PASSIONATE BREEDERS
ARE ALWAYS LEARNING.

Breeding Management for Success

Archive document IAMS COMPANY

Iams is since 1999 a registered trademark of The Procter & Gamble Company. This is an archive document used historically by the Iams Pet Food company or for Iams Pet Food products. Any and all mentions included herein needs to be replaced in context of the time and geography of its initial use as circumstances and products may have changed since then. Products and relative data are for US only. No assertion or further use of these documents can be made without P&G's authorization.

BREEDING MANAGEMENT FOR SUCCESS

Russ L. Kelley, MS
Presented 2002

DEVELOPING BREEDING PROGRAMS

Successful breeding programs do not just simply happen, they are developed, often reflecting years of effort. To be successful, one of the first things that a breeder must ask and answer is "What am I trying to accomplish"?

This question is just as important to the breeder that owns one dog as it is to the breeder who owns 50. But how does one effectively answer this question? First, create a mental picture of what you feel would be the perfect dog. Once you have this image, list out the traits that make your perfect dog perfect. This should answer the question "what am I trying to accomplish." The next step would be to establish a set of well defined goals for the breeding program.

Unfortunately, many breeders simply rely on luck. Goals will serve as a reference point allowing the breeder to evaluate their efforts. These goals should be well defined and concise, as poorly defined goals will not positively contribute to any breeding program. If so, one could simply breed any bitch to any dog. Although setting goals for one's breeding program can be a daunting task, the task can often be simplified by first critically evaluating the bitch. A simple, but effective, point to start is by asking: Knowing what I know now, would I still buy this bitch?

This is probably one of the most difficult questions for the breeder to answer because the vast majority of bitches are acquired as puppies or young adults, thus there is an emotional bond after years of companionship. It is imperative that the evaluation be based on fact, however, not emotion. If the answer is no, simply do not breed her. But if the answer is yes, further analysis is warranted before the final decision to breed is reached.

What are the strengths and weakness of this bitch? By listing the bitch's traits into categories, the breeder will not only be able to evaluate whether the bitch is worthy of being bred, but also what type of dog she should be bred to. But what traits are important? There are no hard rules to answer this question.

The breeder must, as thoroughly as possible, list what traits they are trying to acquire (or maintain) and which traits they are trying to avoid and then evaluate how their bitch measures against those standards. Also, classify the traits as primary and secondary. Primary traits are ones that the breeder deems essential. Secondary traits are traits that are nice to have, but not necessary.

Primary Traits

Concentrate first on the primary traits, which should include traits that are highly heritable, such as conformation. While conformation flaws do not mean that an animal will not perform well in the field; flaws such as hip dysplasia can certainly place limits on an animal's ability and longevity. Does the bitch come for a pedigree with reproductive problems, such as poor milking ability? Other primary traits that could be important, depending on breed, could include nose strength, hunting range, or drive.

A good rule of thumb on trait heritability is that structural traits (conformation) are more heritable than functional traits (reproductive), which are more heritable than behavioral traits (pointing style). Because of this, a breeder should be more critical of traits with high heritability indices, such as conformation.

Secondary Traits

Secondary traits often have little impact on performance. Traits such as coat color or coat markings would be examples of secondary traits. However, the breeder must be careful not to completely dismiss these traits. Remember the mental picture of your perfect dog, it is often these secondary traits that provide the final touches to the animals the breeder is trying to create.

Once a breeder has listed out the strengths and weaknesses of a bitch and still feels that she should be bred, the next step would be to identify a group of potential sires. While this decision is also difficult, the breeder should be half way there. Use the list of strengths and weaknesses for the bitch to identify what traits need to be strengthened. If the bitch is slightly weak in conformation, identify only potential sires with strong conformation.

Basically, try to offset any weakness in the bitch by selecting a sire that is strong in that trait. In turn, the bitch's strengths should offset any weaknesses of the sire. One of the biggest errors a breeder can make is to select breeding stock based on convenience. Breeding your bitch to the dog next door will get you puppies, but probably not the type of puppies you want. Remember that as a breeder, you should be striving to produce puppies that improve the breed in both form and function.

