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

Table 11 Fertility indices and various measures of negative energy balance (4510 lactations in 6 herds).

	Mean\value	Unobserved Heat^b	Not pregnant^b	Days Open^c	Rest Period^c
Factor^a		37.3	61.4	107 ± 38	76 ± 19
Lost ≥ 0.75 u BCS from calving to AI	42.9	1.23**	1.13†	3.5**	1.6**
Fat/protein ratio next/preceding AI^d	1.08	1.24**	1.15†	2.9*	2.1**
Daily FPCM in first 90 DIM^d	41.1		0.81*

† p < 0.1 *p < 0.05 **p < 0.01. ^aHerd, year, and parity were used as dummy variables. Effects of summer and calving diseases were included. ^bOdds ratio suffering from the trait compared to a cow without a factor. ^cEstimates of additional days. ^dHighest quarter.

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