Efecto de la inclusión de grasa sobre la performance reproductiva y productiva de cerdas en el sudoeste chaqueño

Abstract

Se evaluó el impacto de la inclusión de grasa sobre los parámetros productivos, reproductivos y hormonales de cerdas y sus camadas, en dos sistemas de producción. Se usaron 60 cerdas (Landrace x Yorkshire), divididas en dos grupos de 30 asignados aleatoriamente a sistemas a campo (SC) e intensivo (SI). Cada grupo se subdividió en tres subgrupos con dietas experimentales D0, D1 y D2, con 0%, 3.5% y 7% de grasa, respectivamente. Se tomaron muestras de sangre en distintas etapas post-destete para medir insulina, glucosa, hormona luteinizante (LH) y ácidos grasos no esterificados (NEFA). Las variables evaluadas incluyeron número de lechones nacidos vivos (LNV), muertos (LNMu), momificados (LNMo), peso al nacimiento (PN), lechones al destete (LD y PD), tasa de supervivencia pre-destete (%SPP), ganancia diaria de peso (GDPV), consumo de alimento (ADFI) y energía (ADEI), variación de peso parto-destete (ΔBW), e intervalo destete-celo (IDC). Se encontró que la inclusión de grasa al 7% mejoró LNV, PN y LNT en el 3° y 4° parto en ambos sistemas. No se encontraron diferencias significativas para LNMu y LNMo. La grasa al 7% también benefició GDPV, LD, PD y %SPP, especialmente en el sistema a campo. Se observó un efecto positivo en ADEI y ADFI y una reducción en ΔBW e IDC en el sistema a campo. Aunque no hubo cambios en glucosa e insulina, la grasa aumentó los niveles de LH y redujo NEFA. En conclusión, la inclusión de grasa mejoró variables productivas y reproductivas en los sistemas estudiados.

The objective of this Thesis was to evaluate the effect of fat inclusion at different levels on productive, reproductive and hormonal parameters of sows and their litters in two production systems and from the Ist to the 4th parity. Sixty sows (Landrace x Yorkshire) were divided into two equals groups and were randomly assigned to two systems: field (SC) and intensive (SD). Within each system, the sows were divided into 3 homogeneous groups and were randomly assigned to experimental diets DO, D1 and D2, corresponding to diets for the gestation and lactation stages with 0, 3.5 and 7% fat, respectively. During gestation, the diets were fed at a rate of 2.5 kg/day/animal, while during lactation the feeding was ad libitum. Blood samples were taken from the external jugular vein on the day of weaning and on days 3, 5 and 7 thereafter from all SI sows for determination of serum levels of insulin, glucose, luteinizing hormone and non-esterified fatty acids (NEFA). The productive and reproductive variables studied were the number of piglets born alive (LNV), dead (LNMu) and mummified (LNMo), litter total size (LNT), birth weight (BW), number (LD) and weight (PD) of piglets at weaning, pre-weaning survival rate (%SPP) and average daily weight gain of piglets at birth-weaning (GDPV), average daily feed intake (ADFI) and energy (ADEI) of sows during lactation, farrow-to-weaning weight variation (ABW) and wean-to-estrus interval (IDC). Mean, maximum, minimum temperatures and relative humidity in both systems were also recorded throughout the experiment. Statistical analyses were performed with the MLM module ofINFOSTAT software. The inclusion of 7% fat improved the number of LNV (p < 0.05), and LNT (p < 0.05) in the 3rd and 4th parity for both systems. No significant differences were detected for LNMo and LNMu (p > 0.05) between systems or diets. No significant effect of parity number was detected for GDPV, LD, PD, ADFI, ADEI, ABW or IDC variables (p > 0.05). However, the inclusion of 7% of fat had positive effects on GDPV (p < 0.05), LD (p < 0.05), PD (p < 0.05) and %SPP (p < 0.05) mainly in the field system. Also, a positive linear response to supplementation was observed in both systems for ADET and ADFI variables (p < 0.05). The ABW was lower in sows consuming the D2 in the field system (p < 0.05) and the ADFI was significantly lower in sows with consuming the D2 in both systems (p < 0.05). Fat inclusion did not alter serum glucose and insulin levels (p > 0.05) but did alter LH levels (p < 0.05) and decreased serum NEFA concentration (p < 0.05). Based on these results, it can be concluded that the inclusion of fat has improved the productive and reproductive variables of sows and their litters in the production systems studied in the southwestern Chaco region.