reduced milk yield by 2.51 kg/cow/day, milk concentrations of saturated fatty acid by 20.24%, omega6/omega3 ratio by 39.45%, atherogenicity index by 48.36%, thrombogenicity index by 39.86%, dry matter intake by 2,25kg/d, and ingestion of NDF by 0,87kg/day and CP by 0,45kg/day; and NDF digestibility by 5% in treatment 6% when compared with 0% treatment. With inclusion 6% canola oil in the diet of dairy cows was observed a linear increase in milk concentration of unsaturated fatty acids by 34.08%, omega-3 by 115%, rumenic acid (CLA) by 16.50%, oleic acid by 44.87% and the h/H index by 94.44%, when compared with control diet. The blood concentrations of total cholesterol, HDL and LDL linearly increased in 34.88 mg/dL, 11.69 mg/dL, and 23.98 mg/dL, respectively, according to inclusion of canola oil from 0 to 6% in the diet. No effect of inclusion of canola oil was observed on ruminal pH, and concentrations of ammonia nitrogen and propionic acid. The variables acetic and butyric acids, and acetic/propionic ratio, were linearly reduced with inclusion of canola oil. The inclusion of canola oil in the diet of lactating cows reduces the dry mater intake, milk yield and fat content, but increases the milk concentration of fatty acids with human health benefits, as CLA, omega-3 and oleic acid. Canola oil does not cause problems to health of cows, as blood and ruminal variables are within normal ranges for lactating cows. (AU)

• FAPESP's process: 12/15050-0 - Effect of different inclusion levels of canola oil in the diet of dairy cows on production, milk composition, blood and ruminal parameters
• Grantee: Katiéli Caroline Welter
• Support Opportunities: Scholarships in Brazil - Master