MANAGING THE BROOD BITCH - Pre-Breeding

Proper management of the brood bitch does not begin at breeding. Just as one must prepare a dog for competitive or hunting activity, one should also prepare the bitch for an upcoming breeding. Before being bred, the breeder should take every precaution to ensure that the bitch is in ideal health. A visit to your veterinarian for a physical examination is a worthwhile step.

Prior to breeding, every bitch should be current on all vaccinations and free from infections and parasites. It is also a good idea to request documentation of health status on the sire, regardless of source. While relatively uncommon today, Brucella canis remains a serious threat and can destroy years of efforts.

In addition, the breeder should ensure that the bitch is in good physical condition. Like all dogs, the breeding bitch should receive daily exercise and be maintained on a diet that matches energy needs relative to energy output. The breeder should strive to condition the bitch to possess evident muscle tone while also possessing a slight degree of body fat. This type of body condition will help promote a healthy endocrine system that will be critical for the success of the reproductive process.

When to Breed

For decades, dog breeders have searched for a method to accurately predict the correct time to mate. Vulvular swelling, pro-estral bleeding, willingness to stand, flagging of the tail, swabs of the vaginal wall, and arbitrary day timing have all been utilized. However, none of these methods are accurate enough to allow certainty in timing a mating. Traditional timed breeding is still widely utilized and often achieves 90% pregnancy rates.

The most common approach to timed matings is to breed the bitch on the second and fourth day after she is willing to accept the male. However, current knowledge about canine endocrinology allows for more accurate estimates for the best mating time.

The reproductive cycle of the bitch is composed of four phases: proestrus, estrus, metrus (diestrus), and anestrus. Each phase can be distinguished, although not always easily, via physical or endocrine events. One of the endocrine events, the rise in circulating progesterone levels, can be utilized to accurately predict ovulation. Bitches may ovulate on the third day of spotting blood or as late as 21 days later.

The fact that fresh dog semen can live and remain viable in the uterus for around 5 days is nature's way of ensuring that most bitches get pregnant. However, unlike fresh semen, fresh chilled extended stored semen only remains viable for around 3 days and frozen semen for around 1 day. Thus if artificial insemination (AI) is going to be used, breeders should utilize a more sophisticated system than the traditional timed method to ensure success.

Ideally, the kennel veterinarian is involved in determining the correct mating day. Testing of the bitch should begin on day 5 of proestrus (bleeding) or when the veterinarian determines the tests are appropriate. Blood samples should be collected every two to three days until hormone changes signifying ovulation are detected. Once the first increase in progesterone is detected, mating should be scheduled four to six days later.¹

If AI is being considered, the testing should continue until progesterone levels have reached 5 ng/ml which would indicate that ovulation has occurred. The bitch should be bred 2-3 days after ovulation, which would correspond to the fertile period.

Breeding

For any dog breeder, there are two basic choices available for breeding a bitch: a natural mating or artificial insemination. The physical mating of dogs can be simple or frustrating. Male dogs vary considerably in their willingness to mate and some may require manual help or at least psychological encouragement. A ready, easy breeding male is a valuable asset.

During the physical mating, the female is often restrained (muzzle and leash) as a bite or escape effort can injure the male. However, bitches that are aggressive or overly reluctant to breed should be evaluated to ensure the timeliness of the mating (see section "When to Breed"). Many of these resistant bitches are in late proestrus as opposed to true estrus.

Remember that most males are always willing to breed before the bitch is receptive, thus they are not good indicators. Ideally, copulation will result in a true tie with dog and bitch assuming the butt-to-butt position for several minutes. During this time, the male continues to ejaculate, depositing the semen near, but not into, the cervical opening of the female. Without this prolonged ejaculation, the chance of successful fertilization is decreased.

