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Dairy animal welfare (Proceedings)
Dairy production systems in the US have changed considerably over the last several decades due to forces that promote economic efficiency of production and to scientific and technological advances that afford opportunities for change.
Dairy production systems in the US have changed considerably over the last several decades due to forces that promote economic efficiency of production and to scientific and technological advances that afford opportunities for change. Societal values and concerns about animal well-being and specifically about livestock production systems and their impact on animal well-being have also changed throughout that time. It would be worthwhile for dairy producers and veterinarians to critically evaluate production practices for their impact on the animals. Optimizing animal well-being is not only a moral imperative, but should also assure optimal animal productivity.
In general dairies have not experienced the type of extreme criticism that has been focused on the swine or poultry industries. This is probably attributable to multiple factors that work in favor of animal welfare even during a process of industrialization. Dairy producers have traditionally had a strong animal welfare ethic and, as mentioned above, most dairies are still operated by individuals or families who maintain this approach. In general it is fair to say that dairy animals are well cared for in the modern dairy industry. Typical dairy husbandry provides good nutrition, circumstances that promote animal interaction and normal expression of individual and herd behavior, space and opportunity to get exercise, and protection against adverse weather conditions. There are exceptions to these generalizations. Numerous animal welfare concerns exist in the industry, but they tend to be complexities of the balance between an excessive focus on economics and production efficiency rather than an expression of disregard for, or diminution of the importance of the animals themselves.
There is clearly pressure on producers to increase production efficiency and total production as the means to improve their business and maintain their livelihood. In such an environment animal welfare may be important to the producer, but it is not the motivation for change. Rather, economics and growth drive change, while animal welfare is an important, but secondary, consideration. Additionally, as the enterprise grows it may no longer be the producer or the family members who provide primary animal care. Without an appropriate training process for employees, a system that has specific guidelines for animal handling and welfare, a monitoring system for assessing these features, and a decision making system that adjusts to specific individual animal needs, then it is very easy for the producer to believe that animals are faring better than is truly the case. Very few dairies, as they get very large, make the time investment to specifically focus on animal welfare and the employee training and monitoring required for enhancement of animal welfare. In this situation individual animals can fall outside the average for the herd and go unnoticed. For example, an animal with a debilitating disease may suffer for a considerable time before being euthanized, even though the producer would not conceive of letting the animal suffer if it had been noticed earlier. In other words, when production systems get very large, it is easier to 'say' that each individual is valued than it is to take action based on that principle.
To be realistic, it seems foolish to look at old style and small-scale dairy production systems and suggest that they provided ideal animal welfare. Clearly, some managers and some settings provided good animal welfare with grazing systems and exercise and low stress. Other circumstances in similar time, style and place could provide squalor, starvation, poor housing and exposure to the elements, due to monetary constraints, lack of information, or lack of resources. In similar fashion the modern, large scale, intensified dairy systems have the potential to provide for excellent animal welfare, but may produce new disease problems, inadequate attention to individual animal problems, and improper training for employees to recognize and manage animal problems.
It is not news to dairy producers that heat has profound negative effects on their cattle. Virtually all of the dairy trade periodicals contain frequent articles about the problem and new ideas on how to manage it. There are several striking and sobering aspects of the response the dairy industry has had to this problem. The movement of the industry to areas where heat stress is common is not being made for the benefit of the animals, but for purely economic/cost of production reasons. The overwhelming majority of literature that focuses on heat stress details the effects of the phenomenon on production parameters, with scarcely a mention of the fundamental animal suffering that takes place while production is declining. Thus, heat stress is seen almost exclusively as an economic/production problem, rather than as the animal welfare issue that it really is. There are means to reduce the impact of heat on the cattle, including modified shelters, fans that move large volumes of air around the cattle, water spraying misters, and alterations in diet. These mitigations are broadly applied, and it would be accurate to say that the problem is taken seriously.
Cow Comfort, Exercise and Housing Design
Producers, veterinarians, and design consultants have learned to ask some of the relevant questions about cow environment and behavior that have been ignored out of ignorance in the past. How much slope and what texture should footing surfaces have to promote drainage, provide good traction for cow locomotion, maintain normal hoof health and avoid injury? What bedding materials and what bedding maintenance are optimal to keep cows comfortable? What stall and stall divider designs and dimensions provide the optimal environment for cows to lie down and rise again comfortably with minimal risk of injury, minimal manure contamination and optimum udder health? What amount of time should cows spend lying down and ruminating versus eating or exercising? What restraint chutes and alleyway designs promote the best access to the cows for treatment and the least likelihood of cow injury? What handling techniques should be taught and promoted to farm workers and animal handlers? Recent publications are beginning to more definitively address the facility design features that improve the cow's environment. Other publications use the term 'cow comfort' to define this area of animal welfare concern and link it closely with cow productivity. Increasingly facilities have been designed and/or remodeled with the best interests of the cows as the top priority.
