Impact of simplified methods of growth recording on genetic parameter estimates of Tunisian local goat population under a low input production system

Figures & data

Figure 1. Number of records and mean weights of local kids at given period.

Table 1. Percentage of growth records from weekly recording which coincide with an exact standard age.

Weights recording method^a	W10^b	W30^b	W60^b	W90^b	W120^b	W150^b	Mean (%)
Week 1	12	21	22	13	13	9	15
Week 2	10	18	14	12	9	6	11
Week 3	6	16	15	3	6	4	8
Week 4	5	2	7	2	8	6	5
Week 5	2	5	3	2	3	1	3
Week 6	2	3	2	0	2	1	2
Week 7	0	3	2	0	2	1	1

^aRecording of weights from Week 1 to 7.

^bWage: weight at a given age (10, 30, 60, 90, 120 and 150 days).

Table 2. Descriptive statistics for traits studied at standard ages and for estimates from simplified recording schemes.

Weights recording method^a	Parameters	W10^b	W30^b	W60^b	W90^b	W120^b	W150^b
Exact age	Mean	3.39	4.93	7.87	9.44	11.67	13.22
	Minimum	1.2	2.32	3.34	4.34	6.03	6.23
	Maximum	4.12	5.45	8.64	11.12	13.33	16.36
	S.D.	0.73	0.87	1.51	1.7	1.88	2.33
Week 1	Mean	3.35	4.78	7.83	9.43	11.55	13.11
	Minimum	1.26	2	3.24	4.14	6.02	6.14
	Maximum	4.36	5.38	8.15	11	13.22	16.24
	S.D.	0.7	0.92	1.53	1.76	1.84	2.32
Week 2	Mean	3.34	4.64	7.82	9.41	11.66	12.99
	Minimum	1.26	2.1	3.14	4.23	6.13	5.87
	Maximum	4.40	5.38	8.18	10.18	13.23	16.27
	S.D.	0.69	0.84	1.56	1.72	1.84	2.37
Week 3	Mean	3.32	4.68	7.78	9.39	11.58	13.13
	Minimum	1.23	2.14	3.17	4.26	5.82	6.19
	Maximum	4.45	5.34	8.08	10.18	12.21	16.24
	S.D.	0.69	0.84	1.53	1.71	1.92	2.31
Week 4	Mean	3.30	4.51	7.78	9.39	11.63	13.01
	Minimum	1.25	2.14	3.7	4.17	5.81	5.91
	Maximum	3.87	5.13	3.15	9.98	12.23	15.81
	S.D.	0.68	0.79	1.36	1.74	1.94	2.36
Week 5	Mean	3.28	4.45	6.98	9.35	11.54	12.24
	Minimum	1.35	2.11	2.77	3.81	5.22	5.93
	Maximum	3.98	5.28	7.8	9.78	12.38	15.26
	S.D.	0.64	0.78	1.40	1.84	2.10	2.10
Week 6	Mean	3.26	4.44	7.03	9.25	11.29	12.13
	Minimum	1.23	2.17	2.8	3.83	5.67	5.93
	Maximum	4.17	5.18	7.15	9.77	11.5	15.26
	S.D.	0.67	0.75	1.41	1.81	1.87	2.06
Week 7	Mean	3.25	4.37	7.02	9.15	11.00	12.04
	Minimum	1.26	2.11	2.89	3.85	5.77	5.93
	Maximum	4.16	5.18	7	9.17	11	14.30
	S.D.	0.66	0.75	1.37	1.76	1.76	2.03

^aRecording of weights from Week 1 to 7.

^bWage: weight at a given age (10, 30, 60, 90, 120 and 150 days).

Table 3. Descriptive statistics for traits studied at standard ages and for estimates from simplified recording schemes when birth weight is missing.

Weight recording methods^a	Parameters	W10^b	W30^b
Exact age	Mean	3.39	4.93
	Minimum	1.20	2.32
	Maximum	4.12	5.45
	S.D.	0.73	0.87
Week 1	Mean	3.35	4.78
	Minimum	1.26	2.00
	Maximum	4.36	5.38
	S.D.	0.69	0.92
Week 2	Mean	3.36	4.84
	Minimum	1.28	2.40
	Maximum	4.46	5 .60
	S.D.	0.69	0.81
Week 3	Mean	3.38	4.72
	Minimum	1.85	2.57
	Maximum	4.90	5.80
	S.D.	0.51	0.71
Week 4	Mean	3.40	4.87
	Minimum	1.37	3.20
	Maximum	3.98	5.40
	S.D.	0.67	0.55
Week 5	Mean	3.30	4.85
	Minimum	1.74	3.00
	Maximum	4.20	5.60
	S.D.	0.52	0.61
Week 6	Mean	3.31	4.61
	Minimum	1.29	2.50
	Maximum	5.20	5.60
	S.D.	0.67	0.70
Week 7	Mean	3.54	4.49
	Minimum	1.80	2.50
	Maximum	6.20	6.60
	S.D.	0.58	0.66

^aRecording of weights from Week 1 to 7.

