Table 2.

Mean with SD of production parameters in high and low yielding cows by parity and farm

	Farm 12				Farm 9
	Primiparous cows		Multiparous cows		Primiparous cows		Multiparous cows
	High	Low	High	Low	High	Low	High	Low
	(n = 12)	(n = 12)	(n = 12)	(n = 11)	(n = 10)	(n = 9)	(n = 9)	(n = 10)
Days in milk	116	109	125	125	128	113	130	132
Milk yield (kg/d)	48.1	38.6	70.7	52.6	37.2	25.5	41.8	32.1
	± 1.3	± 1.2	± 4.3	± 3.3	± 7.1	± 2.7	± 3.4	± 3.4
Fat (%)	3.31	3.34	3.20	3.86	3.64	3.83	3.19	3.86
	± 0.57	± 0.61	± 1.25	± 0.90	± 0.36	± 0.62	± 0.48	± 0.67
Protein (%)	2.85	2.94	2.86	3.23	2.91	2.94	2.87	3.03
	± 0.22	± 0.20	± 0.27	± 0.28	± 0.22	± 0.30	± 0.23	± 0.23