Alterations in Essential Fatty Acids, Immunoglobulins (IgA, IgG, and IgM), and Enteric Methane Emission in Primiparous Sows Fed Hemp Seed Oil and Their Offspring Response

SIMPLE SUMMARY: One of the main problems in the sows’ farrowing sector is related to the health of their piglets and environmental impact as well. Hemp seed oil, characterised by an excellent polyunsaturated fatty acid profile and a favourable n-6:n-3 ratio, can contribute positively to enriching sow diets in essential fatty acids that are beneficial to health. Our study highlights that a higher n-3 fatty acids intake by sows fed diet-based hemp seed oil determines a fluctuation in the plasma concentration of major sows and their offspring’s immune markers (IgA, IgG, IgM). The suckling piglets receive significant Ig and essential fatty acids via maternal secretion. A milk intake with an ameliorated n-3 polyunsaturated fatty acid composition reduces the diarrhoea frequency of piglets. Enteric methane, known as a greenhouse gas indicator, can be impacted positively as well. New potential predictors for enteric methane, such as feed intake, n-6:n-3 ratio, linolenic fatty acids, and lean meat can be considered. Throughout the lactation period, milk fatty acids and plasma immunoglobulins fluctuate significantly. ABSTRACT: This study shows the effects of dietary hemp seed oil on the milk composition, blood immunoglobulins (Ig), and enteric methane (E-CH(4)) production of primiparous sows, and their offspring’s response at three time points. A bifactorial experiment was conducted for 21 days (d) on 18 primiparous sows (195 ± 3 days old). The sows were fed two diets: (i) a control diet (SO) based on soybean oil (1.6%), with an 18.82 n-6:n-3 polyunsaturated fatty acids (PUFA) ratio; (ii) an experimental diet (HO) based on hemp seed oil (1.6%), with a 9.14 n-6:n-3 PUFA ratio. The milk contained an elevated level of linoleic acids (LA), n-3 FA, and especially alpha-linolenic acids (ALA), while the n-6:n-3 ratio declined using hemp oil. The Ig concentration was higher in colostrum than in milk. In the first few hours, the IgG in the plasma of piglets was more than double that of maternal plasma IgG (+2.39 times). A period effect (p < 0.0001) for IgG concentration in the plasma of piglets was recorded (40% at 10 d, respectively 73% lower at 21 d than 12 h after parturition). However, the sow diet did not affect Ig (p > 0.05). The frequency of diarrhoea declined after about 7 d. The value of the rate of diarrhoea was 6.2% lower in the PHO group. We found a 4.5% decline in E-CH(4) in the HO group. Applying multiple linear regression, feed intake, n-6:n-3 ratio, ALA, and lean meat were potential indicators in estimating E-CH(4). In conclusion, sow dietary hemp seed oil increased lean meat %, milk EFA, and milk IgM. Significant changes in the other dependent variables of interest (body weight, plasma Igs in sows and offspring, E-CH(4) production) were not recorded. There was reduced diarrhoea which shows that EFA could play a therapeutic role in the incidence of diarrhoea and in lowering of E-CH(4) emission in sows and progeny. All dependent variables were significantly altered at different time points, except for fat concentration in milk and sow plasma IgG.