Table 4. Comparative performance of milk production in Holstein and Jersey cows by THI range

THI	Holstein (kg/d)	Jersey (kg/d)	Total1) (kg/d)	PSEM	p-value
					THI	Breed	THI × Breed
61–63	28.77abx	19.75ay	25.63	0.801	0.000	< 0.001	0.036
64–66	27.13bx	17.99bcy	23.83	0.605	0.000
67–69	29.24ax	17.98bcy	25.13	0.463	0.000
70–72	29.14ax	16.82cy	23.94	0.491	0.000
73–75	29.06ax	16.92cy	24.02	0.469	0.000
76–78	28.68abx	17.68bcy	23.95	0.563	0.000
79–81	28.49abx	17.29bcy	23.85	0.514	0.000
82–84	28.63abx	18.61aby	24.26	0.493	0.000

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