Colostrum: it offers more than passive immunity
By John A. Ellis, DVM, PhD, dip ACVP, dip ACVM
Colostrum is the “high octane” milk produced by mammals during the periparturient period of pregnancy. It can be considered “high octane” because it contains factors not found in the “regular” milk produced during the rest of lactation.
Traditionally, the necessity of colostrum for providing life-assuring passive immunity to the immunologically-naive neonate has been most recognized in large animal medicine. However, colostrum is equally essential to companion animal species, since compared to humans (and mice), all domestic animals receive very little if any immunoglobulin transplacentally.1 Extensive literature exists on the use of colostrum for the passive immunization of neonates in cattle, and to a lesser extent, other livestock as well as pets.1,2
Recently, there has been growing interest in the administration of bovine colostrum (BC) to animals and humans beyond the neonatal period. This article will consider the current theory, data and practice related to supplemental post day-one use of BC in companion animals.
The components of colostrum
Colostrum is produced during the last few weeks of pregnancy, and contains a combination of mammary gland secretions together with proteins that are actively transferred from the blood under hormonal influence, resulting in a nearly 100-fold higher concentration of immunoglobulin as compared to regular milk.1
In major domestic animals, the predominant immunoglobin in both colostrum and milk is made up of IgG subtypes. In primates, including humans, IgA predominates. Generally, aside from being a source of protein, bovine immunuglobulins would be of little benefit in other species1 because of two constraints. First, pathogen species and/or serotypes differ among species; therefore, the antibodies in BC would generally be ineffective against pathogens such as dog and cat parvoviruses. Second, colostral antibodies, like plasma antibodies, can coat or opsonize pathogens, making it easier for phagocytes such as neutrophils and macrophages to destroy them; for this to occur, however, the FC (fragment crystallization) part of the antibody has to bind to the phagocyte, and this tends to be a species-specific interaction.
Fortunately,most of the other active ingredients in BC have a propensity for cross-reaction in other species, such as humans, dogs and cats.
- Bovine colostrum contains a variety of factors related to the innate or nonspecific immune system, including lactoferrin, lactoperoxidase and lysozyme, all of which can have direct “toxic” effects on bacteria and/or viruses.3
- Colostrum also contains soluble mediators or cytokines, including interleukins and interferon. These “messengers” are involved in immune regulation, inflammation and immune cell recruitment.3
- The sugars or oligosaccarhides in colostrum may affect the growth of pathogens, but perhaps more importantly, they promote the growth of beneficial microflora in the large intestine, thereby affecting overall gut health.4
- In addition to various immune mediators, bovine colostrum also contains a variety of growth factors, including insulin-like growth factors, as well as epithelial, endothelial, fibroblast and platelet-derived growth factors.5These offer both local health-promoting activity in the gut, and act systemically.
Although there are some species differences in the composition of colostrum, the main reason BC has been used as a supplement in other animals is a simple matter of production volume and accessibility. Calves ingest/require two to four liters of colostrum in the first few hours of life, yet modern high-producing dairy cattle make about 15 liters of high quality colostrum over a 24-hour periparturient period (as well as lower quality colostrum for several days thereafter).2 Depending on the dairy, some of that “extra” colostrum is frozen to administer to calves that for some reason did not ingest colostrum or received an inadequate amount or relatively poor quality maternal colostrum, for example from a first calf heifer. Since colostrum by law cannot be included in the milk supply for human consumption, extra colostrum has historically been discarded or fed to a lucky barn cat. This unused extra colostrum is now used for the production of colostrum supplements, generally in the form of powder.
The science behind colostrum use in companion animals
Many more studies have been performed on the supplemental use of BC in humans than in companion animals. A recent exhaustive review of the human literature concerning BC usage stringently evaluated the methodological quality of more than 1,300 publications.6 The authors justifiably and conservatively concluded that the available studies suggest BC has immunological and other benefits, but further studies are required before well-supported recommendations can be made for clinical applications.
Limitations cited in the available literature include: heterogeneity in study populations; variation in outcome measures; variation and inconsistency in colostrum products tested; and factors related to experimental design, such as blinding of investigators, randomization of subjects, and failure to include appropriate (caloric) controls, such as whey protein, when evaluating BC supplementation. All these factors make it difficult to compare among studies and draw consistent conclusions, especially concerning specific BC products.
Similar considerations limit the extant literature onveterinary uses of BC as a supplement. However, acknowledging these caveats, what are reasonable uses for bovine colostrum in companion animals, based on available data and current immunological and physiological thinking?
