Estimation of genotype by temperature-humidity index interactions on milk production and udder health traits in Montbeliarde cows

Table 4 Genetic standard deviations of slopes at a temperature-humidity index (THI) of 70, genetic standard deviations of the trait at a THI of 70 and days in milk (DIM) = 150d and genetic correlations between slopes at a THI of 70 and breeding value at a THI of 50 and DIM = 150d

	MY	FC	PC	FY	PY	SCS
Genetic standard deviation of slope at THI = 70 (per unit of additional THI)
L1	0.051 kg/d	0.038‰	0.023‰	1.395 g/d	1.576 g/d	0.011
L2	0.047 kg/d	0.034‰	0.018‰	1.719 g/d	1.649 g/d	0.012
Genetic standard deviation of the trait at THI = 70 and DIM = 150d
L1	1.33 kg/d	2.07‰	1.36‰	42.81 g/d	37.96 g/d	0.599
L2	1.40 kg/d	2.01‰	1.35‰	48.67 g/d	40.04 g/d	0.487
Genetic correlation between slope at THI = 70 and breeding value at THI = 50 and DIM = 150d
L1	− 0.27	− 0.53	− 0.29	− 0.67	− 0.50	+ 0.64
L2	− 0.46	− 0.87	− 0.45	− 0.47	− 0.51	+ 0.33

MY milk yield, FY fat yield, PY protein yield, FC fat content, PY protein content, SCS somatic cell score, L1 first lactation, L2 second lactation

ISSN: 1297-9686