Review/Oorsig Volume 22, Issue 03 - Page 30

Oorsig/Review • • storage area for food substances like glycogen, vitamins (A, D, K and certain B vitamins) and minerals, synthesizing of essential substances like vitamin A, albumin, globulin and other plasma proteins. The disturbance of normal liver function will have a severe impact on the immune status of the body in general and certain organs in particular, i.e.; • • the uterus may become more prone to infection due to a failure of the liver to break down certain hormones, a reduction in the formation of immunoglobulins may generally affect the immune status of the body. The immediate post partum period is a critical period for the dairy cow and in this period the prevalence of certain conditions is relatively high. The common postpartum diseases of dairy cows are metritis, mastitis, milk fever, displaced abomasum, retained placenta and ketosis. A cow with TYPE II KETOSIS will be more likely to contract one or more of the above mentioned conditions and will usually respond poorly to treatment for the specific condition. Cows with TYPE II KETOSIS also will manifest a reduced breeding efficiency as evidenced by both a prolonged calving to first oestrus period and an increased number of services per conception. Predisposing factors of type II ketosis • • Poor reproduction Poor reproduction performance results in extended lactations, which gives the cows time to become overconditioned on the lactation ration towards the end of their lactations. Obesity During the last half of the lactation period, when the hormonal regulation of lactation still results in cows to be very efficient in their ability to utilise feed, the ration and intake may far exceed the nutritional requirements of the cow. In obese cows there is a greater adipose tissue mass ready to be broken down and this predisposes them to excessive adipose mobilization and a fatty liver. It must also be remembered that fat cows tend to have a reduced feed intake in late gestation and early lactation, which will exacerbate the lipolysis. 30 • • • Post partum disease Type II ketosis may occur as either a predisposing cause or as an effect of postpartum disease. It is not always possible to say which came first. Diet A sudden change to an inadequate or inferior ration in especially the steam-up period will encourage lipolysis and predispose to type II ketosis. Pre- and postpartum stress Will lead to lypolysis (adrenergic stimulation) and poor feed intake Clinical findings of ketosis Wasting form » » » » » » » » » » » » » » » » Rapid loss of weight/mobilization of s/c fat reserves (“Woody” appearance). Marked drop in production (milk yield) over 2 - 4 days. Inappetance - first refuse grain and later may Y\H[YH[^K\[[\\\\Y[[X[[ݙH܈X] [Z[[[ݙ[Y[XܙX\Y [\H[Y[ܛX[ ][H[\X^HHX\[[H[ܙX\YYX\\H\NZ[ۜ\][ۋ]X\وX][Z[ Y[ZBX]ۙJK]ۙH\\]]H[Z[[\[B]^ N[]]]H[XYX]BX]\\[K\\ܛB[H[[\Y ]\[\\[ۋY\[Z] [[[\\[XY[ Z[[\[ݙ[Y[ܛ[وYXY\[X[[YZ[[ \X[[\ȋYܛ\X[و[وHܙH[X][˜[[]][ۋ\\Y\\XH[[[˂Xۙ\H]\•\X[HH]Y[[X\Xœ[\\\YܙHHܛY[X[^[Z[][ۈ\X\\HY[YHH[X\B]\H[[\Y\\H\[ًX[Y\][ۜو\HRH]\•\H\[[ܙX\H[H][[Hو[[ۂ\\\[Hۙ][ۜΈX\]\Y]]\\XYXX\[K]\؛[\]Z[Y][Y[X[\˂H\ۜH\\H܈Hۘ\[\\\[Hۙ][ۜ\\X\\X[H܂[\HRH]\]XZ