In many cases, dairy cows during dry period are the most forgotten group in a dairy cow unit. However, these cows are the most important group of the herd.
Improving the care, feeding and management of these animals can improve the milk production and health status of cows during the postpartum period. Conversely, if these animals are ignored their will be significant losses in milk production, increased health problems, high cost of treatments and medication, reduced fertility and in many cases a high mortality rate.
It is therefore understandable that special attention is required in terms of feeding and management of cows during the dry period, in order to reduce losses and maximize the economic benefit for the producer.
Importance of the dry period
Cows need to go through the stage of dry period where these animals rest from the previous lactation, the breast is reconstructed and body condition is improved. If necessary lost body weight is regained.
It is also the period during which the embryo grows with great pace. This allows the animal to maintain himself, to prepare for the next lactation and to meet the demands of pregnancy. It has been reported that two-thirds of the unborn calf growth occurs during this time.
It must also be noted that the dry period, which coincides with the last term of pregnancy, is the period during which the cow has a decreased appetite and cannot easily cover its needs, with results in a negative energy balance; a condition that can be devastating for the animal.
Introduction to dry season
Introducing animals to the dry period means stopping the milking of the animal. The procedure to be followed includes:
• Stop milking animals.
• Introducing an intra-mammary antibiotic to protect animals from the likelihood of mastitis to each quadrant of the breast.
• Dip teats in an appropriate disinfectant.
Animals with high milk production and where it is difficult to abrupt the cessation of milking, it is required to reduce the amount of feed administered one week before entering the dry period. At the same time the quality of coarse feed which is administered to these animals can be changed (hay, silage, hay) from the level of high quality to the lowest quality, in order to reduce feed consumption and therefore the milk production. With these practices the discontinuation of milk production becomes easier and the animals enter the dry season.
The cows entering the dry period should be removed from the group which will continue milking and should be housed in a separate room.
The reasons for this are:
• Avoidance of mixing the animals and contaminating the milk with antibiotics.
• Animals have different nutritional needs from animals in milking.
The ration of cows in the dry period consists of a large amount forages and only a small proportion of concentrate feed. The total feed consumption is 50-60% of the consumption of milking cows and their needs for energy, protein and other components is much smaller. So if dry period animals consume dairy feed then feed is wasted and costs rise. Furthermore, problems will occur with animals becoming overweight which will cause problems in parturition and health problems such as toxemia, ketosis, hypocalcaemia etc.
The room which will house the dry period animals should be dry, clean and warm. It should also be disinfected often as the animals are susceptible to mastitis and general diseases.
Studies have shown that a cow which is admitted to a dry period for less than 40 days will give significantly less milk in comparison to a cow which is admitted for a duration of 60 days in the next lactation. Ideally, a time period 70 days or more would be most beneficial to the animal. Keeping the animals in dry period however is not economical to the producer because the maintenance cost during this period will not be covered by the additional milk which will be given. Therefore producers choose to keep animals in a dry period for 50-60 days which is the most economically efficient strategy.
It is also critical in the meantime to vaccinate the animals accordingly by the farm's veterinarian in order to protect the cow as well as the newborn calf.
One or two groups of dry period?
Cows during the dry period, if the farm's size allows, should be separated into two groups. The reason lies in the fact that the needs of animals during the first thirty days are very different than those of the last three weeks. If the animals are split into two groups, the producer can manage animals in a better manner which will lead to fewer problems in parturition and the next lactation.
The first group will have the cows from the beginning of the dry period up to 21 days before parturition and the second group of cows 21 days before calving until calving. Cows in the first group do not have particularly high needs for nutrition and care. The second group however, is very demanding with regards to both care and in terms of nutrition. These are perhaps the most demanding group of cows in a unit.
The dry period is a period during which there is the greater risk of developing metabolic diseases such is the toxemia pregnancy, hyperketonemia, hypocalcaemia, dystocia during calving and fertility reduction.
These diseases are mainly caused due to errors in animal nutrition. The animals that are at the stage of the dry period and more particularly as they approach calving, have difficulty consuming large amounts of feed, which results in a negative energy balance which has adverse consequences as catabolism of fat from their body meets their needs. The more mistakes are made the greater the problems and losses.
Working with an expert in animal nutrition is essential to determine the needs of the animals, grouping the animals and taking all the necessary measures for the animals.
Animal Nutritionist, MSc
VitaTrace Nutrition Ltd