Effects of excessive energy intake and supplementation with chromium propionate on insulin resistance parameters, milk production, and reproductive outcomes of lactating dairy cows

Abstract

a b s t r a c tThis experiment compared insulin resistance parameters, milk production, and reproductive outcomes in: (1) lactating dairy cows consuming adequate or excessive energy, and (2) lactating dairy cows consuming excessive energy and receiving or not Cr-propionate supplementation. Seventeen primiparous and multiparous, non-pregnant, lactating Holstein cows (initial days in milk ¼ 76 72) were assigned on d 0 to: (1) concentrate intake to meet their requirements of net energy for lactation (NE L ) without Cr supplementation (MAN; n ¼5), (2) concentrate intake to exceed their NE L requirements without Cr supplementation (HIGH; n ¼ 6), and (3) HIGH with 2.5 g/d of Cr propionate (HIGHCR; n ¼ 6). Throughout the experiment (d 0 to 210), cows were offered corn silage for ad libitum consumption, and individually received a corn-based concentrate twice daily. Concentrate intake was formulated to allow diets to provide 100% of daily NE L requirements of MAN, and 160% of daily NE L requirements of HIGH and HIGHCR cows. Cow BW, BCS, and milk production were recorded weekly. Blood samples were collected weekly, prior to and at 2 and 4 h after the morning concentrate feeding. Six glucose tolerance tests (GTT) were performed, every 42 d, by infusing cows with 0.5 g of glucose/kg of BW. Follicle aspiration for in vitro embryo production was performed via transvaginal ovum pick-up 2 d after each GTT. Increase in BCS from d 0 to 210 was greater (P r0.04) in HIGH and HIGHCR vs. MAN. Milk production was similar (P ¼0.92) between treatments. Within weekly samples, serum non-esterified fatty acids concentration were greater (P r0.05) for MAN vs. HIGH and HIGHCR. Serum insulin concentrations and insulin:glucose ratio were often greater (Pr 0.05) for HIGH, intermediate for HIGHCR, and lesser for MAN (treatment  day interaction, Po 0.01). During the GTT, serum insulin concentrations and insulin:glucose ratio were greater (P r0.05) for HIGH compared with HIGHCR and MAN from 10 to 60 min relative to the time of glucose infusion. Proportion of embryo produced per oocyte collected was greater (Pr 0.02) for MAN vs. HIGH and HIGHCR, and similar (P ¼0.59) between HIGH and HIGHCR. In conclusion, lactating cows consuming excessive concentrate and NE L experienced increased insulin resistance and reduced proportion of embryo produced per oocyte collected compared with cows consuming adequate amounts of energy, whereas Cr-propionate supplementation was effective in alleviating insulin resistance caused by excessive NE L intake.

Effects of concentrate type and chromium propionate on insulin sensitivity, productive and reproductive parameters of lactating dairy cows consuming excessive energy

“…From day 0 to 182, cows received concentrate treatments described in Table 1. Concentrate intake was formulated to each individual cow so the diet (concentrate + corn silage) provided 100% (day −15 to −1) or 160% (day 0 to 182) of their daily net energy for lactation (NE L ) requirements, as previously described and accomplished by Leiva et al (2015). All dietary treatments were formulated to similarly exceed CP, mineral and vitamin requirements (NRC, 2001).…”

“…GTT were performed on days −3, 60, 120 and 180 by intravenously infusing cows with 0.5 g of glucose/kg of BW, following the same procedures, sampling scheme and calculations for area under the curve (AUC), I : G, glucose clearance rate and half-life described by Leiva et al (2015).…”

“…dairy cows (Leiva et al, 2014 and2015). This syndrome, characterized by persistent hyperglycemia despite increased insulin secretion, has been shown to impair welfare and reproductive parameters of dairy cattle (Adamiak et al, 2005;Leiva et al, 2015;Baruselli et al, 2016).…”

“…This syndrome, characterized by persistent hyperglycemia despite increased insulin secretion, has been shown to impair welfare and reproductive parameters of dairy cattle (Adamiak et al, 2005;Leiva et al, 2015;Baruselli et al, 2016). Given that excessive energy intake is common and often inevitable among late-lactating and non-lactating cows in commercial dairies (Van Saun and Sniffen, 1996), nutritional strategies that mitigate insulin resistance are warranted to optimize productivity and welfare of dairy cattle.…”

“…Accordingly, Cr-propionate supplementation prevented the decrease in insulin sensitivity caused by excessive energy intake in lactating and non-lactating dairy cows (Leiva et al, 2014 and2015). Hyperinsulinemia is also known to downregulate insulin receptors in cells and cause insulin resistance (Moller and Flier, 1991).…”