The diet of pregnant and lactating broodmares

In the world of horses, attention is often mainly focused on the optimal management of sport horses, that is, on optimizing athletic performance. However, a job well done always comes from far away, therefore in this newsletter we have decided to talk about the small precautions to keep in mind when feeding and managing broodmares. For clarity of presentation, and also to emphasize some concepts, we have divided the text into the two physiologically very different moments that a broodmare goes through: gestation and lactation. There is also another very important phase, namely mating, which we will talk about in due time. Now we focus on the phases of current relevance given the period:

Gestation

Gestation in horses normally lasts between 335 and 345 days, that is about 11 months, however for the first 7 months the requirements are practically unchanged compared to a horse that does not work. In other words, the needs of a pregnant mare are practically those of a horse in maintenance for most of the gestation. This consideration is important, because it is necessary that the mares maintain as much as possible the same body condition they had at the time of mating throughout the entire gestational period, since, if this were not the case, the probability of dangerous metabolic syndromes occurring in the delicate period around foaling would increase.

Conversely, in the final stages of pregnancy, from the eighth to the eleventh month of gestation, similarly to what happens in other mammals, fetal development accelerates considerably, so consequently the nutritional needs of the mare also increase significantly. This implies both supporting the somatic development of the fetus by increasing the protein intake in the diet (INRA suggests adding proteins in the order of about 50 g of protein/head/day in the eighth month up to about 200 g of protein/head/day in the eleventh month), and providing more energy, because fetal fat deposition occurs mainly during this period.

Finally, another small precaution is to ensure that pregnant mares are given selenium, preferably with high bioavailability, so that it can be transferred to the fetus. In fact, the secretion of selenium with milk is very low, therefore it is important that the future foal builds up reserves of this important trace element during intrauterine life, otherwise there is a risk of carential myodystrophies. At the same time, it is recommended to pay close attention to the quantities of selenium administered with the diet because, however important it may be, it is also a highly toxic trace element beyond certain dosages! HorseNutrition adds inorganic selenium to all its products. In addition, in NutriStar, the feed dedicated to broodmares, and in other high-end products, selenium in organic form with high bioavailability is also added along with all the other fundamental micro and macro elements, as well as the right amounts of vitamins.

Lactation

Contrary to what common sense might suggest, mares are decent milk producers. In fact, a broodmare produces, at the peak of lactation which occurs around the third-fourth week after foaling, an average of 12 - 15 kg of milk per day. Production then stabilizes around these levels in the second and third month of lactation and then begins to gradually decrease.

Considering that 1 kg of equine milk, at peak, contains on average 12 g of fat, 18 g of protein and an overall gross energy value of 480 Kcal, it goes without saying that with these productions the nutritional needs of a lactating mare undergo a really remarkable surge! At the same time, the very strong increase in requirements does not go hand in hand with the appetite of the mares, which increases on average by 2 - 3 kg of dry matter per day, that is about 20 - 25%.

For this reason, during lactation it is necessary to increase and concentrate the amount of energy supplied with the diet. Furthermore, although it is absolutely physiological for mares to partially satisfy their increased nutritional needs by drawing on body fat reserves, the need to implement adequate rationing strategies is evident, such as, for example, the administration of foods with high unsaturated fat content such as NutriStar.