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

Table 5 Differences between adjusted weaning weights of single-born, single-reared and twin-born, twin-reared lambs (expressed as single - twin) in high- versus low-performance flocks from the core and validation data sets following application of different adjustment protocols

Data set	Adjustment protocol	Flock performance level		Difference (low – high)
Data set	Adjustment protocol	Low	High	Difference (low – high)
Core	Simple additive	0.72 ± 0.48	−0.82 ± 0.55	1.54 ± 0.73^†
	Simple multiplicative	1.26 ± 0.42^**	−1.89 ± 0.48^**	3.16 ± 0.64^***
	Flock-specific multiplicative	0.19 ± 0.43	−0.32 ± 0.49	0.51 ± 0.65
	Simple multiplicative with interaction	1.70 ± 0.42^**	−1.29 ± 0.48^*	2.98 ± 0.64^***
	Flock-specific multiplicative with interaction	0.62 ± 0.44	0.32 ± 0.50	0.31 ± 0.67
Validation	Simple additive	−0.55 ± 0.80	−1.89 ± 0.54^**	1.34 ± 0.97
	Simple multiplicative	−0.35 ± 0.68	−2.56 ± 0.46^***	2.21 ± 0.82^*
	Flock-specific multiplicative	−0.83 ± 0.69	−1.44 ± 0.47^**	0.61 ± 0.84
	Simple multiplicative with interaction	0.11 ± 0.68	−1.96 ± 0.46^***	2.07 ± 0.82^*
	Flock-specific multiplicative with interaction	−0.38 ± 0.71	−0.88 ± 0.48^†	0.51 ± 0.86

Based on seven (of 28) flocks in the core dataset (Table 1) and nine (of 34) flocks in validation data with the lowest flock means for weaning weight and on seven flocks in the core dataset and nine flocks in the validation data with the highest flock means for weaning weight; ^†, *, **, ***: P < 0.10, 0.05, 0.01, and 0.001, respectively

ISSN: 1297-9686