Finding the optimal stocking rate is more important than ever to drive profits on your farm and to get the best out of your herd.
If optimal stocking rate is passed, then optimal efficiency will be passed, which means the return from additional units of production will drop and potentially generate a negative return.
Finding the optimal stocking rate is key, as with ongoing pressures around derogation, banding, and the amount of fertiliser you are permitted to spread, farmers must find the sweet spot in terms of stocking rate to drive profits with the right amount of cows on the right amount of land.
From a regulation point of view, it is crucial, and it is going to be a driver of net margins on the farm and will reduce the costs of production, which have sky rocketed in the last number of years.
In order to get the full benefits from a cow and help her reach her full genetic potential, cows need at least 19-20kg dry matter (DM)/cow/day according to a Teagasc study.
Stocking rate
Peak growth occurs in late May according to PastureBase Ireland, where on average over the last five years, there was peak growth of 71kg DM/ha.
Being stocked at 2.5 cows/ha intersects the average growth curve in mid-April and stays in surplus until October, which many could argue is too low to be stocked at, as you will be dealing with surplus grass in the main growing season.
A surplus of silage is not a bad thing, but consistently making excessive surpluses is counterproductive.
Five-year average grass growth rate and interactions with various stocking rates as per Teagasc are as follows:
Teagasc’s Stuart Childs, Nora O’Donovan, Adrian O’Callaghan and Donal Patton delved into what happens when stocking rates aren’t matched by a farm’s grass-growing capacity.
When stocked at three cows/ha, grass is not getting completely ahead of the cows and the surplus of growth over demand enables the farm to remove bales to manage grass quality. It also allows reseeding to ensure that sward quality is maintained.
When stocked at 3.5 cows/ha, growth only exceeds demand for a month and is followed by higher demand than growth for the rest of the year.
When stocked at four cows/ha, again, based on average national growth over the last five years, the farm will never grow beyond demand for the whole year.
What are these different stocking rates costing you in terms of extra supplementation and is an excessiove stocking rate costing you?
Growth rate (kg DM/ha) required to sustain different stocking rates with varying levels of fresh weight concentrate input (assuming 20kg total DM intake per day) as per Teagasc are as follows:
Stocking rate (LU/ha) Growth (kg DM/ha) Required (2kg of concentrates) Growth (kg DM/ha) Required (3kg of concentrates) Growth (kg DM/ha) Required (4kg of concentrates) Growth (kg DM/ha) Required (5kg of concentrates) 2.5 46 44 41 39 3 55 52 50 47 3.5 64 61 58 55 4 73 70 66 63
Excessive stocking rates can hinder cow performance as the cows may simply be not getting DM/day as there may be an underestimation of what they need and cows are going to need extra silage in the shoulders of the year which is all costly.
Stocking rates of 2.5 to three cow/ha will allow the farmer to build adequate covers for the end of August, with a small bit of intervention and this will help with building a grass wedge in to graze in October and early November.
Higher stocking rates create work as silage is removed from the diet later in the spring; silage needs to be introduced in August to build cover in autumn; or cows are fulltime on silage earlier than farms that are stocked to match the growth capacity.
On top of this, higher stocked farms are going to find it difficult to take out paddocks that are gone too strong during the grazing season as it may result in a deficit the following week.
Also, if you are stocked at 3.5 cows/ha, you are going to have a month of surplus grass and to turnaround a total reseed, you are going to need two months at a minimum, making it impossible to reseed without going in with extra meal or silage.
Without reseeding, swards age and grass growth reduces over time resulting in even lower growth rates than the farm requires.
The costs associated with stocking your milking platform higher than three cows/ha is creating a marginal system at best as these are the costs associated with it without taking into account housing, slurry capacity, water storage and so on.
Matching stocking rate to your average growth rate will maximÂise output while minimising input cost and this quite simply the key to having a highly profitable farm.
Farmers need to find out what their farms growth capacity is in order to match their stocking rate with that and minimise costs.