Effects of birth-rearing type on weaning weights in meat sheep are systematically associated with differences in mean performance among flocks

Table 3 Least-squares (LS) means (kg) and adjustment factors for effects of birth-rearing type, dam age class, and their interaction on lamb weaning weights of single and twin lambs

Data set	Dam age class	LS means for birth-rearing type			Single lamb adjustment factor
Data set	Dam age class	11	22	Average	Additive, kg	Multiplicative
Core	2	31.4 ± 0.2	26.3 ± 0.1	28.8 ± 0.1	−5.1	0.84
	3 to 6	32.6 ± 0.2	28.1 ± 0.1	30.4 ± 0.1	−4.5	0.86
Yearling^a	1	29.1 ± 0.2	24.1 ± 0.2	26.6 ± 0.2	−4.9	0.83
	3 to 6	32.9 ± 0.2	28.5 ± 0.2	30.7 ± 0.2	−4.4	0.87
Aged dams^b	3 to 6	29.8 ± 0.2	25.4 ± 0.2	27.7 ± 0.2	−4.5	0.85
	>6	28.8 ± 0.3	24.1 ± 0.2	26.5 ± 0.2	−4.7	0.84

^aIncludes flocks from the core dataset that also have at least 50 records on yearling dams
^bincludes flocks from the core dataset that also have at least 50 records on > 6-year-old dams

ISSN: 1297-9686