The rapidly growing population has increased demand for protein quantities and, following a shortage of plant-based feed protein sources and the prohibition of animal-based feed protein, has forced the search for new sources of protein. Therefore, humans have turned their attention to edible insects. Black soldier fly larvae (BSFL) (Hermetia illucens L.) are rich in nutrients such as fat, protein and high-quality amino acids and minerals, making them a good source of protein. Furthermore, BSFL are easily reared and propagated on any nutrient substrate such as plant residues, animal manure and waste, food scraps, agricultural byproducts, or straw. Although BSFL cannot completely replace soybean meal in poultry diets, supplementation of less than 20% has no negative impact on chicken growth performance, biochemical indicators and meat quality. In pig studies, although BSFL supplementation did not have any negative effect on growth performance and meat quality, the feed conversion ratio (FCR) was reduced. There is obviously less research on the feeding of BSFL in pigs than in poultry, particularly in relation to weaning piglets and fattening pigs; further research is needed on the supplementation level of sows. Moreover, it has not been found that BSFL are used in ruminants, and the next phase of research could therefore study them. The use of BSFL in animal feed presents some challenges in terms of cost, availability and legal and consumer acceptance. However, this should be considered in the context of the current shortage of protein feed and the nutritional value of BSFL, which has important research significance in animal production.

Under the background of the current shortage of feed resources, especially the shortage of protein feed, attempts to develop and utilize new feed resources are constantly being made. If the tomato pomace (TP) produced by industrial processing is used improperly, it will not only pollute the environment, but also cause feed resources to be wasted. This review summarizes the nutritional content of TP and its use and impact in animals as an animal feed supplement. Tomato pomace is a by-product of tomato processing, divided into peel, pulp, and tomato seeds, which are rich in proteins, fats, minerals, fatty acids, and amino acids, as well as antioxidant bioactive compounds, such as lycopene, beta-carotenoids, tocopherols, polyphenols, and terpenes. There are mainly two forms of feed: drying and silage. Tomato pomace can improve animal feed intake and growth performance, increase polyunsaturated fatty acids (PUFA) and PUFA n-3 content in meat, improve meat color, nutritional value, and juiciness, enhance immunity and antioxidant capacity of animals, and improve sperm quality. Lowering the rumen pH and reducing CH₄ production in ruminants promotes the fermentation of rumen microorganisms and improves economic efficiency. Using tomato pomace instead of soybean meal as a protein supplement is a research hotspot in the animal husbandry industry, and further research should focus on the processing technology of TP and its large-scale application in feed.

Eight healthy multiparous Saanen dairy goats (41.50 ± 1.84 kg) were assigned to a double 4 × 4 Latin square design. The four treatment diets were: (1) negative control, rice straw (NC); (2) first positive control, sticky corn stover silage (PC1); (3) second positive control, PC1 with 1 g/d commercial purple corn pigment (PC2); and (4) anthocyanin-rich purple corn stover silage (PSS; AR). Dry matter intake did not differ (P > 0.05) among the treatments. Goats receiving the NC tended (P < 0.05) to reduce nutrient apparent digestibility, nitrogen (N) absorption, N retention, and volatile fatty acid production relative to the other groups. The levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and superoxide dismutase (SOD) in plasma were greater (P < 0.05) in goats fed PC2 and AR compared with NC and PC1. The inclusion of PC2 and AR increased (P < 0.05) the abundance of nuclear factor (erythroid-derived 2)-like 2 (NFE2L2), but decreased (P < 0.05) the level of tumor necrosis factor in the mammary gland. Moreover, goats receiving AR tended to increase (P < 0.05) the levels of SOD2, GPX1, and GPX2 mRNA expression in the mammary gland. There were significant (P < 0.05) positive correlations between DPPH scavenging activity, total antioxidant capacity, SOD, catalase enzymes in plasma and the abundance of NFE2L2 in the mammary gland. In addition, stronger (P < 0.05) positive correlations were noted between the expression of several inflammation-related and antioxidant genes. Collectively, the results from the current study indicated that the consumption of anthocyanin-rich PSS by dairy goats had the potential to enhance antioxidant potential by improving antioxidant capacity in plasma and by modulating the abundance of several inflammation-related and antioxidant genes in the mammary gland.

The present study used 16 multiparous lactating Saanen dairy goats (body weight, 41.80 ± 2.92 kg; mean ± standard deviation) with healthy and symmetrical udders. Goats were divided into 2 blocks of 8 goats based on milk yield averaged from 75 d in milk in a randomized completed block design. The 2 study groups were the control (CSSS), in which goats were fed sticky corn stover silage, and the treatment (TPSS), in which goats were fed anthocyanin-rich purple corn (Zea mays L.) stover silage (PSS). The results indicated that the TPSS group led to an elevation in the content of milk lactose relative to the CSSS. The inclusion of anthocyanin-rich PSS had no effect on the level of 5 particular anthocyanins [i.e., cyanidin-3-glucoside, delphinidin, cyanidin, pelargonidin (Pel), as well as total anthocyanins in milk]. The pelargonidin-3-glucoside and malvidin were unable to be detected in both groups. However, the TPSS resulted in higher levels of peonidin (Peo) and malvidin-3-O-glucoside (M3G) compared with the control. Moreover, goats receiving TPSS exhibited a higher level of superoxide dismutase (SOD) in plasma and milk relative to the CSSS. Interestingly, some positive correlations were detected between the certain milk components [i.e., fat and total solids as well as fat and solids-not-fat (SNF); protein and SNF; and total solids and SNF]. In addition, the positive correlations were observed between individual anthocyanins (cyanidin-3-glucoside, delphinidin, Peo, M3G, cyanidin, and Pel) and total anthocyanins. Specifically, stronger positive correlations were noted between several antioxidant enzymes and anthocyanin composition in milk (total antioxidant capacity and Pel; SOD and Peo as well as SOD and M3G). Taken together, PSS with abundant anthocyanins can transfer anthocyanins to the milk and enhance the amount of antioxidants in lactating dairy goats.

A reversed-phase high-performance liquid chromatography with diode-array detection (HPLC-DAD) was developed and validated to estimate the phenolic acids (gallic acid, caffeic acid, syringic acid, p-coumaric acid, sinapic acid, and ferrulic acid), flavonoids (catechin rutin, myricetin, quercetin, apigenin, and kaempferol), ascorbic acid, and eugenol. The chromatogram condition was set in suitable wavelength 272 nm and run flow rate 0.7 μl/minutes using HPLC Agilent Technologies 1260 Infinity, a reversed-phase Zorbax SB-C18 column (3.5 μm particle size, i.d. 4.6 mm × 250 mm) with the mobile phase solution (1:9, HPLC-grade acetonitrile:1% acetic acid). The linearity, precision, limit of detection, limit of detection, and accuracy were R2 > 0.9907, relative standard deviation < 1%, 0.005 μg/ml, 0.015 μg/ ml, and 96%–102%, respectively. As a result, all the selective compounds were successfully separated, identified, and quantified. The enormous contents were found in quercetin and eugenol, expressing crude content (mean, 5.989 mg/g) and residue content (mean, 1.934 mg/g) for quercetin, while crude content (mean, 3.209 mg/g) and residue content (mean, 0.184 mg/g) for eugenol. Consequently, this method could be applied, repeated, and developed for the later observation, especially in commercially inclination of Piper betle analysis.