Effects of Extruded Flaxseed and Conjugated Linoleic Acid on Growth Performance in Holstein Milk-Fed Calves

The aim of this study was to investigate the effects of extruded flaxseed and conjugated linoleic acid on growth performance, blood parameters in Holstein suckling calves. This experiment was carried out with 30 newborn Holstein calves with an average age of 1-8 days, and about 36±2 kg body weight, with 6 treatments and 5 replications in a completely randomized factorial design (3×2). The treatments included: 1) Basal diet (control), (2) Basal diet with 3% flaxseed extruded and without conjugated linoleic acid, (3) Basal diet with 3% extruded flaxseed, and 10 g of conjugated linoleic acid, (4) Basal diet with 6% flaxseed extruded and without conjugated linoleic acid, 5) Basal diet with 6% flaxseed extruded and 10 g without conjugated linoleic acid, and 6) Basal diet with 10 g conjugated linoleic acid without extruded flaxseed. The calves were housed in individual pens and fed with whole milk approximately at 10% of birth weight and they had free access to the feed starter and water. Blood samples were collected from the jugular vein on the 30 and 75 day of the trial. Also, growth performance and feed conversion ratio were calculated. The results showed that final weight was affected by extruded flaxseed (P =0514). While conjugated linoleic acid and their interacting was not affected on final weight. The results showed that adding conjugated linoleic acid and extruded flax in starter calves had not significant effect on daily gain in the first and second months and whole period. Daily feed intake was not affected by experimental treatments in the first and second months and whole periods. Blood parameters (glucose, cholesterol, total protein, albumin and triglyceride), and skeletal growth parameters were not affected by adding conjugated linoleic acid and extruded flaxseed. Based on the results of this study, supplementation of extruded flaxseed could not improve growth performance, skeletal growth and blood parameters.