Induction of eggshell apex abnormalities in broiler breeder hens

Figures & data

Table 1.  Serology, PCR, mycoplasma culture of the oviduct, total egg production, production of eggs with EAA and eggshell strength of the experimental SPF breeder hens

	Week	Control (n=12)	Ms1 i.t. (n=12)	Ms2 i.t. (n=12)	Ms1IBV i.t. (n=12)	Ms2IBV i.t. (n=12)
IBV D1466 HI test^a	D0	3.5 (0.2)^A	3.6 (0.3)^A	3.7 (0.2)^A	3.8 (0.3)^A	3.5 (0.2)^A
	W12	3.6 (0.1)^A	3.8 (0.3)^A	4.1 (0.2)^A	8.8 (0.5)^B	7.9 (0.3)^B
M. synoviae ELISA^b	W12	0/12^A	12/12^B	12/12^B	12/12^B	12/12^B
M. synoviae PCR trachea-positive^b	W12	0/12^A	5/12^B	4/12^B	2/12^AB	4/12^B
M. synoviae oviduct culture-positive^b,c	W12	0/12^A	0/12^A	1/12^A	1/12^A	1/12^A
Egg production and production of eggs with EAA
Total egg production	D0 to W12	712	–^d	454	449	368
Mean daily egg production/chicken^a	D0 to W12	0.66 (0.02)^A	–	0.42 (0.02)^B	0.41 (0.02)^B	0.34 (0.02)^B
Production of eggs with EAA	D0 to W12	0	–^d	0	9	0
Proportion (%) of eggs with EAA^b	D0 to W12	0^A	–	0^A	2^B	0^A
Eggshell strength (Newtons)
Non-affected eggs (20 to 24 eggs)^a	W11 to W12	39.2 (2.2)^A	37.4 (2.1)^A	36.1 (2.1)^A	35.7 (2.3)^A	31.4 (1.8)^AB
Eggs with EAA (six eggs)^a	W11 to W12				11.5 (1.8)^B
Control = not infected; Ms1 = single inoculation with M. synoviae EAA strain; Ms2 = double inoculation with M. synoviae EAA strain; Ms1IBV = IBV inoculation prior to the M. synoviae EAA strain inoculation; Ms2IBV = IBV inoculation prior to the first M. synoviae EAA strain inoculation. Means with the same uppercase superscript letter within the same row (for eggshell strength also between rows) differ significantly (P < 0.05). ^aMean (standard error of the mean) and statistical analysis with Kruskal–Wallis one-way analysis of variance. ^bTwo-sample proportion test. ^cPositive cultures were identified as M. synoviae by PCR. ^dEgg picking occurred, therefore results of egg production and the production of eggs with EAA could not be included in the analyses.

Figure 1.  Weekly egg production per experimental group was registered from 2 weeks (W-1 and W-2) before M. synoviae EAA challenge until W12 after mycoplasma inoculation. Ms1 is not included as results were influenced by egg picking. Control = not inoculated; Ms1 = single inoculation with M. synoviae EAA strain; Ms2 = double inoculation with M. synoviae EAA strain; Ms1IBV = IBV inoculation prior to the inoculation of the M. synoviae EAA strain; Ms2IBV = IBV inoculation prior to the first inoculation of the M. synoviae EAA strain.

Figure 2.  Eggs with EAA were only produced by the Ms1IBV group (IBV inoculation prior to the inoculation of the M. synoviae EAA strain).