Downer Cow Problems
Downer cow problems have achieved considerable notoriety in some settings, particularly when they occur in animals penned prior to slaughter or at sale barns. In many such cases the cause of the problem in the individual animal was weakness or debility, which was the reason the animal was sent to sale or slaughter and was also the cause of the final 'downer' event. In other words, many of these cases represent very poor judgment by the original owner, who has chosen to defer an animal health problem to another buyer or to eliminate the problem by slaughter. Most such cases clearly should have been dealt with on the original farm, either with treatment or euthanasia. On dairies these downer cow cases cannot be completely avoided. Some are due to unforeseeable or unpreventable circumstances. Sooner or later all cattle owners have animals that become downers. Except on a case-by-case basis it is difficult to generalize what the most appropriate disposition of such animals may be.
Infectious Disease Problems
There are numerous infectious diseases of concern to dairy operations that represent challenges to animal well-being. Information from the National Animal Health Monitoring System Dairy 2007 Study demonstrates that infectious diseases represent a tremendous area of concern in dairy animals. Clinical mastitis occurs in 16.5% of all dairy cows, respiratory problems in 3.3%, and diarrhea in 2.5%. Approximately 50% of the 14% dairy cow lameness reported in the survey was apparently infectious in nature. In dairy calves, scours, diarrhea and respiratory problems are responsible for 80% of all calf deaths from a day of age to weaning, and death rates of calves through that age range averaged 7.8% in the NAHMS survey. It is common for 35 to 50% of dairy calves to become ill and require medical attention between birth and weaning (approximately 8 weeks of age). These estimates of average disease incidence provide only one side of the infectious disease picture. Even more troublesome than ongoing disease losses is the development of explosive new infectious problems. Infectious agents are still as important as ever and perhaps even more problematic as animal density and herd size increase.
There are numerous management procedures that can be implemented to decrease animal exposure to infectious agents, but that have not been widely adopted in modern dairy management. These procedures may be called biosecurity or biocontainment practices, and include separation of different animal groups, prevention of contact between healthy and sick animals, cleaning and hygiene procedures, minimizing manure contamination of premises or feed, and so on. Looking more specifically at calf management, for example, some infectious diseases are spread from dams to newborns and the time of separation of the calf from the cow can have an impact on the transmission of these diseases. In the NAHMS survey about 55% of operations separated newborn calves from the dams immediately after birth. Twenty-two percent of operations separated the calves beyond 12 hours after birth. Seven percent of operations allowed calves to stay with their dams more than 24 hours. Fecal contamination is a common means for spread of many enteric infections. Developing more fully integrated approaches to infectious disease control could have a profound impact on dairy animal welfare.
Calf Management Practices
Calf rearing practices in the modern dairy industry present some very real problems regarding animal welfare. An excessive number of dairy calves die from infectious diseases (estimated 7 to 8% between birth and weaning), but this figure does not reflect the entire story.
Newborn calf care
The implicit assumption in current calf rearing systems is that humans assume the role of the dam and properly care for the newborn. It seems fair to say that modern calf raisers very commonly fail to meet the standards of any reasonable natural cow mother. The ideal is for newborn calves to receive good mothering, which at a minimum includes drying the haircoat after delivery to ensure a thermal protective barrier, stimulating the calf to rise and move, encouraging suckling and colostrum consumption, and seeking or providing a sheltered environment. These simple aspects of calf care are routinely ignored in many dairy settings. Many calves are retrieved from the calving pen and placed into other holding or housing facilities to be looked at or fed at a later time. In fact many people leave the calves with the cows to avoid having to do these chores, assuming the cow will show good maternal instincts. Since dairy cows are not selected for maternal traits, this default mode is inappropriate, because leaving the calf to be cared for by a dam that may or may not provide good mothering is effectively a plan for inadequate care. The responsibility for calf care clearly falls to the producer and dairy management personnel, either by assuring that cows provide such care, intervening if they don't, or simply adopting a routine policy of having the care provided by humans as surrogate mothers. Having shouldered the responsibility of rearing baby calves, it is imperative that the task be done properly.
