Effect of Feeding a Low Level of Encapsulated Fish Oil to Dairy Goats on Milk Yield,Composition, and Fatty Acid Profile

Contradictory results have been found in the response of dairy goats to the supplementation of fish oil in their diet to improve the n-3 polyunsaturated fatty acids (PUFA) in milk. The responses to the inclusion of fish oil in the diet of ruminants either induced milk fat depression, increased milk fat content, and/or negatively impacted milk yield. The objective of this study was to determine whether including a low dose of encapsulated fish oil in the diet of goats can modify yield, milk composition, and the fatty acid (FA) profile of milk. Ten Alpine goats were divided into two homogeneous subgroups and assigned to either the control or experimental diet. The control animals received the basal diet without supplementation of fish oil, whereas the experimental group was given the same basal diet supplemented with encapsulated fish oil (1.14 g /kg of concentrate) for 56 days. Milk samples were analyzed for chemical composition and FA profile. The inclusion of encapsulated fish oil in the goat diet did not affect the yield and composition of goat milk. The effect of diet was not significant on the FA profile of goat milk, except that 20:0 was lower (P < 0.05) in the milk of goats that received fish oil. The low dose of encapsulated fish oil supplement used in this study did not impact (P > 0.05) the PUFA content of goat milk or milk composition and yield; however, the atherogenicity index (AI), which is beneficial to heart health, was lower (P < 0.05) in the milk of goats that received fish oil as a supplement in their diet compared to the control.     

Cross‐linking of bovine and caprine caseins by microbial transglutaminase and their use as microencapsulating agents for n‐3 fatty acids

Bovine and caprine caseins were cross‐linked with microbial transglutaminase (mTG). The mTG‐cross‐linked bovine or caprine casein dispersion, mixed with 14.5% maltodextrin (DE = 40), was used to prepare emulsions with 10.5% algae oil. Oxidative stability of emulsions was evaluated by peroxide values (PVs) and anisidine values. Adding liposoluble rosemary extract rich in carnosic acid and δ‐tocopherol lowered the formation of hydroperoxides and their subsequent decomposition products in emulsions. Emulsions stabilised with liposoluble rosemary extract rich in carnosic acid and δ‐tocopherol were spray‐dried at 180/95 °C. Algae oil microencapsulated with mTG‐cross‐linked bovine casein reduced PV by ≈ 34%, while the algae oil microencapsulated with mTG‐cross‐linked caprine casein with low levels of α_s1‐casein reduced PV by ≈ 42% at 4 weeks of storage at 30 °C. The investigation suggests that liposoluble rosemary extract rich in carnosic acid and δ‐tocopherol effectively protected algae oil during the coating process with mTG‐cross‐linked bovine and caprine caseins. The above results clearly indicated that the choice of milk caseins (bovine vs. caprine) cross‐linked with mTG impacts the oxidative stability of spray‐dried algae oil emulsions (microcapsules) enriched with n‐3 fatty acids.     

Magnetic penetration depth in high-T c superconducting Tl2Ca1Ba2Cu2O8−δ single crystals

The temperature dependence of Cu-O plane magnetic penetration depth,λ _ab (T), for T1-2122 single crystals has been determined by measuring the low-field d.c. magnetization using a SQUID susceptometer. Almost full (97%) diamagnetism at low temperature was reached by carefully minimizing the background field, which is an essential condition for this method.λ _ab (0) was obtained uniquely by a self-consistent condition to be 182 nm. Results of our measurements show a deviation from the single-band BCSs-wave prediction. The exponential behavior in very limited temperature regions may be reconciled with the BCS-like prediction. However, ourλ(T) data follow the theoretical prediction very accurately for ap-wave polar state pairing.