While natural matings are still considered the most effective method by most reproductive experts, AI does offer some distinct advantages and is growing in popularity among dog breeders. This is in part due to advancements in AI techniques, but probably more so due to the demand that the breeders place on themselves to breed their bitches to the top males, regardless of the distance between kennels. In addition, many stud dog owners prefer to AI, even if they own the bitch, to decrease the chance of injury to their valuable dog.

The AI process, while not difficult, will not be discussed in depth in this document since it is recommended that anyone interested in learning this technique seek professional training or at least supervision by a person experienced in the art of male collection and bitch insemination. We make this recommendation due to the fact that injuries resulting from the inexperienced hand can permanently disable a valuable animal.

Artificial insemination can be performed using either fresh, fresh chilled extended, or frozen semen. Fresh semen AI is merely the collection of semen from the male followed by vaginal insemination of the bitch. The use of fresh semen AI is often used and preferred by owners of extremely valuable males. As mentioned earlier, this reduces the chance of the male being injured during copulation. Although not necessary, it is recommended that the semen be evaluated to ensure that the sperm is mobile. One drawback to fresh semen AI, like natural matings, is it requires that the dog and bitch be housed at a common site or at least in very close proximity.

In contrast, fresh chilled extended semen is collected from the dog, processed, and stored refrigerated for several days until needed. The major advantage of fresh chilled extended semen is that it allows semen to be shipped from practically anywhere in the world to the bitch. This allows breeders more economical access to the highest quality males possessing the traits they seek. Since it is much less expensive to ship a semen vial in a cooler than the bitch or stud, the use of fresh chilled extended semen has increased dramatically over the past few years.

To date, the majority of AI matings involving frozen semen are done because the dog is no longer fertile or in most cases alive. If frozen semen will be used, the breeder is strongly urged to work with their veterinarian or a veterinarian specializing in reproduction. This recommendation is based on 1) the reduced viability time of frozen sperm and 2) cost. Semen worthy of cryogenic preservation is often very expensive, in some cases several thousand dollars per dose.

In matings utilizing extremely expensive semen, the breeder may also wish to consider working with a reproductive specialist to employ the use of transcervical insemination or intrauterine surgical semen deposition. Although more expensive, both generally offer a greater chance of pregnancy than would a simple vaginal insemination.

NUTRITIONAL SUPPORT DURING PREGNANCY AND LACTATION

Nutrition is one of the most critical components related to an animal's performance in the field. The same is true for the reproducing bitch. In fact, outside an animal's genetics, nutrition is probably the single most important component to a successful breeding. Unfortunately, many breeders fail to appreciate the nutritional demands placed on the bitch during pregnancy and lactation.

Much as an umbrella protects us during a rainstorm, optimal nutrition will help protect the bitch and her progeny from the various metabolic and environmental stresses that will occur during the pregnancy and lactation periods.

During the reproductive process, a bitch's diet must support three areas: 1) her body maintenance, 2) the growth of her reproductive tissues, and 3) the growth and development of her offspring (Figure 1).

However, the requirement and nutrient priority are not equal between the areas. Once the bitch has undergone maternal recognition of pregnancy, the developing offspring will have the highest nutrient priority followed by her reproductive tissues, with her body's maintenance having the lowest priority. A key component to remember is that unlike the bitch, the developing offspring have two sources of nutrients: the bitch's diet and the bitch's body (Figure 1).

Should the bitch's diet fail to meet the required nutrient levels, the bitch will respond by sacrificing her body's maintenance and mobilize nutrients from her body's fat, muscle, and skeletal tissue for the developing offspring and reproductive tissues. In extreme cases, her only solution may be to reduce the demand by decreasing the number of offspring or aborting the pregnancy all together.

To what extent the bitch is able to offset these nutrient shortfalls remains unclear. However, since deficiencies in maternal nutrition in other species have now been associated with adult disorders in progeny,² it is critical that the breeder make all attempts to supply optimal maternal nutrition.

