The effects on meat quality resulting from alternative dietary protein sources (Spirulina and Hermetia meal) in poultry diets are studied to determine the overall suitability of these ingredients considering state-of-the-art packaging practices—highly oxygenated modified atmosphere packaging (HiOx MAP). We monitored standard slaughterhouse parameters, such as live weight, carcass weight, dressed yield, and pH at 20 min and 24 h post mortem. In addition, we studied the effects that 3 and 7-day storage in HiOx MAP has on the overall product physico-chemical and sensory properties. In addition to previously supported effects of HiOx MAP, we found that meat quality could be improved when Spirulina replaces 50% of the soy protein in broiler diets; however, this substitution results in a dark reddish-yellowish meat colour. On the other hand, the substitution with Hermetia larval meal results in a product that does not differ from the standard fed control group, with the exception that the breast filet has a more intense flavour that decreases over storage time. All-in-all Spirulina and Hermetia meal have the potential to replace soybean meal in broiler diets without deteriorating meat quality.

Two age-dependent nitrogen (N) balance studies (average body mass 25 and 60 kg) utilized 16 male castrated piglets and 16 barrows to measure N utilization parameters of diets with complete substitution of SBM by alternative protein sources (SM, HM), but different AA fortifications. Lysine supplementation up to 80% of the recommended lysine (Lys) supply in diets HM (A) and SM (A) yielded similar protein quality data (63.6 ± 2.1 and 63.7 ± 3.4). Surprisingly, only in piglet diet HM (AA) did the extended AA supplementation (Lys, methionine (Met), threonine (Thr)) enhance protein quality (72.8 ± 6.7) significantly (p = 0.004). Similar trends were observed in growing pigs. However, when the level of histidine (His) in diet SM (AA) was increased, feed protein quality (71.8 ± 1.3) was significantly (p < 0.001) improved indicating the importance of adequate His supply in diets with a complete substitution of SBM by the algae meal (SM) under study. AA efficiency data extend the possibilities to explain the observed responses on protein quality. When an adequate AA balancing in the diet is guaranteed, from nutritional point of view both of the alternative proteins may replace SBM in pig diets.

Two experiments were conducted with laying hens (Lohmann Brown) in an individual cage system and with single feeding conditions. Experiment 1 (n = 24) was a performance trial (22 to 61 wk) to evaluate phytase effects on performance and nutrient utilization in corn-soybean meal (CSM1) and wheat-soybean meal (WSM1) basal diets (0.12% NPP; 3.1% Ca) supplemented (300 U/kg) with an experimental microbial phytase (CSM2 and WSM2) or 1.5 g/kg inorganic P (CSM3 and WSM3). Experiment 2 (n = 16) was also conducted as a performance trial (22 to 61 wk) only using CSM diets with dietary treatments similar to those in experiment 1. In addition, parallel N and P balance experiments in 2 age periods (26 and 33 wk, respectively) were conducted. In experiment 1, no significant (P < 0.05) differences in mortality, feed intake, egg production, egg weight, or body weight were observed. Tibia bone mineral composition was significantly affected by microbial phytase. Microbial phytase in the low-P CSM diet significantly (P < 0.05) improved the feed conversion ratio. In experiment 2, only feed conversion ratio was significantly improved by microbial phytase. The phytase supplementation had no significant effect on P excretion, P balance, P utilization, N balance, N utilization, or AMEn in the balance experiments.

1. Experiments were conducted to establish the requirements and optimal dietary ratio of lysine to threonine for fast growing male chickens (genotype Ross 308) depending on age, daily protein deposition and of dietary amino acid efficiency. 2. A total of 216 growing chickens were utilised in nitrogen-balance studies in three age periods (10 to 25 d; 30 to 45 d; 50 to 65 d) using graded levels of protein supply (60 to 360 g/kg crude protein) in lysine or threonine limiting diets. 3. Supplementation of crystalline amino acids (L-Lys, L-Thr, DL-Met and L-Arg) provided the following amino acid ratios: lysine limiting diets (Lys:Met + Cys:Thr:Arg = 1 : 1·01 : 0·91 : 1·14), threonine limiting diets (Lys : Met + Cys : Thr : Arg = 1 : 0·85 : 0·54 : 1·16). 4. The principles of the diet dilution technique using an exponential function were applied for the modelling of lysine and threonine requirements. For equal daily protein deposition, optimal lysine to threonine ratios 1 : 0·69 (10 to 25 d), 1 : 0·70 (30 to 45 d) and 1 : 0·74 (50 to 65 d) were established. 5. For the commercial growth period of fast growing chickens, the derived optimal lysine to threonine ratio was constant (1 : 0·69). The applied modelling procedure gave conclusions for quantitative requirements and optimal dietary lysine:threonine ratios in line with actual recommendations.