Insulin resistance in divergent strains of Holstein-Friesian dairy cows offered fresh pasture and increasing amounts of concentrate in early lactation

Abstract

The objective of this study was to determine whether the physiological response to an intravenous glucose challenge would be affected by genetic strain or concentrate supplementation in grazing Holstein-Friesian cows in early lactation. North American (NA; n = 30) or New Zealand (NZ; n = 30) cows were randomly allocated to 1 of 3 feeding treatments. All cows were offered a generous pasture allowance, and 4 of the 6 groups received either 3 or 6 kg of dry matter (DM)/cow per day of concentrates. During wk 5 of lactation, all cows underwent an intravenous glucose challenge. Cows of NA origin produced more milk than NZ cows, but there was no significant strain effect on milk fat or protein yield. Milk yield and the yield of individual components increased with increasing level of concentrate eaten, but there were no significant strain x diet interactions. During wk 1 to 6, mean body weight and body condition score decreased in all treatments. Average body weight was greater in NA cows, but body condition score was greater for NZ cows. There was no strain or diet effect on the length of the postpartum anovulatory interval, with cows ovulating before 40 d postpartum on average. Glucose fractional turnover rate was greater in NZ cows compared with those of NA origin and in all cows receiving 6 kg of DM concentrates, indicating a less severe insulin resistance in those treatments. Consistent with this, the time taken to dispose of half the peak glucose concentration was less when 6 kg of DM concentrate was fed, and tended to be less in NZ than in NA cows. There was no effect of genetic strain on glucose area under the curve (AUC) at 60 or 120 min, but AUC at both time points was less in cows receiving 6 kg of DM concentrates per day. Neither genetic strain nor nutrition affected basal or peak insulin concentrations, insulin increment, or insulin AUC, and there were no strain x diet interactions for any of the glucose challenge response variables measured. In conclusion, differences in milk production between NA and NZ cows in early lactation can, at least in part, be explained by the greater degree of insulin resistance in the NA cows, and this insulin resistance can be overcome by supplementing grazing cows with 6 kg of DM concentrates.

Physiological adaptations and ovarian cyclicity of Holstein and Montbéliarde cows under two low-input production systems

“…Breed differences on plasma glucose, BHBA and insulin were observed during the first weeks postpartum, whereas effects on BCS appeared at week 5 and thereafter. These results confirm that detection of BCS differences is delayed relatively to changes in metabolic and hormonal milieu, and that BCS effects provide a retrospective of physiological regulations of nutrient partitioning (Chagas et al, 2009). Plasma leptin concentration tended to be greater for HOLS at week −4, despite no differences in prepartum BCS.…”

Hormones, metabolites, and reproduction in Holsteins, Jerseys, and their crosses

“…However, our results agreed with Tanaka et al (2008) that the insulin concentrations decrease from wk 1 to wk 2. Insulin concentrations were lower in second lactation than first lactation (0.72 vs. 0.81 ng/mL) and could be attributed to the dairy cows producing more milk in second lactation (r = -0.28), which has been shown to have greater insulin resistance (Chagas et al, 2009). Our results support this statement as our cows had significantly lower insulin concentrations in second lactation compared with first lactation.…”

“…Dairy cows that are selected for increased milk yield have greater insulin resistance (Chagas et al, 2009), which is coupled with increased body lipid mobilization and a lower BCS nadir (Smith and McNamara, 1990;Roche et al, 2006;Kay et al, 2009). Reduced insulin concentrations during prolonged NEB postpartum may impair ovarian function and inhibit conception .…”

A prospective cohort study of digital cushion and corium thickness. Part 2: Does thinning of the digital cushion and corium lead to lameness and claw horn disruption lesions?

“…This is partly an effect of genotype, whereby body fats are mobilized to provide feed for the neonate through a homeorhetic process (in part, mediated by insulin resistance). Higher producing cows have higher levels of insulin resistance (Chagas et al, 2009) and consequently mobilize greater amounts of body fat and lose more condition (Smith and McNamara, 1990;Roche et al, 2006;Kay et al, 2009). Claw horn disruption lesion is known to be a disease of higher producing cows (Amory et al, 2008;Bicalho et al, 2008), and as such, the link between body condition loss and CHDL may not be causal, but both could be predisposed by another common factor, such as genotype.…”