The objective was to determine the effects of drying and blanching methods on the nutrient utilization of black soldier fly larva (BSFL; Hermetia illucens) meal by pigs using in vitro assays. Two-step and three-step in vitro assays were employed to simulate the gastrointestinal tract of pigs. Four BSFL meals were prepared using the following pretreatment methods: (1) microwave drying at 80 °C for 32 min, (2) hot-air drying at 60 °C for 17 h, (3) blanching for 5 min in boiling water and hot-air drying at 60 °C for 17 h, and (4) 2% citric acid solution blanching for 5 min in boiling solution and hot-air drying at 60 °C for 17 h. After the drying process, each BSFL was defatted and ground to obtain BSFL meals. The nitrogen (N) concentration in the test ingredients ranged from 8.5 to 9.4%, and the ether extract ranged from 6.9 to 11.5% on an as-is basis. The amino acid (AA) concentration in the BSFL meals ranged from 2.80 to 3.24% for Lys and 0.71 to 0.89% for Met on an as-is basis. Hot-air-dried BSFL meal had a greater in vitro ileal disappearance (IVID) of N compared with microwave-dried BSFL meal (p < 0.05). However, blanched BSFL meals in water or 2% citric acid solution before hot-air drying had a lower (p < 0.05) IVID of N compared with microwave-dried or hot-air-dried BSFL meal. Blanched BSFL meals in water or 2% citric acid solution before hot-air drying showed a lower (p < 0.05) in vitro total tract disappearance of dry matter and organic matter compared with microwave-dried or hot-air-dried BSFL meal. Microwave-dried BSFL meal had a lower (p < 0.05) IVID of indispensable AA, except for His, Lys, Met, and Phe, compared with hot-air-dried BSFL meals. However, blanched BSFL meals in water or 2% citric acid solution before hot-air drying showed a lower (p < 0.05) IVID of indispensable AA compared with microwave-dried or hot-air-dried BSFL meal. In conclusion, hot-air-dried BSFL meal presented greater nutrient utilization compared with microwave-dried BSFL meal for pigs. However, blanching in water or citric acid solution negatively affected the nutrient digestibility of BSFL meal based on in vitro assays.

The present study was aimed to investigate the effects of supplemental β-mannanase on in vitro ileal disappearance (IVID) and in vitro total tract disappearance (IVTTD) of dry matter (DM) in barley, canola meal, copra meal, corn, corn distillers dried grains with solubles, cottonseed meal, palm kernel meal, soybean meal, and wheat for pigs. Feed ingredient samples were finely ground and divided into the control group and the treatment group. The samples of the control group were prepared to contain 990 g/kg test ingredient and 10 g/kg cornstarch, whereas the samples of the treatment group were prepared to contain 990 g/kg test ingredient and 10 g/kg β-mannanase product (8,000 units/kg in the mixed sample). A 2-step in vitro ileal digestion technique, which simulated the digestion and absorption processes in the stomach and small intestine, was used to determine the IVID of DM in test ingredients, whereas a 3-step in vitro ileal digestion technique, which additionally simulated the digestion process of the large intestine, was used to determine the IVTTD of DM in test ingredients. The in vitro digestion procedures were performed in triplicate for each sample. The addition of βmannanase increased (p = 0.003) the IVID of DM in wheat and tended to increase (p = 0.063) the IVID of DM in soybean meal. The IVTTD of DM in barley, cottonseed meal, and palm kernel meal was improved (p < 0.05) by the addition of β-mannanase. In conclusion, the digestibility of nutrients for pigs may be improved when β-mannanase is added into diets containing barley, cottonseed meal, palm kernel meal, soybean meal, or wheat.

Gonadotropin products are available for inducing estrus of gilts. A concern is a potential negative effect of the estrus inducer on the farrowing performance. This study aimed to evaluate the effects of an estrus-inducing agent on gilt productivity at a commercial farm. A total of 60 gilts that had not shown estrus for more than 14 days were treated with an estrus inducer. Among these gilts, 51 exhibited estrus and underwent artificial insemination. Additionally, 64 gilts naturally went into estrus and were also artificially inseminated during the same period. The pregnancy rates for the natural estrus group and the estrus inducer treatment group were 93.7% and 92.2%, respectively, showing no difference. Furthermore, there were no significant differences observed in farrowing performance between the two groups, including total litter size (11.5 vs. 11.4), stillbirths (0.38 vs. 0.42), fostering piglets (11.1 vs. 11.1), and the number of weaned piglets (10.9 vs. 10.7). Wean-to-estrus interval also did not differ between the two groups. Taken together, we failed to find any detrimental effects of estrus inducers on the reproductive performance of gilts.

The objectives were to determine the effects of graded inclusion rates of wheat bran (WB) on apparent ileal (AID), apparent total tract (ATTD), and hindgut digestibility of nutrients and tested the influence of ileal digesta collection on proceeding fecal nutrient digestibility in pigs. Six barrows with an initial mean body weight of 70.7 ± 5.7 kg fitted with an ileal T-cannula were used. The animals were assigned to a replicated 3 × 3 Latin square design with three diets and three periods. A basal diet was based mainly on wheat, soybean meal, and cornstarch. Two additional diets were formulated to contain 20 or 40% of WB at the expense of cornstarch. Each experimental period consisted of a seven-day adaptation period and a four-day collection period. After the adaptation period, fecal samples were collected on day 8, and ileal digesta were collected on days 9 and 10. Another set of fecal samples was collected on day 11 to determine the influence of ileal digesta collection on proceeding total tract nutrient digestibility. The AID of energy, dry matter (DM), organic matter (OM), crude protein, and phosphorus linearly decreased (p < 0.05) with an increasing inclusion rate of WB from 0 to 40%. The ATTD of energy, DM, OM, crude protein, ether extract, and phosphorus linearly decreased (p < 0.01) as the inclusion rate of WB increased. Hindgut digestibility of DM, OM, and ether extract linearly increased (p < 0.05) with an increasing inclusion rate of WB. The ATTD of GE and most nutrients did not differ between the two fecal collection periods of before and after ileal digesta collection. Taken together, the inclusion of a fiber-rich ingredient reduced ileal and fecal digestibility of nutrients but increased hindgut digestibility of some nutrients, and total tract digestibility of nutrients did not differ whether the fecal samples were collected before or after two days of ileal digesta collection in pigs.