A Dairy Herd Case Investigation with Very Low Dietary Cation–Anion Difference in Prepartum Dairy Cows

Abstract

During the periparturient period, subclinical hypocalcemia (total plasma Ca concentration <2.0 mmol/l) is a potential problem for the dairy cow; consequently, its prevention is essential for success of fertility and productive performance. Dietary cation–anion difference (DCAD) has been defined as the difference in milliequivalents of cations (Na, K) and anions (Cl, S) per kilogram of dry matter (DM) and has a direct impact on blood acid–base metabolism. Diets rich in K and Na induce metabolic alkalosis, interfering with tissue sensitivity to parathyroid hormone, and diets rich in Cl and S (anionic salts) cause metabolic acidosis, reducing the risk of hypocalcemia. Consequently, the use of anionic salts has become a popular method to prevent hypocalcemia in dairy cattle. Monitoring diets with anionic salts can be done by measuring urine pH, with optimal values between 6.2 and 6.8 for Holstein cows. The objective of this report is to present a herd case investigation involving a dairy farm feeding a very low DCAD (−143 mEq/kg DM), expecting improved Ca homeostasis. The diet of −143 mEq/kg (urine pH 5.2–5.8) was changed to a diet with −53 mEq/kg DM (urine pH 6.2–6.8). Blood samples were taken at the time of calving for 10 cows that calved before and then for 10 cows that calved after changing the diet. Cows with extremely low DCAD had Ca concentrations of 2.11 ± 0.22 mmol/l and cows with a more moderated DCAD, 2.11 ± 0.16 mmol/l (P > 0.05). Several other blood metabolites (P, Mg, Na, K, Cl, albumin, globulins, blood urea nitrogen, creatinine, and GGT) were also similar between groups. This very low DCAD during the prepartum period may severely compromise animal physiology unnecessarily, with little advantage over normal calcium concentrations at parturition, when compared with a less negative DCAD (−53 mEq/kg DM). Feeding a less negative DCAD ration (−53 mEq/kg DM) did not decrease plasma Ca levels right after parturition compared to a DCAD ration of −143 mEq/kg DM, reinforcing the lack of benefit of a more negative DCAD.

Feeding a Negative Dietary Cation-Anion Difference to Female Goats Is Feasible, as Indicated by the Non-Deleterious Effect on Rumen Fermentation and Rumen Microbial Population and Increased Plasma Calcium Level

“…Our results showed that all plasma levels of Glc, UN, ALT, AST, AKP, TP, Alb, SOD, GSH-Px, MDA, and CAT were unaffected by DCAD variation. This is supported by a previous study of Melendez and Poock [ 9 ], who reported that lowering DCAD had little effect on blood Alb. Our previous study also found that DCAD levels (+300, +150, 0, and −150) had no significant effect on plasma GSH-Px or MDA content in female goats [ 38 ].…”

“…The DCAD level has been an important parameter in the process of formulating diets fed to Holstein cows in recent years [ 3 , 4 , 5 , 6 , 7 ]. Studies have shown that diets with a lower DCAD could enhance health and extend the economic life of transition mammary animals [ 8 , 9 , 10 ]. Recently, attention has been given to the interaction of DCAD with calcium (Ca) [ 11 ], cholecalciferol/calcidiol [ 12 ], 5-hydroxy-l-tryptophan [ 13 ], vitamin D [ 14 , 15 , 16 ], and the duration [ 17 , 18 ] of blood Ca level increases.…”

Reducing dietary cation–anion difference seldom affects rumen fermentation, cellulolytic bacteria populations, and microbiota in goats

“…This is supported by previous study. Melendez and Poock [9] reported that lowering DCAD had little effect on blood Alb. Wu et al [67] found that DCAD level (+ 300, + 150, 0, and − 150) had no signi cant effect on plasma GSH-Px and MDA content in female goats.…”

“…The DCAD level has been an important parameter in the process of formulating diets in recent years [3][4][5][6][7]. Studies have shown that diets with a lower DCAD could enhance the health and extend the economic life of transition mammary animals [8][9][10].…”

Prevention Is Better Than Cure: Experimental Evidence From Milk Fever Incidence in Dairy Animals of Haryana, India

“…It is the decrease in blood calcium (Ca) level due to rapid drain of Cite as : Cariappa, A G Adeeth and Chandel, B S and Sankhala, Gopal and Mani, Veena and R, Sendhil and Dixit, Anil Kumar and Meena, B S, Prevention Is Better Than Cure: Experimental Evidence From Milk Fever Incidence in Dairy Animals of Haryana, India (May 23, 2021). DOI: 10.2139/ssrn.3851561 Ca into colostrum after parturition (calving) (Melendez and Poock 2017;Rodríguez, Arís and Bach 2017). As Ca is essential for organs which has smooth muscle functions like uterus, abomasum, teat sphincter and rumen; the deficiency of Ca or MF affects these organs hampering fertility and productive performance (Melendez et al 2019;Caixeta et al 2017).…”