Table 6.

Effects of dietary manganese (Mn) supplementation on reproductive organ and ovarian follicle development of duck breeders at the end of the trial (34 wk).

Variables2	Mn supplemental level (mg/kg)1						SEM	P-value
	0	20	40	80	120	160		ANOVA	Linear	Quadratic
Oviduct weight (g)	49.5	45.9	44.6	45.6	46.3	53.2	0.81	0.011	0.097	0.001
Oviduct length (cm)	45.6	39.0	37.6	40.4	44.9	39.7	0.81	0.009	0.869	0.688
Ovary weight (g)	61.9	53.0	55.1	58.3	62.4	56.6	1.89	0.685	0.805	0.965
F1 weight (g)	5.17	5.08	5.50	5.17	5.33	5.33	0.097	0.858	0.599	0.852
F2 weight (g)	50.0	45.7	49.0	49.9	55.2	50.0	1.71	0.782	0.391	0.667
F3 weight (g)	9.58	8.90	8.86	9.73	10.3	9.40	0.233	0.515	0.341	0.605
Number of POF	20.3	18.7	19.7	20.5	20.9	20.9	0.438	0.720	0.220	0.473
Total POF weight (g)	13.6	14.5	14.9	15.1	15.7	15.2	0.553	0.926	0.338	0.509
Mean POF weight (g)	7.61	7.48	7.91	8.24	9.86	8.49	0.460	0.732	0.212	0.409
POF percentage (%)	78.75	87.2	88.7	87.9	87.9	88.1	0.774	<0.001	0.008	<0.001
Number of SYF	9.50	9.58	6.67	10.83	9.58	6.75	0.522	0.099	0.405	0.388
Total SYF weight (g)	1.78	2.24	1.36	1.87	2.00	1.27	0.106	0.050	0.222	0.312
Mean SYF weight (g)	0.19	0.23	0.20	0.18	0.22	0.21	0.008	0.317	0.961	0.961
SYF percentage (%)	3.07	3.65	2.53	3.19	2.81	2.29	0.160	0.156	0.076	0.176
Number of LWF	36.1	43.2	42.9	36.4	45.0	37.6	1.59	0. 422	0.964	0.698
Total LWF weight (g)	1.05	1.25	1.40	1.17	1.41	1.36	0.058	0.411	0.171	0.330
Mean LWF weight (g)	28.5	29.4	33.6	32.0	30.6	35.0	0.852	0.221	0.068	0.192
LWF percentage (%)	1.70	2.40	2.56	2.00	2.29	2.47	0.102	0.119	0.248	0.466
Atretic follicles weight (g)	9.11	4.13	3.32	5.41	3.76	4.04	0.535	0.010	0.061	0.042
Atretic follicles percentage (%)	16.21	7.94	6.22	6.81	6.32	7.27	0.712	<0.001	0.003	<0.001

¹Mean of 6 replicates (2 ducks per replicate) per treatment.

²POF: preovulatory follicles; SYF: small yellow follicles; LWF: large white follicles; F1: the largest POF; F2: the second largest POF; F3: the third largest POF.