The goal of the present study was to evaluate the metabolic and immune response of peripartal
dairy goats to dietary supplementation with fish oil or stearic acid. 15 multiparous alpine dairy
goats were involved in the trial. Starting from the last week of gestation until 3 weeks after
kidding date the experimental diets, based on alfalfa and mix hays and a concentrate mix, were
added either with protected fish oil (FO) or with stearic acid (ST). Feed intake, body weight,
energy balance, milk production and composition were measured weekly. Adipose tissue
biopsies were performed on day -7, 7 and 21 relative to kidding date and samples were
immediately fixed in formalin, paraffin embedded and Hematoxilin Eosin stained. The results
discussed in the present work are relative to a subsample of 8 goats, representative of the two
experimental groups. Hematological and histological data were analyzed by a Generalized
Estimating Equation (GEE) in IBM SPSS 19.0 was used. Production parameters were analyzed
by a MIXED repeated model in SAS 9.2. No differences were observed between FO and ST in
milk production, BCS, weight, dry matter intake and milk components except for a higher milk
protein percentage in the 7 to 21 d period for ST. BHB serum content was higher in ST overall
the experiment, whereas NEFA and ALAT serum content were higher at day 7 in FO compared
to ST (P < 0.08). ALAT was higher also at day 21 in FO. Treatment had no effect on blood
cellular component except for WBC in FO group, where a significant decrease at 7 d was
observed. WBC and HCM parameters were in the physiological range for dairy goats during
transition period. Histologic adipose tissue analysis revealed a significant decreased adipocytes
surface between -7 and 21 d in ST, whereas in FO the adipocyte surface reduction was related to
the -7 to 7 d interval reaching a plateau until day 21. The EB pattern and the NEFA serum
content at 7d in particular for FO are well correlated with histologic observations indicating
goats were using fat depots to cope their negative energy balance. NEFA levels did not confirm
the histological evidence at day 21 for ST suggesting a possible different action on
subcutaneous adipose tissue during time. Results suggest a modulation in lipid storage
management during peripartal negative energy balance by saturated vs. unsaturated dietary fatty
acid supplementation that did not affect production levels of goats