Campbell and Phillips³ and Ontko and Phillips⁴ provided some of the earliest insight into the specialized nutritional requirements for the reproducing bitch. In both studies, diets known to be sufficient for canine growth and maintenance were found to be inadequate for reproduction.

However, these studies were conducted almost 50 years ago and it is doubtful that any modern growth formula would not be sufficient for reproduction. But, sufficiency should not be the target. Sufficiency does not equate to optimal nutrition. Sufficiency simply means the bitch is able to complete the reproductive process. Collins⁵ concluded that the stress associated with reproduction would manifest even the smallest of nutrient inadequacies in diets assumed to be complete.

These dietary inadequacies may not be severe enough to inhibit the bitch from reproducing, although most likely they will prevent her from performing at her genetic potential.

Essential and Non-essential Nutrients

Nutrient supply is routinely described relative to gross composition with diets; for example, X% protein, Y% fat, and so forth. But just as the old saying "All diets are not created equal" is true, the same can be said of dietary nutrients during pregnancy and lactation. In a broad sense, dietary nutrients are defined as essential and non-essential. Essential nutrients cannot be adequately produced by an animal's body to meet the animal's requirement, thus must be obtained through the diet. Essential nutrients would include the essential amino acids, essential fatty acids, as well as various minerals and vitamins. Conversely, non-essential nutrients can be supplied via the diet or produced by the body should dietary sources fail to supply sufficient quantities.

This concept does not hold true for the developing offspring. Puppies (embryonic, fetal or nursing) are dependent upon the bitch to supply them with all nutrients. Because many of the metabolic pathways to produce non-essential nutrients are not functional until late neonatal life, all nutrients are in a sense "essential".

However, this is not to imply that one should simply switch to a diet that contains the highest available nutrient content (protein or energy or both) or use various dietary supplements to enhance a food. Excess-nutrition can be as detrimental as nutrient deficiencies. Excess dietary energy can often contribute to increase pup morbidity and excessive maternal weight gain, which dramatically increases the chance 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.

The key to optimal nutrition is supplying a food that has a balanced nutrient profile at levels that meet the animal's needs. As Mosier⁶ stated in 1977, "only by feeding well managed balanced diets can the health of an individual be maximized". Thus components within the dietary matrix that should be considered are not only the level of protein, fat, carbohydrate, vitamins and minerals, but also the type of protein and fat and the ratio of nutrients such as protein to fat.

WHAT TO FEED?

Owners or handlers of competitive or sporting dogs generally have higher performance expectations than the average dog owner, thus this question is often a little easier to answer. They have experience in what performance formula has provided them with positive results as well as those that have not. For the breeding bitch, the same logic must be applied, only to a higher extent. Most competitive or sporting dogs will require around twice the nutrition during the active season as they do in the off-season. However, the nutritional requirements for the pregnant or lactating bitch are not constant. Her requirement levels are influenced by the stage of the reproductive cycle as well as her litter size and genetic ability (milk). During early and mid gestation (first 5 weeks), the energy requirements of the bitch are approximately equal to maintenance. However, as fetal growth accelerates during late gestation (Figure 2), the bitch's energy requirements also grow (Figure 3), with additional increases occurring during lactation. While not common, some bitches may require up to 5 times normal requirements during peak lactation (days 21-34 post-whelping).

Again, you may ask, "what should I feed?" First and foremost, select a commercially available premium food from a reputable company that is formulated with animal based protein sources and recommended for gestation and lactation. While there are many "homemade" 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 proven 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. The lipid (fat) 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 Iams Company comparing three diets demonstrated positive benefits of feeding this dietary matrix (Eukanuba® Premium Performance Formula).⁷ When fed throughout the reproductive cycle, this diet resulted in fewer misconceptions, a reduced number of stillbirths and more consistent-sized litters from breeding to breeding (Figure 4).⁷

The exact amount of food required will vary depending on breed and metabolic rate, however, the level of intake should be closely monitored to target a caloric intake similar to maintenance levels, thus avoiding over-feeding the bitch.

