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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #207506
Title: Effect of Application of Ammonium Chloride and Calcium Chloride on Alfalfa Cation-Anion Content and Yield

Author
item Goff, Jesse
item BRUMMER, E - IOWA STATE UNIVERSITY
item HENNING, S - IOWA STATE UNIVERSITY
item DOORENBOS, R - IOWA STATE UNIVERSITY
item Horst, Ronald

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/16/2007
Publication Date: 11/20/2007
Citation: Goff, J.P., Brummer, E.C., Henning, S.J., Doorenbos, R.K., Horst, R.L. 2007. Effect of Application of Ammonium Chloride and Calcium Chloride on Alfalfa Cation-Anion Content and Yield. Journal of Dairy Science. 90(11):5159-5164.

Interpretive Summary: Reducing prepartal dietary cation-anion difference (DCAD) can reduce hypocalcemia and milk fever at calving. This study investigates if it is possible to reduce DCAD of forages by increasing chloride content of the plants by amending soil chloride. Ammonium chloride, calcium chloride, or a mix of the two was applied to alfalfa plots once in the spring at 0, 56, 112, or 168 kg Cl ha**-1. Chloride content of the alfalfa harvested at all four cuttings that year was increased and DCAD decreased by chloride fertilization. Alfalfa chloride content was maximized with the 112 kg Cl ha**-1 treatment, with no negative effect on alfalfa yield. Chloride fertilization can improve DCAD values of alfalfa for use in pre-calving dairy rations.

Technical Abstract: Periparturient hypocalcemia, or milk fever, occurs in dairy cattle when their dietary cation-anion difference (DCAD) is too high. DCAD can be favorably altered to prevent milk fever by either decreasing K and Na or increasing Cl and S in forages for cows in late gestation. The objective of this study was to test the hypothesis that fertilization of alfalfa with Cl could increase Cl in forage thereby improving DCAD. We conducted a field experiment at two Iowa locations in which established plots of ‘5454’ alfalfa were fertilized in April 2001 with 0, 56, 112, or 168 kg Cl ha**-1 using ammonium chloride, calcium chloride, or a mix of the two sources with equal amounts of chloride coming from each source. Plots were harvested four times in 2001 and once in 2002 and plant tissue analyzed for mineral composition. Chloride fertilization with either source resulted in increased plant chloride content over all four cuttings. Averaged across both locations, chloride levels were elevated from 0.52% in control plots to 0.77, 0.87, and 0.89% Cl in plots treated with 56, 112, and 168 kg Cl ha**-1. Chloride fertilization had no effect on plant potassium, sodium, calcium, magnesium, or phosphorus. Chloride concentrations in tissue from untreated plots were higher in Ames (0.77%) than in Nashua (0.29). Chloride treatment reduced DCAD in Nashua but not in Ames. The higher chloride level in the Ames plots resulted in a lower pre-treatment DCAD level (184 meq kg**-1) relative to Nashua plots (390 meq kg**-1). These results suggest that chloride fertilization can elevate chloride content and improve DCAD values of alfalfa for use in pre-calving dairy rations.