Performance of grazing crossbred cattle supplemented with minerals: calcium, phosphorus and zinc
| dc.contributor.author | Phiri, Elliot Chikula Jailos Henderson | |
| dc.date.accessioned | 2023-06-16T08:45:50Z | |
| dc.date.available | 2023-06-16T08:45:50Z | |
| dc.date.issued | 2001 | |
| dc.description | Thesis | en_US |
| dc.description.abstract | A study was conducted from 1997 to 1999 in Iringa region, Tanzania in order to evaluate the mineral status and performance of grazing crossbred dairy cattle as affected by season and nature of mineral supplementation. Initially concentration of calcium, (Ca), phosphorus (P) and zinc (Zn) in soil, grass pasture and blood plasma were measured. Seasonal effect was apparent (P< 0.05) in soil and pasture mineral concentration. Soil calcium (4.46 - 5.67 me /100g), was adequate during the dry and the rainy season. Soil phosphorus (P< 0.05) was low during the rainy season and high in the dry season (11.9 - 14.8 vs 28.1 - 31.8 ppm) whereas zinc (0.81 - 1.02 ppm) was deficient in both seasons. Pasture Ca (0.33 - 0.39%) and P (0.25 - 0.34%), were adequate whereas Zn (21.2 - 25.2 ppm) was inadequate for the sampled periods. Blood plasma Ca (<2.20 mmol/1), inorganic phosphate (< 1.28 mmol/1) and Zn (<12.2 pmol/1) were marginal to normal values in the sampled dairy cattle. Other minerals in the soil and grass pasture were also analysed. Sodium (Na) (0.31 - 0.37 me /100g), potassium (K) (0.36 - 0.42 me /100g), iron (Fe) (76.4 - 101 ppm) and copper (Cu) (1.38 -2.24 ppm) were adequate during the dry and the rainy seasons. However, magnesium (Mg) (0.99 - 1.57 me /100g) was deficient in both seasons. Pasture K (2.05 - 2.67%), Na (0.21- 0.23%) and Fe (154 - 190 ppm) were adequate whereas Mg (0.15 -0.17%) and Cu (2.53 - 4.57 ppm) were inadequate in the sampled periods. In an attempt to quantify the requirement for supplementation of Ca, P and Zn forty eight dairy cows in their first, second and third parity were allocated to eight groups, comprising six cows based on breed, parity, stage of lactation and milk yield. Group 1 was control group receiving no mineral supplement; group 2 (Ca) received 10 g of Ca in the form of calcium carbonate (CaCCh); group 3 (P), received 8 g of P in the form of sodium monophosphate (Na2HPC>4.2H2O) and group 4 (Zn) received 400 mg of Zn in the form of zinc oxide (ZnO). The rest of the groups received a combination of Ca and P or Zn or both. Animals were drenched with the minerals daily as of May 1997 to March 1999. Performance was evaluated in terms of cow’s health status, milk yield and reproductive performance and by measurement of blood parameters and metabolites which affect health, energy and protein balance before supplementation started and thereafter at every two month intervals. Significant differences (P< 0.05) were observed between groups in terms of performance. Low plasma Ca, Pi and Zn were more prevalent in the dry season (P < 0.05) especially in the month of July and during calving period in the month of March. None of the Ca, P and Zn formulations were able to rectify the low plasma Ca observed during these periods, however, Ca supplementation in the form of CaCCh. improved tissue P and Zn status. Diy season supplementation with concentrates, hay and fresh forage improved plasma Ca, Pi and Zn concentrations. Cows supplemented with Ca in the form of CaCOj only were superior (P< 0.05) in terms of body condition, less cases of mastitis and anaplasmosis, short calving interval (< 365 days) and high milk yield with high fat and protein content compared to the other groups. General health status, live weight gain, body condition score were affected negatively with P supplementation in the form of Na2HPO4.2H2O alone. Supplementation with Ca/Zn in dairy cows maintained copper balance, however, the other formulations resulted in reduction in copper balance. Supplementation of P/Zn maintained stable levels of blood selenium concentration during both the dry and rainy season. Calcium and Zn supplementation reduced the blood selenium concentration in the rainy season. Since incidences of low plasma Ca, Pi and Zn occurred during the dry season, supplementation with concentrate, hay and fresh forage during the dry season should be encouraged to the farmer and other farmers with similar problems for better metabolism of Ca, P and Zn. However caution should be taken with type and the amount of Ca, P and Zn fed to the animals to avoid interactions between these elements other minerals like Cu and Se. Since P requirements for tropical grazing cattle is not known with certainty, further research on P requirements in grazing crossbred cows is recommended. Magnesium and Cu were inadequate in forage, supplementation of these minerals in the diet was recommended. The effects of Ca, P and Zn supplementation on Cu and Sc balance need more research in order to quantify the effects and understand the mineral interaction mechanisms involved. | en_US |
| dc.description.sponsorship | Danish International Development Agency (DANIDA) through SUA/MU/RVAU Enreca Project | en_US |
| dc.identifier.uri | http://www.suaire.sua.ac.tz/handle/123456789/5314 | |
| dc.language.iso | en | en_US |
| dc.publisher | Sokoine University of Agriculture | en_US |
| dc.subject | Dairy cattle-minerals | en_US |
| dc.title | Performance of grazing crossbred cattle supplemented with minerals: calcium, phosphorus and zinc | en_US |
| dc.type | Thesis | en_US |