Effect of total replacement of inorganic with organic sources of key trace minerals on performance and health of high producing dairy cows

The aim of this trial was to compare the effect complete replacement certain inorganic trace minerals with organic, chelated (Bioplex®, Selplex®; Alltech Inc, USA) against standard and reduced mineral levels in feed on performance health dairy cows during a 10-week (W0-W10) period. Three treatment groups, each containing 36 cows, were assigned one three diets that varied only composition: (1) Inorganic (CON) Cu (1,042 mg/kg), Se (26 mg/kg) Zn (4,200 as per normal industry inclusion levels; (2) (INORG) (-35%: 680 (-60%; 10 (-66%; 1,360 (based lower organic diet 3); (3) Organic (proteinates selenium-enriched yeast) (ORG) Cu, INORG levels. ORG group had highest milk yield (32.6 kg; P=0.0165) least (31.3 kg), production (energy corrected 31.5 kg (P=0.008) vs CON 31.0 30.7 protein synthesis (ORG 1,024 g/d (P<0.0001) 1,013 982 g/d) (P<0.01) lactose content. There no differences between treatments plasma Zn, GSH-PXE Pregnancy rate number artificial insemination services appeared improved. Mastitis rates lowest for (two affected), four six group. Somatic cell counts consistently (P<0.05), being less than 300,000 counts, compared peaks 380,000 550,000 groups. Five affected by lameness group,