[討論] 氯化鈣，改善母豬生產(chǎn)性能？

牧羊雪 · 發(fā)表于 2006-7-5 19:54:42

Sow feed additives on the market: Are they worth it?
Joel DeRouchey, PhD, Mike Tokach, PhD, Steve Dritz, DVM, PhD, Bob Goodband, PhD,
and Jim Nelssen, PhD

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Altering the dietary electrolyte balance (dEB; calculated as mEq/kg of (Na% *
434.98) + (K% * 255.74) – (Cl% * 282.06) of dairy cattle is a common practice among dairy nutritionists to improve health and performance. Goff and Horst (1998) reported a 53% reduction in the incidence of milk fever among dairy cows fed diets with a low dEB. Also, dEB is frequently increased during lactation to help buffer the rumen and prevent digestive problems in high intake cows.

Recently an increase in interest in altering the diet acidity or dEB of sow diets to improve sow performance has been evaluated. Two main areas have been researched; 1)methods to reduce urine pH to improve urinary tract health; and 2) increasing blood Ca levels to decrease stillbirths.

Feeding methods to reduce sow urine pH for improvement in the health of the
urinary tract have been evaluated by two different means: 1) addition of organic sources(organic acids with do not alter the dEB of the diet); and 2) addition of inorganic sources(mineral sources). Dee et al. (1994) suggested manipulation of diets using citric acid could lower urine pH and, thereby, decrease the likelihood of urinary track infections in sows. However, DeRouchey et al. (1998) were not successful in reducing urine pH using citric acid alone or a combination product of fumaric, lactic, propionic, formic and citric acids (Acid Lac®, Kemin Industries) included in the diet. However, urine pH was reduced with the addition of an inorganic phosphoric acid based additive (Kem-Gest®,Kemin Industries).

Tilley (1997) reported from South Africa the first data in which sows fed lactation rations with a lowered dEB had greater survivability of piglets and litter weight gains.DeRouchey et al. (2003) reported improved piglet survivability, reduced blood and urine pH and decreased total urinary bacteria as the dEB of the diet was reduced from 500 to 0 mEq/kg (typical corn-soy lactation ration dEB = 185 to 220 mEq/kg). DeRouchey et al.(2003) utilized Calcium chloride and hydrochloric acid as a diet acidification sources and sodium bicarbonate to increase dEB. Both Tilley (1997) and DeRouchey et al. (2003) reported sows had increased blood Ca concentrations as dEB was lowered. This can be explained (Seldin and Giebisch, 1989) as the result of more bone mobilization to buffer the extracellular fluid with the increase in H+ concentration in the blood as dEB was decreased. Also, Ca absorption is increased with a decrease in blood pH. While bicarbonate feed additives can be used to increase performance in high intake dairy cows, those advantages have not been proven in lactating sows. Dove and Haydon (1994) and DeRouchey et al. (2003) reported no improvement in sow performance as dEB of the lactation diets was increased.

Since blood Ca concentrations have been shown to increase in sows fed a decreased dEB diet, it has been theorized that this may decrease the number of stillbirths due to more Ca available for muscle contractions during the birthing process.
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