^bWage: weight at a given age (10, 30, 60, 90, 120 and 150 days).

Table 4. Test of significance of environmental factors and interactions on W10 with the presence of birth weight.

Source of variation	Exact age	Week 1^a	Week 2^a	Week 3^a	Week 4^a	Week 5^a	Week 6^a	Week 7^a
Year of birth	**	**	**	**	ns	ns	ns	*
Month of birth	**	**	**	ns	ns	ns	ns	ns
Age of female	**	**	**	**	*	**	**	**
Sex of kids	**	**	**	**	**	**	**	**
Year × month	**	**	**	*	*	*	*	*
Year × sex	**	**	**	**	**	**	**	**
Month × sex	**	**	**	*	*	*	*	*
Sex × age of female	**	**	**	ns	ns	ns	**	**
R^2	0.83	0.82	0.82	0.76	0.62	0.62	0.59	0.55

^aRecording of weights from Week 1 to 7.

*p < .05 (significant); **p < .01 (highly significant).

ns: non significant; R² : model determination coefficient.

Table 5. Test of significance of environmental factors and interactions on W60 with the presence of birth weight.

Source of variation	Exact age	Week 1^a	Week 2^a	Week 3^a	Week 4^a	Week 5^a	Week 6^a	Week 7^a
Year of birth	**	**	**	**	**	ns	ns	ns
Month of birth	*	*	*	ns	*	ns	ns	ns
Age of female	**	**	**	*	**	**	**	**
Sex of kids	*	*	*	*	*	**	**	**
Year × month	**	**	**	*	**	*	*	*
Year × sex	**	**	**	*	**	*	ns	ns
Month × sex	*	*	*	**	*	ns	ns	ns
Sex × age of female	**	**	**	*	**	ns	ns	ns
R^2	0.72	0.76	0.72	0.76	0.62	0.62	0.59	0.55

^aRecording of weights from Week 1 to 7.

*p < .05 (significant); **p < .01 (highly significant).

ns: non significant; R²: model determination coefficient.

Table 6. Test of significance of environmental factors and interactions on W10 with the lack of birth weight.

Source of variation	Exact age	Week 1^a	Week 2^a	Week 3^a	Week 4^a	Week 5^a	Week 6^a	Week 7^a
Year of birth	*	*	*	*	*	ns	**	**
Month of birth	ns	ns	ns	ns	ns	ns	ns	ns
Age of female	*	*	**	*	**	**	**	**
Sex of kids	*	*	*	*	*	**	*	*
Year × month	**	**	*	*	*	**	**	**
Year × sex	*	*	*	*	*	*	*	*
Month × sex	*	*	*	*	*	ns	ns	ns
Sex × age of female	**	**	**	**	**	*	*	*
R^2	0.63	0.62	0.62	0.62	0.57	0.58	0. 55	0.55

^aRecording of weights from Week 1 to 7.

*p < .05 (significant); **p < .01 (highly significant).

ns: non significant; R²: model determination coefficient.

Figure 2. Direct heritability estimates using weights at standard ages and alternative weekly recording schemes.

Figure 3. Maternal heritability estimates using weights at standard ages and alternative weekly recording schemes.

Figure 4. Genetic correlations between weights obtained with records taken at exact standard ages.

Table 7. Genetic correlations of weight traits estimated with the simplified weights recording method.

Growth recording method^a	Week 1	Week 2	Week 3	Week	Week 5	Week 6	Week 7
Week 1	1.00
Week 2	0.89	1.00
Week 3	0.53	0.68	1.00
Week 4	0.47	0.56	0.57	1.00
Week 5	0.35	0.46	0.48	0.57	1.00
Week 6	0.34	0.35	0.36	0.45	0.42	1.00
Week 7	0.29	0.22	0.22	0.27	0.21	0.16	1.00

^aRecording of weights from Week 1 to 7.