Broad phenotypic impact of the effects of transgenerational heat stress in dairy cattle: a study of four consecutive generations

Table 1 Composition of PD16, the Israeli breeding index

Trait	Index coefficient	Genetic SD	Fraction of the index^a
Milk (kg)	0	910	0.000
Fat (kg)	8.48	32.1	0.212
Protein (kg)	21.2	22.6	0.373
Somatic cell score	− 300	0.47	0.110
Fertility (%)	26	7.15	0.145
Persistency (%)	10	5.44	0.042
Herd-life (days)	0.6	205	0.096
Maternal calving difficulty (%)	− 3	5.46	0.013
Maternal stillbirth (%)	− 6	2.21	0.010

SD standard deviation
^aComputed as the product of the absolute value of index coefficient and the genetic SD for each trait, divided the sum of the index contributions for all traits

ISSN: 1297-9686