09 Nov 2013
World famous dairy equipment producer De Laval invited many scientists, dairy experts and De Laval dealers around the globe to discuss problems of cow longevity at the Conference in Tumba, Sweden. More than 15 presentations from Canada, USA, Sweden, The Netherlands, France, Israel, Denmark and many other countries described problems of cow longevity. High rates of involuntary culling on a dairy farm because of illness or reproductive problems occur due to poor cow welfare which reduces the profitability of dairy farms. Removing the main causes of involuntary culling will lead to improved animal welfare and improved farm profits. The rates of involuntary culling are still very high in Armenia, especially among high productive imported cows. Many farmers in Europe and North America have a low rate showing that they have adopted housing and management practices that control the prevalence of the underlying health problems. As stated in the presentation, Dr. J. Rushen and A. M. de Passillé, UBC Dairy Education and Research Centre, Agassiz, Canada, researchers have identified that the majority of cows are now culled because of poor health and welfare. This can be seen when we look at the reasons the producers give for culling the cows. In most intensive dairy production systems in Europe and North America, dairy cows are culled mainly because of reproductive problems, mastitis or poor udder health, lameness and problems with feet and legs, and other forms of illness or injury. Calf illness and mortality is also a contributor to reduced longevity and poor calf management can have a negative impact on the cow’s later productivity. While cattle have the potential to live 20 years or longer, on most of the dairy farms that have imported cows from Europe have high rate of culling in first couple of years, few dairy cattle will live longer than 6 years in these farms for many reasons. Many factors effect in cow mortality after importation. First of all, this is the stress of long distance transportation. Then, the most important factor is the environment where the imported cows are kept and fed. Most of the farms don’t have housing and feeding conditions. Armenia has animal welfare standards neither for local nor for imported cows. Cows are moved from nice barns and green pastures in Austria or Germany into Armenian farming reality, where almost no or small number of farmers know what is animal welfare, cow comfort concept and general farm management principles. Local cattle breeds are used to poor housing, bad quality feed and hygiene conditions. In such conditions, local cattle can survive and even produce some food. Higher yielding cows tend to be more likely to suffer from the problems that lead them to be culled. Farmers who are chosen to import cows should go through the intensive training on modern farm management, improve their barn and feed production, not the way they would like but how the imported cows would like to see. In other words, they should construct new or redecorate old barns based on cow’s eye view of barn design. The critical factors are most likely related to whether or not the imported cows can fulfill high priority behavior and avoid fear, pain and discomfort which lead to illness and early culling. However, many producers in Armenia do have good cow longevity and low rates of involuntary culling. These farms have local cows, buy good quality input supplies, such as semen for artificial insemination, feed additives and implement what science has shown in last couple of decades. They demonstrate the best management practices which have resulted in significant improvements in animal welfare and farm profitability, reaching up to 3500 to 4000 litter of milk from local breeds. Lene Munksgaard from the Department of Animal Science, Aarhus University, reported at the conference that cattle are light‐active animals, and dairy cows are social animals and many dairy cows live in groups either in loose housing systems or at pasture. Therefore, cows have to compete with the group members for access to resources like food and lying areas. Competition can induce stress responses, and under time constraints, especially high producing dairy cows, may be in a trade‐off situation between lying and eating when they are kept in the same barn with local cows. To provide the high producing dairy cow with proper working conditions she should have free access to feed and resting areas. Furthermore, regrouping should be avoided or at least balanced. Christer Bergsten, a Professor in Technological Systems for Animal Production from the Department of Biosystems Technology, Swedish University of Agricultural Sciences, provided longtime take‐home messages on why it is important to invest in construction of new barns to the conference participants. Invest in soft resilient flooring with rubber of excellent quality; Invest in drainage of urine on solid floors by sloping floors with