Effects of increased inclusion of algae meal on finishing steer performance and carcass characteristics

Microalgae: Potential for Bioeconomy in Food Systems

The efficient use of natural resources is essential for the planet’s sustainability and ensuring food security. Colombia’s large availability of water resources in combination with its climatic characteristics allows for the development of many microalgae species. The use of microalgae can potentially contribute to sustainable production in support of the agri-food sector. The nutritional composition (proteins, carbohydrates, fatty acids, vitamins, pigments, and antioxidants) of microalgae along with the ease of producing high biomass yields make them an excellent choice for human and animal nutrition and agriculture. Several species of microalgae have been studied seeking to develop food supplements for pigs, ruminants, poultry, fish, crustaceans, rabbits, and even bees. Important benefits to animal health, production, and improved bromatological and organoleptic characteristics of milk, meat, and eggs have been observed. Based on the functional properties of some microalgae species, foods and supplements have also been developed for human nutrition. Moreover, because microalgae contain essential nutrients, they can be utilized as biofertilizers by replacing chemical fertilizers, which are detrimental to the environment. In view of the above, the study of microalgae is a promising research area for the development of biotechnology and bioeconomy in Colombia.

Effects of red macroalgae Asparagopsis taxiformis supplementation on the shelf life of fresh whole muscle beef

This study was conducted to evaluate the effect of red macroalgae Asparagopsis taxiformis supplementation for cattle on the shelf life of fresh beef steaks (longissimus dorsi). Three treatment groups (seven steers per treatment) included: 1) Control diet, 2) Control diet + 0.25% of macroalgae inclusion (low dose, LD), and 3) Control + 0.5% of macroalgae inclusion (high dose, HD). After the animals were harvested, the strip loins from all animals were collected and aged for 14 days at the meat lab of the University of California, Davis. Then the strip loins were cut into steaks, packaged, and placed on a retail display case for 6 days. During a retail display, instrumental color (L*, a*, and b*) of lean muscle and external fat surfaces were measured every 12 h. Bacterial counts for total aerobic mesophilic bacteria (AMB), aerobic psychrotrophic bacteria (APB), and lactic acid bacteria (LAB) were assessed on days 0, 3, and 6 of retail display. The thiobarbituric acid reactive substances (TBARS) analysis was conducted to measure the lipid oxidation and the pH was also assessed on days 0, 3, and 6. No interactive effect between treatments and time on the shelf life of steaks was observed. The HD red macroalgae supplement decreased (P < 0.05) the lightness (L*) of the surface muscle of the steaks, while the lightness of the external fat was not affected (P < 0.05) by treatments throughout the retail display. The external fat yellowness of the steaks was lower (P < 0.05) in LD and HD treatment groups compared with the control group. An increase (P < 0.05) in counts of AMB, APB, and LAB was observed on the steaks from the steers in the HD treatment group while steaks in Control and LD group had similar bacterial numbers throughout the retail display. The results indicated that the shelf life of steaks from cattle in LD group remained the same as that of the Control group, but the HD of A. taxiformis caused a darker color of steaks with higher microbial counts, which may lead to a shortened shelf life due to undesirable appearance and faster microbial spoilage.

Meeting Global Feed Protein Demand: Challenge, Opportunity, and Strategy

Feed protein supplements are one of the most expensive and limiting feed ingredients. This review offers a comprehensive analysis of how the expected expansion of animal production, driven by the rising world population and living standards for more animal-sourced foods, is creating a global shortage of feed protein supply. Because ruminants, chickens, and pigs contribute to 96% of the global supply of animal protein and aquaculture is growing fast, means of meeting the feed protein requirements of these species are elaborated. Geographic variation and interdependence among China, Europe, and North America in the demand and supply of feed protein are compared. The potential and current state of exploration into alternative feed proteins, including microalgae, insects, single-cell proteins, and coproducts, are highlighted. Strategic innovations are proposed to upgrade feed protein processing and assessment, improve protein digestion by exogenous enzymes, and genetically select feed-efficient livestock breeds. An overall successful and sustainable solution in meeting global feed protein demands will lead to a substantial net gain of human-edible animal protein with a minimal environmental footprint.

Performance, insulin sensitivity, carcass characteristics, and fatty acid profile of beef from steers fed microalgae

Heterotrophic production of microalgae biomass provides a consistent, high-quality source of docosahexaenoic acid (DHA; C22:6 n-3) in triglyceride oils that could be used as a ration supplement for feedlot steers to improve nutritional qualities of beef. Sixty Angus × Simmental steers (438 ± 6.4 kg) were allotted to two treatments (30 steers each, six pens, five steers/pen) to determine the effects of ForPLUS (DHA-rich microalgae Aurantiochytrium limacinum; 63.6% fat; 17.9% DHA; 30 mg/kg Sel-Plex; Alltech Inc.) on performance, insulin sensitivity, LM fatty acid composition, and meat quality. Steers were fed basal diets containing 45% corn, 30% distillers dried grains with solubles, 20% corn silage, and 5% supplement. Basal diets were formulated to contain 16.1% CP and 1.32 Mcal/kg NEg. Treatments were delivered to steers in a ground corn-based top-dress (454 g total/steer) and contained no microalgae for control steers or 100 g/steer daily of ForPLUS for microalgae steers. A glucose tolerance test (GTT) was performed 10 d prior to slaughter. Steers were slaughtered when a target pen BW of 621 kg was achieved. Fatty acid oxidation potential was determined by measuring thiobarbituric acid reactive substances (TBARS) on LM samples collected 24 h after slaughter and aged for 48 h or 21 d. Weight and BW gain did not differ during the study (P ≥ 0.13); however, steers fed microalgae remained in the feedlot seven more days compared to steers fed the control diet (111 vs. 104 d; P = 0.04). Overall DMI decreased (P = 0.002) and G:F increased during the second half of the study (P = 0.04) in steers fed microalgae compared to steers fed the control diet. Steers fed microalgae secreted less insulin (P = 0.01) and took longer to clear glucose (P = 0.01) during a 2-h GTT. Carcass traits did not differ between treatments (P ≥ 0.23). Microalgae had no effect on n-6 content (P = 0.67), but more than doubled the n-3 fatty acid percentage and the n-3:n-6 ratio of the LM (P < 0.0001). The percentage of n-3 fatty acids C20:5 and C22:6 were increased (P < 0.0001) 4-fold and 6.25-fold, respectively, by microalgae supplementation. Concentration of TBARS did not differ in LM aged for 48 h (P = 0.91); however, when aged for 21 d, steers fed microalgae tended to produce LM with greater TBARS concentration compared to steers fed the control diet (P = 0.08). In conclusion, DHA-rich microalgae decreased DMI of steers, and increased n-3 fatty acids and beef oxidation in steaks aged for 21 d.