. 2023 Jul 26;102(10):102964. doi: 10.1016/j.psj.2023.102964

Table 3.

Effect of dietary energy and protein levels on the reproductive performance of breeding pigeons in winter (first laying cycle)¹.

Treatments (n = 8)	CP/%	ME/MJ/kg	Average laying interval/d	Fertility rate/%	Hatchability/%	Average birth weight/g	35-day laying rate/%	40-day laying rate/%	50-day laying rate/%
I	15.0	12.2	39.896	97.301	94.141	17.504	22.917^c	50.000	97.917^a
II	15.0	12.4	39.313	93.068	90.193	15.863	25.000^bc	70.833	97.917^a
III	15.0	12.6	40.104	95.322	85.385	16.522	16.667^c	50.000	89.583^b
IV	16.5	12.2	38.908	92.910	86.730	15.829	25.000^bc	60.417	97.917^a
V	16.5	12.4	39.229	89.899	88.223	16.262	29.167^bc	58.333	100.000^a
VI	16.5	12.6	38.354	95.392	86.203	16.530	35.417^abc	66.667	100.000^a
VII	18.0	12.2	38.688	98.958	88.621	16.477	33.333^abc	64.583	97.917^a
VIII	18.0	12.4	38.500	92.955	86.929	16.569	43.750^ab	68.750	97.917^a
IX	18.0	12.6	37.312	92.301	82.186	15.863	50.000^a	75.000	100.000^a
SEM			0.263	0.861	0.933	0.180	2.399	2.748	0.759
Main effect
CP (n = 24)	15.0		39.771^a	95.230	89.906	16.630	21.528^B	56.944	95.139^b
	16.5		38.831^ab	92.734	87.052	16.207	29.861^B	61.806	99.306^a
	18.0		38.167^b	94.738	85.912	16.303	42.361^A	69.444	98.611^ab
ME (n = 24)		12.2	39.164	96.390	89.831	16.604	27.083	58.333	97.917
		12.4	39.014	91.974	88.448	16.231	32.639	65.972	98.611
		12.6	38.590	94.338	84.591	16.305	34.028	63.889	96.528
P values	CP		0.047	0.453	0.189	0.606	0.001	0.176	0.044
	ME		0.649	0.115	0.058	0.664	0.405	0.500	0.480
	C*M		0.327	0.328	0.181	0.450	0.019	0.337	0.035

All results are presented as mean ± SEM (n = 8).

Different lowercase letters in the data of the same column indicate significant differences (P < 0.05), and different capital letters indicate extremely significant differences (P < 0.01).

C*M, the interaction of the crude protein with metabolic energy.