Response to supplements

Ideally, use supplements early as a tool to help maintain a slow rotation, rather than just for more milk production. Buy supplements on an energy basis. Consider how easy the supplements will be to feed out and what the wastage will be. Look for every opportunity to reduce wastage when feeding supplements; this improves milk production responses and helps bring down the cost of the feed eaten. It also makes feed reserves last longer.

When grazing residuals are less than seven clicks on the rising plate meter (1450kg DM/ha), supplements are an option. The return from supplements depends on the payout, the severity and length of time of the feed deficit, and the quality and utilisation of the supplement as shown in Tables 1 and 2. Substitution of supplement for pasture can be a real problem, leading to wastage of pasture and hence unnecessary expenditure.

Table 1. Response to supplement offered (purchased) in spring

Response	Residuals & APC	Supplement	Other
g/kg DM 11ME	Residuals & APC	Supplement	Other
>0 to 30	9.5 clicks or 1800kg DM/ha. At or above APC target	Quality < 10.5 ME; Wastage 30% plus (fed in wet weather; poor stack mgt)	Pasture quality in subsequent rotations poor & less pasture grown
40-55	8-9.5 clicks (1600-1800kg DM/ha); stop feeding at target APC	Average quality 10-10.5 ME; Wastage 25%-30%	Supplement feeding stopped too late creating surplus
60-80	6.5-7.5 clicks (1350-1550kg DM/ha if supplement not fed; residuals <8.0 clicks when supplement fed	Good quality 10.5-11.0ME; Wastage 20% or less	Short term feed deficit (<10days). Supplement feeding stopped before APC cover target achieved
90-130	Residual < 6 clicks (1350kg DM/ha) if supplement not fed. When supplement fed residuals 6-7 clicks (1350-1500kg DM/ha); APC well below target (> 300kg DM/ha deficit)	Good quality > 10.5 ME Low wastage 15% or less (feeding maize or PKE in bins/on feed pad)	Cows grazing to < 6 clicks for 10 days plus; supplement feeding stopped in anticipation of target cover being met. Responses increase with the period of severe underfeeding (8.0g/ME at least 2 weeks; 10g/ME 4 weeks; 12g/ME 5 weeks)