Description and evaluation of the Farmax Dairy Pro decision support model

Figures & data

Fig. 1  Example of the Farmax Dairy Pro user interface.

Table 1  Summary data for the SuperP and Massey datasets.

	Super		Massey
	2006/2007	2007/2008	1997/1998	1998/1999
Effective area (ha)	8	8	40	40
Peak cow numbers	29	29	100	100
Stocking rate (cows/ha)	3.6	3.6	2.5	2.5
Breed	F12 J4^1	F12 J4	Friesian	Friesian
Herd breeding worth	190	190	10	10
Start liveweight (kg)	539	548	532	482
Calving start	13 Jul	13 Jul	12 Jul	12 Jul
Once-daily milking	3 Mar	25 Jan	NA^2	NA
Dry-off date	20 Apr	25 Mar	30 Apr	17 Apr
Average total intake (% liveweight)	3.08	3.35	3.34	3.07
Composition of diet
Pasture (%)	74	75	76	74
Maize silage (%)	20	20	10	0
Pasture silage (%)	0	1	14	26
Turnips (%)	5	4	0	0
^175% Friesian, 25% Jersey.
^2Not available.

Table 2  Actual and predicted milk, milksolids (fat + protein), fat and protein yields per hectare and per cow for the SuperP and Massey datasets.

	Yield (kg/ha)		Yield (kg/cow)
	Actual	Predicted	Actual	Predicted
SuperP 2006/2007
Milk	16487	17456	4548	4815
Milksolids	1480	1479	408	408
Fat	837	830	231	229
Protein	643	649	177	179
SuperP 2007/2008
Milk	15896	16567	4385	4570
Milksolids	1386	1407	382	388
Fat	792	787	218	217
Protein	594	620	164	171
Massey 1997/1998
Milk	10211	10339	4084	4136
Milksolids	815	812	326	325
Fat	463	458	185	183
Protein	352	353	141	141
Massey 1998/1999
Milk	9855	9976	3942	3990
Milksolids	773	780	309	312
Fat	437	440	175	176
Protein	335	340	134	136

Fig. 2  Actual (–▴–) and predicted (○) monthly average liveweight, body condition score, milksolids yield, milksolids concentration and average pasture cover (APC) for SuperP in the 2006/2007 and 2007/2008 seasons.

Fig. 3  Actual (–▴–) and predicted (○) monthly average liveweight, body condition score, milksolids yield and milksolids concentration for the Massey herd in the 1997/1998 and 1998/1999 season.

Table 3  Measures of model accuracy for the SuperP datasets.

	LWT (kg)	BCS	Milk (kg)	FY (kg)	PY (kg)	MS (kg)	MS% (%)	APC (kgDM/ha)
2006/2007
Mean (actual)	493	4.24	17.7	0.90	0.69	1.60	9.15	2544
Mean (simulated)	479	4.31	18.0	0.86	0.67	1.54	8.71	2485
Mean bias (%)	−2.8	1.5	1.5	−4.1	−2.9	−3.7	−4.8	−2.3
R ^2	0.95	0.61	0.70	0.68	0.65	0.67	0.85	0.46
MPE (%)	3	5	23	20	23	21	5	7
v	0.81	1.15	0.71	0.77	0.67	0.73	1.23	1.04
C b	0.00	0.10	0.01	0.71	0.77	0.45	0.03	0.00
CCC	0.00	0.18	0.01	0.58	0.62	0.37	0.02	0.00
2007/2008
Mean (actual)	488	4.38	19.4	0.97	0.73	1.71	8.86	2018
Mean (simulated)	484	4.79	19.9	0.95	0.75	1.70	8.71	1902
Mean bias (%)	−0.7	9.3	2.2	−2.6	2.2	−0.5	−1.6	−5.7
R ^2	0.80	0.77	0.86	0.82	0.83	0.83	0.79	0.88
MPE (%)	2	11	17	15	18	16	3	7
v	0.91	1.51	0.70	0.78	0.70	0.74	1.05	0.98
C b	0.00	0.08	0.01	0.67	0.74	0.40	0.03	0.00
CCC	0.00	0.07	0.00	0.61	0.68	0.37	0.02	0.00
Notes. LWT = liveweight, BCS = body condition score, FY = fat yield, PY = protein yield, MS = milksolids (fat + protein), MS% = MS percentage, APC = average pasture cover, R ^2=coefficient of determination, MPE = mean prediction error, v=variance ratio; C b=bias correction factor; CCC = concordance correlation coefficient.

Table 4  Measures of model accuracy for the Massey datasets.

	LWT (kg)	BCS	Milk (kg)	MS (kg)	MS% (%)
1997/1998
Mean (actual)	457	4.47	16.1	1.34	8.09
Mean (simulated)	463	4.27	16.8	1.32	8.01
Mean bias (%)	1.2	−4.5	4.2	−1.1	−1.0
R ^2	0.96	0.76	0.85	0.79	0.70
MPE (%)	2	7	15	14	3
v	1.07	0.71	0.77	0.89	0.79
C b	0.00	0.10	0.01	0.53	0.03
CCC	0.00	0.09	0.01	0.47	0.03
1998/1999
Mean (actual)	472	4.33	16.2	1.28	7.92
Mean (simulated)	426	4.03	16.7	1.32	8.08
Mean bias (%)	−9.8	−6.9	3.3	3.2	2.0
R ^2	0.06	0.67	0.96	0.94	0.39
MPE (%)	11	9	16	14	5
v	0.76	0.56	0.68	0.79	0.65
C b	0.00	0.11	0.01	0.54	0.03
CCC	0.00	0.09	0.01	0.52	0.02
Notes. LWT = liveweight, BCS = body condition score, MS = milksolids (fat + protein), MS% = MS percentage, R ^2=coefficient of determination, MPE = mean prediction error, v=variance ratio; C b=bias correction factor; CCC = concordance correlation coefficient.

Fig. 4  Predicted (—) monthly milksolids (MS) production and average pasture cover (APC) compared with predicted values for scenario 1 (▵) and scenario 2 (□) for SuperP in the 2006/2007 and 2007/2008 seasons.

Table 5  Predicted milk, milksolids, fat and protein yield per hectare, end body condition score (BCS) and average pasture cover (APC) for the SuperP scenarios.

		Scenario
	Predicted	1	2
SuperP 2006/2007
Milk yield (kg/ha)	17456	18543	19606
Milksolids yield (kg/ha)	1479	1576	1669
Fat yield (kg/ha)	830	884	935
Protein yield (kg/ha)	649	692	735
End BCS	4.5	4.5	5.0
End APC (kgDM/ha)	2234	2237	2000
SuperP 2007/2008
Milk yield (kg/ha)	16567	17266	17131
Milksolids yield (kg/ha)	1407	1470	1457
Fat yield (kg/ha)	787	823	816
Protein yield (kg/ha)	620	647	642
End BCS	4.8	4.8	4.7
End APC (kgDM/ha)	1654	1323	1502