As stated earlier, during the first 5 weeks of pregnancy, the breeder should continue to feed the bitch a 30% protein, 20% fat diet at maintenance levels (energy basis). It is possible that you may observe a change in the bitch's appetite at approximately 3 weeks post-breeding, first decreasing followed by a dramatic increase. But this may not indicate that you are overfeeding or underfeeding the bitch. This period of pregnancy parallels maternal recognition of pregnancy and embryonic implantation that may trigger these appetite changes. 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 (Figure 3).⁸ For example, if the bitch is consuming 1,000 calories/ day for maintenance, by the end of week 6, she should be consuming approximately 1,500 calories/day. One can generally obtain this information from the product manufacturer. It will be necessary to closely monitor the bitch for weight gain 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 would expect a Labrador Retriever to gain more weight (as a percentage) than a English Setter since they 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 Supplements

The use of dietary supplements for the gestating bitch has been the topic of many debates. Numerous publications have hinted at the benefits of nutrient supplementation.^3,4,9 Some of the most commonly mentioned nutrients include protein, calcium, and vitamins. In practice, the only reason to utilize dietary supplements is when the diet fails to supply the needed amount of a given nutrient.

However, the theory of supplementation is often much easier than putting it into practice. The majority of currently available commercial foods are formulated to provide a balanced supply of nutrients, with "balanced" being the key word.

A critical point to remember is that nothing can be added to or taken away from a diet without affecting the overall nutrient profile. One should also remember that few supplements are pure sources of a given nutrient. For example, cottage cheese (for calcium) and liver (for protein) are two commonly used diet supplements for the breeding bitch. However, since neither of these foods are composed of a single nutrient, the net result supplies more than just the desired nutrient. For example, both cottage cheese and liver add large quantities of phosphorus. In fact, cottage cheese adds more phosphorus than calcium, the targeted nutrient (Table).

Thus if incorporated into the diet, the calcium to phosphorus ratio of the diet will be altered. While the intention is good, it is important not to confuse an increase in the level of nutrition required with a need to change the diet profile. The bitch does require that nutrient intake be increased during the latter phase of pregnancy and lactation, however, the increase does not mean that the diet profile should be altered. It is critical to remember that during these periods, the bitch will be consuming a greater volume of food, which will increase her nutrient intake but maintain dietary balance with regard to the formulation (Table).

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 evaluations 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 efforts 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.

Eukanuba is a registered trademark of The Iams Company.

REFERENCES

1. Hutchison R. Maximizing neonatal survival, in Proceedings. Canine Reproduction for Breeders, New York, 2001; 18-21.
2. Godfrey KM, Barker DJ. Fetal nutrition and adult disease. Am J Clin Nutr 2000; 71(5 Suppl):1344S-1352S. 3. Campbell JE, Phillips PH. Reproduction studies in dogs. J Nutr 1952; 47: 621-629.
4. Ontko JA, Phillips PH. Reproduction and lactation studies with bitches fed semipurified diets. J Nutr 1957; 65: 211-218.
5. Collins DR. The reproducing bitch. In: The Collins Guide to Dog Nutrition. 6th ed. New York:: Howell Book House, 1987; 231-236.
6. Mosier JE. Nutritional recommendations for gestation and lactation in the dog. Vet Clin N Am 1977; 7(4):683-692.
7. Kelley RL. Canine Reproduction: What should we expect? In: Reinhart GA, Carey DP, eds. Recent Advances in Canine and Feline Nutrition, Volume III: 2000 Iams Nutrition Symposium Proceedings. Wilmington, OH: Orange Frazer Press, 2000; 225-242.
8. Lepine AJ. Feeding management of the reproductive cycle, in Proceedings. Canine Reproductive Health; Proceeding from The North American Veterinary Conference. 1997: 27-29.
9. Moser E. Feeding to optimize canine reproduction efficiency. Prob Vet Med 1992; 4:545-550