Study of nutritional strategies to improve rearing, quarantine, and adaptation periods of replacement gilts
- Autores: Lluís Fabà
- Directores de la Tesis: Josep Gasa Gasó (dir. tes.), David Solà Oriol (codir. tes.)
- Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2019
- Idioma: español
- Tribunal Calificador de la Tesis: Gonzalo González Mateos (presid.), Joaquim Segalés Coma (secret.), Pieter Langendijk (voc.)
- Programa de doctorado: Programa de Doctorado en Producción Animal por la Universidad Autónoma de Barcelona
- Materias:
- Enlaces
- Tesis en acceso abierto en: TESEO
- Resumen
The present PhD thesis hypothesized reductions of lameness, osteochondrosis (OC) and claw lesions due to dietary treatments (nutrients with specific roles in bone and claw development) fed to rearing gilts, and (or) by reducing growth rates. Similarly, additional nutrients (acting over the immune system) could enhance performance under hostile Porcine Reproductive and Respiratory Syndrome virus (PRRSv) environment. In Chapter III, 360 young gilts were reared under dietary Con (control); TM (trace minerals as additional 10, 20 and 50 mg/kg of copper, manganese, and zinc, respectively); Met (102% methionine:lysine); and TM plus Met; to evaluate lameness, performance, and claw lesions (to first parity). Gilt lameness (7.8%) reduced (P<0.05) average daily gain (ADG). Gilt lameness was highest (14.8%, P<0.01) for Con compared with TM (2.0%), Met (5.3%), or TM plus Met (6.5%). On the sow farm, overall lameness increased to 21%. Con females showed highest (P < 0.01) prevalence of lameness (20.8%) than TM (6.5%), Met (11.1%), or TM plus Met (7.6%) at weaning. In Chapter IV, a subsample of heavy gilts (10/dietary treatment) finishing rearing (Chapter III) were classified for final ADG as low (838 ± 36.3 g) or high (922 ± 31.1 g) and used to study gait, OC, tibia strength, metacarpal mineralization, and using computerized tomography, whole bone density (scaled by density degree). Dietary treatment TM increased (P<0.05) 0.75 mm the tibia length vs. Con and TM plus Met, and the whole bone density vs. Con and Met. Proportion of highly dense bone increased in TM and Met vs. Con (P<0.05). Tibia strength and metacarpal ash increased (P<0.05) for TM compared with Con. Total score of gross OC lesions was lower in TM plus Met compared with Con (P<0.05). However, growth classification showed no general effects. In Chapter V, 240 gilts were used under 2×2 factorial arrangement with factors: 1) control or TM plus Met (as Chapter III); and 2) standard (requirement) lysine (Lys) or low Lys (19% lower); to evaluate lameness, performance, and claw lesions (up to first parity). Low Lys did not affect feed intake but reduced 6.35% ADG and 3.80% the final BW compared with standard (P<0.001). Gilt lameness (7.9%) did not affect growth (P>0.05), and was not affected by dietary treatments. Sow farm lameness and claw lesions were unaffected by dietary treatments. In Chapter VI, 100 PRRSv naïve gilts were distributed to 4 dietary treatments as Con (control), VitA (vitamin A 18,000 IU/kg), TT (0.34 tryptophan:Lys and 0.80 threonine:Lys), and Ω3 (10 g/kg fish oil); which were exposed to PRRSv at day 11 post-allotment; and a fifth group as Sham (Con in separate facility); to evaluate growth, viremia, and acute immunity. A 100% viremia was observed at day 2 post-infection (dpi). Positive gilts 9 dpi were 7.8 kg lighter than Sham. Gain 9 dpi increased in TT vs. Ω3 (P=0.036) and Con (P=0.054). Gain 9-to-15 dpi increased (P=0.041) in TT vs. Con. Viremia was not modulated through diet, but IFNα and IL8 increased acute for VitA and IL6 for TT, yet, without performance effects. In conclusion, TM or Met enhanced bone, combined reduced OC, but lameness resulted controversial. Reducing 19% Lys reduced growth (6.35%) but not lameness, nor combined with TM plus Met. The TM and Met during growth could not overcome sow farm lameness and claw lesions. Feeding TT before and during PRRS marginally improved early weight gain compared with Con and Ω3.
