Effects of level of dietary cation-anion difference and duration of prepartum feeding on performance and metabolism of dairy cows

Abstract

The objectives were to evaluate the effects of feeding diets with 2 levels of negative dietary cation-anion differences (DCAD) during the last 42 or 21 d of gestation on performance and metabolism in dairy cows. The hypothesis was that extending feeding from 21 to 42 d and reducing the DCAD from -70 to -180 mEq/kg of dry matter (DM) would not be detrimental to performance. Holstein cows at 230 d of gestation were blocked by parity prepartum (48 entering their second lactation and 66 entering their third or greater lactation) and 305-d milk yield, and randomly assigned to 1 of 4 treatments arranged as a 2 × 2 factorial. The 2 levels of DCAD, -70 or -180 mEq/kg of DM, and 2 feeding durations, the last 21 d (short) or the last 42 d (long) prepartum resulted in 4 treatments, short -70 (n = 29), short -180 (n = 29), long -70 (n = 28) and long -180 (n = 28). Cows in the short treatments were fed a diet with DCAD of +110 mEq/kg of DM from -42 to -22 d relative to calving. After calving, cows were fed the same diet and production and disease incidence were evaluated for 42 d in milk, whereas reproduction and survival was evaluated for 305 d in milk. Blood was sampled pre- and postpartum for quantification of metabolites and minerals. Reducing the DCAD linearly decreased prepartum DM intake between -42 and -22 d relative to calving (+110 mEq/kg of DM = 11.5 vs. -70 mEq/kg of DM = 10.7 vs. -180 mEq/kg of DM = 10.2 ± 0.4), and a more acidogenic diet in the last 21 d of the dry period reduced intake by 1.1 kg/d (-70 mEq/kg of DM = 10.8 vs. -180 mEq/kg of DM = 9.7 ± 0.5 kg/d). Cows fed the -180 mEq/kg of DM diet had increased concentrations of ionized Ca in blood on the day of calving (-70 mEq/kg of DM = 1.063 vs. -180 mEq/kg of DM = 1.128 ± 0.020 mM). Extending the duration of feeding the diets with negative DCAD from 21 to 42 d reduced gestation length by 2 d (short = 277.2 vs. long = 275.3 d), milk yield by 2.5 kg/d (short = 40.4 vs. long = 37.9 ± 1.0 kg/d) and tended to increase days open because of reduced pregnancy per artificial insemination (short = 35.0 vs. long = 22.6%). Results suggest that increasing the duration of feeding diets with negative DCAD from 21 to 42 d prepartum might influence milk yield and reproduction of cows in the subsequent lactation, although yields of 3.5% fat- and energy-corrected milk did not differ with treatments. Reducing the DCAD from -70 to -180 mEq/kg of DM induced a more severe metabolic acidosis, increased ionized Ca concentrations prepartum and on the day of calving, and decreased colostrum yield in the first milking, but had no effects on performance in the subsequent lactation. Collectively, these data suggest that extending the feeding of an acidogenic diet beyond 21 d is unnecessary and might be detrimental to dairy cows, and a reduction in the DCAD from -70 to -180 mEq/kg of DM is not needed.

Meta-analysis of the effects of prepartum dietary cation-anion difference on performance and health of dairy cows

“…Recommendations for concentrations of Ca, Mg, and P for prepartum cows fed acidogenic diets have not been extensively researched in typical dose-titration ex-periments. Diets with negative DCAD induced hypercalciuria, and, depending on dietary Ca intake, urinary Ca losses can increase from approximately 1 to 2 g/d when fed alkalogenic diets to approximately 8 to 11 g/d when fed acidogenic diets (Lopera et al, 2018;Rodney et al, 2018). Despite the increased urinary Ca loss, these cows maintain an estimated positive Ca balance of more than 10 g/d in the last week of gestation when fed diets with 0.55 to 0.65% Ca (Lopera et al, 2018;Rodney et al, 2018).…”

“…Diets with negative DCAD induced hypercalciuria, and, depending on dietary Ca intake, urinary Ca losses can increase from approximately 1 to 2 g/d when fed alkalogenic diets to approximately 8 to 11 g/d when fed acidogenic diets (Lopera et al, 2018;Rodney et al, 2018). Despite the increased urinary Ca loss, these cows maintain an estimated positive Ca balance of more than 10 g/d in the last week of gestation when fed diets with 0.55 to 0.65% Ca (Lopera et al, 2018;Rodney et al, 2018). The early work by Ender et al (1971) with cows fed alkalogenic or acidogenic diets in the last 2 wk of gestation and with intakes of Ca ranging from 30 to 150 g/d showed no differences in prepartum Ca balance when cows consumed an average of 50 g/d (Ca balance +14 g/d) or 136 g/d (Ca balance +17 g/d).…”

Impact of a Ration Negative in Dietary Cation–Anion Difference and Varying Calcium Supply Fed before Calving on Colostrum Quality of the Dams and Health Status and Growth Performance of the Calves

“…For example, reducing the DCAD from −70 to −180 mEq/kg diet dry matter (DM) decreased colostrum yield by 1.4 kg but had no effect on the birth weight of calves [7]; whereas increasing the duration during which the low DCAD diets were fed from 21 to 42 d prepartum, decreased the birth weight by 2.8 kg [8]. In contrast, feeding a low DCAD diet containing −157.9 mEq/kg DM did not affect prepartum DMI, fetal growth, and colostrum yield compared to the control (+188.5 mEq/kg DM [9]).…”

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

“…The animal treatment procedures were approved by the local animal care and use committee. Using a randomized block design, 18 Qianbei miscellaneous goats (a native goat breed in the southwest of China; 30.07 kg initial weight and aged 13 months) were allotted to 3 treatments of six replicates of 1 goat per replicate. Animals were fed one of three diets with different DCAD levels (mmol/kg DM): +350 (HD), +100 (CON), and −150 (LD).…”

“…Recently, attention was given to the interaction of DCAD with calcium (Ca) concentration [11], cholecalciferol/calcidiol [12], 5-hydroxy-l-tryptophan [13], vitamin D [14][15][16], and duration [17,18] of blood Ca level increases. Results of these studies indicated that lower DCAD in association with the above factors was effective in improving homeostasis of peripheral blood Ca.…”