Effects of Low ω6:ω3 Ratio in Sow Diet and Seaweed Supplement in Piglet Diet on Performance, Colostrum and Milk Fatty Acid Profiles, and Oxidative Status

Abstract

The ratio of omega-6 (ω6) to omega-3 (ω3) polyunsaturated fatty acids (PUFAs) in the diet contributes to animal health and performance modulations because they have mostly opposite physiological functions. Increasing ω3 PUFAs content in the maternal diet can stimulate antioxidative capacity in sow and piglets; however, the optimal ratio of ω6 and ω3 PUFAs in the sow diet is still under discussion. Rich sources of bioactive constituents such as brown seaweed are an excellent supplementation to promote animal health and antioxidant status. However, the knowledge of the effects of this compound, specifically in post-weaning piglets, is still limited. Moreover, the combined effect of a low ω6:ω3 PUFAs ratio in sow diet and seaweed supplementation in post-weaning piglets' diet has never been studied. This research aims to assess the combined effect of a low ω6:ω3 ratio in sow diets and seaweed supplementation in piglet diets on their growth and oxidative status. We also assessed the impact of a low ω6:ω3 ratio in the maternal diet on reproduction, milk fatty acid (FA) profile, and plasma leptin concentration. Two sow diets (n = 8 each) contained either a control ratio (CR, 13:1 during gestation, starting from day 28 (G28) and 10:1 during lactation) or a low ratio (LR, 4:1 from G28 until the end of lactation (L-End)) of ω6:ω3 FA by adding soybean oil or linseed oil, respectively. Reproductive performance was evaluated. Colostrum and milk at lactation day 7 (L7) and L-End were collected to analyze FA profile. Plasma was collected at G28, G79, G108, L7, L14, and L-End for determination of leptin and oxidative status. At weaning, 20 male piglets were selected per sow group to form 4 diet treatments (n = 10 each), which were supplemented with or without 4 g/kg seaweed. Recording of growth performance and collection of blood were performed at days 0, 7, 15, and 21 of post-weaning for oxidative status. LR diet increased (p < 0.05) the survival rate of piglets at weaning, and individual and litter weight gains. Colostrum and milk at L7 and L-End had lower (p < 0.05) ω6:ω3 ratio in LR sows. Interaction between dietary treatments on sows and piglets was revealed for all examined growth parameters at most time points (p < 0.05). LR diet did not affect plasma leptin levels and oxidative status. These findings suggest that the seaweed supplement during post-weaning could not improve growth rate and oxidative status of piglets born from mothers receiving a low dietary ω6:ω3 ratio (4:1) during gestation and lactation. However, this low ratio was beneficial for weaning survival rate, sucking piglets' weight gain, and ω3 enrichment in colostrum and milk.

Keywords: piglet; seaweed; sow; ω6:ω3 polyunsaturated fatty acids.

Figure 1

Low dietary ω6:ω3 ratio in sow improves body weight gain of neonatal piglets. Sows were fed diets with ω6:ω3 ratio = 13:1 during gestation, starting from day 28 (G28) and 10:1 during lactation (CR) or ω6:ω3 ratio = 4:1 from G28 until the end of lactation (LR). A1: Litter weight development during neonatal period. A2: Piglet weight development. A3: Litter weight gain per subperiod. A4: Piglet weight gain per subperiod. Data are LSM ± SE, n = 6 for CR group and n = 8 for LR group.

Figure 2

Fatty acid (FA) profile (g/100 g FAs) of colostrum and milk collected on day 7 (L7) and the end of lactation (L-End) from sows fed diets included ω6:ω3 ratio = 13:1 during gestation, starting from day 28 (G28) and 10:1 during lactation (CR) or ω6:ω3 ratio = 4:1 from G28 until L-End (LR). A1: SFA, MUFA and PUFA concentrations. A2: Individual concentrations of ω6 PUFAs. A3: Individual concentrations of ω3 PUFAs. A4: ω6:ω3 ratio. SFA = Saturated FAs, MUFA = Monounsaturated FAs, PUFA = Polyunsaturated FAs, TLA = Linoleaidic acid, LA = Linoleic acid, GLA = γ-linolenic acid, DGLA = dihomo-γ-linolenic acid, AA = Arachidonic acid, ALA = α-linolenic acid, ETA = Eicosatrienoic acid, EPA = Eicosapentaenoic acid, DHA = Docosahexaenoic acid. Data are LSM ± SE; n = 5, 5 and 6 for CR group and 6, 7, 8 for LR group for colostrum, milk collected at L7 and L-End. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.

Figure 2

Fatty acid (FA) profile (g/100 g FAs) of colostrum and milk collected on day 7 (L7) and the end of lactation (L-End) from sows fed diets included ω6:ω3 ratio = 13:1 during gestation, starting from day 28 (G28) and 10:1 during lactation (CR) or ω6:ω3 ratio = 4:1 from G28 until L-End (LR). A1: SFA, MUFA and PUFA concentrations. A2: Individual concentrations of ω6 PUFAs. A3: Individual concentrations of ω3 PUFAs. A4: ω6:ω3 ratio. SFA = Saturated FAs, MUFA = Monounsaturated FAs, PUFA = Polyunsaturated FAs, TLA = Linoleaidic acid, LA = Linoleic acid, GLA = γ-linolenic acid, DGLA = dihomo-γ-linolenic acid, AA = Arachidonic acid, ALA = α-linolenic acid, ETA = Eicosatrienoic acid, EPA = Eicosapentaenoic acid, DHA = Docosahexaenoic acid. Data are LSM ± SE; n = 5, 5 and 6 for CR group and 6, 7, 8 for LR group for colostrum, milk collected at L7 and L-End. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.

Figure 3

Concentrations of leptin and oxidative stress indicators of sow plasma during gestation and lactation periods. A1: Leptin; A2: The derivatives of reactive oxygen metabolites (d-ROMs); A3, A4: Advanced oxidation products of proteins (AOPP); A5: Thiobarbituric acid reactive substances (TBARS); A6: Ferric reducing ability of plasma (FRAP). CR: sow diet with ω6:ω3 ratio = 13:1 during gestation, starting from day 28 (G28) and 10:1 during lactation; LR: sow diet with ω6:ω3 ratio = 4:1 from G28 until L-End. G: days of gestation, L: days of lactation. Data are LSM ± SE; n = 6–8 sows per group. ** p < 0.01.

Figure 4

Concentrations of oxidative stress indicators of piglet plasma during the post-weaning period. A1: The derivatives of reactive oxygen metabolites (d-ROMs); A2: Advanced oxidation products of proteins (AOPP, µmol/L); A3: AOPP (µmol/g protein); A4: Thiobarbituric acid reactive substances (TBARS); A5: Ferric reducing ability of plasma (FRAP). CRCT: piglets fed no seaweed (SW, Ascophyllum nodosum), which were nursed by sows fed dietary ω6:ω3 ratio = 13:1 during gestation, starting from day 28 (G28) and 10:1 during lactation. CRSW: piglets fed SW, which were nursed by sows fed dietary ω6:ω3 ratio = 13:1 during gestation and 10:1 during lactation. LRCT: piglets fed no SW, which were nursed by sows fed dietary ω6:ω3 ratio = 4:1 from G28 until the end of lactation. LRSW: piglets fed SW, which were nursed by sows fed dietary ω6:ω3 ratio = 4:1 from G28 until the end of lactation. Data are LSM ± SE; n = 10 piglets/group. SD, PD, and SD × PD: effect of sow diet, piglet diet and their interaction between 4 groups at the same sample point.