Yuri Katagiri Dalmoro

Permanent grassland management commonly includes moderate mineral N fertilization, which can differentially affect botanical composition, dry matter (DM) yield and forage quality of grasses, legumes and forbs. We hypothesized that increasing N would enhance grass dominance and DM yield but raise fiber and reduce metabolizable energy (ME) content. We evaluated long-term N fertilization, cutting time and their interaction on DM yield and ME of grasses, legumes and forbs in a permanent mountain grassland. The field experiment, established in 1967, used a randomized block design (4 replicates, 3 cuts/year) with five treatments: unfertilized (Control), PK without N (N0), and PK plus 80 (N80), 120 (N120) or 180 (N180) kg N/ha per year; forage was sampled in 2014–2016. Increasing N raised grasses to ~92% of biomass at N180 and reduced legumes and forbs (p < 0.001). Mean DM yield rose from 2.5 (Control) to 9.8 t/ha (N180; p < 0.001). High N (N120, N180) lowered ME of grasses in later cuts (8.9 vs. 10.1 MJ/kg DM in the third cut), whereas legumes and forbs maintained high ME. Moderate N fertilization (80–120 kg N/ha) best balanced DM yield, legume and forbs contribution and ME content.

Insect meal as a protein source has been considered a sustainable way to feed animals. H. illucens and T. molitor larvae meal are considered high-protein sources for poultry, also presenting considerable amounts of fatty acids, vitamins, and minerals. However, other potential components in insect meal and insect oil have been more extensively studied in recent years. Chitin, lauric acid, and antimicrobial peptides can present antimicrobial and prebiotic functions, indicating that low levels of their inclusion in insect meal can beneficially affect broilers’ health and immune responses. This systematic review was developed to study the impact of insect products on the health parameters of broilers, and a metanalysis was conducted to evaluate the effects on performance. A database was obtained based on a selection of manuscripts from January 2016 to January 2023, following the mentioned parameters. Both H. illucens and T. molitor meal or oil products had positive effects on poultry health status, especially on the ileal and cecal microbiota population, immune responses, and antimicrobial properties. The average daily gain was greater in broilers fed T. molitor meal compared to H. illucens meal (p = 0.002). The results suggest that low levels of insect meal are suitable for broilers, without resulting in negative effects on body weight gain and the feed conversion ratio, while the insect oil can totally replace soybean oil without negative impacts.

Insect meal as a protein source has been considered a sustainable way to feed animals. H. illucens and T. molitor larvae meal are considered high protein sources for poultry, also presenting considerable amounts of fatty acids, vitamins, and minerals. However, other potential components in insect meal and insect oil have been more studied nowadays. Chitin, lauric acid, and antimicrobial peptides can present antimicrobial and prebiotic functions, indicating that low inclusions of insect meal can beneficially affect broilers` health and immune responses. This systematic review was developed to study the impact of insect products on health parameters of broilers, and a metanalysis was conducted to evaluate the effects on performance. A database was obtained based on a selection of manuscripts from 2016 to January 2023, following the mentioned parameters. There were positive effects of both H. illucens and T. molitor meal or oil products on poultry health status, especially in microbiota population, immune responses, and antimicrobial properties. The average daily gain was greater in broilers fed T. molitor meal compared to H. illucens meal (p = 0.002). The results suggest that low levels of insect meal were suitable for broilers, without result in negative effects on performance, while the insect oil can totally replace soybean oil without negative impacts.