Ewe and lamb health

Maintenance of a stable trace element status can be a challenge in many sheep flocks. Late in the season, many sheep are exposed to poor quality grazing and forage which has quite low trace element and nutritional values. Sheep are also subjected to the stresses of harsh outdoor conditions and exposed on hillsides to extreme weather variations.

Foot problems are also very common occurrences in flocks and this painful lameness can significantly impede mobility and grazing and lead to inadequate nutritional intake. Soil and herbage composition can vary in different geographical areas and can determine the various specific trace element deficiencies that are found in local regions.

All these factors acting together can contribute to deficiencies of selenium, vitamin E, vitamin B12, copper, cobalt, selenium, zinc, and iodine in sheep. This deficiency is made worse during pregnancy when higher than normal nutritional and metabolic drains are being made on the ewe, because of the extra demands from the developing foetus.

The tupping season brings many extra demands on the requirements for adequate trace elements and vitamin intake for the ewe.

Ovulation and multiple ovulations in the ewe are dependent on high-quality nutrition and supply of key trace elements and certain vitamins such as, folic acid and beta carotene. Vitamin B12, selenium and vitamin E are required for ovulation and good fertility status.

To facilitate the possibility of multiple ovulations of healthy ova in the cycling ewe, these trace elements must be supplied pre-tupping in quantities to compensate for their likely shortfall on herbage in late summer/autumn.

Selenium governs foetal growth and immunity, but in deficiency states it may give rise to muscle stiffness and white muscle disease in young lambs. Selenium and vitamin E serve as potent antioxidants, lowered incidences of retained placentas, mastitis, metritis, and cystic ovarian disease and improve immunity, conception rate, fertility, and production.

Many lambs on pasturesuccumb to borderline trace element and vitamin deficiencies, which may or may not be obvious to the farmer. Although outward clinical signs may be minimal, the result of such deficiencies lies in the extra length of time the lamb takes to gain bodyweight and, it’s susceptibility to other diseases. Problems tend to affect the whole group rather than individual animals.

All these factors acting together can contribute to borderline deficiencies of selenium, vitamin E, vitamin B12, copper, cobalt, zinc, and iodine in sheep.

Trace element shortages all negatively impact on the general health of the lamb and also lower its immunity status. This low immunity can predispose to parasitic infestation. The most common trace element deficiencies in sheep include Copper, Cobalt, Selenium/Vitamin E and to a lesser extent Iodine and Manganese.

ProVitaMin drench is a highly concentrated complex mineral and vitamin drench that can be used for rams, sheep and lambs. It comprises 26 broad spectrum elements, supplying chelated minerals, vitamins and nutrients to swiftly elevate levels. ProVitaMin is an easy-to-use solution with supplementary rates as low as 10ml per adult and 3.5ml for lambs. SPECIAL OFFER: ProVitaMin drench BUY 2.5 litre, get 1 litre FREE. Available on sheep and cattle drench. While stocks last.

Adequate calciumintake is essential to maintain appetite and vigour in grazing sheep. Hypocalcaemia in sheep on pasture is a complicated issue and it can occur sporadically in grazing sheep leading to anorexia and loss of condition and occasionally more serious conditions.

A dietary shortage of calcium can occur on some poor-quality pastures, on rough mountain forages or on grain-based diets. Even where dietary levels of calcium are normal, some specific plants and forages can contain inhibitors which may block calcium uptake. Thus, nutrient analysis may sometimes be warranted in cases of calcium deficiency.

In several cases, despite the dietary intake of calcium being normal, a complexity of factors may surprisingly interact to cause reduction of calcium blood levels, resulting in hypocalcaemia. This may be attributed to various external stress factors negatively impacting on the endocrine system and thus blocking the absorption of calcium from the gut or inhibiting its release from stores in the bones (absorption and resorption).

Vitamin D is primarily responsible for calcium absorption from the intestine. Resorption and release of calcium from bones is controlled by parathormone from the parathyroid gland and also by “bone nibbling# cells called “osteoclasts”. Both systems must operate optimally in order to keep blood calcium levels normal, i.e., correct absorption and resorption.

External stresses can adversely affect this finely tuned internal regulating system. Such a stress related hypocalcaemia can stunt growth rate and lead to a variety of other metabolic disturbances. Calcium may also be absorbed less efficiently from lush pastures, and this may in part be due to decreased salivation leading to increased plasma bicarbonates, which can also inhibit release of calcium from the bone.

Hypocalcaemia in grazing sheep is commonly the result of failure of the endocrine mechanism to promote the influx of calcium from bone and the alimentary tract rather than from inadequate dietary calcium. As feed deprivation may produce hypocalcaemia in sheep, any disease that causes anorexia could precipitate some degree of hypocalcaemia.

Older ewes are more susceptible, as the ability to release calcium from bones reduces with age. The deficiency can be caused by feed change, e.g., change of diet or pasture, feed deprivation, or diets with low levels of vitamin D or protein as calcium absorption can be affected.

The use of calcium supplements such as Provita Bovicalcan help to maintain blood levels of calcium especially at times of stress, bad weather conditions or poor grazing over the summer/autumn period. Adequate calcium will help to boost the metabolic activity, and maintain growth, health and productivity and ensure ewes are in good condition for tupping.

Written by Dr T.B. Barragry PhD MSc, MVB, MRCVS, Vet Pharmacologist