For most farmers, September was a dream month, enabling plenty of grass to be built up in front of stock.
The trouble is that so far, October weather hasn’t obliged, with very heavy rain across most of the country. Ground and grazing conditions are on a spectrum – it all depends on soil type and how much rain falls on it.
Having a lot of grass in front of youngstock is a blessing for those on good ground, as the chances are it will all be grazed between now and housing.
But for those on heavier ground, it’s a different situation.
Yes, younger stock don’t do as much damage as older, heavier stock, but that usually means that the youngstock are moved to the wetter and more marginal ground while the heavier stock graze the drier parts.
For 2021-born calves or weanlings, management over the winter is all about target weights
The net result is that on heavy land, housing won’t be too far away unless the weather improves.
For 2021-born calves or weanlings, management over the winter is all about target weights. On 1 November, February-born calves with an expected mature liveweight of 580kg should weigh 232kg liveweight, or 40% of their mature liveweight. No matter how good the thrive was this summer, there will be some animals above and below this target.
The key word here is target. Note, it’s not called minimum weight, it’s the target weight. That means heifers that are heavier than this are off target in the same way that heifers lighter than this are also off target.
This is important, as heifers gaining too much weight lay down fat in the udder and are also found to have lower fertility performance in subsequent lactations.
Depending on the range of weights relative to target, there might be two or three feeding regimes over the winter
The weight of the animals relative to target should be used to determine the winter diet. This shouldn’t be a once-off decision. Animals should be weighed every four to six weeks during the housing period. For some farmers, this will be once or twice during the winter, but for those with longer winters, it may mean weighing three or even four times.
Depending on the range of weights relative to target, there might be two or three feeding regimes over the winter. Animals should be assigned to each regime based on their liveweight, with heifers re-ordered after each weighing.
Target liveweight on 1 December is 251kg, or 43% of mature liveweight, target on 1 January is 271kg, or 47% of mature liveweight and target on 1 February is 290kg, or 50% of mature liveweight.
The primary diet for replacement heifers should be reasonably good-quality grass silage. Weight gain over the winter for dairy replacements is usually low, at 0.4kg to 0.5kg/day on average, even with some meal in the diet.
This low weight gain is OK provided that heifers gain almost 1kg/day when at grass, because the average weight gain over the rearing period needs to be in the order of 0.7kg/day.
Farmers shouldn’t skimp on the quality of the silage fed to youngstock – they should get the best of what’s available to them. If that means opening a second pit or feeding good-quality bales instead of what is being fed to dry cows, then so be it. In most cases, extra meal will also be required but how much is fed is all dependent on the weight of the heifers.
Those behind target should be getting around 2kg or 3kg per day, presuming grass silage quality is close to 70% DMD. To know silage quality, it must be tested. Those that are on target weight will probably require 0.5kg or 1kg of meal per day in addition to ad lib silage.
As growing animals, they require protein, unlike finishing cattle which have a lower protein but higher energy requirements
Those that are well above target weight do not need meal. Regular weighing will be needed to make sure that stock are getting the right amount of feed to meet their needs.
The type of meal fed to weanlings over the winter should be high in protein, at 15% to 16% crude protein. As growing animals, they require protein, unlike finishing cattle which have a lower protein but higher energy requirements. Most meal merchants manufacture rations specially designed for weanling heifers.
In the past, some farmers might have fed home-mixed rolled barley and soya bean meal. With the price of straights going up and issues with sourcing soya bean meal for small deliveries in some cases, meal merchants might be able to offer a better solution this winter.
The importance of fresh, clean water cannot be overemphasised
Meal should be fed once a day in a clean trough or on top of the silage, but it’s critical that all the cattle in the shed can eat the meal at the one time. Where diet feeders are used to feed silage and meal mixed together, it’s less important that animals can feed at the one time.
The importance of fresh, clean water cannot be overemphasised. Turnout in early spring should be targeted at the lightest heifers.