The AgriPost
Mycoplasma Pneumonia Strikes Down Baby Dairy Calves I haven’t seen a case of mycoplasma pneumonia in dairy calves for many years and then a similar case popped up on a farm visit in the last couple of months in which several calves had perished. I am not a veterinarian, so I told this dairy producer that he should call his vet and get a proper diagnosis as well as send away cultures for mycoplasma conformation. Regardless of its outcome, it was a good lesson for the both of us that a few measures on the dairy farm should be put in place to prevent devastating mycoplasma infections in baby calves. The calf barn that I visited years ago failed to take such precautions. It was a 1,000-head lactation operation located stateside and they nearly lost all of their 200 pre-weaned dairy calves due to mycoplasma pneumonia. I’ll never forget it; I was invited by a local feed dealer to help him drop off a couple of tons of baby calf starter into a large metal hangar that housed these calves. When we went inside, I saw several rows of plastic or wooden hutches with an individual calf inside each of them. Housing conditions for these calves were deplorable. It was wintertime and because the hangar was not insulated, there was a fine rain that literarily fell from the high ceiling, causing most of the calves and their bedding to be constantly wet. A deep hacking cough resounded by many calves within these metal walls and I remember many sick calves with yellow discharge from their nose as well as swollen knees, encrusted droopy ears with a definite tilt to their head. My experience was confirmed by a few veterinary books that I had on hand. Their fine print states that three types can cause disease in cattle. Mycoplasma bovis (m. bovis) being the most common mycoplasma pathogen in pre-weaned Mycoplasma bovis (m. bovis) dairy calves. Subsequent university research adds that 4-day to 10-week old animals are the most susceptible group to mycoplasma infections, which causes respiratory lung lesions (pneumonia – coughing and nasal discharge), arthritis (swollen knees) and ear infections (tilted head). It is also my understanding that dairy calves diagnosed with m. bovis suffer about a 50 - 80% mortality rate, and even those dairy calves treated early on by intense drug-therapy have a 50 – 75% relapse rate. Such high mortality and relapse rates caused by mycoplasma pneumonia in baby calves are shocking to me. However, given its biology, I can understand how it can quickly invade a calf barn. Once it enters the calf’s body (through respiratory and digestive mucosal linings), the disease is easily transported via the bloodstream and onto other tissues, all the while releasing its poisonous toxins. Given that a calf is diagnosed with mycoplasma pneumonia, typical antibiotics used to treat other common bacterial diseases are highly ineffective. That’s because antibiotics often work on the premise that they adversely alter the pathogen’s cell wall protection. Since mycoplasma has no cell wall, but is a drop of cytoplasm encased within a thin membrane, antibiotics such as penicillin are ineffective treatments. Furthermore, vaccines against m. bovis are available, but are also not particularly effective, since the mycoplasma has the unique ability to alter the chemical structure of its cell membrane, which evade the calf’s natural and illicit immune responses. These disease characteristics make mycoplasma hard to control. However, we often make it easy for mycoplasma to get established, since the greatest source of mycoplasma infection originates from either feeding calves contaminated colostrum or waste milk produced from lactating cows infected with mycoplasma-type mastitis. These cows may transfer the pathogen to only a few calves, which in turn spread it further by nose-to nose contact to the rest of the calf barn members. Due to its insidious nature and lack of therapeutic treatment, I believe that the best offense against mycoplasma infections in dairy calves is to implement a good prevention program. Consider three practical methods of preventing mycoplasma infections: - Do not feed waste milk. – It is a common practice amongst dairy producers to feed preweaned calves unsalable milk from the lactation herd. For example, in a 2004 study involving 14 large California dairy herds; it was found most mycoplasma-identified calves either were fed non-treated whole milk (50%) or pasteurized hospital milk (36%). To prevent a major mycoplasma opportunity, do not feeding any waste milk to calves less than four weeks of age. - Pasteurize waste milk – If waste milk must be used, it is essential that it be properly pasteurized. There are two major methods to kill mycoplasma in waste milk; a continuous flow system which heats waste milk to 72 °C for 15 seconds, or a batch system that can heat smaller volumes of milk (re: 500 litres) at 63 °C for 30 minutes. If waste milk is too heavily contaminated with other bacteria, this pasteurized milk may still be unsafe for pre-weaned calves to drink and should disposed. - Feed a high quality commercial milk replacer – All the major ingredients found in most commercial milk replacers are either processed milk or milk-by-products of the cheese industry. Calf milk replacers should contain homogenous, free-flowing, non-caking powders, which are formulated (with a mineral and vitamin pack) to meet dietary nutrient requirements for good calf health and growth. This is good advice since many dairy producers have the potential for a mycoplasma outbreak in their dairy calves and may not even realize it. It’s a highly contagious disease among dairy calves that enter the calf barn (or calf hutch) through unwarranted feeding practices. Therefore, it is important to close these loopholes by preventing mycoplasma disease from striking baby calves in the first place.
February 23, 2018
Supporting the Growth of Canada’s Organic Sector The Canadian organic industry is one of Canada’s fastest growing agricultural sectors, thanks to Canada’s hardworking organic farmers and food processors who are respected around the world for supplying nutritious, sustainable, and high-quality organic products. With more than $5.4 billion in retail sales in 2017, growing the Canadian organic sector will contribute to the Federal government’s ambitious goal of reaching $75 billion in annual agrifood exports by 2025. Agriculture and Agri-Food Minister Lawrence MacAulay announced the Government of Canada is providing $72,500 for the Canadian Organic Growers for the development of a userfriendly guide to the Canadian Organic Standards. This guide will provide organic producers, processors, handlers and manufacturers in Canada as well as those wishing to enter it, a clear understanding of what is required to become a certified organic producer in Canada. As well, the Canada Organic Trade Association (COTA) has received an additional $95,114 through the AgriMarketing Program, towards their international market development strategy. The funding will enable COTA to attend international conferences and trade shows and lead outgoing missions to raise awareness of Canadian organic products in key markets in Europe, US, Asia and South America.