Skip to main content
ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #196745
Title: DEVELOPMENT OF METHODOLOGIES TO REDUCE THE DCAD OF HAYS FOR TRANSITION DAIRY COWS

Author
item Horst, Ronald
item PECINOVSKY, K - IOWA STATE UNIVERSITY
item MOORE, K - IOWA STATE UNIVERSITY
item THORESON, D - IOWA STATE UNIVERSITY
item RUSSELL, J - IOWA STATE UNIVERSITY
item BRUMMER, E - IOWA STATE UNIVERSITY
item Goff, Jesse

Submitted to: American Dairy Science Association Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/11/2006
Publication Date: 7/9/2006
Citation: Horst, R.L., Pecinovsky, K.T., Moore, K.J., Thoreson, D.R., Russell, J.R., Brummer, E.C., Goff, J.P. 2006. Development of methodologies to reduce the DCAD of hays for transition dairy cows [abstract]. American Dairy Science Association-American Society of Animal Science 2006 Joint Annual Meeting. p. 442.

Interpretive Summary:

Technical Abstract: Excessive potassium (K) content of forages can cause metabolic alkalosis in the cow and subsequently hypocalcemia and milk fever. Reducing K content of forages can be a means of reducing the incidence of milk fever and achieving a more favorable dietary cation anion difference (DCAD) for the transition cow. A reduction in forage K can be achieved by restricting K fertilization. In addition, increasing the chloride (Cl) content could also result in a more favorable DCAD for the periparturient cow. This study tests the hypothesis that Cl fertilization without K addition to hays will result in decreasing forage DCAD. Four forage species were seeded in four blocks of four 3 x 16 m plots. In the spring of 2004 each plot was divided into four subplots that were randomly treated with one of four treatments including: 1) Control (C); 2) 100 lbs Cl as CaCl2; 3) 200 lbs K2O as K2CO3; and 4) Cl + K2O as a combination of treatments 2 and 3. The four forage species to be evaluated were: Smooth Bromegrass (SB); Orchardgrass (OG); Reed Canarygrass (RC); and 4) Alfalfa (AF). In plots not receiving K2O fertilization the K content of the plants was lower (p < .01) regardless of species and across all cuttings (Control, 1.92%; CaCl2, 1.77%) relative to those receiving K2O (K2O, 2.15% and Cl + K2O, 2.24%). Plots fertilized with Cl resulted in a 2-3-fold elevation in tissue Cl in all the hays tested (p < .01). This effect was observed for each of the three cuttings. Mean treatment Cl values across all cutting and species were control, 0.32%; CaCl2, 0.90%; K2O, 0.34%; Cl + K2O, 0.84%. DCAD was also significantly (p < 0.05) reduced in plots treated with Cl alone relative to C; OG (365 vrs 600); RC (105 vrs 438); and OG (172 vrs 426). The combination of Cl + K2O resulted in an attenuation of this effect. Alfalfa DCAD appeared to be unaffected by Cl fertilization due to a compensatory Na accumulation. These data suggest that Cl fertilization without K addition may be an effective means of decreasing the DCAD content of hay. The effect of Cl fertilization on yield, hay quality and palatability is currently under investigation.