During episodes of cold or inclement weather, calf care practices become even more important because these young animals are more susceptible to environmental challenges than their more mature counterparts. Strategies to provide protection from the elements should be especially targeted towards smaller calves, calves that experience dystocia, calves that aren't doing well or any calf in extremely cold weather. Whether a calf can maintain body heat depends on a combination of factors, including sufficient feed energy to withstand the cold, sufficient thermal insulation, dry hair, wind speed and humidity, good nutrition and physiological soundness. Extremely important is appropriate housing, and the hutch structures must be windproof, watertight, well ventilated and properly positioned so the elements are coming from the back or sides. It is very important that they are well bedded. This kind of environment retains the heat more, retains the dryness and blocks the wind so the calf can maintain itself in the cold. In some circumstances calf jackets or blankets may be warranted. Simply placing a calf in a hutch without concern for these other details may not be enough to protect it from extremes of weather conditions.
Calves exposed to prolonged cold need additional energy to maintain body heat production. Some dairy calf feeding programs fail to meet these needs during bouts of cold weather. In these circumstances calves utilize their meager body fat reserves quickly for heat production, and then may die from starvation rather than the cold itself. This "starving calf" problem is common and happens when young calves, typically between two and four weeks of age, are not yet eating much solid feed. Such calves are still reliant upon fluid feeding for energy, and if only provided a fixed amount of milk replacer, instead of proportional to body weight, they are in danger of undernourishment. The likelihood of this problem increases in situations where the producer elects to feed low quality replacer to save cost. A producer might feed a lower quality/lower fat content replacer to a 70 lb (32 kg) calf sufficient for survival, but when that same amount is continually fed to a 100 lb (45 kg) calf, in cold weather the calf can suddenly die at the critical two-to-four weeks of age.
Calf feeding and nutrition
As discussed above, calves can be, and typically are, weaned from fluid feed by four to eight weeks of age, but only if they are consuming sufficient solid feed for their survival and growth. The most compelling reason to wean calves to solid feed is that fluid diets are quite costly, both due to the cost of the feed ingredients (milk or milk replacer) and due to the labor cost. Conversely, solid feed diets are fairly economical. Therefore the primary reason to convert calves to a solid diet is an economical one, although it is also apparent that calves grow faster and have fewer health problems once they have been weaned to solid diets. This last statement, and the feeding practices used to wean calves early, warrant closer scrutiny.
For several reasons the diet calves receive prior to weaning is very restricted. Feeding calves milk or milk replacer by bucket or nipple feeder has been common practice on most dairies for over 50 years. Such feeding is time and labor intensive and the fluid diet is relatively expensive. Under natural conditions a baby calf left with its dam would typically nurse 6 to 8 times per day and consume 16 to 24% of body weight in fluid milk. To bucket feed dairy calves similarly would be a very time consuming and costly process. Thus, most calves are fed only two times a day. The maximum amount most calves are provided at a feeding approximates 4 to 5% of body weight, because higher volumes can be associated with digestive disturbances. This means that most calves receive a maximum of 8 to 10% of body weight as fluid feed per day. Given the normal nutrient density of fluid milk, this provides only enough energy for body maintenance plus a small amount of growth. Calves fed in this manner may be expected to gain approximately 0.45 lb (200g) per day, compared with approximately 2.2 lb (1kg) per day for calves fed ad libitum. The problem of poor growth is particularly true for calves fed milk replacer compared to their milk-fed counterparts, because the energy density in most milk replacers is less than that in whole milk. In other words, the most common calf feeding practices do not provide optimal nutrition, and in fact are so close to being true starvation that in some circumstances calves may indeed die from lack of energy in colder weather, as discussed above.
The observation that calves grow better after weaning is probably less a tribute to the benefits of solid feed than the fact that before weaning the calves are relatively starved. This method of calf rearing has evolved over such a prolonged time that most producers actually believe that 8 to10% body weight feeding of milk is optimal for the calf, despite the evidence that the calves remain very lean and are at high risk of disease. In fact this system did not evolve with the best interests of the calf in mind; rather it evolved as the least cost, lowest labor input solution. Recent research, directed at the question of how to feed calves for optimum growth and health, has begun to demonstrate to producers that the extra cost of a higher plane of nutrition for baby calves may be well worthwhile as a wise investment in the health, growth, and future productivity of calves. Furthermore, there are feeding strategies that have been demonstrated to meaningfully benefit the calf and still allow weaning at a desirable early age, such as feeding the calf more energy during the first weeks of life and then decreasing fluid feeding to encourage solid feed intake later. Hopefully in the near future the methods of calf feeding will be directed towards the best interest of the animal, rather than the lowest cost for time and feed investment.
