BODY CONDITION & REPRODUCTION

BODY CONDITION & REPRODUCTION

written by Brenna Weaver

Reproductive output is a central source of income for a breeder. Identifying deficits and mitigating as many problems in your breeding program as possible are keys to success. There’s nothing more frustrating than a mare failing to conceive repeatedly or a stallion suffering from subfertility. In this, body condition plays a vital role – a horse deprived of nutrients necessary for ideal function is frustrating from an emotional and financial viewpoint.

BODY CONDITION SCORES

The Body Condition Score System was developed in 1983 by Dr. Don Henneke and collegues. This invaluable and straightforward tool allows veterinarians and horse owners alike the ability to rate accurately the overall condition of horses. It measures stores of fat in six key regions: neck, withers, ribs, behind the shoulder, loin, and tailhead. The body condition score (BCS), is achieved by both visual indications and manual palpation of these regions. A horse is then given a score between 1 and 9, with a 1 being emaciated and 9 being obese (see chart).

Score 1 – Poor: Horse is extremely emaciated. There is no fatty tissue. The vertebrae, ribs, tail head, and bones of withers, shoulder, and neck are clearly evident. Score 2 – Very thin: Horse is emaciated. There is very slight tissue cover over his bones, and the vertebrae, ribs, tail head, and bones of the withers, shoulder, and neck are evident. Score 3 – Thin: There is slight cover of fat over the horse’s body. The individual vertebrae and ribs are not visible. The withers, shoulder, and neck are not excessively thin. Score 4 – Moderately thin: The ridge of the horse’s spine and the outline of his ribs are evident. The tail head may or may not be visible. Withers, shoulders, and neck are not excessively thin. Score 5 – Moderate: Horse’s spine and ribs are not seen but ribs can be felt. The tail head is spongy. Withers, shoulders, and neck are round and smooth. Score 6 – Moderately fleshy: There is a slight crease down the spine. The horse’s ribs and tail head feel spongy. There are fat deposits along the withers and neck, and also behind the shoulders. Score 7 – Fleshy: There is a crease down the spine. The ribs have fat filling between them. The tail head is spongy, and there are fat deposits along the withers and neck, and also behind the shoulders. Score 8 – Fat: There is an obvious crease down the horse’s spine. Ribs are hard to feel. There is soft fat surrounding the tail head, and there are fat deposits along the withers, behind the shoulders, and on the inner thighs. The neck is large in size. Score 9 – Extremely Fat: There is an obvious crease down the spine. There is patchy fat on his ribs, bulging fat on the tail head, withers, and behind the shoulders,

IDEAL RANGE FOR MARES

Mares bear the brunt of the work when it comes to reproduction - growing embryos, delivering foals, and providing critical nutrition during the first six months of a foal’s

life can take a toll on her body. It is absolutely critical to the success of any breeding program that mares be conscientiously monitored year-round in order to maximize their ability to conceive, carry, and deliver the next generation. Studies at Texas A&M have yielded valuable information regarding the correlation between BCS and mare fertility. One of these studies, which included 927 mares, placed mares in three categories at foaling according to their BCS: thin, moderate, and fat. The thin mares’ score was 4.5 or less, moderate mares between 5 and 6.5, and fat mares in the study scored 7 and above. The study found that mares foaling in thin condition suffered impaired performance when it came time to re-breed, even when provided necessary energy requirements for lactation 1 . Even though these thin mares’ rebreeding efficiency was improved with increased feed intake, the study

noted that to do so was quite costly and posed its own set of health risks to the mares (i.e. colic and founder). Pregnancy rates among thin mares was noted to be only 78%, much lower than the rates of moderate or fat mares, and took 2.5 cycles to reach conception.

The fat mares made use of their stored fat for efficient reproduction and lactation, even while they were losing weight during the course of the study. They had no foaling problems and experienced high rebreeding efficiency 1 of 98%, with an average of 1.5 cycles to reach conception. Mares in a more moderate condition or better (BCS of 5-6.5) cycled earlier, had a 100% conception rate during the breeding season, and took 1.75 cycles on average to reach conception. They also sustained more pregnancies than thin mares.

Additional research suggests that mares with body condition scores of 4 or less will delay ovulation at the start of breeding season, and can do so by three or even four weeks 2 . They also suffer pregnancy losses at a greater rate than better kept mares. The findings of these studies indicate that a mare should be brought into a breeding season with a body condition score between five and seven, and maintained at a 5 or better throughout the year.

A primary concern for breeding stallions is maintaining proper body condition throughout the active breeding season. While less formal research has been conducted on the specific effects of body condition scores and how they correlate to improved or impaired reproductive performance in stallions, we do know that nutrition is absolutely vital when it comes to cell production and proper reproductive function. It has been recommended that a stallion enter breeding season with a BCS of 6 to 7 3 . Stallions should be fed to support maintenance of their score throughout the breeding season with little significant change in their weight 3 .

OTHER FACTORS

While the BCS system is an important tool for measuring overall horse health, a few other matters to consider are:

Coat & Hoof Quality: A horse can receive enough calories to maintain weight, but can still have nutritional deficits that can affect their reproductive function. Hair coat and hoof quality are good indicators of this. If your horse maintains weight, but fails to bloom, with a shiny, soft haircoat and good overall hoof quality, you may need to consider altering their diet, as there could be underlying deficiencies. Consult your veterinarian and/or equine nutritionist to create a customized ration to meet their individual needs, and even rule out other potential health concerns.

Location, location, location!: Geography matters, and soil quality varies greatly depending on location. Different soil types contain widely different levels of

key nutrients that can support healthy reproduction. Knowing exactly what is in forage and grain rations can help you form a plan backed by actionable information. You can readily have soil, grain, and forage analyzed in order to do this.

Age is more than a number: The nutritional requirements of older mares and stallions are more demanding than those of a horse in the prime of its life. You may need to make alterations to your feeding program for older horses to keep them at optimum function.

Jumpstart Digestion: Teeth are the bridge between food and productivity. You’ve heard the phrase, “No hoof, no horse,” and the same principle applies to teeth. They are the first step in digestion and by extension, nutrient-absorption. Most horses in their prime can have a dental done once a year, but not every horse is the same, and younger and older horses may need more assistance. While your mare is getting her pre-breeding season examinations, it won’t hurt to have your vet take a look at her teeth, just for good measure. Stallions are orally fixated creatures more often than not, so make sure to have your vet or equine dentist check him as well.

Paying close attention to and measuring the overall body condition of your herd is your first line of defense against problems during breeding season. As always, good veterinary, farrier, and dental care are of utmost importance, as well as an individualized whole-horse approach. Consult the professionals on your breeding team and make use of their insight and knowledge to get the most of your breeding program.

References: 1. Evans, P. (2005). Body Condition Scoring: A Management Tool for Evaluating All Horses. Retrieved from https://pdfs. semanticscholar.org/4596/c468a4a3b4c7b1318f3d67bdb1a03e508db6.pdf 2. Hiney, K. (n.d.). Body Condition of Horses. Retrieved from http://pods.dasnr.okstate.edu/docushare/dsweb/Get/ Document-8661/ANSI-3920web color.pdf 3. Gibbs, P. G. (n.d.). Stallion Nutrition. Retrieved from https://animalscience.tamu.edu/wp-content/uploads/ sites/14/2012/04/nutrition-stallion-nutrition.pdf