The Benefits of Transition Milk for Calves
20 October 2023On many dairy farms, calves are fed calf milk replacer (CMR) after receiving adequate colostrum. The length of colostrum feeding varies from farm to farm and there is no right or wrong system, ranging from a single four litre feed to feeding colostrum for up to three days. The use of transition milk after colostrum feeding is of increasing interest, although it does bring more challenges in terms of hygiene and disease risks depending on the health status of the herd. However, it can also bring health and performance benefits too and save on CMR.
Thanks for subscribing! Please check your email for further instructions.
Benefits of Transition Milk
Transition milk is from milkings two to six and is an intermediate between colostrum and whole milk. Its composition can be variable, but it will still have higher milk solids than whole milk (see table 1 below). Transition milk will also contain antibodies although not at the levels found in colostrum. While the ability of the calf to absorb antibodies is negligible after 24 hours, the presence of antibodies in transition milk can still provide some localised protection to the gut lining. This will be especially beneficial if the cows are vaccinated against the main causes of scour.
| Colostrum | Transition Milk | Transition Milk | Milk | |
|---|---|---|---|---|
| Milking | 1 | 2 | 3 | 6 |
| Total solids (%) | 23.9 | 17.9 | 14.1 | 12.9 |
| Fat (%) | 6.7 | 5.4 | 3.9 | 4 |
| Protein (%) | 14 | 8.4 | 5.1 | 3.1 |
| Lactose (%) | 2.7 | 3.9 | 4.4 | 5.0 |
| Antibodies (%) | 6 | 4.2 | 2.4 | 0.09 |
| IgG (the main antibody) (g/100ml) | 3.2 | 2.5 | 1.5 | 0.06 |
| IGF-1 (µg/L) | 341 | 242 | 144 | 15 |
| Lactoferrin* (g/L) | 1.84 | 0.86 | 0.46 | - |
*Involved in iron transport, immune system support (is a natural antioxidant) and protects against micro-organisms.
Source: Adapted from Foley and Otterby, 1978 & Blum and Hammond, 2000
In addition, transition milk contains bioactive compounds, growth factors and hormones which have been shown to aid the development of the gut microbiome. One of the hormones present, IGF 1 (insulin-like growth factor), is partly responsible for intestinal development. Calves fed transition milk have been shown to have a more developed gut, as measured by an increased surface area of small intestine for more nutrient absorption, compared to those receiving CMR after one feed of colostrum (research by Michigan State University).
In the short-term, studies have shown improved daily liveweight gain in the pre-weaning period when calves were fed transition milk from days two to four. While longer-term effects have not been studied, it has been suggested that first lactation performance may be improved, as higher weight gains pre-weaning are associated with increased milk production.
Considerations
If feeding transition milk, care must be taken to ensure the milk is heated to the correct temperature before feeding, and that good hygiene practices are adhered to when collecting and storing the milk prior to feeding. It must not be left out at ambient temperature for extended periods before feeding, as bacteria can double every 20 minutes.
When feeding transition milk bear in mind the additional cost for labour and equipment for collecting, pasteurising (if already doing so with colostrum), storage and reheating. The health status of the herd must also be taken into account, as feeding transition milk increases the risk of disease transfer with an even higher risk if the milk is not pasteurised.
The saving on CMR if feeding five to six litres at 15% inclusion for three days, with CMR at £2500/T ranges from £5.63-£6.75 per calf per day. As transition milk should not be going for human consumption, this could be an attractive option, saving on CMR the longer transition milk is fed.
Reference available on request.
Lorna MacPherson, SAC Consulting
lorna.macpherson@sac.co.uk; 07760 990901
Sign up to the FAS newsletter
Receive updates on news, events and publications from Scotland’s Farm Advisory Service