Mineral status of browsing goats in the North Western province of Sri Lanka as influenced by feeds , soils and seasons mineral status of browsing goats in the North Western province of Sri Lanka as influenced by feeds , soils and seasons
Date
2006
Authors
Mahusoon, M. M.
Journal Title
Journal ISSN
Volume Title
Publisher
Univrersity of Peradeniya
Abstract
A scries of studies wore carried out lo investigate (he mineral status of free brow/ing goals as related to soil, forage and seasons in (he North Western Province ofSri Lanka. The flrsl study was conducted lo determine the macro- and micromiiicral status of soil, forage and goals. Cross-bred male and female goats '(Jamnapari X Indigenous, Saanen X Indigenous, Jamnapari X Saanen, Boer X Indigenous and Jamnapari X Kollukkaehiya) at different physiological conditions vi?.; suckling (<6 mouth), growing (6-12 month), matured (>! year), pregnant (>l year), laclaling and non-laclating does reared under the extensive management systems in three different agro-climatic /.ones (dry, intermediate and wet) in the North Western Province of Sri Lanka were used. Soil organic matter, pit, calcium (Ga), magnesium (Mg) and potassium (K) were higher in the dry /.one compared lo other two /.ones. Mean Ca and Mg contents in soil were adequate in all three /ones. Mean soil K content was adequate in dry and intermediate /one white deficient in wet / o n e . Soil phosphorus (P) and sodium (Na) were the most likely deficient minerals in soils.
No deficiency levels were indicated in forage Ca, Mg and K in all the zones, forage P and Na were all higher in shrub, herb and vines. Deficiency levels were indicated for P and Na in tree leaves and grasses. It appears thai ration formulation for range goats in the North Western Province should include Na and P. Plasma analysis has shown lluil Ga levels were lowest in milking and adult animals in all three /.ones. Phosphorus was lower in young animals than old. Magnesium levels increased will) the age. Plasma K levels were similar in all status in the dry region hut male and femal .suckling in (he intermediate zone and milking and non-lncialing does in the wet zone indicated below the critical value, Plasma Na levels decreased progressively with the age. High correlations were (bund between macromincral contents of soil and forage in the diets mid plasma of the animals.
The micromincrals of soils revealed thai soil copper (Cu), zinc (Zn). iron (Fe) and manganese (Mn) were adequate in all three zones and found to be high in wet zone. The highest range of Cu was found in trees non-leguminous fodder while highest concentration of Zn was observed in trees leguminous fodders and shrubs. Iron and Mn contents were higher limn the dietary requirement. Blood plasma Cu levels were found lo he increased wllh the age but plasma Zn concentration was observed in vice-versa. Plasma Cu level increased with age could be associated with its role lo oestrogen level. Zinc levels of plasma found lo be higher in young animals that could be related the high Zn-binding enzyme necessary for growth and development. The concentration of plasma Fe recorded higher among the pregnant animals. Plasma Mn level was found to be high in adult animals. Croats maintained under free range browsing systems showed no deficiency in micromincrals.
The second study was carried out to examine Mo supplementation on nematode infcelion and weight gain as related to season. Four treatments consisting of 10 goats each were used as control - free grazing only (To); free grazing plus mineral block without Mo (T|); free grazing plus mineral block with molybdenum of 2 mg Mo kg"1 block (Ta) and free grazing plus mineral block with molybdenum of 10 mg Mo kg*1 block (T.t). The study continued during rainy and dry seasons for one year. The experimcnla! results showed that the concentrations of minerals in forage were higher during the rainy season.
Calcium, Mg, K, Fc and Mn contents in all forages were above the recommended levels during both rainy and dry seasons. During the rainy season 2 3 % and 32% forage samples were deficient in Na and P while in dry season the respective deficiencies were 0 1 % and 100%. Forage Cu and Zn contents were inadequate during both rainy and dry seasons. Mineral concentrations in plasma increased due to mineral supplementation. Plasma Ca, Mg, K, Zn, Fc and Mn contents were above the critical level recommended during both seasons, while 2 0 % and 3 3 % of plasma samples were deficient in P and Cu, respectively. Molybdenum supplementation reduced the nematode egg count and improved hacmalocril value, hemoglobin concentration and body weight gain of goats suggesting beneficial effects of molybdenum.
A final experiment was carried out to evaluate the effects of three different sources of phosphorus supplements on growth performance, nutrient utilization, mineral balance, nitrogen retention, rumen parameters, blood biochemical profile and plasma mineral contents of goals. The experimental diets were prepared using three different sources of phosphorus i.e., dicnlcium phosphate (DCP), highly soluble Bppawcle rock phosphate (IIHRP) and l-ppawclc rock phosphate (I'iRP). Twelve young growing male cross-bred (Saanen x Jamnapari) goats were divided into four groups and each group was undergone into four treatments. The treatments were: control (To) -without any phosphorus supplementation; phosphorus supplemented with DCP (T|); phosphorus supplemented willi IIHRP (T2) and phosphorus supplemented with P.RP (Ti). The experimental results revealed that phosphorus supplementation increased feed intake, weight gain and nutrient digestibility. Mineral balances and nitrogen retention were improved by supplementing phosphorus sources. Rumen parameters and blood biochemical profile were also improved by phosphorus supplementation. Plasma mineral contents were higher while adding phosphorus sources. Among the phosphorus supplemental diets, highly soluble Kppnwele rock phosphate showed the highest responses to the above mentioned parameters. Therefore, highly soluble Kppawele rock phosphate (IIKRP) could be used as phosphorus supplementation instead of dicaiclum phosphate which is expensive and low availability.
Therefore it was concluded that macro- and micromincrals of Ca, Mg, K, Cu, Zn, l'e and Mn were adequate while Na and P were deficient in soil of dry. intermediate and wet zone oIThc North Western Province of Sri Lanka. Plasma macro- and mieromiiiernls of goals reflected the physiological status of die animal. Most of the forage showed adequate levels of all micronulrienls, which were also reflected in animals. Inclusion of Mo at It) mg kg"' block was beneficial to goats for improving blood parameters, suppression of worm infestation and live weight gain. Supplementation of IIKRP significantly increased Iced intake, weight gain and nutrient digestibility while mineral balances and nitrogen retention, rumen parameters and blood biochemical profile were also improved.
Description
Keywords
Goats , Mineral status