cleansing urine canals; Preferably invest in rubber, matted and slatted flooring with scrapers, traditional or robotic; Invest in feed stalls with rubber mats; Prepare firm and water drainable exits and gateways to pasture are the key messages which are very relevant to Armenian farmers, especially those who imported or are applying to import high productive cows from Europe. Then, Dr. Frank J.C.M. van Eerdenburg from the Department of Farm Animal Health, Faculty of Veterinary Medicine, University of Utrecht, added some key points on importance of climatic conditions, which are actual in continental climate which we have in Armenia with very hot summer and cold winter. They are: there should be no dirty smell inside the barn; the temperature inside should not be >5 °C above the outside; when the temperature outside is >20 °C inside the barn should be installed ventilation with cold water spraying system; there should be no draught or dead spaces; the relative humidity in the barn should be between 50‐ 80% ; dust and cobwebs is an indicator for poor ventilation. Toxic gasses in the barn “Ammonia (NH3) is one of the most common toxic gasses in animal barns. The concentration should not exceed the standard for cattle barns. In barns with manure cellars, mixing of the manure can release other gasses as well. Methane (CH4) and hydrogen sulfide (H2S) are often released in large amounts and may cause danger (explosions) and health problems, but if hydrogen cyanide (HCN) (almond‐like smell) is present, a serious health hazard is eminent for both cows and humans,” stated Dr. Frank J.C.M. van Eerdenburg. Barn temperature Cows prefer (compared to human standards) a relatively cool environment. The optimal temperature range to house high producing dairy cattle is between –5 and +15˚C . Lactating, high producing dairy cattle have a lower critical temperature (LCT) of –30˚C. This implies that above –30 ˚C they will not need extra feed for maintaining their body temperature. For dry cows, this LCT lies between –5˚C and 0˚C. At environmental temperatures above 15 ˚C, lactating cows will reduce DMI in order to reduce their basal metabolic level. As a consequence, they will produce less milk. Therefore, during warm summer days, a farmer needs to supply cooling. If the cows are outside, shade and ample fresh, cool, water is required. Based on the data presented by Dr. Frank J.C.M. van Eerdenburg, cows don’t need heating in the winter time and doors and windows should be widely opened for lactating cows if the temperature outside is not below – 30 C. Temperature difference between inside and outside Since cows prefer a cool climate, the amount of ventilation should not be reduced when temperatures drop below 0˚C. This will increase the difference between in‐ and outside temperature. Because of the fact that the difference between the rectal temperature of the cows and the environment increases there is more warming up of the barn air, due to an increased sensible heat loss. The temperature inside the barn should not exceed 5 ˚C above the outside in order to prevent draft and air‐born droplet infections (see below). In cold periods the ventilation should thus be increased. However, if the temperature drops below 0 ˚C, precautions should be taken to prevent freezing of water, conduits and manure on the floor. During the summer, the temperature inside the barn should be lower than outside. Relative humidity The relative humidity in the barn should be between 50‐80%. Cows on a high production level produce around 10 kg of moisture per day. This is released in the environment of the cows (barn). A high relative humidity is not desirable because it can harm the cows in two ways. Firstly, under warm conditions, they cannot evaporate as much water as they need, and thus they will suffer from heat stress more seriously. Secondly, under cooler outside conditions, the incoming fresh air will cool the warm, humid, air in the barn and since the amount of water, which can be present in the air, is temperature dependent, condensation will occur and an aerosol will be formed. The cows will inhale the aerosol and in this way air born infectious agents can be transmitted very easily since the particles, on which condensation will take place, can be bacteria or viruses. Because surrounded by water, they will survive for a longer period and the cows will inhale them deep into their lungs. As concluding remarks, Dr. Frank J.C.M. van Eerdenburg’s stated that cows produce more milk in a more comfortable environment and cows may live longer in a more comfortable environment. We argue that having clear animal welfare standards in Armenia, that have been developed by the dairy industry itself in North America and Western Europe, combined with greater use of local breeds, technical support and extension services available in the country, will help Armenian farmers to overcome many challenges they have today.
by Gagik Sardaryan
