The seeds of most plants are rich in various nutrients and can provide a lot of useful health benefits. The objective of this study was to determine and compare differences in fat, fatty acids, crude protein and amino acids concentrations for chia and flax seeds. Study was carried out using brown and gold seeds of Flax (Linum usitatissimum L.) and Chia (Salvia hispanica L.). The mean protein content in tested seeds ranged from 211.8 to 252.5 g/kg dry matter and in chia seed was about 13.10% higher than the average value of crude protein content in brown and gold flax seed (223.25 g/kg dry matter). Differences in the content of individual amino acids among the seeds were not statistically significant (P <0.05), except that for glutamic acid. Percentage of the essential to the total amino acids, which is considered as indicator of protein quality, was 37.87%, 33.76% and 35.18%, for chia, brown and gold flax seed respectively, which demonstrates the high quality of these proteins. The average fat content of flax seeds was about 71.42 g/kg higher than that in chia seed (321.37 g/kg dry matter). The fatty acids composition showed the presence of palmitic, stearic, oleic, linoleic, α- linolenic and arachidic fatty acids in all tested samples. The α-linolenic acid constitutes on average 54.38% of the total fatty acids of flax seeds and 63.79% of chia seed, and for linoleic acid it was 15.30% and 18.89%. All seeds had low n-6 PUFA / n-3 PUFA ratio. Results of our study confirmed the excellent quality of protein and fat in chia seed, brown and gold flax seed samples. There was no significant effect of the flax seed coat colour for all measured values. Chia seed is the richest of n-3 PUFA α-linolenic fatty acid in the vegetable world. Both, flax seed and chia seed are the good choice of healthy food to maintain a balanced serum lipid profile. It must be pointed that flax seeds must be ground to release their nutrients, but chia seeds do not.

Two N balance experiments were conducted to study the individual response of growing pigs to limiting amino acid (AA) intake. Series of fifteen diets with increasing concentration of sulphur amino acids (SAA, Expt 1) or methionine in the presence of excess cystine (Expt 2) were fed sequentially to nine pigs during a 15-day experimental period. The concentration of the AA under test ranged from 50% to 140% of the requirement while other essential AA were given in a 25% excess relative to the limiting AA. N retention was related to the limiting AA intake using rectilinear and curvilinear models. In Expt 1, the quadratic-plateau model fitted the individual data significantly better (p = 0.01) than the linear-plateau model. No difference was found between the two models in Expt. 2, presumably due to the sparing effect of excess cystine on methionine utilization. Exponential, saturation kinetics or four-parameter logistic models fitted to data for all pigs showed that their goodness of fit was similar to those of quadratic-plateau or linear-plateau models. Significant differences (p < 0.05) were found between individual plateau values for N retention within each experiment while the slopes of the regression lines did not significantly differ either in Expt 1 (p = 0.07) or Expt 2 (p = 0.45). There was a positive correlation between the slope and plateau values of the linear-plateau model in Expt 1 (r = 0.74, p = 0.02) but no significant correlation was found in Expt 2 (r = -0.48, p = 0.13). Marginal efficiencies of SAA and methionine utilization derived from the linear-plateau model were 0.43 and 0.65 respectively. Based on linear-plateau and quadratic-plateau models, daily requirements of SAA and methionine for a 50 kg pig were estimated to be 13.0 and 5.9 g and 14.3 and 6.1 g respectively.

No abstract

In contrast to inorganic Zn, organic Zn sources are absorbed via peptide or AA transport systems resulting in a higher digestibility and availability. Bioavailability of organically bound Zn seems also to be influenced by the type of complex being used. Forty-two gilts (Large white × Landrace) with initial BW of 24 ± 1.4 kg were allotted to 6 treatments of 7 pigs each. Pigs were fed diets based on corn (Zea mays), barley (Hordeum vulgare), and soybean (Glycine max) meal containing either low or high Zn supplementation with ZnO, Zn-Met 1:2 complex, Zn-Gly, Zn proteinate (Zn-Prot), or Zn-yeast. Diets were fed during a 10-d adaptation followed by a 4-d quantitative collection. Daily feed allowance was restricted to 1400 g/pig. Pigs were weighed at the start and end of adaptation and collection and feed consumption was monitored daily. Dietary Zn addition was 10 and 100 mg/kg feed for ZnO and 10 mg/kg feed for other Zn sources. Corresponding ADG ranged from 437 to 587 g with the lowest (P < 0.05) ADG for 10 ppm ZnO. Only Zn-Met addition increased (P < 0.02) Zn digestibility and retention (P < 0.05). Organically bound Zn, in particular Zn from Zn-Met 1:2 and Zn-yeast, can replace higher dosages of ZnO due to better bioavailability indicating that type of chelate is important for Zn retention. Organically bound Zn may reduce Zn excretion, which consequently may lower the environmental impact.

No abstract