If mares are too fat, the first dietary change should be a reduction in concentrate intake. Although there does not appear to be any reproductive advantage to a condition score above 7, it may be beneficial for mares to have a body condition score slightly above 5 before the coldest part of winter. If they have a condition score above 5 at the onset of winter, they will have a buffer of expendable body fat that can be used during severe cold.
The goal is to make certain that mares do not have a BCS below 5 at the beginning of the breeding season. Figure 2. Horse has a BCS of 4: The ribs are faintly visible, and the back has a slight ridge along it. The neck is not noticeably thin, but the shoulder structure is becoming visible. Figure 3. Horse has a BCS of 5: The ribs are not visible, neck is not thin or fat, withers and spine and hip structures are not visible. Figure 4.
Horse has a BSC of 6: Ribs are not visible, neck is slightly thick, some fat filling in behind shoulder, in flank, and over withers. Figure 5. Horse has a BCS above 7: The neck is thick, fat is filling in behind shoulder and in flank, and the ribs are becoming hard to palpate. To determine whether this horse is a BCS 8 or 9, palpation of the tail head, ribs, and other areas would be necessary.
A foal has already attained about 60 percent of its mature height at birth. She can provide this nutrition by eating and processing additional nutrients in her diet, or by robbing nutrients from her body to meet the needs of the developing fetus. Optimal feeding programs will minimize the need for mares to use their own body stores. Table 1 shows the effect of gestation on the nutrient requirements of 1,pound mares.
This is a new recommendation; previously it was suggested that nutrient needs did not increase until the eighth month of gestation. Many mares in Kentucky will be grazing good quality fall pasture during the middle months of gestation.
Good quality pasture may provide enough energy to maintain a BCS above 5 without much concentrate supplementation. However, Kentucky pasture alone may not meet the mineral requirements of gestating mares.
If pregnant mares are not receiving any concentrate, a mineral supplement should be given at least once a day. A convenient supplement source is a balancer pellet Figure 6 , also called a supplement pellet, which is sold by many feed companies. Feeding pounds of a typical balancer pellet during mid-gestation should ensure adequate daily mineral intakes of mares that are grazing pasture. A salt block should be available to provide sodium chloride for horses.
Although trace mineral salt blocks and other mineral blocks are available for horses, most horses will use them inconsistently. Therefore, it is difficult to count on these blocks to meet the mineral needs of every mare. Figure 6. What is a balancer pellet? A balancer pellet is a concentrated source of minerals and vitamins. It is fed in small amounts each day pounds. It is used when the diet provides adequate calories, but not trace nutrients.
A balancer pellet is not needed if the diet already contains at least 3 pounds of a fortified commercial concentrate formulated for broodmares.
The amount of protein in a balancer pellet can vary widely. When horses are receiving a high protein forage it is not necessary to use a high protein balancer pellet. Typical composition of a balancer pellet:. Good-quality pasture can provide calories and protein, but a daily supplement, such as a balancer pellet, is usually necessary to ensure that the mineral needs of pregnant mares are being met. Pregnant mares should be maintained at a BCS of at least 5. A slightly higher BCS will ensure that the mares have a buffer of body stores at foaling and in early lactation.
When forage quality or quantity is not enough to maintain body condition, concentrate should be added to the diet. A commercially manufactured concentrate that is fortified to meet the needs of broodmares is an excellent choice when concentrate is needed in the diet.
As mares approach the end of gestation, appetite may decline, so concentrate intake may have to be increased. A typical diet for a thoroughbred-type mare in the last month of gestation might be pounds of good quality hay and pounds of a concentrate. However, some general guidelines are as follows. Good-quality pasture or hay can sustain a mare.
NRC data suggest that the nutrient requirements of pregnant mares increase at five months of pregnancy, rather than the previously suggested eight months. According to the University of Kentucky Cooperative Extension, many mares in Kentucky will graze good-quality pasture during midgestation, which provides sufficient energy to keep her in proper body condition score BCS without much concentrate feed supplementation.
A typical diet for gestating mares during latter pregnancy is 20 to 25 lbs good-quality hay, plus 6 to 8 lbs of concentrate. If a mare is on poor winter pasture, the hay and concentrate may need to be increased. Of course, overnutrition is more likely to a problem than undernutrition in thoroughbreds and quarter horses. Coverdale has investigated whether the equine fetus's metabolism e. But we have seen differences in metabolism, especially alterations in glucose and insulin.
So what take-home message did Coverdale find for equine practitioners and horse owners? While feeding a mare at maintenance energy during early pregnancy is still recommended, the role of functional nutrients such as amino acids, vitamins and trace minerals during early gestation is poorly understood. Certainly a fetus is programmed to be what it is genetically, but is there a nutritional component we're still not aware of that affects foal phenotype during the first trimester?
Our data provide justification for keeping mares more at the traditionally acceptable BCS of 6. It's unwise to spend extra money on excessive amounts of high-concentrate diets.
It's not only an unsafe management practice for the mare, it could potentially limit the metabolism of the developing foal. Postmortem photographs of the stifle joints in a quarter horse weanling with severe osteochondrosis dissecans OCD. Some experts wonder if feeding a broodmare differently during early pregnancy could prevent OCD and other muskuloskeletal problems. Photos courtesy of Dr. Holly Mason. In practice she has seen a fair number of acquired contractural limb deformities, physitis swelling around the growth plates of certain long bones in foals and osteochondritis dissecans OCD.
It's not uncommon for broodmares to inadvertently be fed an unbalanced ration throughout gestation, Mason continues. Mason agrees with Coverdale's assessment that a mare in early pregnancy should be fed at maintenance energy per NRC recommendations.
Additionally, she accedes that the role amino acids, vitamins and trace minerals is not entirely understood in the pregnant mare. Mason says she tries to work with her clients' goals, whether they're conservative or aggressive in exploring new strategies in broodmare nutrition. Mason also recommends a hay analysis. It's not cost-prohibitive. Not only is there general variability among types of hay, but also geographic and price variability, she says. It's common in Texas, for example, to feed coastal Bermuda grass hay.
She says she likes to see a balanced intake of vitamins and minerals throughout gestation. And since BCS is a subjective measure, I recommend using scales or body weight tapes. During the latter portion of gestation, the reproductive tract can compete with the gastrointestinal tract for space within the abdomen, and some mares won't consume enough forage to meet their needs.
Mason says she would like to see further research on IUGR and associated endocrine abnormalities that might have lifelong influences. As with all horses, provide a pregnant mare with free-choice access to a fresh, clean water source and a salt block or loose salt. One type of hay or pasture to avoid is fescue , which is often infected with an endophyte that causes problems in pregnant mares, including prolonged gestation, difficult delivery, and lack of milk.
Make sure all bedding is free of fescue, too. Rely on an equine nutritionist. The fundamentals of feeding a pregnant mare are straightforward, though occasionally a scenario pops up that requires the help of a professional. When in doubt, recruit a nutritionist for assistance. Contact a KER nutrition advisor today. Subscribe to Equinews and get the latest equine nutrition and health news delivered to your inbox. Sign up for free now! Search Library Entire Site. Library Section Only.
Everything Except Library. Presented by.
0コメント