| Autor(es): |
dos Santos, Luan Sousa
[1]
;
Pomar, Candido
[2]
;
Reis Furtado Campos, Paulo Henrique
[3]
;
da Silva, Welex Candido
[1]
;
Gobi, Jaqueline de Paula
[1]
;
Veira, Alini Mari
[1]
;
Fraga, Alicia Zem
[1]
;
Hauschild, Luciano
[1]
Número total de Autores: 8
|
| Afiliação do(s) autor(es): | [1] Sao Paulo State Univ Unesp, Sch Agr & Vet Sci, BR-14884900 Jaboticabal - Brazil
[2] Agr & Agri Food Canada, Dairy & Swine Res & Dev Ctr, Sherbrooke, PQ J1M 0C8 - Canada
[3] Univ Fed Vicosa, Dept Anim Sci, BR-36570900 Vicosa, MG - Brazil
Número total de Afiliações: 3
|
This study evaluated the responses of individual daily precision (IPF) and conventional 2-phase (CON) feeding systems (FS) in terms of pig growth performance, nutrient balance, serum parameters, and meal patterns of growing pigs reared under thermoneutral (TN: 23 C) and heat stress (high temperature {[}HT]: 30 C) conditions. The animals in each treatment were assigned on the basis of equal BW to the experimental treatments (12 animals per treatment at 41.0 4.87 kg of BW). The experiment lasted 55 d (phase 1 from days 0 to 27 and phase 2 from days 28 to 55). Pigs fed CON received within each phase a constant blend of diets with high and low nutrient density supplying the estimated nutrient requirements of the group, whereas the IPF pigs received daily a personalized blend providing the estimated amount of nutrients according to individual feed intake and body weight information. Body mineral content, and lean and fat masses were assessed through dual-energy X-ray absorptiometry at the beginning and end of each phase. Data were analyzed using a linear mixed-effect model, with fixed effects of the FS, temperature (AT), and the 2-way interaction between FS and AT and random effects of blocks. In relation to CON pigs, IPF pigs reduced (P < 0.05) Lys (19%), protein (16%), and P (14%) intake without impairing (P > 0.05) body composition. Nitrogen excretion was 24% lower (P < 0.05) in IPF pigs than in CON pigs; however, both groups had similar N retention efficiency thoroughly the trial. Amount of time feeding, feed intake rate, and feed intake per meal were 15% lower (I' < 0.05) in pigs raised under HT than under TN conditions. During the phase 2, only amount of time feeding, feed intake rate, and feed intake per meal were decreased (P < 0.05) in pigs under HT conditions during nocturnal (2000 to 0500 h) and diurnal (0501 to 1959 h) periods. Haptoglobin levels were affected by the AT, showing an increase of 70% and 43% in HT at 28 and 55 d of the experiment, respectively Pigs raised under HT conditions had 10% lower (I' < 0.05) serum albumin concentration at day 55 than those under TN conditions. For serum urea concentrations, IPF pigs had 28% lower (P < 0.01) levels than CON pigs. Even though HT conditions considerably reduced growth performance and activated inflammatory responses in growing pigs, IPF was not able to rescue performance during HT; however, it was equally effective at improving nutrient utilization and maintaining body composition in HT and TN conditions. (AU) |