Different situations may affect the profitability of the sheep feedlot business. Within those situations farmers usually pay attention to the big ones; low daily weight gains, high mortality rates, labor that is not fully utilized to mention a few.
Oftentimes, small problems get through under the radar, causing significant damage to your business profits. Within those, there is one that has come to my attention lately and it concerns rectal prolapses.
A rectal prolapse, is the protrusion of the rectal mucosa through the anus sphincter. A condition that if left unattended can end up in the animal’s death. Although the condition can and should be treated, in most cases euthanasia is recommended. The incidence of this condition in the feedlot can cause severe damage to the company´s profit. A normal incidence of rectal prolapses should remain under 1%. Even a 2% animal loss due to this phenomenon, in a feedlot of 1,000-head can be translated to more than one thousand dollars.
The best approach to solve this issue is through prevention. In order to have a good management plan for this it’s important to understand the nature of rectal mucosa and which factors increase its occurrence.
Anatomic: very short and medium tail docking. The tail should be docked at the third joint, after the caudal fold, so that it fully covers the vulva. This length should be the same in males and females as some institutions suggest. According to a study in Texas, there is a strong correlation between the length of the tail and the incidence of the prolapses. The longer the tail, the less incidence of the problem. The reason is mainly related to anatomic and mechanical origins. Although the anus sphincter has some muscles itself, the tail helps the mechanical process of keeping it closed. So when long enough (3 joints long or full vulvae coverage) the area gains a stronger mechanical force to keep the sphincter closed and thus content contained. This is especially important when respiratory diseases are accompanied by cough or digestive ailment, resulting in tenesmus or constipation. A longer tail then helps to increase the mechanical strength of the area and avoid the presentation of rectal prolapses.
Image 1: Tail Docking Guideline
Genetic: genetic causes have also been attributed to this phenomenon. The lack of strength of the anus sphincter and the fat deposition around the rectum seem to be related to genetic causes. This means that rams that present prolapse incidence of over 2% should be taken out of the reproduction program of your lamb provider.
Poorly balanced ration: high protein and low fibre rations generate a strong tenesmus that can end up in a rectal prolapse. Shortage of water supply exacerbates the problem.
Digestive diseases: digestive diseases that cause diarrhoea, increase the presentation of tenesmus or constipation and as a result, the incidence of rectal prolapses.
Cough: respiratory diseases (independent of the cause of origin) can lead to animals that cough which can increase susceptibility to rectal prolapses.
Most of these factors are preventable. A holistic approach offers better and more consistent results. The first aspect to prevention of rectal prolapses starts with a good dialogue between the farmer and sheep provider. Ask for your lambs to be tail docked at the third palpable joint of the tail. Establish a strong two-way communication when rectal prolapses are presented in your flock, provide them with sufficient information so that they can take action on it. Realize a frequent egg count to keep the parasites under control and drench them when needed. Avoid dust, mould or any agent that could possibly trigger a respiratory disease.
Finally, ask your feed consultant for advice in regard to your feed ration. Not only should your animal´s weight gain potential be discussed, but the need to avoid nutrient wastage.
Unbalanced rations are not only negative for your animal’s health but also seriously jeopardize your business finance. Following these management principles should help you keep the feedlot incidence of prolapses below 1%.
 Tenesmus: a continual desire or feeling to evacuate the intestinal bowel. Caused by afflictions such as inflammation or irritation of the intestinal mucosa, diarrhea, coughing and low fibre diets among others.
- Dickson, H; Jolly, S (2011). National procedures and guidelines for intensive sheep and lamb feeding systems. Meat & Livestock Australia, Australia.
- Hopkins, F; Warren, W. Rectal (2009) Prolapse in lambs. Department of Animal Sciences University of Tennessee, Agricultural Extension Services, USA.
- Justin, L, (2008). Causes, prevention and treatment of rectal prolapses in sheep. North Dakota State University. Viewed 22 Jan 2016. https://library.ndsu.edu/repository/bitstream/handle/10365/5339/as1388.pdf?sequence=1
- Kennedy, GF (2013). Ask a vet sheep. Viewed 6 of April 2016. https://askavetsheep.wordpress.com/2013/05/30/rectal-prolapse/
- Merck Sharp & Dohme Corp, (2009-2015).The Merck Manual of Veterinary Medicine. Kenilworth, U.S.A. Viewed 6 of April 2016. http://www.merckvetmanual.com/mvm/digestive_system/diseases_of_the_rectum_and_anus/rectal_prolapse.html
- Sheep Standard and Guidelines Writing Group, (2013). SHEEP STANDARDS AND GUIDELINES – TAIL DOCKING DISCUSSION PAPER. Australia. Viewed 6 of April 2016. http://www.animalwelfarestandards.net.au/files/2011/05/Sheep-Tail-docking-discussion-paper-5.3.13.pdf.