I am getting ready to breed my female cat. What role does nutrition play? 
Optimal nutrition for reproduction is important for:
- Conception/successful pregnancy
- Providing the mother (queen) with her best ability to deliver her kittens
- Thriving kittens both before and after birth
The various stages of reproduction - heat (estrus), pregnancy, lactation, and weaning - provide unique stresses to the body. Each provides specific nutritional concerns that should be addressed to maximize both queen and kitten health.
What nutritional issues are relevant leading up to pregnancy?
Good nutrition sets the stage for successful breeding and pregnancy. A malnourished queen - both over- and under-weight - will suffer reproductive consequences, as will her kittens. Obesity is the most common nutrition-related problem in reproducing queens. Obesity can decrease the number of eggs released at ovulation, resulting in smaller litter sizes. Also, obesity can decrease milk production during lactation, negatively impacting kitten health and growth. An overweight or obese queen should lose weight before breeding. There are no specific nutritional requirements for a queen during her heat cycle.
How should I feed my cat during her pregnancy?
Cats are typically pregnant for 63-65 days, but pregnancy can range from 58-70 days. The pregnancy is divided into trimesters, and a healthy, well-fed queen will experience steady weight gain throughout the pregnancy. This weight gain appears to function as energy storage to support upcoming lactation. Overfeeding can result in obesity at the end of pregnancy, which increases the risk for difficult or prolonged labor and added stress on the kittens. Conversely, underfeeding during pregnancy can result in embryo loss, abnormal fetal development, spontaneous abortion or stillbirth, small litter size, and low birth-weight kittens who fail to thrive. It is important that the queen not lose weight or condition during this time, so monitor her weight and body condition, increasing food as needed.
A highly-digestible, high quality kitten/growth/development formulation is generally recommended during feline pregnancy. The best options are those diets that have passed feeding trials for gestation/lactation or for all life stages. Feeding multiple small meals may help the queen to maintain adequate nutrient and calorie intake especially in the final trimester. It may be wise to change to kitten food before breeding and pregnancy to prevent any unnecessary stress associated with changing food.
I have heard that lactation is even more energy intense than pregnancy. Is this true?
Absolutely. At delivery, queens will lose about 40% of the weight they have gained during pregnancy, and the rest will be lost during lactation due to the workload placed on the queen's body. Once the kittens are born, the queen can increase her food intake because she will have more room in her abdomen, but the energy density of the food must be high enough or she will not be physically able to consume enough to sustain milk production, weight, and body condition. Periodic assessments of the queen's body condition provide opportunities to fine-tune feedings. Feeding during lactation is best accomplished using a highly-digestible, high quality kitten food.
Peak milk production occurs at 3-4 weeks of lactation, but the peak energy requirement occurs at 6-7 weeks postpartum (after birth). This is primarily due to the fact that the kittens are also consuming the queen's food as they approach weaning age.
Free-choice feeding during the first 3 to 4 weeks of lactation provides many advantages, unless she only has one or two kittens. The queen can eat on her own schedule, she can consume smaller amounts of food each time she eats, and the kittens can begin sampling solid food as soon as they are able (at about 3 weeks of age). Free-choice feeding while nursing only one or two kittens is not advised because it allows the mother to make much more milk than she needs, potentially predisposing her to mastitis (inflammation of the milk glands).
Do I need to change how I feed my queen as she weans her kittens?
Restricting food to the queen before and during weaning can help her taper off her milk production, making her a bit more comfortable. On day one of weaning, withhold the queen's food, allowing the kittens to eat their food while they are away from their mother. They can all be together that night, and the kittens will suckle a bit. On day two of weaning, the kittens are separated from the queen and she is fed about 25% of her pre-breeding portion and formulation. Over 4 or 5 days, increase to the full pre-breeding portion and feeding schedule. Kittens should not be allowed access to nurse during this time, as it will delay the process of drying up the queen's milk production.
With a bit of planning and input from your veterinarian, you can create a nutritionally sound plan for pregnancy and lactation, setting the stage for producing healthy kittens.
