Laserfiche WebLink
Mass Balance of Nitrogen Loading <br /> Nitrate loading calculations for properties: <br /> Definition:Au is the abbreviation for animal unit. One animal unit represents 1000 lbs. of body weight. <br /> Nitrogen content of manure from dairy cattle: <br /> Classification of cow: Lbs. N per Au <br /> Lactating cows . 56 lbs. <br /> Dry cows& Bred heifer .45 lbs. <br /> Heifers .40 lbs. <br /> Calves .40 lbs. <br /> Baby calves .40 lbs. <br /> Animal units for typical Holstein dairy cattle, generally accepted by the State Water Quality Control Board: <br /> Lactating cow 1.4 Au's <br /> Dry cow/breed heifer 1.2 Au's <br /> Heifer(1 yr.-bred) 1.1 Au's <br /> Calves(3 mo.- 1 yr.) 5 Au's <br /> Baby calves .25 Au's <br /> Nitrogen Production Calculations- Whole Herd <br /> Projected animal units: Animals A.U.'s each A.U.'s <br /> Lactating cows 1600 1.4 2240 <br /> Dry cows and bred heifers 1106 1.2 1327 <br /> Heifers(1 yr.-breeding) 282 1.1 310 <br /> Calves 845 0.5 423 <br /> Baby calves 282 0.25 70 <br /> Totals 4114 Head 4370 A.U.'s <br /> Nitrogen Production- By Housing Style <br /> Cattle in Freestall and Flushed Concrete Lanes <br /> Type of Animal A.U.'s Ib of N/day N/day <br /> Lactating cows 2,240 0.56 1,254 <br /> Dry cows and bred heifers 0 0.45 0 <br /> Heifers(1 yr.-breeding) 0 0.45 0 <br /> Calves 0 0.45 0 <br /> Baby calves 0 0.45 0 <br /> Total lbs. N per day before losses, for housing style 1,254 <br /> Cattle in Corrals and Flushed Feed Lanes <br /> Lactating cows 0 0.56 0 <br /> Dry cows and bred heifers 1,327 0.45 597 <br /> Heifers(1 yr.-breeding) 310 0.45 140 <br /> Calves 423 0.45 190 <br /> Baby calves 282 0.45 127 <br /> Total 2,342 <br /> Total lbs. N per day before losses,for housing style 1,054 <br /> r <br /> 0 <br /> - o <br /> a <br /> u <br /> U <br /> M <br /> W <br />