What are Production Diseases, and How do We Manage Them?

Table 3 Effects of calving diseases and traits on milk yield variables for 5974 lactations^a.

Trait or disease	Peak yield		Month of peak^c		Persistency (%)^d		305-days yield^e
	Milk	ECM	Milk	ECM	Milk	ECM	Milk	ECM
Primiparous cows (2315 lactations)^a
Edema	1.1**	0.9**	-0.2†				213*	173*
Retained placenta	-0.6*	-0.6*	0.1†		-0.6*	-0.9**	-161*	-191**
Primary metritis					-0.9**	-1.3**	-150*	-172**
LDA					-0.3*	-3.3*
Ketosis	2.1*	2.3*					479†
Multiparous cows (3659 lactations)^b
Twin		0.6†
Induction	-1.3†	-1.5*
Stillbirth	-1.2*	-0.9**
Mastitis at calving	-6.9**	-5.4**	0.5**	0.9**		-2.8**	-1240**	-1248**
Edema	-2.2†
Retained placenta	-1.2**	-1.0**	0.3**	0.4**	-0.6*	-0.4†	-136†
Primary metritis	-1.1**	-0.8**	0.2**	0.3**	-0.9**	-0.8**	-243**	-184**
LDA	-4.4**	-4.0**	0.7**	0.9**	-3.2**	-2.8**	-821**	-731**
Ketosis			0.2**	0.2**	-0.6†	-0.6*

†p < 0.1, *p < 0.05. **p < 0.01 ^aEffects of herd, year, summer and BCS at calving were included in all models; ^bEffects of herd, parity, year, summer, BCS at drying off, length of dry period, and changes of BCS at the dry period were included in all models; ^cEffect of peak yield was also included; ^dPersistency = [peak yield/180-days yield*100]. Effects of peak yield, month of peak yield, and high SCCs were also included. ^eEffect of high SCCs was also included.

ISSN: 1751-0147