By Russ L.Kelley, MS
Research and Development Division The lams Company, Lewisburg, Ohio
INTRODUCTION
The goal of any breeding program should focus on the generation of an adequate size litter of healthy viable puppies reflecting the genetic potential of the bitch. To achieve this goal, the breeder will be required to not only select the proper breeding stock, but to also develop a plan by which the stock will be managed. While the basis of the program must be applicable to an entire kennel, it must also have some degree of flexibility to meet the needs of each individual bitch.
PRE-BREEDING
Prior to any mating, the breeder should take every precaution to ensure that the bitch is in ideal health. This includes not only being current on all vaccinations and free from infections and parasites, but also in optimal physical condition. To ensure this, animals should be exercised regularly and maintained on a diet that matches energy needs relative to energy output. An important note to remember is that the reproductive process does not begin at mating, but several weeks prior to the mating process when ovarian follicles are being recruited for the upcoming cycle. Because of this, it is important that the breeder not confuse optimal physical condition with athletically finished. The breeding bitch should have evident muscle tone, but also have a slight degree of body fat. This body condition will help promote a healthy endocrine system that will influence the degree of reproductive success.
WHAT TO FEED?
Nutrition has long been recognized as an influential factor in bitch reproduction.(1-8) The recommendations from these references are generally vague in that they recommend feeding a high-quality food with sufficient energy for reproduction. There are a few publications (2,5) that have addressed the effect of certain nutrient classes on canine reproduction. However, past research has directed little effort to defining diet "quality" or to the role of specific nutrients in canine reproduction. Additionally, there has been a severe lack of studies designed to separate diet sufficiency and "optimal nutrition". There are numerous diets, both commercially available and home recipes, that have been recommended as sufficient for reproduction. This merely means that animals were able to reproductively perform within expected levels while consuming a defined diet. Unfortunately, these expected levels are often well below the level that the bitch is genetically capable of performing.
Almost thirty years ago, Collins(9) surmised that the stress associated with reproduction would manifest even the smallest of nutrient inadequacies in diets assumed to be complete. The inadequacies of a diet may not be severe enough to halt the bitch from reproducing; however, they most likely will prevent her from performing at her genetic potential and/or would require an increased nutrient mobilization from her body stores to meet the nutritional requirements of her progeny. Furthermore, since deficiencies in maternal nutrition in other species have now been associated with adult disorders in progeny (10) it is essential that we understand and optimize maternal nutrition. It is also critical that the breeder keeps in mind that the mother must supply all essential nutrients for the developing puppies. Because of this, the bitch must obtain a sufficient supply from her diet or mobilize these nutrients from her body stores. These essential nutrients would include all of the essential amino acids (building blocks for proteins), the essential fatty acids (functional components of cellular membranes and the endocrine system), as well as various vitamins and minerals.
However, this is not to imply that one should simply switch to a diet with the highest available nutrient (protein or energy or both) content or use various dietary supplements in an attempt to enhance a food. Over-nutrition can be as detrimental as nutrient deficiencies. Excess dietary energy can often contribute to extreme maternal weight gain, which dramatically increases the risk of dystocia during parturition. The use of dietary supplements can supply excessive amounts of nutrients such as minerals, thus altering the balanced dietary matrix of the diet.
Again, you may ask, "what should I feed?" First and foremost, select a commercially available premium food with animal-based protein sources that is recommended for gestation and lactation and is produced by a reputable company. While there are many "home-based" diet recipes circulating, it is extremely difficult to achieve a complete and balanced diet using these recipes. These diets can often be deficient in vitamins, minerals, or other nutrients and are undefined with regard to amino acid and fatty acid levels. They may also vary over time due to an inconsistent ingredient supply. Commercial formulas offer distinct advantages by allowing the breeder to feed a product of known nutrient content and type to support the reproductive process.
Approximately two weeks prior to breeding, the bitch should be transitioned (if necessary) from her maintenance diet to a diet comprised of approximately 30% highly digestible animal-based protein and 20% lipids (fat). The lipid portion of the diet should be balanced for fatty acid content to supply an omega-6 to omega-3 fatty acid ratio in the range of 5:1 to 10:1. Findings from a recent study conducted by The lams Company involving over 17,000 canine matings demonstrated benefits of feeding such a dietary matrix (Eukanuba@ Premium Performance Formula) compared against two other diets.(11) When fed throughout the reproductive cycle, this diet resulted in fewer missed conceptions, a reduced number of stillbirths and more consistent-sized litters from breeding to breeding.!! The exact amount of food required will vary depending on breed and metabolic rate; however, caloric intake should be similar to maintenance levels, thus avoiding over-feeding the bitch.
PREGNANCY
During the first 4 weeks of pregnancy, the breeder should continue to feed the bitch the above-mentioned 30-20 (% protein and fat) diet at maintenance levels. It is possible that you may observe an increased appetite in the bitch at approximately 3 weeks post-breeding. This, however, may not indicate that you are underfeeding the bitch. During this period, maternal recognition of pregnancy and embryonic implantation may trigger an increased appetite in the bitch. It is very important that the bitch be maintained on her normal routine during this period to prevent any undue stress, which could be detrimental to the pregnancy.
