B.V. Avarvarei


B.V. Avarvarei, Elena-Liliana Chelariu, R. Rosca

To concrete the fodders' nutritive value was established multiple regression equations in which the independent variables are connected with their content in raw protein, raw cellulose and ash. For hay, the equations that presents the nutritive value of the fodders expressed in milk nutritive units (UNL), meat nutritive units (UNC) and digestible raw protein (PDIN and PDIE) on a kg of dry matter, were calculated after Demarquilly system. The net energy (EN) of the fodders represents the quantity of energy totally used by animals to maintain the vital functions and for synthesis of different husbandry products. In 2008, on a meadow from Iasi area, at control variant were obtained 0.82 UNL/kg DM and 0.78 UNC/kg DM, and at N64 fertilization these values increased to 0.85 respectively 0.82, and at N128 P72 variant the values were 0.85 UNL/kg DM and 0.81 UNC/kg DM. The quantity of digestible protein at one kilo of DM at control variant was of 72 g in the case of digestible protein based on the energy from the quota (PDIE) and 53 g in the case of digestible protein based on the nitrogen from quota (PDIN). At fertilization with nitrogen fertilizers or with nitrogen on a phosphorous agro-fund, protein increased together with the doses increasing from 78 g PDIE and 62 g PDIN at N64 variant, to 81 g PDIE and 70 g PDIN at N128 P72 variant. To calculate the milk quantities, respectively weight increase, it was taken in consideration that for one litre of milk with 4 % fat are necessary 0.7 UNL, and for a kg weight increase, around 8 UNC. At control variant could be obtained 2027 l milk and 169 kg weight increase, and at N64 variant cu the quantities increased to 3813 l milk and 322 kg weight increase. At fertilization with N128 P72 could be obtained 5186 l milk and 432 kg weight increase, and at the variant with 7 t/ha vinassa + P108 the obtained milk quantity, increases at 5876 l, and the weight increase to 497 kg. The fodders' nutritive value expressed in UNL and UNC increased at the same time with the increasing of the mineral and organic fertilizers doses. Regarding the energetic value it was observed that both milk net energy (ENL) and meat net energy (ENC) recorded increases function of kind and dose of the administrated fertilizers. The number of UNL and UNC recorded at a hectare of permanent meadow was function of the fertilization level. The level of fertilization also, influenced the milk quantities and weight increases.

Key words: Nutritive value, energetic value, fodder, fertilization