Bull calf management
The last topic I'd like to address under the heading of calf management practices is the management of newborn bull calves. Calf management has tended to receive less attention by dairy producers than some other management concerns. This is probably due to the fact that calf problems are further removed from revenue generation than some other issues, such as cow health and milk quality. Bull calves and their management are often yet lower on the priority list. Since the development and widespread use of artificial insemination as a means of breeding milk cows, plus the adoption of selective breeding strategies to improve genetics for milk production, most bulls are not destined to be used as breeding animals. Yet approximately 50% of calves are males, and therefore producers have a large number of animals born each year that will not play a role in milk production. Some producers raise bull calves to be sold or slaughtered, but the majority of dairy producers prefer to sell bull calves early in life to decrease the feed, housing and management costs that rearing these animals would require. Bull calf economic value has tended to be very low. In some times the market for these calves has been poor enough that it costs more to sell the calf at auction than the selling price received. It is difficult to marshal appropriate management attention to bull calves that will not become production animals on the dairy, and frequently bull calves receive very little attention. Unfortunately, this can lead to significant morbidity and mortality that can go unnoticed except to the buyer (veal operations and dairy beef rearing units). Clearly it is appropriate to treat bull calves like heifers in attending to their needs as newborn animals, that is, provision of colostrum, warmth, and nursing care, as described above. Unfortunately, many producers are guilty of overlooking these needs because the effects of poor bull calf management are not a major economic liability, and subsequent poor bull calf health and survival are likely to be someone else's problem. It is important for dairy producers to realize that it is an ethical obligation to care for newborn bull calves with the same attention afforded to heifer calves, even when the economic reward is limited or nonexistent.
Birthing/Calf Delivery Problems
Probably because newborn calves are not the major direct source of revenue for dairy producers, it appears that calf delivery and newborn calf management are undervalued as areas of concern. The problem of dystocia has been almost ignored. Few dairy producers incorporate breeding strategies to decrease dystocia occurrence, or have delivery management and newborn calf management protocols that specifically address the problem. The effects of dystocia are highly variable, depending on the severity of the problem. In affected calves, dystocia produces trauma and asphyxia that decrease calf vitality, predispose to infectious or non-infectious disease, and may result in stillbirth or neonatal mortality. Affected dams may develop reproductive tract problems that impair reproductive function, and in severe cases trauma and paralysis can result in euthanasia or culling.
Despite, or perhaps as a result of, the inattention the dairy industry has paid to calving difficulty, the rate of dystocia in dairy animals is substantially higher than in beef cattle. National surveys show that approximately 3% of beef cows and 17 % of primiparous beef heifers, with a total of 4% of cattle across all age groups, need calving assistance. In sharp contrast the average for all dairy cattle is 18.4% assisted deliveries and dairy first-calf heifers require assistance for almost 32% of calvings. As described above, infectious disease is typically considered the main cause of dairy calf morbidity and mortality, and national surveys estimate that on average 35 to 50 % of all dairy calves will be treated for illness and 7 to 8% will die prior to eight weeks at time of weaning. However, most producers do not monitor calf death losses that occur before calves are identified in official records. Stillbirth incidence is typically not included in evaluation of dairy calf mortality, and calves that die prior to 24 hours of age are grouped with stillbirths. Since most calf loss estimates exclude stillbirth losses, they underestimate the magnitude of newborn dairy calf health problems. Estimates from some studies, suggest that loss of calves less than one day of age, approximately equals the death loss of calves beyond a day of age. The Dairy 2007 study reported that 14% of calves are stillborn or dead before 48 hrs. This would equate to more than 50% of all calf deaths, very similar to estimates of the distribution of beef calf losses. Such an estimate also reflects the trend seen in neonates of other species. This means that the current estimates of dairy calf losses, although very high, only represent half of the story, since this other proportion of losses is typically not tallied.
Calving area management, delivery management and newborn calf management should be extremely important areas of dairy management focus. Events that occur here can affect calf morbidity and mortality, treatment costs, transmission of herd disease agents (including zoonotic pathogens), dam health and reproductive performance, and ultimately the cost/benefit of replacement heifer rearing. The combined effects of all of these on dairy health and productivity should be profound. Furthermore, dairy replacement heifer raising is the second leading expense for dairy operations, behind feed costs for the lactating herd. Yet attention to this area of management has been lax. It appears that the short and long term benefits of newborn calf health or the costs of calving management problems have not been clearly identified and conveyed to producers. Thus, dairy producers have failed to see economically compelling reasons to direct valuable time and management to changes in these areas. Because calving occurs year-round in dairy operations, it is easy to overlook insidious, ongoing losses unless they are measured and monitored. Looking at his situation from an animal welfare perspective presents a sobering picture. Here is a welfare concern that seems to be all but ignored, and yet, if addressed in a meaningful way that decreased animal losses could derive substantial benefit to the animals plus improve economic returns for the producer.
