Metabolism of early-lactation dairy cows as affected by dietary starch and monensin supplementation

Abstract

The objective of this study was to evaluate the effect of dietary starch content and monensin (MON) on metabolism of dairy cows during early lactation. Before parturition, primiparous (n=21) and multiparous (n=49) Holstein cows were fed a common controlled-energy close-up diet with a daily topdress of either 0 or 400mg/d monensin. From d 1 to 21 postpartum, cows were fed a high-starch (HS; 26.2% starch, 34.3% neutral detergent fiber, 22.7% acid detergent fiber, 15.5% crude protein) or low-starch (LS; 21.5% starch, 36.9% neutral detergent fiber, 25.2% acid detergent fiber, 15.4% crude protein) total mixed ration with a daily topdress of either 0mg/d monensin (CON) or 450mg/d monensin (MON), continuing with prepartum topdress assignment. From d 22 through 63 postpartum, all cows were fed HS and continued with the assigned topdress treatment until d 63. Cows fed HS had higher plasma glucose and insulin and lower nonesterified fatty acids (NEFA) than cows fed LS during d 1 to 21 postpartum. Cows fed LS had elevated early-lactation β-hydroxybutyrate (BHBA) compared with cows fed HS. Cows fed HS had greater insulin resistance and increased plasma haptoglobin in the early lactation period. There was no effect of MON on postpartum plasma NEFA. Cows fed MON had higher plasma glucose compared with CON cows, which was driven by a MON × parity interaction in which primiparous cows fed MON had greater plasma glucose concentrations than cows fed CON. Cows fed MON had lower plasma BHBA compared with CON, which was contributed to by a MON × parity interaction in which primiparous cows fed MON had lower BHBA concentrations than CON. Starch treatment had no effect on overall liver triglyceride content. Primiparous cows fed MON had increased liver triglyceride content compared with CON primiparous cows, and multiparous cows fed MON had decreased liver triglyceride content compared with CON cows. Multiparous cows fed LS with MON had higher liver glycogen content than multiparous cows fed the LS without MON, with no effect of MON treatment for multiparous cows fed HS. There was no effect of starch or MON treatment on liver capacity to oxidize propionate to CO2, and effects of starch on gluconeogenesis were not significant. Cows fed MON tended to have greater capacity to convert propionate to glucose than CON. Supplementation with MON increased the ratio of glucose to CO2, which indicated that cows fed MON had a greater propensity to convert propionate to glucose. Overall, cows fed more propiogenic diets in early lactation (high starch or monensin) exhibited improved energy metabolism during early lactation.

Monensin controlled-release capsule administered in late-pregnancy differentially affects rumination patterns, metabolic status, and cheese-making properties of the milk in primiparous and multiparous cows

“…The reduced ketogenesis was not coupled with any increase in the glucose concentrations in blood. Although not seen consistently (McCarthy et al 2015), an increased glucose level was reported in some previous studies with monensin (Duffield et al 2008b) and was also expected considering the numerical increase of C3 availability detected in the rumen fluid of our treated cows.…”

“…Monensin is known to be effective in increasing the milk yield (MY) and can affect the milk components (Duffield et al 2008a(Duffield et al , 2008bMcCarthy et al 2015). Nevertheless, its effect on the casein content, titratable acidity, and clotting features of milk has been poorly investigated, and these are the focal points in cheesemaking systems.…”

Short communication: Concentrations of nonesterified fatty acids and β-hydroxybutyrate in dairy cows are not well correlated during the transition period

“…All animals were clinically healthy before enrollment, and all diets fed to cows fell within normal composition ranges typically fed to transition dairy cows on commercial dairy farms in the United States. Longitudinal data for NEFA and BHBA concentrations from d 21 prepartum to 21 postpartum were recruited to address the present objective from 4 separate experiments [Smith et al (2008) Plasma concentrations (Smith et al, 2008;Yasui et al, 2014;McCarthy et al, 2015b) and serum concentrations (Mann et al, 2015) of NEFA were analyzed by enzymatic analysis using a commercial kit [HR Series NEFA HR (2), Wako Pure Chemical Industries, Osaka, Japan]. Data for NEFA were reported as microequivalents per liter and converted into millimoles per liter by multiplying by a factor of 0.001.…”

Metabolic profiles of cow's blood; a review

“…Feeding a highly saturated free fatty acid supplement in a low dietary forage neutral detergent fiber diet during the first 29 days postpartum might have primed the cows to limit fat mobilization at the expense of milk . McCarthy et al . reported that cows fed more propiogenic diets in early lactation (high starch or monensin) exhibited improved energy metabolism during early lactation.…”

“…McCarthy et al15 reported that cows Likewise, reducing the number of diet changes before calving could facilitate ruminal adaptation to the lactation diet and improve energy balance postpartum 16. …”