Abstract
The study objective was to examine the effects of feeding growing pigs in-shell hazelnuts (Corylus spp). Barrows (n = 36; 58.0 ± 0.73 kg body weight) were sorted into pens (6 pigs/pen; 4.05 m2/pig) across two study replicates. Pens were randomly assigned (n = 3 pens/treatment/replicate) to receive a balanced corn-soybean meal diet (control) or a diet diluted with in-shell hazelnuts (HAZEL; 90% control and 10% hazelnuts). Hazelnuts were pulverized using a roller mill before incorporation into the diet. Composition of the hazelnuts was 7.11% CP, 19.84% crude fat, and 53.32% ADF; C18:1 accounted for 74.93% of the total fat. Pigs were individually weighed every 28 days and feed disappearance by pen was recorded. Within replicate, all pigs were harvested on the same day after either 68 or 69 days of feeding. Two chops (last-rib location; 2.54 cm thick) were collected from each carcass to assess pork quality. One cube (2.54 cm3) of fat was removed from half of the chops (1 sample/pig) and analyzed for fatty acid profile. The R software (v. 4.0.2) package afex (v. 0.28) was used for statistical analysis by GLM (ADG, ADFI, G:F) or mixed models with subsampling (carcass traits and fatty acids). All models included fixed effects of treatment, replicate, and their interaction; mixed models included the random effect of pen and P-values were determined by parametric bootstrapping. Control pigs grew 6% more efficiently than HAZEL pigs (P = 0.03), but ADG and ADFI were not affected by treatment (P > 0.05). Depth of backfat, hot carcass weight, chop color, intramuscular fat, and pH were not impacted by treatment (P > 0.05). Fat from HAZEL pigs had more C18:1 and less C16:0 (P = 0.01) than control pigs. Supplementation of hazelnuts to pigs may alter pork fat composition.
Keywords: pigs, hazelnuts, fatty acids