Duckweed is gaining attention in animal nutrition and is considered as a potential alternative protein source for broiler chickens. In order to evaluate the nutritional value of duckweed, three individual batches were investigated. They consisted of a mixture of Lemna minuta and Lemna minor (A, 17.5% crude protein), Spirodela polyrhiza (B, 24.6% crude protein) and Lemna obscura (C, 37.0% crude protein). Treatment diets contained 50% batch A, 50% batch B, and 25, 50 and 75% of batch C. All diets were fed to broiler chickens (Ross 308) from an age of 21 to 27 days. Diets with a share of 50 and 75% of batch C led to decreased feed intake (109.3 and 74.9 g/day, respectively) compared to the control. Standardized ileal digestibility of crude protein and amino acids differed significantly between duckweed batches, at values for methionine between 49.9 and 90.4%. For all amino acids, batch A consistently had the lowest and batch C the highest digestibility. Batches had different tannin contents of 2943, 2890 and 303 mg/kg for batches A, B and C, respectively. The apparent ileal digestibility of phosphorus differed significantly between all batches (50.8–78.9%). Duckweed can be used as a protein feed for broiler chickens. However, a defined and stable biomass composition optimized for the requirements of broiler chickens is needed.

Black soldier fly, H. illucens larvae, efficiently convert low-value organic substrates into high-value products, offering solutions to global challenges in sustainable food production and biotechnology. This study investigated the impact of dietary protein levels (10%, 14%, 16%, and 20% crude protein, CP) on BSFL growth, nutrient utilization, and energy retention using isoenergetic diets (18.5 ± 0.3 MJ/kg dry matter) under commercial-scale conditions. Larvae were harvested after 8 days of feeding, with 5 replicates per treatment. Optimal growth performance and feed conversion ratios were observed in larvae fed 14% CP diet, with a quadratic relationship between dietary CP and biomass gain (p < 0.001, R² = 0.870). Ash and calcium deposition peaked in CP20-fed larvae and were lowest in CP14-fed larvae. Phosphorus and glucosamine deposition remained unaffected, while chitin deposition correlated positively with larval weight. Nitrogen and amino acid retention were highest in CP14-fed larvae but reduced in CP20-fed larvae (p < 0.001, R² = 0.573–0.902). CP10-fed larvae showed impaired growth and nitrogen deposition but increased fat deposition. These findings establish the CP14 diet as the optimal formulation for scalable BSFL production, providing critical insights into dietary protein effects on BSFL physiology and enabling the development of efficient feeding strategies for industrial-scale farming.

Enteric diseases in piglets, such as post-weaning diarrhea (PWD), often require antibiotic treatment of the entire litter. Grape polyphenols may help overcome PWD and thereby reduce the need for antibiotics. The potential of a grape extract (GE; continuous in-feed supplementation) on performance of weaning piglets, compared with both negative (NC; corn-based diet) and positive control (PC; NC + in-feed antibiotic (amoxicillin) in a therapeutic dosage for day 1–day 5 post weaning) was assessed. Apparent total tract digestibility (ATTD) and microbial metabolites were also evaluated on two sampling points (day 27/28 and day 55/56). We assigned 180 weaning piglets (6.9 ± 0.1 kg body weight (BW)) to 6 male and 6 female pens per treatment with 5 piglets each. Animals from PC showed higher BW on day 13 compared with NC and GE, and a tendency for higher BW on day 56 (p = 0.080) compared to NC. Furthermore, PC increased the average daily feed intake in the starter phase (day 1–day 13), and the average daily gain in the early grower phase (day 14–day 24). Overall, GE improved the ATTD at the same level as PC (ash, acid-hydrolyzed ether extract), or at a higher level than PC (dry matter, organic matter, gross energy, crude protein, P). There were no effects on microbial metabolites apart from minor trends for lactic acid and ammonia. Dietary inclusion of GE may have beneficial effects compared to therapeutic antibiotics, as frequently used at weaning.

