Outwintering cuts dairy costs

Out-wintering in-calf dairy heifers could cut variable and fixed costs by 48%, according to new research at Harper Adams University College.

Addressing delegates at the British Society of Animal Science annual conference, Harper Adams’ Simon Marsh said out-wintering in-calf heifers offered the potential to increase herd size, within the restraints of NVZ restrictions without the capital costs associated with waste storage.

In-calf heifer of 21 months old were either housed or out-wintered. Those housed were offered unlimited grass silage, whole-crop and initially 1.5kg of concentrates for the first 48 days before being replaced with 100g of minerals. Out-wintered heifers on stubble turnips were initially offered ad-lib straw, which was replaced with haylage after 48 days.

“At first housed heifers had a better condition score and higher DLWG compared with those out-wintered, which were losing on average 0.30kg a day compared with housed heifers, which were gaining on average 0.77kg a day. This necessitated the change from feeding straw to haylage for out-wintered heifers and compensatory growth was recorded in these animals, with a daily liveweight gain of 1.37kg from 48 days to the end of outwintering,” said Mr Marsh.

“At turnout housed heifers had a marked growth check. So despite out-wintered heifers losing weight initially, overall from start to finish there was no difference in total growth, with out-wintered heifers having slightly higher daily liveweight gain of 0.88kg compared with 0.82 kg a day for housed heifers,” he said.

Mr Marsh said out-wintering had no welfare implications in relation to locomotion and dirtiness and 0.75ha (1.85 acres) provided sufficient stubble turnips for one heifer for 120 days.

“Producers have to be prepared for low use of stubble turnips, with wastage of 56-62% and the roots mainly being left ungrazed. But heifers do consume about 90% of the leaves, with haylage intakes consisting of half of daily intake,” he said.

“Out-wintering on stubble turnips plus haylage allows heifers to calve at 24 months, at a target daily liveweight gain of 0.7-0.85kg. And, as the results show, overall variable costs can be reduced by 25%, with out-wintering costing 58p/kg compared with housing at 77p/kg and total costs reduced by 48% – 0.78p/kg for outwintered stock vesrus 150p/kg for housed heifers,” he said.