Effect of parity number, year and season farrowing on reproductive performance in Large White pigs

The increasing risks of environmental pollution by nitrogen of pig farms wastewater compel researchers to explore the possibility to reduce protein level in diets for growing-finishing pigs. The objective of this work was to evaluate the effect of low-protein diets balanced by the bioavailable essential amino acids, on the growth rate, efficiency of nutrient utilization and nitrogen excretion with urine and feces in growing-finishing pigs. The experiment was performed on three groups of Landras × Large White piglets, 12 piglets each, and included two periods, growing and fattening. Piglets in group I (control) were fed the complete feed with following levels of components: for growing period: crude protein and metabolizable energy - 172 g, 12.56 MJ and limiting amino acids, g/kg feed: lysine - 7.7 (true available for absorption in the intestine - 5 88), threonine - 4.83 (- 3.75), methionine 4.73 (- 3.82), and in the fattening period - 153 g, 12.34 MJ, 5.75 (- 5,08), 4.5, (- 3.49), 3.06, (- 2.47) g/kg respectively. In group II, the crude protein level was reduced to 151 g/kg in growing period and to 142 g/kg in fattening periods, and in group III - to 134 and 130 g/kg respectively. The content of true available lysine, methionine and threonine in the diets of groups II and III in both periods was adjusted to respective values in the control group by the addition of synthetic amino acids. The live weight gain during the finishing period in І and ІІ groups was approximately the same (40.62 and 40.28 kg, 752 and 746 g, respectively); in group ІІІ it was by 6.2% less than in control group. The efficiency of using feed nitrogen in group II was higher by 6% compared with group I. Nitrogen excretion in II and III groups was reduced by 24.4 and 33.8% in urine and by 20.7 и 36.0% in feces respectively. The results of this study indicate that reducing the level of crude protein in the diet for growing-finishing pigs with the addition of synthetic essential amino acids, reduces the flow of nitrogen into the environment with urine and feces, without adversely affecting productive performance.    Key words: Environmental pollution by nitrogen; Growing-finishing pigs; Nitrogen of pig excreta; Low-protein diets; Supplements of essential amino acids   References Fastinger, N.D., Mahan, D.C. (2006). Determination of the ileal amino acid and energy digestibilities of corn distillers dried grains with solubles using grower-finisher pigs. Journal of Animal Science, 84, 1722-1728. Figueroa, J.L., Lewis, A.J., Miller, P.S., Fischer, R.L., Gomez, R.S., Diedrichsen, R.M. (2002). Nitrogen metabolism and growth performance of gilts fed standard corn-soybean meal diets or low-crude protein, amino acid-supplemented diets. Journal of Animal Science, 80, 2911-2919. Gomez, R.S., Lewis, A.J., Miller, P.S., Chen, H.-Y. (2002). Growth performance, diet apparent digestibility, and plasma metabolite concentrations of barrows fed corn - soybean meal diets or low-protein, amino acid supplemented diets at different feeding levels. Journal of Animal Science, 80, 644-653. Kendall, D. C., Richert, B. T., Sutton, A. L., Frank, J. W., De Camp, S. A., Bowers, K. A., Kelly, D., Cobb, M. (1999). Effects of fiber addition (10% soybean hulls) to a reduced crude protein diet supplemented with synthetic amino acids verses a standard commercial diet on pig performance, pit composition, odor and ammonia levels in swine buildings. Journal of Animal Science, 77(Suppl.1), 176-184.   Liu, H., Allee, G.L., Berkemeyer, J.J., Touchette, K.J., Spencer, J.D., Kim, I.B. (1999). Effect of reducing protein level and adding amino acids on growth performance and carcass characteristics of finishing pigs. Journal of Animal Science, 77(Suppl. 1), 69-79.   Niyazov, N.S.-A., Kal’nitskii, B.D. (2014). Productivity and nitrogen metabolism in pigs fed low protein diets with different levels of essential amino acids. Reports of the Russian Academy of Agricultural Sciences, 5, 60-63 (in Russian) Otto, E.R., Yokoyama, M., Ku, P.K., Ames, N.K., Trottier, N.L. (2003). Nitrogen balance and ileal amino acid digestibility in growing pigs fed diets reduced in protein concentration. Journal of Animal Science, 81, 1743-1753.  Ryadchikov, V.G. (2006). Norms and diets for feeding farm animals: methodology, errors, perspectives. Agricultural Biology, 4, 6881 (In Russian). Stein. H.H., Seve, B., Fuller, M.F. et al. (2007). Invited review: Amino acid bioavailability and digestibility in pig feed ingredients: Terminology and application. Journal of Animal Science, 85, 172-180. Zervas, S., Zijlstra, R.T. (2000). Effects of dietary protein and oat hull fiber on nitrogen excretion patterns and postprandial plasma urea profiles in growing pigs. Journal of Animal Science, 80, 3238-3246