Dry cow management

Management of the dairy cow’s dry period is becoming increasingly recognised as crucial to the production and health of the cow during her next lactation.  The dry period (usually six to eight weeks) serves to give the cow a ‘rest’ so that her udder can repair and recover in readiness for the next lactation.  However it is also a time to focus on how the rumen can be managed to ensure high dry matter intakes of quality feed after calving.  Successful dry cow management involves:-  monitoring the condition of the cow, ensuring that her nutritional needs are met - paying attention to health issues.  This should lead to an easy calving with minimal health problems and pave the way for a profitable lactation.

This year has yet again seen sustained periods of wet weather that has made grazing difficult resulting in lower milk production over the summer months. Poor milk prices have also made it uneconomic to feed higher concentrate levels and the challenge is to ensure that cows in late lactation are approaching the correct condition for drying off. Inspect those cows four to six weeks from drying off and estimate what condition they’re in – ideally they should have a Condition Score (CS) of 3, that is, fit not fat.  Thinner cows should be fed an additional 1-2 KG/day of concentrate no greater than 18 percent protein.  It is more efficient for a cow to improve condition in late lactation rather than when dry, providing that she is not producing yields in excess of 15 l/day.  However most of a calf’s growth is in the last eight weeks of pregnancy and feeding to improve condition at this stage may result in large calves leading to difficult calvings.

Given the current economics of milk production, an option is to dry off lower yielding, thin cows earlier than usual to give them a dry period of eight plus weeks.  However ensure that an appropriate dry cow tube is used to give adequate protection for the extended period – if in doubt consult your veterinary surgeon.

Greater emphasis is now placed on feeding management of the cow when she is dry, particularly as she nears calving and preparing for the next lactation.  Nutrition at this time is largely influenced by the condition of the cow, and how far she is off calving.  Ideally cows should be dried off in condition score 3 and maintained at this level until calving.  However this can be difficult to achieve, especially in a spread calving pattern that makes it challenging to group cows according to condition score and calving date.  At this time of year dry cows are normally grazed on poorer, stemmier grass and this bulky forage is usually adequate to maintain condition, retaining rumen capacity and function.  Thinner cows (condition score less than 2.5) should be grouped separately and receive better quality forage plus 2 KG of concentrate.  Fat cows should be offered a restricted diet to achieve condition loss, that is, bare pasture and stemmy big bale silage.  

The last four weeks before calving are important as intakes decline, yet the cow needs adequate energy to support the growing calf and her own maintenance.  Therefore the nutrient density of the diet needs to increase and concentrates usually need to be fed.  There has been a recent trend towards straw based diets to maintain rumen capacity near calving.  It is vital that the diet supplies sufficient energy and minerals/vitamins and a specific dry cow mineral supplement needs to be offered.  It is also beneficial to feed 1-2 KG/cow/day of the milking ration approximately one week before calving to adapt the rumen to the post-calving diet in early lactation.

The cow’s udder is very susceptible to infection just after drying off and she should be moved to a clean area after dry cow treatment.  Try to avoid grazing dry cows in wooded areas at this time of year as they may be susceptible to dry cow mastitis (felon) due to the greater number of flies in the area at this time.  Drying off is also a good time to control parasites and give some vaccinations, as well as routine hoof trimming.

There are a number of conditions associated with the cow around the time of calving and in the first few days afterwards, that is, milk fever, displaced abomasums, and ketosis.  Most of these cases can be related to dry cow management and are largely connected to the cow’s metabolism during this time.  Milk fever remains the most common of these and occurs when the cow quickly mobilises her body reserves of calcium into milk.  This results in a rapid drop in blood calcium levels which become too low to support normal nerve and muscle function, causing the cow to go down.  Milk fever can also lead to other complications such as retained cleansings and mastitis.  The dry cow’s diet should be managed to limit calcium supply but this can be difficult as grazed grass in late summer is higher in calcium and lower in magnesium which increases the risk.  The solution is to replace some of the grazing with silage (grass or preferably maize) or straw and/or supplement with an appropriate dry cow mineral.  

In summary, the dry cow period should not be thought of as the end of one lactation, but as the beginning of the next.  The focus should be on preparing the cow so that she calves down ‘fit not fat’, and that her diet in the dry period has sufficient nutrients and minerals to provide for the growing calf and prepare her for an increase in intakes after calving.  Attention to detail in management at this time pays dividends, resulting in a relatively easy calving with the cow back on her feet and milking with no setbacks, and on track for a productive and healthy lactation.

John Blair, UDF member from Larne, discusses the condition of late lactation cows with the author.