Nutritional Chloride Deficiency in Early Lactation Holstein Cows

Open Access
Publisher Website
Google Scholar
Abstract
Beginning 1 wk postpartum, weekly changes of feed and water intake, body weight, milk production and electrolyte concentrations in serum, saliva, urine, milk and feces were observed for 8-11 wk. Three dietary treatments differing in NaCl and NaHCO3 supplementation but containing equal Na concentrations were used. Dietary Cl percents were low 0.10%, medium 0.27% and high 0.45%. Consistently changes were significant for feed and water intake, body weight, milk production and electrolyte concentrations in serum, urine, milk and feces of cows fed the low Cl diet. By wk 8, body weight had declined from 575.0 .+-. 56.7 to 476.7 .+-. 54.3 kg, and daily milk production decreased from a peak of 27.7 .+-. 2.4 to 19.2 .+-. 3.9 kg for cows fed the low Cl diet. Serum Cl decreased from 106.0 .+-. 2.8 to 75.5 .+-. 6.7 meq/l during the same time. Cows on the low Cl diet developed clinical signs of a deficiency characterized by depraved appetite, lethargy, hypophagia, emaciation, hypogalactiae, constipation and cardiovascular depression. Metabolic alterations were summarized as a severe primary hypochloremic, secondary hypokalemic, metabolic alkalosis.