Effect of Application of Ammonium Chloride and Calcium Chloride on Alfalfa Cation-Anion Content and Yield

• Published in: Journal of dairy science Vol. 90; no. 11; pp. 5159 - 5164
• Main Authors: Goff, J.P, Brummer, E.C, Henning, S.J, Doorenbos, R.K, Horst, R.L
• Format: Journal Article
• Language: English
• Published: Savoy, IL American Dairy Science Association 01.11.2007; Am Dairy Sci Assoc
• Subjects: alfalfa; ammonium chloride; Ammonium Chloride - pharmacology; Animal productions; Anions - analysis; Biological and medical sciences; calcium chloride; Calcium Chloride - pharmacology; Cations - analysis; chlorine; cow feeding; crop yield; dietary cation anion difference; feed composition; feed rations; field experimentation; Food industries; forage crops; Fundamental and applied biological sciences. Psychology; harvest date; Medicago sativa; Medicago sativa - chemistry; Medicago sativa - drug effects; Medicago sativa - growth & development; Milk and cheese industries. Ice creams; milk fever; Minerals - analysis; potassium; pregnancy; sodium; sulfur; Terrestrial animal productions; Vertebrates; Iowa; Ammonium; milk fever; Dairy product; dietary cation-anion difference; Fever; Calcium chloride; Anions; alfalfa; Chlorides; Content; Dairy industry; chloride; Cations; Yield; Application; Milk
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2007-0070

A major factor predisposing the cow to periparturient hypocalcemia, or milk fever, is being fed a prepartum ration with a high dietary cation-anion difference (DCAD). The DCAD can be favorably altered to prevent milk fever by 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 application of Cl to alfalfa could increase Cl in forage, thereby lowering DCAD. We conducted a field experiment at 2 Iowa locations in which established plots of alfalfa were treated in April 2001 with 0, 56, 112, or 168 kg of Cl/ha using ammonium chloride, calcium chloride, or a mix of the 2 sources with equal amounts of chloride coming from each source. Plots were harvested 4 times in 2001 and once in 2002 and plant tissue analyzed for mineral composition. Applying chloride from either source once in the spring resulted in increased plant chloride content over all 4 cuttings for that year. 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 of Cl/ha, respectively. Chloride application had no effect on plant potassium, sodium, calcium, magnesium, or phosphorus. These results suggest chloride application can elevate chloride content and lower DCAD values of alfalfa, and also maintain crop yield.