Feeding Lambs for Ultimate Grades

August 7, 2020

We are now well into summer with lambs across the country thriving off the plentiful grass we have seen later on in the growing season following the warm dry spring causing a slow start for many area’s. However, we are now approaching the time of year where we start to see grass growth slow down, dropping protein and energy available from forage and increasing the amount of fibre in the crop.

For many flocks this change in forage quality also coincides with weaning, bringing a lot of change for lambs as they leave their mothers and have to stand on their own “four” feet. In order to support lambs during this period it is crucial that we continue to keep lambs on an even plane of nutrition to continue to drive daily live weight gains ensuring a good finish on all lambs sold. Providing an additional concentrate source of feeding alongside grass at this time of year is an ideal way to ensure lambs continue to thrive during this difficult period.

With lots of different concentrates available on the market, it is important when choosing a concentrate for your lambs to look at the bagging label to ensure you are buying the best quality feed available to suit your system. When assessing the bagging label two main factors should be considered: Raw materials and the mineral profile of the feed.

Raw materials are always listed on a bagging label in descending order with the most abundant first. For best results you should always look for a concentrate using top quality raw materials such as protein from soya providing a good source of bypass protein in the diet, distillers dark grains or rapeseed meal. Maize is one of best quality starch sources breaking down slower in the rumen with some utilised further down the digestive system making better use of nutrients available. This slower breakdown also provides a better environment for rumen microbes compared to a diet higher in only barley or wheat. However, a ration providing a source of all 3 main starches can be hugely beneficial for rumen health and performance. A good quality source of fibre in the diet such as beet pulp can also be beneficial in order to slow breakdown of the ration down resulting in a slower absorption of nutrients increasing diet efficiency and overall daily live weight gain.

Mineral profile of the diet is also hugely important to consider. Generally, when looking at the bagging label of a concentrate the vitamin and mineral content of a feed is always declared below the raw materials making it important to always check the small print. Some of the main minerals to consider when looking at a concentrate for growing lambs are Vitamins A, B12 and E and Selenium, all vital for growth, health and immunity. A high inclusion of ammonium chloride is also especially important if feeding to tup lambs in order to prevent urinary calculi (gravel). It is also vital that a fresh, clean water source is also provided to lambs at all times.

The energy levels in a concentrate feed source is also equally as important for growth of the lamb as protein therefore it is also important to check your concentrate is providing a high level of metabolic energy (ME) ideally between 12.5 – 13.0 MJ/kg DM. In order to ensure optimum intakes, the addition of an intake stimulant is also beneficial to aid palatability and further promote live weight gains .

Recent results from gradings returned to a customer from lambs sold dead weight in July 2020, have showed tremendous results from concentrate feeding. Lambs were fed a high energy, maize based Davidsons creep feed from one week of age right through to finish. 60 lambs were sent to slaughter averaging 400g/day live weight gain. At kill out 76.6% graded E with the remainder of lambs all U grade with a 20.5kg net weight. Feed cost throughout came to an average of £6.30 with the average price of lambs sold at £105, bringing the net gain less concentrate feed cost to £98.70/head.

Author – Lorna Shaw

Table 1: Lambs Grade and Average Net Kg – Lambs sold dead weight July 2020

Grade

Number of lambs

Average Net Kg

E3L

45

21.2

E2

1

21.4

U3L

14

19.8

Entire Group

60

20.5

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