- Respiratory disease
Upper respiratory tract infection (URTI) is one of the most common infectious disease syndromes encountered in veterinary practice. Bovine colostrum could be beneficial as a prophylactic against URTI, especially if given to animals before and during boarding or other “stressful” events involving exposure to infected animals. From a clinical perspective, there have as yet been no field trials to directly address this issue in cats and dogs; however, an association between BC supplementation and reduced clinical or subclinical UTRI has been reported in children, performance athletes, and most recently, in race horses.6,7
The mechanism of action for this disease-sparing could arise from the direct action of colostral antimicrobial factors, such as lactoferrin. In culture at least, bovine lactoferrin has been shown to have antiviral activity on feline and canine herpesviruses and feline calicivirus.8, 9, 10Alternatively, or in addition, disease-sparing could result from the cumulative action of colostral factors in supporting or enhancing immune function. Enhancement of antibody responses to canine distemper vaccination in BC-supplemented dogs compared to non-supplemented controls supports this concept.11Human literature, especially as related to UTRI in athletes, also supports the concept of immune enhancement, and specifically suggests the role of BC in increased salivary IgA levels.6 Importantly, as suggested by the human literature, BC may have little beneficial effect once an animal has clinical respiratory disease; therefore. the timing of BC supplementation may be critical to observe a desired effect.6
- Diarrhea and gut health
Both etiologically defined and idiopathic diarrhea presents frequently in small animal practice. Three studies in dogs examined gut-related issues in the context of BC supplementation, and suggest that BC can favorably alter (increase the diversity of) gut microflora and increase fecal IgA, as well as positively affect fecal consistency.11,12,13As suggested in both veterinary and human studies of BC supplementation, reducing diarrhea, promoting a healthy gut and suppressing gut inflammation could be mediated by the direct antimicrobial and endotoxin-neutralizing effects of several BC components. In addition, the growth factors in BC may promote mucosal integrity and tissue repair6.
- Periodontal disease
Periodontal disease (PD) and associated tooth loss is the number one health problem in small animal practice. By just two years of age, 70% of cats and 80% of dogs have some form of periodontal disease.14Since the condition is multifactorial, involving complex interactions between host genetic factors, diet and oral microbes, it is difficult to develop a model in which to specifically assess prophylactic and therapeutic interventions such as BC supplementation15.
Several factors in BC could counteract or delay periodontal disease. Since oral bacteria are thought to be the inciting factor in PD, the antimicrobial factors in BC such as lacterferrin, lactoperoxidase and lysozyme could have a direct effect on the oral bacterial load. PD is an inflammatory process associated with tissue damage, and immune-modulating factors in BC reduce the pathogenic host response to infection. As well, the many growth factors in BC could, through activity on fibroblasts and epithelial cells, aid repairing damaged tissue.5,16 At this juncture, unpublished anecdotal observations tend to support the prophylactic/therapeutic use of BC for PD in canine and feline patients.
- Coat and hair quality
A small-scale unpublished study, relying on owner observations, suggests that BC supplementation may improve the hair coat in dogs This would be consistent with the activity of epidermal and/or fibroblast growth factors in colostrum, and warrants further investigation.5
- Senesce in aging
A major factor of aging across mammalian species is the weakening and loss of skeletal muscle together with bone resorption (Degens, 2010). Insulin-like growth factor-1 (IGF-1) is an anabolic hormone responsible for muscle hypertrophy and regeneration. It decreases with age, but is in high concentration in BC.17 Although there are no published studies on the effects of IGF-1 in dogs or cats, in a recent study of 50-60 year old exercising humans17, it was found that both whey protein and BC promoted more lean muscle mass, but only the BC increased leg strength and reduced bone resorption. These results suggest that BC together with exercise may combat age-related degredation of the musculoskeleton in dogs as well.
Dosage and administration
Based on the multi-systemic effects of BC, all cats and dogs, regardless of age, may benefit from BC supplementation. Certainly, as discussed, specific outcome measures may be difficult to quantify, especially inpets with no apparent disease.
One of the major confounding variables in human studies is the variations in dose and how the dose has been determined — they range from 14 mg three times per day to 60 gm daily.6 A reasonable starting point in pets may be a teaspoon (about 5 gm),11,13 depending on the size of the pet, given twice dailyor at the normal feeding time. BC powder is hydroscopic and sticks to individual pieces of dry food. It mixes well with wet or fresh food, or can simply be “top-dressed”. Almost universally, anecdotal owner observations indicate that BC is very palatable, and often even increases the palatability of food for most animals. Work in humans suggests that higher doses may be necessary to observe anabolic effects.
