The effects of relative gain and age on peripheral blood mononuclear cell mitochondrial enzyme activity in preweaned Holstein and Jersey calves

Abstract

Mitochondria are central to metabolism, nutrition, and health, but many factors can influence their efficiency. The objectives of this study were to determine if the mitochondrial enzyme activities of citrate synthase, complex I, complex IV, and complex V from peripheral blood mononuclear cells in Holstein and Jersey dairy calves were affected by age or relative gain as a percent of initial weight. Twenty-three Holstein and 23 Jersey heifer calves were enrolled between 3 and 6 d of age and whole blood samples were collected via jugular venipuncture at 1, 2, and 8 wk of age. Crude mitochondrial extracts were obtained from the peripheral blood mononuclear cell fraction at each time point and subsequently assayed for enzymatic activity. Age-dependent changes in activity were observed in complex V for both breeds. In Jersey calves complex IV and citrate synthase activity differed with age. Complex I activity was greater for high relative gain Jerseys and tended to be greater for high relative gain Holstein calves. Holstein calves had greater incidence of scours compared with Jersey calves, and in both breeds scouring calves exhibited greater complex V activity compared with those without scours. These data suggest that age and immune challenge in the form of scours affect mitochondrial complex V activity. Additionally, complex I activity may serve as a marker for calf growth potential because it was influenced by relative gain and not age.

Peripheral blood mononuclear cell mitochondrial enzyme activity is associated with parity and lactation performance in early lactation Holstein dairy cows

“…In contrast to complex I, complex IV activity did not differ by production group, but was greater in primiparous cows, compared with multiparous cows for peak milk, milk fat, and feed efficiency (Table 2). These results are in contrast with a previous study by Niesen and Rossow (2019), which showed no age-related changes in complex IV activity in preweaning Holstein dairy calves. The lack of change in complex IV enzyme activity in calves may be attributed to the support role of complex IV within the electron transport chain or its link to cellular apoptosis pathways.…”

“…Within the electron transport chain, complexes I and IV are 2 of the 3 enzymes that form the electrochemical gradient that drives ATP production through complex V. High-producing cows had greater complex I activity for peak milk, milk yield, ECM, FCM, milk fat, TS, and feed efficiency, compared with low producers across parities (Table 2). Niesen and Rossow (2019) found that preweaning Jersey calves with increased complex I activity had increased BW gain, compared with those with lesser BW gain. High gain Holstein calves tended to have increased complex I activity.…”

“…The sample size of cows per treatment (high vs. low) was estimated to be 11, based on a 2-tailed test, with a difference of 30% between electron transport chain enzyme complex activities, with a power of 0.90 and an α of 0.05. Estimates of sample size were based on the cows available for the project and past studies, involving mitochondrial measurements (Acetoze et al, 2017;Niesen and Rossow, 2019), and the minimum sample size was 10 cows per treatment. To be included in the study, cows needed to be at a similar stage of lactation (70 ± 11 DIM) and were fed the same diet using Calan Broadbent Feeding System (American Calan Inc.).…”

Mitochondrial Impairment in Well-Suppressed Children with Perinatal HIV-Infection on Antiretroviral Therapy

“…CIV and CS activity were obtained by spectrophotometry using the Abcam Ò Complex IV Human Enzyme Activity Microplate Assay Kit and the Abcam Human Citrate Synthase Activity Assay Kit, respectively. [15][16][17] Briefly, 10 and 120 lg of total buffy coat protein were added to each well of both assays, respectively. Microtiter plates were coated with enzyme-specific antibodies that captured only native protein.…”