Lysine requirements for Escherichia coli lipopolysaccharide-challenged growing pigs

• Ano de defesa: 2020
• Autor(a) principal: Barcellos, Joyce
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Zootecnia
• Palavras-chave em Português: Lisina na nutrição animal; Suínos - Crescimento; Inflamação; Crescimento exponencial; Nitrogênio na nutrição animal; Exigências Nutricionais dos Animais
• Link de acesso: https://locus.ufv.br//handle/123456789/29398

To evaluate the effect of an E. coli lipopolysaccharide (LPS) challenge on the digestible lysine (Lys) requirement for growing pigs using the model established at the University of Goettingen, a nitrogen balance assay was performed. Seventy-two castrated male pigs [19 ± 1.49 kg body weight (BW)] were allocated in a 2 x 6 factorial design composed by two immune activation states (control and LPS-challenged) and 6 dietary treatments with Nitrogen (N) levels (0.94; 1.69; 2.09, 3.04, 3.23, and 3.97 % N, as fed), with Lys being limiting in the dietary levels, with six replicates and one pig per unit. The challenge consisted of an initial LPS dose of 30 μg/kg BW via intramuscular (IM) injection and a subsequent dose of 33.6 μg/kg BW after 48 h. The experimental period lasted 11 days composed by a 7-day adaptation period, and a subsequent 4-day collection period which N intake (NI), N excretion (NEX), and N deposition (ND) evaluated. Inflammatory mediators and rectal temperature (RT) were assessed during each 4-d collection period. A 3-way interaction (N levels × LPS-challenged × time) for IgG (P <0.05) was observed. Additionally, 2-way interactions (LPS-challenge × time) were verified for IgA, ceruloplasmin, transferrin, haptoglobin, α-1-acid glycoprotein (α1AGp), total protein, RT, and (N levels × time) for transferrin, albumin, haptoglobin, total protein and RT (P < 0.05). LPS- challenged pigs showed lower (P < 0.05) feed intake. A 2-way interaction (N levels × LPS- challenged) was observed (P < 0.05) for NI, NEX and ND, with a dose-response evident (P < 0.05). LPS-challenged pigs showed lower NI and ND at 2.09 % of N and 1.69 to 3.97 % of N (P < 0.05), respectively and higher NEX at 3.23 % of N (P < 0.05). The parameters obtained by the nonlinear model (N maintenance requirement, NMR and theoretical maximum N deposition, ND max T) were 152.9 and 197.1 mg/BW kg0.75 /d for NMR, and 3.524,7 and 2.077,8 mg/BW kg0.75 /d for ND max T, in the control and LPS-challenged groups, respectively. The estimated digestible Lys requirement were 1994.83 and 949.16 mg / BW Kg0.75 / d, respectively, for control and LPS-challenged pigs. The daily digestible Lys intake required to achieve 0.68 and 0.54 times the NR max T value were 18.12 and 8.62 g/ d, respectively, and the optimal dietary digestible Lys concentration may change depending in the feed intake levels. Based on the derived models parameters obtain in N balance trial with lower cost and time, it was possible to differentiate the digestible Lys requirement for swine under the challenging conditions. Keywords: Exponential model. Growing pigs. Inflammatory response. Lysine requirement. Nitrogen balance.