Colostrum is being used in a growing number of veterinary practices for a variety of illnesses as well as for health enhancement.
1Tizard I. “Immunity in the fetus and newborn”. Veterinary Immunology,9th ed., 2013; 225-239.
2Godden S. “Colostrum management for dairy calves”. Veterinary Clinics of North America — Food Animal Practice, 2008; 24(1):19-39.
3Stelwagen K. et al,“Immune components of bovine colostrum and milk”. Journal of Animal Science, 2008; 87(13 Suppl):3-9.
4Gopal PK, Gill HS.“Oligosaccharides and glycoconjugates in bovine milk and colostrum”.British Journal of Nutrition, 2000; 84 (Suppl 1):S69-S74.8.
5Pakkanen R, Aalto J. “Growth factors and antimicrobial factors of bovine colostrum”.International Dairy Journal, 1997; 7:285-297.
6Rathe M, et al.“Clinical applications of bovine colostrum therapy: a systematic review”.Nutrition Reviews, 2014; 72(4)237-254.
7Fenger, CK, et al. “Bovine colostrum supplementation optimizes earnings, performance and recovery in racing Thoroughbreds”. Comparative Exercise Physiology, 2014; 10(4): 233-238.
8McCann, KB, et al. “The effect of bovine lactoferrin on the ability of feline calicivirus to infect cell culture”. Journal of Applied Microbiology, 2003; 95(5): 1026 -1033.
9Tanaka T, et al. “Antiviral activity of lactoferrin against canine herpesvirus”. Antiviral Research, 2003; 60(3): 193-199.
10Satyara E, et al. “Supplementation of diets with bovine colostrum influences immune function in dogs”. British Journal of Nutrition, 2003; 110:2216-2221.
11Hellwig P, et al. “Effects of bovine lactoferrin on the immune system and the intestinal microflora of adult dogs”. Archives of Animal Nutrition, 2008; 62(2): 152-161.
12Giffard J, et al. “Benefits of bovine colostrum on fecal quality in recently weaned puppies”. The American Scoiety for Nutritional Sciences, 2004; 2126S – 2127S.
13Niemiec, B. “Peridontal disease”. Topics in Companion Animal Medicine, 2008; 23(2):72-80.
14Giannobile, W, et al. “Comparison of canine and non-human primate animal models of periodontal regenerative therapy: results following a single sdministration of PDGF/IGF-1”. Journal of Periodontology, 1994; 65:1169-1174.
15Torre, C, et al.“Bovine colostrum increases proliferation of canine skin fibroblasts”. Journal of Nutrition, 2006; 136: 2058S
16Degens H. “The role of systemic inflammation in age-related muscle weakness and wasting”. Scandinavian Journal of Medicine & Science in Sports, 2010; 20:28-38.
17Whitney RD, et al. “The effect of bovine colostrum supplementation in older adults during resistance training”.International Journal of Sport Nutrition and Exercise Metabolism, 2014; 24:276-285.
Safety and product standards
Available data and anecdotal observations indicate that BC is generally considered safe and well-tolerated in dogs and cats. After all, it is just “high octane” milk. However, because it is milk, idiosyncratic reactions can occur in individual animals, and possibly in lines within a breed, based on an intolerance to milk sugars or a true hypersensitivity to milk proteins. Excluding mild idiosyncratic reactions, there are no reports in the literature of serious side effects or toxicities in humans using BC supplementation.
Most natural or manufactured pharmaceutical products or “drugs” contain one or very few bioactive compounds or ingredients. This is also probably true for many if not most herbal or other natural-source remedies, in which the active ingredients may or may not have been identified. In marked contrast, as discussed earlier, BC contains a multitude of bioactive compounds with different and often overlapping activities, making it very difficult to “license” BC for a particular activity (at the exclusion of others), under the auspices of standard regulatory practices.
Further complicating any standardization of bioactivity, as mirrored in the many brands of BC, are variations in colostrum (milk) collecting times, processing and formulation. Many of the “goodies” in colostrum are labile and variably susceptible to standard dairy processing methods, including pasteurization as well as other procedures sometimes used in the production of BC powder.
All BC products are not created equal. It is important to inquire about what quality control criteria have been applied in the production of any brand of BC. A lack of transparency should be a red flag. For many reasons, it is important to also ask about the cows being milked – their food sources, environmental conditions, etc.