Body weight estimation from body measures in Cornigliese sheep breed

Figures & data

Table 1. Descriptive statistics of body weight and body measures in Cornigliese sheep breed.

	No. of observations	Mean ± SD	Minimum	Maximum	CV, %
Dataset 1
BW, kg
Overall	303	39.30 ± 27.20	4.00	117.80	69.21
Females	178	47.00 ± 29.30	4.00	117.80	62.34
Males	125	28.30 ± 19.40	4.00	108.10	68.55
HW, cm
Overall	303	65.60 ± 12.30	35.00	90.00	18.75
Females	178	68.60 ± 12.30	40.00	87.00	17.93
Males	125	61.30 ± 11.00	35.00	90.00	17.94
ChC, cm
Overall	303	75.30 ± 21.30	34.00	125.00	28.29
Females	178	81.00 ± 22.30	35.00	125.00	27.53
Males	125	67.20 ± 16.60	34.00	120.00	24.70
BL, cm
Overall	303	64.00 ± 14.70	30.00	100.00	22.97
Females	178	66.60 ± 14.80	34.00	93.00	22.22
Males	125	60.30 ± 13.80	30.00	100.00	22.89
Dataset 2
BW, kg
Overall	156	53.80 ± 27.70	5.20	117.80	51.49
Females	109	60.70 ± 26.20	5.70	117.80	43.16
Males	47	37.60 ± 22.70	5.20	108.10	60.37
HW, cm
Overall	156	70.10 ± 12.00	45.00	88.00	17.12
Females	109	73.20 ± 10.70	45.00	87.00	14.62
Males	47	62.90 ± 11.90	45.00	88.00	18.92
ChC, cm
Overall	156	86.20 ± 20.40	40.00	125.00	23.67
Females	109	91.80 ± 19.00	40.50	125.00	20.70
Males	47	73.20 ± 17.60	40.00	120.00	24.04
BL, cm
Overall	156	70.70 ± 12.60	33.00	100.00	17.82
Females	109	72.40 ± 12.50	35.00	93.00	17.27
Males	47	66.80 ± 12.30	33.00	100.00	18.41
HCr, cm
Overall	156	72.80 ± 12.10	47.50	92.00	16.62
Females	109	75.90 ± 10.80	48.00	91.00	14.23
Males	47	65.70 ± 12.00	47.50	92.00	18.26
ChW, cm
Overall	156	21.80 ± 4.90	10.00	34.00	22.48
Females	109	23.00 ± 4.60	12.00	34.00	20.00
Males	47	18.90 ± 4.20	10.00	30.00	22.22
ChD, cm
Overall	156	29.30 ± 6.50	17.00	40.00	22.18
Females	109	31.00 ± 6.10	17.00	40.00	19.68
Males	47	25.10 ± 5.50	17.00	40.00	21.91
CrW, cm
Overall	156	24.60 ± 6.30	11.00	38.00	25.61
Females	109	26.20 ± 6.10	11.00	38.00	23.28
Males	47	20.90 ± 5.20	11.00	36.00	24.88

BW: Body weight; HW: Height at withers; ChC: Chest circumference; BL: Body length; HCr: Height at croup; ChW: Chest width; ChD: Chest depth; CrW: Croup width; CV: Coefficient of variation.

Table 2. Phenotypic correlation coefficients among body weight and body measures in Cornigliese sheep breed.

	HW	ChC	BL	HCr	ChW	ChD	CrW
BW
Overall	0.888	0.950	0.859	0.908	0.852	0.926	0.896
Females	0.890	0.954	0.871	0.870	0.828	0.905	0.867
Males	0.872	0.920	0.854	0.950	0.823	0.934	0.913
HW
Overall	–	0.905	0.889	0.985	0.797	0.898	0.868
Females	–	0.905	0.898	0.977	0.754	0.874	0.855
Males	–	0.885	0.863	0.991	0.786	0.899	0.836
ChC
Overall		–	0.859	0.917	0.873	0.920	0.914
Females		–	0.867	0.886	0.846	0.882	0.890
Males		–	0.846	0.946	0.858	0.961	0.924
BL
Overall			–	0.836	0.747	0.838	0.771
Females			–	0.826	0.722	0.841	0.732
Males			–	0.866	0.786	0.857	0.860
HCr
Overall				–	0.794	0.896	0.865
Females				–	0.752	0.870	0.848
Males				–	0.782	0.901	0.844
ChW
Overall					–	0.878	0.911
Females					–	0.842	0.895
Males					–	0.890	0.896
ChD
Overall						–	0.895
Females						–	0.856
Males						–	0.938

All coefficients resulted significant with p < .001.

BW: Body weight; HW: Height at withers; ChC: Chest circumference; BL: Body length; HCr: Height at croup; ChW: Chest width; ChD: Chest depth; CrW: Croup width.

Table 3. Multiple regression coefficients for body weight (kg) estimation from body measures (cm) in Cornigliese sheep breed.

Dataset 1	No. of observations	Intercept	HW	ChC	BL					RMSE	R^2	AIC
Overall	303
Model 1		–61.708	0.184	0.980	0.236					8.211	0.910
Model 2		–58.158	–	1.037	0.301					8.240	0.909	1586
Females	178
Model 1		–64.285	0.130	1.005	0.314					8.427	0.919
Model 2		–61.611	–	1.042	0.363					8.431	0.918	942
Males	125
Model 1		–53.852	0.290	0.706	0.281					7.053	0.871
Model 2		–48.694	–	0.810	0.373					7.148	0.866	622
Dataset 2	No. of observations	Intercept	HW	ChC	BL	HCr	ChW	ChD	CrW	RMSE	R^2	AIC
Overall	156
Model 3		–71.454	0.321	0.744	0.319	–0.206	–0.305	0.911	0.448	7.190	0.936
Model 4		–71.102	–	0.831	0.330	–	–	1.022	–	7.211	0.934	778
Females	109
Model 3		–66.914	0.138	0.766	0.288	–0.230	–0.296	1.185	0.526	7.870	0.916
Model 4		–70.685	–	0.814	0.258	–	–	1.224	–	7.810	0.914	563
Males	47
Model 3		–76.207	0.896	0.581	0.320	–0.235	–0.665	–0.044	1.082	4.985	0.965
Model 4		–77.286	0.690	0.552	0.314	–	–0.639	–	1.061	4.876	0.965	140

Model 1: multiple regression model on dataset 1 with all variables (HW, ChC, and BL); Model 2: multiple regression model on dataset 1 with stepwise procedure; Model 3: multiple regression model on dataset 2 with all variables (HW, ChC, BL, HCr, ChW, ChD, and CrW); and Model 4: multiple regression model on dataset 2 with stepwise procedure.

HW: Height at withers; ChC: Chest circumference; BL: Body length; HCr: Height at croup; ChW: Chest width; ChD: Chest depth; CrW: Croup width; RMSE: Root mean standard error; R²: Coefficient of determination; AIC: Akaike Information Criterion.

Figure 1. Actual body weight vs. estimated body weight. Model 1: the underlying regression equation is: y = –0.0068x² + 1.5643x – 6.7174; R² = 0.944. Model 2: the underlying regression equation is: y = –0.0065x² + 1.5373x – 6.3193; R² = 0.940. Model 3: the underlying regression equation is: y = –0.0058x² + 1.5527x – 8.5986; R² = 0.961. Model 4: the underlying regression equation is: y = –0.0057x² + 1.5380x – 8.2466; R² = 0.958.