2008 Savremena poljoprivreda 57 1-2.indd - Poljoprivredni fakultet ...

144
mg/g bone ash and for the phosphorus content 185.5 mg/g bone ash in LE group,
while the values for control group were 366.5 mg/g and 178.3 mg/g of bone ash,
respectively.
Key words: boron, bones, broiler, performance
INTRODUCTION
The functional role provided by boron within the animal body has been more and
more discussed, especially with regards to the prevention of demineralization and bone
mass losses caused by the favoring of vitamin D 3 utilization (Merian et al., 2004; NRC,
1980, 1994). Because boron may become a common nutritional supplement in animal
feed, too, we have proposed to establish the dose from which the microelement does not
have negative effects anymore and may intervene in a bioproductive way. So, we have tested
decreasing levels of boron in broiler feed, beginning with the dose of 300 mg/kg combined
fodder and up to 20 mg B/kg NC and the results are presented in this paper work.
MATERIAL AND METHOD
As boron source, we have used a phosphatic composition with low-density boron which
has been proposed for patenting and which belongs to the ternary system P O -B O -
2 5 2 3
Na O (Drinceanu et al., 2006). Within the production process of this product, we have
2
melted a mixture of raw matter including sodium tripolyphosphate, diammonium phosphate
and boracic acid in a bakehouse with continuous functioning at temperatures between
850 and 950°C. Then the fused mass is chilled in water and then it is warmed within a
dryer at temperatures of 200–250°C, when the phosphatic glass with boron expands, leading
to a product with a density of 200 g/dm3 . The phosphatic composition with low-density
boron is incorporated as granted within the vitamin-mineral premixes in a proportion
of 0.4-2%. In order to establish the productive effect of this product, we have constituted
2 groups of broilers, namely LM including 20 broilers fed with combined fodder according
to the requirements of this hybrid (Ross 308) and LE, also with 20 broilers, but within
the combined fodder we have incorporated phosphatic glass in a quantity of 0.4 g/kg
CF, assuring a level of 20 mg B/kg NC.
RESULTS AND DISCUSSIONS
In order to make evident the nutritive and productive effect of boron at the level of 20
mg B/kg CF in the two broiler groups, we have established the following indicators:
– feed ingestion;
– body gain;
– specifi c intake at 21 days and 42 days;
–
Ca and P content within the tibia.
The results achieved are presented in Table 1.