Effect of dietary intake of high starch versus pectin and chromium supplementation on serum glucose, insulin and non-esterified fatty acids in milk of lactating cows

Abstract

The objective of this study is to evaluate the influence of the energy source of the diet and chromium supplementation on serum concentrations of glucose, insulin, and non-esterified fatty acids (NEFA) on lactating cows. Forty multiparous lactating crossbred Holstein x Gir cows, within 80 ± 7 DIM will be blocked by milk yield and BCS, and randomly assigned to one of four treatments on d0 of the experiment: 1) diet formulated with corn to reach 160% of requirements for maintenance and lactation, without chromium supplementation (n=10); 2) the same of diet one with chromium supplementation (n=10; 2,5g of Kem TRACETM Chromium Propionate 0,4% - Kemin Industries, Inc. - added in 97,5g of corn meal/animal/day) 3) diet formulated with citrus pulp to reach 160% of requirements for maintenance and lactation, without chromium supplementation (n=10); 4) the same of diet three with chromium supplementation (n=10; 2,5g of Kem TRACETM Chromium Propionate 0,4% - Kemin Industries, Inc. - added in 97,5g of corn meal/animal/day). Serum concentrations of glucose, insulin, and non-esterified fatty acids (NEFA) will be evaluated before feeding. All variables will be analyzed using the MIXED procedure of SAS. Serum concentrations of glucose, insulin, and non-esterified fatty acids will be analyzed as repeated measures.