Protecting cows from stressful agents and conditions is one of our priorities on dairy farms. Especially when it comes to the most delicate moment of a cow’s life.
As we said already, while getting closer to calving, the cow goes through a very intensive period of physical, metabolic and hormonal changes. Thus, we must ensure the best conditions to let her live a calm and stressless period. It is a matter of cow welfare, udder health and production in the subsequent lactation.
Thus, how we dry-off our cows and how we cease milking is of utmost importance, for many reasons.
Drying-off involves the implementation of various measures to prepare the cow for the dry period. These measures are: the cessation of milking, dry cow treatments, use of teat sealants, moving cattle between groups.
OZOLEA always highlights the importance of proper drying-off procedures, in particular for what concerns milk production. Cow welfare and effective management are the two main pillars behind OZOLEA-MAST concept.
How we cease milking can definitely affect cow welfare, udder health and the following milk production. We can stop milking cows by either drying-off abruptly or gradually.
Thus, drying-off abruptly or gradually? The main difference is in timing. The first approach implies ceasing milking on a set day, generally scheduled on the basis of the estimated calving day and desired dry period length. The second one means reducing milking frequency over several days/weeks, with or without diet variation in energy and nutrition intake.
Dairy cows can still produce large quantities of milk towards the end of lactation, and this is the critical point. There would be many considerations about managing milk production for a nice lactation curve along with successful insemination procedures, but this is another long, complex story.
What is critical to know is that, if not properly conducted, the transition from a lactating to a non-lactating state can be really challenging and painful, especially when drying-off abruptly.
From an animal welfare perspective, gradual milk cessation can be more beneficial as it can meet natural behavior of the cow, her social state and biological functionality more closely.
Moreover, how we approach cessation of milking also affects physiological processes such as udder involution, generation of natural protective substances and all those natural strategies that help the cow prevent intra-mammary infections during the dry period.
Udder involution is a particular process and involves the transition of the udder from a lactating to a non-lactating one. Not milking within several hours implies the suppression of prolactin secretion and milk synthesis. Among other processes, non-specific antibacterial substances and natural protective factors, part of the innate immune response at udder level, also increase in mammary secretions. Reducing milking frequency accelerates udder involution while enhancing the innate defense system during the dry period.
Bacteria generally enter the udder through the teat canal. The formation of a keratin plug is a key physical defensive mechanism at each quarter level. The process requires a certain time range: the literature1 indicates that this process is faster in lower producing cows than in higher producing cows.
Milk synthesis continues at the very early stages of the dry period. This implicates a raise in internal pressure in the mammary gland, potentially leading to milk leakage and delayed keratin plug formation. Milk leakage is generally higher in cows with high milk yield at dry-off than those with lower yields.
All these issues are related to an increase in levels of stress perceived by the cow. The mechanisms behind stress are several and complex: unfortunately, they can lead to detrimental effects such as abortion, thus the loss of a lactation.
As we can see, a gradual reduction of milk production is beneficial for many aspects at udder, cow and dairy farm level. From the literature, milk yields of 15 kg/day or less are generally recognized as associable with better udder health. To facilitate the achievement of this goal, we can also restrict nutrient and energy intake. The more widely spread solution is feeding cows with hay only. Concentrates stimulate milk production; thus, we will avoid their use.
Cattle movements among groups is one of the strategies to make the cow comfortable before calving. Dairy cows are creatures of habit: if the dry pen is is positioned near the milking parlor, the cows can be stimulated by the noises and sounds of the milking machine. This leads them to prepare for milking and thus stimulates milk leakage.
Management and housing conditions highly vary among herd and dairy farms. The best way to deal with proper drying-off procedures is to seek for veterinary advice, always keeping in mind that a clean, dry, comfortable environment is vital for dry cows.
However, drying-off abruptly leads to increased risk of mastitis during the dry period and udder issue in the following lactation. Moreover, this practice does not allow the transition to selective dry cow therapy. We have already seen how urgent this process is, due to legislative requirements and the need of solutions against AMR.
In a context of high cow welfare and effective management such as that created with a gradual milk production cessation, a selective dry cow treatment can be conducted by using OZOLEA-MAST. Compared to a conventional therapy, using OZOLEA-MAST on cows suitable for selective treatment allows for a greater reduction in somatic cell count in the third and fourth month after calving. This reduction is a consequence of the tissue regeneration supported by OZOLEA-MAST.
1M.J. Vilar, P.J. Rajala-Schultz Dry-off and dairy cow udder health and welfare: Effects of different milk cessation methods. The Veterinary Journal 262 (2020) 105503
