Abstract :
Eighteen second parity goats were selected for this study and divided in three homogenous
groups of six animals each. Starting from week 2 before the expected kidding date
to week 3 of lactation animals were fed the experimental diets: C, basal transition diet;
PFISH, basal transition diet plus 47 g/day of rumen protected fish oil as source of n-3 fatty
acids; HPALM, basal transition diet plus 47 g/day of hydrogenated palm oil (46.30% C16:0,
40.90% C18:0). Live body weight (LBW), body condition score (BCS), dry matter intake (DMI)
and energy balance were assessed weekly. Milk yield and milk composition were recorded
and analyzed on 4, 7, 15, and 21 days in milk (DIM). Alanine transaminase (ALAT), aspartate
aminotrasferase (ASAT), non esterified fatty acids (NEFA), glucose, -hydroxybutyrate
(BHBA), and cholesterol plasma contents were measured weekly for all the experimental
period. Liver mRNA levels for peroxisome proliferator-activated receptor- (PPARA), acylcoenzyme
A dehydrogenase very long chain (ACADVL), acetyl coenzyme A carboxylase
(ACACA), and carnitine palmitoyl-transferase 1A (CPT 1A) were determined 7 days (±1.43)
before and 21 days after kidding by reverse transcription real time (RT) quantitative PCR (QPCR).
Goats from the three experimental groups experienced negative energy balance after
kidding with higher levels in both HPALM and PFISH than C (P≤0.01) while no differences
were detected among fat supplemented goats. Performance, milk composition, plasma
metabolites and liver enzymes were similar in C, HPALM and PFISH, except for a significant
effect of treatment on milk yield (P≤0.01) in HPALM compared to C goats (3.65 kg/day vs.
2.42 kg/day, P = 0.01) and ALAT content (P≤0.01) in the first 21 DIM in HPALM than C and
PFISH (14.25 IU vs. 17.54 IU and 16.80 IU respectively; P≤0.05). Treatment (P = 0.08), day of
treatment (P = 0.06), and the interaction among treatment and day of treatment (P = 0.08)
showed tendencies to increased plasma NEFA content in HPALM during the post kidding
period respect to PFISH and C. An interaction effect between treatment and day of treatment
was found for PPARA (P = 0.02), CPT1A (P = 0.05), and ACADVL (P = 0.05) mRNA levels.
At 21 days in milk HPALM showed higher values in PPARA mRNA levels than C. mRNA levels
of PPARA, CPT 1A, ACADVL, and ACACA showed trends to increase from 7 days before to 21
days after kidding in HPALM, contrary to PFISH. The present trial shows the effectiveness
of hydrogenated palm oil, as an oil mainly containing C16:0 and C18:0, in enhancing mRNA
expression of PPARA and selected target genes in liver of transition dairy goat