Reports of the underlying mechanisms of dietary grape extract (GE) in overcoming weaning challenges in piglets have been partly inconsistent. Furthermore, evaluations of the effects of GE at weaning in comparison to those of widely used therapeutic antibiotics have been scarce. To explore the mode of action of GE in selected tissues and plasma, we evaluated gut morphology, antioxidant and inflammation indices. Accordingly, 180 weaning piglets were allocated to three treatment groups: negative control (NC), NC and antibiotic treatment for the first 5 days of the trial (positive control, PC), and NC and GE (entire trial). The villus surface was positively affected by GE and PC on day 27/28 of the trial in the jejunum and on day 55/56 of the trial in the ileum. In the colon, NC tended (p < 0.10) to increase crypt parameters compared to PC on day 55/56. The PC group tended (p < 0.10) to increase catalase activity in the ileum and decrease Cu/Zn-SOD activity in the jejunum, both compared to NC. There were no additional effects on antioxidant measurements of tissue and plasma, tissue gene expression, or plasma acute-phase proteins. In conclusion, GE supplementation beneficially affected the villus surface of the small intestine. However, these changes were not linked to the antioxidant and anti-inflammatory properties of GE.

Optimal intestinal development in gilts is a prerequisite for a better farrowing and a higher feed intake in lactation, and these are important facets in improving animal welfare for sows in a high-performance situation. The present study aimed to evaluate the effects of a fiber-rich diet on these topics. Studies with 20 male Topigs castrates and a performance study with 38 female siblings were conducted. Pigs in both of the groups were offered either a control diet (CG) or a high fiber diet (FG) during the second half of the rearing phase (~97 kg BW) until 7 days a.p. At the time of the insemination of the gilts (body weight >170 kg), the castrates were slaughtered and the morphological parameters of the gastrointestinal tract were taken. In the performance study, the feed intake as well as the number and weight of the live and stillborn piglets and the weaning weight of the litters were recorded. The results indicated that the high fiber diet with a greater swelling capacity was beneficial to the development of the gastrointestinal tract (stomach weight CG = 714 g, FG = 812 g, p = 0.007), increased the litter weight (CG =15.9 kg, FG = 20.6 kg, p = 0.045) and resulted in a higher feed intake during lactation overall (CG = 196 kg, FG = 211 kg, p = 0.035).

Undigested P and N are excreted and contribute to the environmental impacts of dairy farming. Degradation of phytate in the rumen has been shown to be high but variable, leading to incomplete phytate-P utilization and resultant antinutritional impacts of phytate along the gastrointestinal tract. We investigated the effect of a novel bacterial 6-phytase (PhyG) on the apparent total-tract digestibility (ATTD) and excretion of DM, phytate-P (PP), P, CP and NDF in lactating dairy cows. Forty-eight lactating Holstein-Friesian cows were assigned to 3 treatments with 16 cows per treatment in a randomized block design. Cows averaged 44.1 kg milk/d, and 124 DIM at the experiment start. Diets were fed ad libitum as a TMR that was formulated to meet nutritional requirements except for P which was fed at 92% of the recommendation. Treatments comprised a control diet (CON) and the control diet supplemented with 2,000 or 5,000 phytase units/kg DM of PhyG. The experiment lasted for 19 d including a 14 d diet adaptation period and a 5 d fecal collection period. Dry matter intake did not differ across treatments. The ATTD of PP in CON was 88.5%, indicating incomplete phytate degradation. The ATTD of ash, P and CP increased linearly, whereas the ATTD of PP and NDF increased both linearly and quadratically with increasing PhyG dose level; with PhyG at 5,000 FTU/kg, the ATTD of PP, P, CP and NDF increased by 9.2, 13.7, 4.1 and 7.5% points above CON, respectively. Fecal excretion of ash, PP, P and NDF were reduced linearly. Supplementation of PhyG also reduced excretion of PP quadratically and CP excretion tended to be reduced linearly. Body weight and milk yield did not differ across treatments, but milk protein yield tended to increase linearly with increasing PhyG dose. The addition of PhyG to the diet of lactating dairy cows improved nutrient utilization and decreased nutrient excretion. It could therefore contribute to reducing the environmental impacts of dairy production.