Establishing blood gas ranges in healthy bovine neonates differentiated by age, sex, and breed type

Calves may have crossed the lower reference limit for plasma glucose even earlier (< 4.3 mmol/L), but CGM data was not recorded between hours 2-17 of transport.

“Calves may have crossed the lower reference limit for plasma glucose even earlier (< 4.3 mmol/L) [41], but CGM data was not recorded between hours 2–17 of transport.”

It cannot be ruled out that differences in electrolyte and protein concentrations reflect normal physiological changes of aging.

“Furthermore, as with glucose, it cannot be ruled out that these differences in electrolyte and protein concentrations reflect normal physiological changes of aging [41, 42]”

Despite age differences, both age groups were within normal reference ranges for corrected chloride at the assembly centre and lairage (95-103 mmol/L) and for TP on Day 7 (39.4-59.3 g/L), while sodium concentrations were above the upper reference limit for both age groups the entire study period (>139.3 mmol/L), suggesting limited biological relevance of the age effect on hydration.

“Despite these differences, both age groups were within normal reference ranges for corrected chloride at the AC and lairage (95–103 mmol/L) [41] and for TP on Day 7 (39.4–59.3 g/L) [42], while sodium concentrations were above the upper reference limit for both age groups the entire study period (> 139.3 mmol/L) [41], suggesting limited biological relevance of the age effect on hydration.”

Both INT and NLD groups had sodium levels elevated above normal reference levels (133.3-140.2 mmol/L) on arrival, which was not observed in IRE calves.

“Both INT and NLD groups had sodium levels that were elevated to above normal reference levels (133.3–140.2 mmol/L; [24]) on arrival, which was not observed in IRE calves”

On arrival, sodium was lower for IRE calves than for INT and NLD calves (139.6 vs. 142.5 and 143.3 mmol/L; p < 0.05).

“Sodium was lower for IRE calves than for INT and NLD calves (139.6 vs. 142.5 and 143.3 mmol/L; p < 0.05); IRE calves were within the reference limits (133.3–140.2 mmol/L [24]) while INT and NLD calves had values above the reference limit on arrival.”

On arrival, IRE calves had sodium within reference limits (133.3-140.2 mmol/L) while INT and NLD calves had sodium above reference limits.

“Sodium was lower for IRE calves than for INT and NLD calves (139.6 vs. 142.5 and 143.3 mmol/L; p < 0.05); IRE calves were within the reference limits (133.3–140.2 mmol/L [24]) while INT and NLD calves had values above the reference limit on arrival.”

On arrival, corrected chloride was lower for IRE calves (97.3 mmol/L) than for INT and NLD calves (99.0 and 98.9 mmol/L respectively; both p < 0.05), although all groups had chloride levels within reference limits (93-101 mmol/L).

“Additionally, corrected chloride was lower for IRE (97.3 mmol/L) than for INT and NLD calves (99.0 and 98.9 mmol/L respectively) on arrival (both p < 0.05), although all groups had chloride levels within the reference limits (93–101 mmol/L [24]).”

Published reference ranges were observed in healthy male and female dairy or dairy cross calves between birth and 4 weeks of age or between 1 and 12 months of age for L-lactate.

“Published reference ranges were observed in healthy male and female dairy or dairy cross calves between birth and 4 weeks of age (21–24, 26) or between 1 and 12 months of age [L-lactate; (25)].”

Age has been demonstrated to have major effects on blood gas variables in calves.

“Age has been demonstrated to have major effects on blood gas variables in calves”

Both treatments fell below the reference limit for glucose in healthy young calves (4.3 mmol/L), indicating hypoglycemia, and exceeded the upper reference limit at the lairage and upon arrival for NEFA (0.29 mmol/L) and BHB (0.15 mmol/L).

“both treatments fell below the reference limit for glucose in healthy young calves (4.3 mmol/L, suggested reference ranges for healthy male calves, 11 to 30 d old, Dillane et al., 2018), indicating they experienced hypoglycemia and exceeded the upper reference limit at the lairage and upon arrival for NEFA (0.29 mmol/L, suggested reference range for healthy male Holstein calves, 5 wk old, Yu et al”

There was an increase in signs of dehydration over the course of transport regardless of pre-transport feeding protocol.

“When compared with reference ranges of un-transported calves (Knowles et al., 2000; Mohri et al., 2007; Dillane et al., 2018), there was an increase in signs of dehydration over the course of transport regardless of pre-transport feeding protocol.”

Both treatment groups exceeded upper reference limits of sodium and potassium at all 3 time points (except potassium for preCTRL at the AC), indicating that calf hydration status was already somewhat compromised before international transport.

“However, both treatment groups exceeded upper reference limits of sodium and potassium (139.3 and 5.37 mmol/L, Dillane et al., 2018) at all 3 time points (except potassium for preCTRL at the AC), indicating that calf hydration status was already somewhat compromised before international transport.”

At the assembly centre and arrival, younger calves maintained plasma glucose concentrations within suggested reference ranges for healthy and unfasted male calves 11 to 30 d old (4.3-7.4 mmol/L), while older calves fell below it.

“At the AC and arrival, younger calves also maintained plasma glucose concentrations within suggested reference ranges for healthy and unfasted male calves, 11 to 30 d old (4.3–7.4 mmol/L) [41], while older calves fell below it.”

Overall, mean values for 11 out of 18 variables (for which reference ranges were available) exceeded the reference ranges published by previous studies after long fasting periods.

“Overall, mean values for 11 out of 18 variables (for which reference ranges were available) exceeded the reference ranges published by previous studies after long fasting periods (21–26).”