At approximately 5 weeks post-breeding, the food intake of the bitch should be increased slightly each day to achieve a 50% increase in energy by the end of week 6. For example, if the bitch is consuming 1,000 calories/day for maintenance, by the end of the 6th week she should be consuming approximately 1,500 calories/day. The amount to feed can be determined by contacting the manufacturer for the metabolizable energy content of the diet, generally reported in kcal/kg or kcal/cup. It will be necessary to closely monitor the bitch during the later portion of gestation to ensure that she is gaining sufficient weight. It is impossible to give an exact percentage of weight that a bitch should gain, since the increase will vary greatly from breed to breed even within similar adult sizes. For instance, one might expect a Golden Retriever to gain more weight than a German Shepherd Dog on average, since retrievers typically give birth to larger litters. However, a good rule of thumb would be to target a 25% weight gain in the bitch by the end of week 8 (day 56) post-breeding.
DIETARY SUPPLMENTS
The use of dietary supplements is a highly debated topic. Everyone knows someone who claims that some special additive will help solve a given reproductive problem. Unforunately, there is little information in the scientific literature to support such claims. It is very important to understand that dietary supplements are needed only when the diet fails to supply the optimal levels of a nutrient. If a breeder is feeding a diet that requires elaborate supplementation regimens, it would be advisable to seek a high-quality food that has been formulated to meet the nutritional needs of the pregnant or lactating bitch.
One of the most touted supplemental regimens for the bitch is to increase calcium intake during pregnancy. While this may seem logical, it is not only unnecessary but it can be detrimental. One of the most critical needs of a lactating bitch is the ability to regulate the deposition and mobilization of calcium for milk production. If the bitch is supplemented with high levels of calcium during pregnancy, her body is not metabolically primed to mobilize calcium from her bones. Therefore, when the demands for calcium are suddenly and dramatically elevated at the initiation of lactation, she is unable to keep up with the metabolic demands, which can result in serious health complications. While her absolute requirement may increase due to pregnancy, one should not confuse this with a percentage requirement change. The bitch will receive any added calcium she may require through her increased food intake.
Another common dietary supplement that is touted is folic acid. This nutrient is highly promoted in humans to help prevent neural tube defects; however, this developmental disorder is very rarely seen in the dog. In addition, most commercial formulas recommended for reproduction typically contain greater that 200% of the level of folic acid set as the Association of American Feed Control Officials (AAFCO) minimum for growth and reproduction; therefore, deficiencies are highly unlikely.
CONCLUSIONS
Feeding your bitch does not have to be complicated. While the science associated with nutrition and reproduction may require years to understand, the actual practice of providing nutrition can be summarized fairly simply: feed the appropriate amount of a diet that meets the animal's needs. While this practice still requires the breeder to make decisions as to the exact diet that will be fed, it does eliminate questions such as to what mix of products and/or supplements must be utilized.
Based on our research in the area of canine reproduction, the greatest success has been achieved feeding a diet, such as Eukanuba@ Premium Performance Formula, consisting of approximately 30% protein (animal source-based) and 20% fat with an omega-6:3 ratio of 5:1 to 10:1. The benefits of feeding this formula have included increased conception rate and live births and more consistent maternal productivity. While nutrition is only one component of bitch management, it is one of the most (if not the most) important. Thus by providing the proper nutrition, the breeder has taken a great step forward in achieving a successful breeding program.
REFERENCES
1. Sokolowski JH. Reproductive patterns in the bitch. Vet Clin N Am
1977; 7:653-666.
2. Mosier JE. Nutritional recommendations for gestation and lactation
in the dog. Vet Clin N Am 1977; 7:683-692.
3. Evans HE. Reproduction and prenatal development. In: Evans HE,
ed. Miller's Anatomy of the Dog. 2nd edition. Philadelphia, PA: W.B.
Saunders Company, 1979; 13-77.
4. Concannon PW. Reproduction in the dog and cat. In: Cole H, Cupps
PT, eds. Reproduction in Domestic Animals. 3rd edition. Orlando, FL:
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Vet Med 1992; 4:545-550.
6. Evans HE. Prenatal development. In: Evans HE, ed. Miller's Anatomy
of the Dog. 3rd edition. Philadelphia, PA: W.B. Saunders Company,
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7. Evans JM, White K. Book of the Bitch: A Complete Guide to Under
standing and Caring for Bitches. New York: Howell Book House, 1997.
8. Bebiak OM, Lawler OF, Reutzel LF. Nutrition and management of
the dog. Vet Clin N Am Small Anim Pract 1987; 17:505-533.
9. Collins DR. The reproducing bitch. In: The Collins Guide to Dog Nutrition. 6th edition. New York: Howell Book House, 1972; 223-228.
10. Langley-Evans SC, Gardner OS, Welham SJM. Intrauterine
programming of cardiovascular disease by maternal nutritional status.
Nutrition 1998; 14:39-47.
11. Kelley RL. Canine Reproduction: What should we expect? In: Reinhart GA, Carey OP, eds. Recent Advances in Canine and Feline Nutrition, Volume III: 2000 lams Nutrition Symposium Proceedings.
Wilmington, OH: Orange Frazer Press, 2000; 225-242.
As taken from the IAMS “Canine Reproduction for Breeders
from a symposium presented at Westminster KC, 2/10/01
from a symposium presented at Westminster KC, 2/10/01
