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

Table 2 Least-squares (LS) means (kg) and adjustment factors for effects of birth type, dam age class, and their interaction on lamb birth weights

Data set	Dam age class, years	LS means for birth type				Additive adjustment (kg) for birth type		Multiplicative adjustment for birth type
Data set	Dam age class, years	1	2	3	Average	1	3	1	3
Core	2	6.31 ± 0.04	5.22 ± 0.03	4.44 ± 0.05	5.33 ± 0.03	−1.09	0.78	0.83	1.18
	3 to 6	6.61 ± 0.03	5.71 ± 0.03	4.90 ± 0.03	5.74 ± 0.02	−0.90	0.81	0.86	1.17
Yearling^a	1	5.67 ± 0.04	4.53 ± 0.04	-	5.10 ± 0.04^c	−1.14	-	0.80	-
	3 to 6	6.59 ± 0.04	5.66 ± 0.03	-	6.06 ± 0.03^c	−0.91	-	0.86	-
Aged dams^b	3 to 6	6.51 ± 0.03	5.64 ± 0.03	4.83 ± 0.03	5.66 ± 0.03	−0.87	0.81	0.87	1.17
	>6	6.48 ± 0.06	5.56 ± 0.04	4.68 ± 0.06	5.57 ± 0.04	−0.92	0.88	0.86	1.19

^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 aged dams
^cexcludes triplet lambs

ISSN: 1297-9686