Table 2. Comparative performance of relative serum volume (%) in Holstein and Jersey cows by THI range

THI	Holstein (%)	Jersey (%)	Total¹⁾ (%)	PSEM	p-value
THI	Holstein (%)	Jersey (%)	Total¹⁾ (%)	PSEM	THI	Breed	THI × Breed
61–63	58.97^a	61.78^b	59.94^a	1.051	0.365	< 0.001	0.886
64–66	45.76^b	53.80^c	51.42^b	1.977	0.270
67–69	59.68^a^y	65.36^ab^x	60.72^a	0.736	0.002
70–72	59.03^a^y	65.33^a^x	60.20^a	0.965	0.011
73–75	59.72^a^y	67.70^a^x	61.28^a	0.764	0.000
76–78	57.37^a^y	63.75^ab^x	58.91^a	0.749	0.000
79–81	59.10^a^y	64.70^ab^x	61.90^a	0.974	0.003
82–84	58.13^a^y	65.83^ab^x	59.08^a	1.047	0.020

Values are expressed as the mean ± SEM of 7 dairy cows in each group.
Values are the average of the data for both breeds in the same THI ranges.
Denote comparisons made within (same breed) columns (p < 0.05).
Denote comparisons made between Holstein and Jersey cows in the same THI range.
THI, temperature-humidity index; PSEM, pooled standard error of the mean.