To evaluate the effects of supplementation of feed additives in the last trimester of pregnancy on placental characteristics and offspring performance, this study was conducted with 48 estrous-synchronized Ghezel ewes that had randomly been assigned to one of the following six groups (n = 8): ad libitum feeding (AL); feed restriction (RF; 60% of ad libitum intake); feed restriction + propylene glycol (PG); feed restriction + propylene glycol + monensin sodium (MS); feed restriction + propylene glycol + rumen-protected choline chloride (RPC); feed restriction + propylene glycol + monensin sodium + rumen-protected choline chloride (PMC). Birth weight, body size, and rectal temperature of lambs were determined within 24 h of birth. The presence of lambs at 87 days of age was used as an index of survival to weaning. The outcome of this study was that the average placental weight of ewes in the AL and MS groups was the highest and lowest, respectively, among the treatment groups (p < 0.01). RPC ewes presented higher placental efficiency compared to AL, RF, and MS ewes (p < 0.05). The largest and smallest crown-to-rump lengths (CRLs) were observed in PMC and RF lambs, respectively (p < 0.01). In addition, lambs born from PMC, RPC, and PG ewes had a longer curved crown-to-rump length (CCRL) than those born from AL and RF ewes (p < 0.01). The concurrent administration of propylene glycol and rumen-protected choline chloride resulted in the highest birth weight among treatment groups (p < 0.01). Lambs born to PMC and RPC ewes had a higher survival rate and rectal temperature than those born to RF ewes (p < 0.05). It can be concluded that although dietary restriction does not have adverse effects on lambs’ performance compared with ad libitum intake, the combined administration of propylene glycol and rumen-protected choline chloride in the ewes’ restricted diet can improve placental characteristics and subsequently amend lambs’ birth weight and body size. Therefore, the combined administration of these additives can be practiced during feed restriction.

Background: Grazing in arid and semi‐arid regions faces pregnant ewes with feed restrictions and hence affects the offspring muscle fibre characteristics. Using feed additives that enhance nutrient availability during foetal muscle development is expected to alter offspring skeletal muscle characteristics.Objectives: This study evaluated the effect of maternal restricted nutrition and supplementation of propylene glycol, monensin sodium and rumen‐protected choline chloride on lamb's muscle fibre characteristics.Methods: Forty‐eight Ghezel ewes were randomly allocated to one of six diets (N = 8) during the last 6 weeks of gestation: ad libitum feed intake (AL); restricted feeding (RF); restricted feeding containing propylene glycol (PG); restricted feeding containing propylene glycol and monensin sodium (MS); restricted feeding containing propylene glycol and rumen‐protected choline chloride (RPC); restricted feeding containing propylene glycol, monensin sodium and rumen‐protected choline chloride (PMC). The muscle samples were obtained from the semitendinosus muscle of 2‐week‐old male lambs (n = 5/treatment) via biopsy and were stained and classified as fibre types I, IIA and IIB.Results: Pre‐parturient maternal feed restriction and administration of propylene glycol, monensin sodium and rumen‐protected choline chloride had no significant effect on fibre‐type composition, fibre density of muscle, muscle cross‐sectional area and volume density of fibres (p > 0.05).Conclusions: Either maternal dietary restriction or supplementation of nutrient flux–involved additives during late pregnancy did not alter muscle fibre development and had no short‐term effects on muscle properties of the resulting offspring as myogenesis occurs in early and mid‐gestation, not late gestation. Therefore, maternal nutrition may not be a problematic issue in sheep production in arid and semi‐arid areas.

This study aimed to evaluate the chemical composition, fermentation characteristics, and nutritional value of whole and defatted black soldier fly larvae (BSFL) meal using the in vitro gas production technique and the Holden method. Samples were prepared and incubated for 2, 4, 6, 8, 12, 16, 24, 36, 48, 72, and 96 h. Rumen fluid was collected from three fistulated sheep fed a diet containing 40% concentrate and 60% forage at maintenance level for one month prior to sampling. The results indicated that defatting BSFL increased crude protein content from 38.10% to 42.85% and reduced ether extract from 24.20% to 16.40%. Defatted BSFL produced significantly greater cumulative gas volumes at all incubation times compared with whole larvae. Gas production at 24 h was 81.96 and 79.03 mL per 200 mg of dry matter, and increased to 141.83 and 114.85 mL at 96 h for defatted and whole larvae, respectively. The fractional rate of gas production (c) was slightly higher for whole larvae than for defatted larvae (0.045 vs. 0.030 mL·h⁻¹). Organic matter digestibility (OMD), metabolizable energy (ME), net energy for lactation (NEL), and short-chain fatty acid (SCFA) production were higher for defatted BSFL compared with whole larvae (91.23% vs. 89.48%, 13.91 vs. 12.61 MJ·kg⁻¹ DM, 10.48 vs. 9.29 MJ·kg⁻¹ DM, and 1.23 vs. 1.21 mmol, respectively). In addition, digestibility values estimated using the Holden method were greater for defatted larvae than for whole larvae (60.90 vs. 55.50%). Overall, the results suggest that defatting black soldier fly larvae enhances their nutritional value and fermentability, indicating their potential as a high-quality feed ingredient for ruminant animals.