I have already stated in part 3 (culling) that quality rats can be produced, even in large litters, providing that excellent feeding meets the nutritional needs of both mother and kittens. Everything contained in this article refers to breeders raising complete (and sometimes large) litters.

The period of pregnancy and lactation places particular nutritional demands on the doe's body, resulting in special nutritional requirements. Kittens likewise are growing at a phenomenal rate and to achieve their potential nutritional needs must be met. This applies to the quality and quantity of the doe's milk as well as the food given to weanlings.

I used to agree with conventional wisdom that there was no need to alter the diet of a pregnant doe and that she would simply increase her consumption of her regular grain mix in order to compensate for the requirements of pregnancy. I no longer believe this to be strictly true. When raising litters I have found that increasing (or introducing) a leafy green mineral rich vegetable source makes a difference to the quality of the kittens (particularly reflected in their tail development). It is not fully understood exactly how tail development reflects nutritional status but I am convinced that it does. Even the meaty tails of large stud bucks sometimes become wasted and square in the decline of illness and old age. Under fed kittens seem to have square tails. Kittens going through a steep growth spurt sometimes get a squarish edge to their tails, that then reverts to beautiful roundness as they slow down into adulthood. I am convinced that tails can be a good overall indicator of the nutritional status of a rat throughout their lives and can be 'read' by the experienced breeder.

I do not feel that it is necessary to do more than continue a pregnant doe's regular diet (assuming this is good quality), slowly increasing the quantity available and with the addition of a large daily portion of curly kale, spring greens, clover or young dandelion leaves. Fat does tend to have more birthing problems so efforts should be made to avoid overfeeding.

Nursing does require a diet that is rich in protein, carbohydrate, minerals (especially calcium, magnesium and phosphorus) and vitamins. It is important that a nursing doe is given the necessary nutrition to enable her to cope with the high demands of her kittens, otherwise she will raid her own skeleton and body tissues in an effort to supply her offspring. Nursing does require between two and four times the normal amount of protein when they are lactating. Digestible protein (as opposed to crude protein) is relatively easy for a rat to absorb. Organic calcium, on the other hand, needs other vitamins and minerals to enable the rat to absorb it - notably magnesium and vitamin D. Another essential mineral for growing bones is phosphorus but, as it occurs naturally in the cereals and grain that they eat as part of their staple diet, we do not need to worry about supplementing it, as a lactating doe would simply increase the amount she would normally eat. A lactating doe may pass up to 200 mg of calcium and 140 mg of phosphorus into the milk in one day.

Over the last year or so I have reviewed my own feeding programme for lactating does and their litters, and now rely heavily on fresh foods. I make a constant provision of a high quality grain mix (based on my normal rat diet but with additions to increase the protein/calorie content. Along side this (and making up at least 50% of the overall diet) I feed large quantities of high quality fresh foods.

• 40% Alpha Herbal rabbit food
• 35% mixed human grade breakfast cereals (chosen to be low sugar and a mixture of types of grain)
• 10% dry (uncooked) pasta
• 10% Alpha puppy kibble (small bite protein 29%)
• 5% seeds (sunflower, pumpkin etc)

• Daily (large) portion of curly kale, clover or young dandelion leaves
• Broccoli
• Carrot
• Chicken (whole wings and drumsticks provide the higher protein flesh and the benefits of mineral rich bones to chew on)
• Egg (scrambled, boiled chopped, mixed into porridge or soaked into wholemeal bread and cooked in a touch of olive oil)
• Fish (raw, cooked and tinned [lowest salt] all acceptable)
• Lactol (bottled or made into porridge or over wholemeal bread)
• EMP and vitalin (made up with lactol into a mash)
• Nature Diet moist puppy food
• Banana and avocado pear

As the babies grow I add in more high carbohydrate foods such as cooked wholegrain rice, pasta, noodles, potato, sweet potato, cous cous alongside the foods listed above.

I try to give at least one protein meal a day and curly kale every day. The rest is in rotation depending on what is available.

There are a number of supplements that are suitable and useful for growing families. Some of these are:

• Calcivet - saturated liquid calcium/magnesium supplement with vitamin D
• Seaweed powder - benefits fertility, muscle, bone and tooth formation, coat and skin condition
• Daily Essentials or Essentials Plus - general multivitamin/mineral supplements

This is a time of rapid (but gradually decreasing) growth, and adequate diet is necessary for a rat to fulfil its physical potential and remain in good health. Growth requires protein for the development of body tissue, calories for energy (from carbohydrate and fat) and vitamins and minerals (notably calcium) for healthy bone and tissue production. Once growth slows right down (usually around 5 to 8 months, stopping altogether at around a year) it is obviously not necessary to give the same quantities of these nutrients, and failure to change feeding patterns can result in obesity and ill health later in life.

This is the period from about 14 to18 days onwards, when kittens first begin to take food other than their mother's milk. Rat kittens are normally fully weaned between 4 and 5 weeks, but continue to benefit from having some 'weaning diet' for some weeks after this. Weaning foods tend to be soft, moist and initially mimic the milky diet the kittens are used to. (See list above)

It cannot be over emphasised how much food a young, growing family will need. Kittens will remain undernourished even if they are given an excellent diet, unless they are given enough of it. As the doe will have eaten a number of placentas and tidied up after the birth she will often eat very little in the first 24 hours post delivery. After this she will begin to eat in earnest and her appetite will increase to match the increasing amount of milk that she is producing for her offspring. This will reach a maximum somewhere around 3 weeks post delivery. After this the volume of food eaten by the babies gradually increases, and the demands of lactation gradually decrease. But the volume of food eaten by the growing family as a whole will continue to increase.

As a general rule the family should have food available to them at all times. If you are returning to empty bowls you need to increase the volume given or the frequency of meals (2 or 3 per day). Whether or not their nutritional requirements are being met is fairly easy to assess, simply by watching the progress of both doe and kittens. Most mothers lose a little weight between the second and fourth weeks when the demands of lactation are at their highest. Equally most does return to excellent condition by the time the babies go to their homes at 6-8 weeks. The kittens should be 'substantial' and plump, their tails round and increasingly thick. Generally those who have been fed to their requirements will have come into their shiny 'adult' coats by 5 and a half to 6 and a half weeks.

I have heard all sorts of claims made about what isn't possible if you don't reduce litter sizes. Only recently someone told me that good typey rats couldn't be sustained over more than 5 generations without culling. I have always considered that claims like these might turn out to be true, but logically thought that it should be possible to meet any litters nutritional needs regardless of litter size. Until I discovered for myself the benefits of a daily dose of green leafy plant material (I use curly kale) I have to admit that I was floundering, having produced a couple of litters where the tails didn't match the big typey bodies they were attached to.

Then there was Tennyson Rêve.
Rêve is by no stretch of the imagination, a large doe She is not lightweight, but certainly neat and racey. She is descended from many generations of un-culled lines. She was mated to her uncle a large typey dumbo. She was my first doe to receive daily greens whist pregnant, throughout lactation, and whose kittens were also fed greens daily from weaning. Indeed they all received the diet outlined above. I should also mention that there were 17 of them including one extremely small runt.

By 6 weeks they were 17 substantial (some huge) kittens with lovely round thick tails. Even the littlest was a chunky normal sized lad with a nice tail. Rêve herself had maintained her weight and condition throughout, not finally weaning the kittens until almost 5 weeks. I am convinced.

Admittedly there may be different reasons (such as poor lactation) why a particular litter may not achieve their full potential, but these are not the norm and it is perfectly possible with excellent nutrition raise repeated generations of complete litters while continuing to improve size and type.