Dairy Veterinarians and Animal Welfare
Animal health issues figure prominently in any discussion of dairy animal welfare, because health and welfare are intimately associated. This being true, it seems obvious that dairy veterinarians are well positioned to positively impact dairy cattle welfare via their role as health care providers and consultants. Veterinarians have opportunities to monitor health events, to help evaluate the impact of nutrition and housing management on animal well-being, to establish treatment and culling protocols, to train workers in animal handling and treatment procedures, and to provide producers and managers with objective assessments of current welfare status plus goals and methods for improvement. Unfortunately, it appears that only a small minority of dairy veterinarians actively pursue animal welfare improvement as an objective of their work. Many more seem content to fill the role of service providers rather than welfare consultants and advocates. It is my strong impression that many veterinarians find it very convenient to assume the attitude that economic efficiency and maximum milk production are the overriding goals of the dairy industry. In turn, this makes it easy to further assume that certain levels of animal disease and discomfort that can follow from particular attitudes and management practices are acceptable trade-offs. In particular, some practitioners may fear that voicing strong concern for animal welfare may alienate or antagonize their clients. It is rewarding to see that certain issues, such as facility design that enhances cow comfort, are being recognized as key links between animal well-being and herd productivity. Hopefully veterinarians will increasingly see the opportunities available to promote dairy animal welfare as strong components of the service they provide.
Dairy Producers and Worker Training
One of the common attributes of dairy producers emphasized in the first part of this paper is their well-established ethic of caring for their animals. I can honestly say that virtually every dairy producer I know sincerely cares about the well-being of their animals, and works to assure that their animals are well cared for. Unfortunately this does not mean that in fact dairy animals always fare well, nor that they really receive optimal care. The numerous concerns presented in the preceding discussion highlight areas where dairy animal welfare is frequently compromised. Some of the reasons are lack of knowledge or tools to deal with the problems, lack of recognition that a problem exists, and possible conflicts between economic constraints and ideal management practices. However, I believe that an equally or more important challenge to improving animal welfare in modern dairy operations relates to the problem of dealing with individual animal welfare on operations of increasing size. In many cases it is not the owner who identifies and manages individual animal problems. Increasingly dairy animals are handled and managed by employees, and in turn these employees frequently do not have the same background, training, or perceptions of the owner. In such circumstances it is easy for producers to believe that observations are made, and actions are taken as they would personally do them, while in reality it is not the case. Few dairies have active worker training programs that meaningfully educate workers about key principles of livestock care, and that then follow up with evaluations of performance at periodic intervals. In many cases the owner and the worker may not communicate well because of language and cultural barriers. I believe that one of the most important means of improving dairy animal welfare is the development and implementation of effective worker training programs. Many of the issues discussed above highlight this need, such as calf care and management, calf delivery management, disease recognition and treatment procedures.
Summary and Conclusions
The dairy industry has undergone steady and remarkable change over the last several decades. Numerous factors have stimulated and shaped these changes, but an overwhelmingly important feature has been the demand for increased economic and business efficiency. This tends to force dairy producers to prioritize economic considerations above animal welfare concerns as they make management decisions. Currently dairy operations in the US vary widely in size, geographic location, facility design, and management, with a trend toward larger size and migration to the western arid states, though there are still many dairies in traditional dairy regions that follow more traditional management practices. With these changes have come new challenges to animal well-being, in addition to some of the older ones. The dairy industry has not had to face some of the extreme criticism that has been focused on other, more industrialized animal production systems. Nevertheless there are areas of concern that should be addressed, and most of these can be improved via education, research, and appropriate management changes. Dairy producers would benefit the welfare of their animals by increasingly making animal welfare a top priority, on par with the priority awarded to economic efficiency in the production system. There are numerous examples of management improvements that would positively impact animal well-being and also improve dairy productivity. Dairy veterinarians can play an important role in helping to educate and advise their clients, monitor for animal welfare problems, and guide implementation of improved management strategies. There is a very real need for improved training of dairy farm workers, because it is more commonly the workers than the owner/operators who directly implement animal care and welfare procedures.
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