We often find that animals are supplemented daily on many dairy farms while they are on the dairy platform, and then they go for a period of time over winter without supplementation. During the dry period, many farms will feed kale or fodder beet, which have their own mineral deficiencies but, in some cases, can also create some mineral interactions which reduce uptake and/or absorption of some key trace elements.
In general, provision of minerals throughout the entire period is difficult, it is more commonplace that some minerals are provided in the transition period (two-four weeks prior to, and two-four weeks post calving).
This article will cover some basics around feeding and mineral supplementation for the transition period. Feeding and nutrition during this period is a key factor in mitigating the occurrence of disease processes. During this time, the cow goes from being dry and pregnant to calved and lactating. A lot of changes occur within the body of the cow during this time, and hence she lives life on a knife-edge.
If we manage these cows correctly, there is the added benefit of reducing most metabolic disorders (e.g. milk fever or ketosis), retained foetal membranes and metritis, lameness, and many other infectious diseases such as mastitis.
During the transition period, the cow goes from laying down body tissue to mobilising the resulting stored energy. Nutrient demand increases hugely in response to the requirements for the final stages of foetal growth (more than 70% of foetal growth occurs within the last 60-70 days of gestation). This reduction is coupled with the fact that during the peri-calving period, there is a significant decline in dry matter intakes at the same time as there is an increased requirement.
As a result, most cows will end up in some form of negative energy balance during this time. The aim of transition cow feeding and management is to minimise this period by prepping the cow and maximising her ability to absorb the required nutrients from the diet.
There are several ways we can manipulate a cow’s ability to perform at her best level. The obvious one is to alter what she is fed. It is well documented that limiting grass in the transition period can assist with this process. This combined with the strategic use of dietary cation-anion diet (DCAD) and minerals can also help. DCAD diets work to help minimise the incidence of milk fever (hypocalcaemia). Some generic DCAD mixes are available, or they can be formulated specifically for your farm based on what feed types and volumes are being offered.
The use of in-shed feeding systems can also allow the provision of other pre-calving mixes and those containing trace elements to be added to the diet. The utilisation of this type of system can allow a mix of minerals and rumen modifiers to be fed directly onto meal or through molasses mixes. Mineral supplementation at this time can be useful to help the cow in providing the calf with the required nutrients. It can also allow for us to provide minerals such as magnesium in a more efficient/less wasteful way than dusting.
The use of rumen modifiers helps to alter the gut microflora to more energy-efficient bacteria. As a result, the bacteria metabolise ingested products and provide more available energy for the cow than for those cows with inefficient bacteria. Feeding well also helps to grow longer papillae within the rumen, and thus will directly increase the absorptive surface whereby energy molecules can be absorbed.
As a result, food is more efficiently digested and utilised within the rumen and absorbed into circulation where it can be used by the cow.
Vetlife can provide general Vetlife mineral mixes or create customised mineral mixes for your farm. We can formulate mixes for general all-year use or we can make up more specific DCAD or in-shed mineral mixes. If you are keen to learn more, please feel free to contact your Vetlife veterinarian who will be able to provide you with the required information or refer you to someone who can help.
By Susan Geddes – Vetlife Oxford
