Dietary incorporation of brown seaweed spent oyster mushroom substrate alters growth performance, physiological responses and meat quality parameters in Boschveld roosters.

Use of brown seaweed (Ecklonia maxima) as a nutraceutical source in indigenous chicken diets is limited by high dietary fibre levels. Inoculating seaweeds with oyster mushroom (Pleurotus ostreatus) spawn (OMS) could enhance the utility of the spent mushroom substrate (SMS). This study investigated the effect of feeding incremental levels of brown seaweed SMS on growth performance, physiological responses, and meat quality parameters in Boschveld roosters. A total of 324, 4-week-old Boschveld roosters were weighed and randomly allotted to 36 pens (9 birds per pen) to produce six replicates per dietary treatment. The diets were formulated as follows: a standard grower diet (CON); and CON containing 150 g/kg of brown seaweed inoculated with OMS at 0 (SMS0), 20 (SMS20), 30 (SMS30), 40 (SMS40) and 50% (SMS50). Birds fed diet CON had the least feed intake (p < 0.05) than all the other SMS treatment levels in weeks 7, 8, 12, 14 and 15. Diet SMS40 promoted higher (p < 0.05) body weight gain (BWG) than CON in weeks 6, 7, 9 and 14. Gain-to-feed ratio linearly increased in weeks 7 [R2 = 0.288; p = 0.010], 11 [R2 = 0.581, p = 0.0001] and 14 [R2 = 0.389, p = 0.004], respectively. Quadratic responses (p < 0.05) were observed for BWG in week 5, white blood cells, heterophils, platelets, lymphocytes, monocytes, and relative spleen and large intestine weights as OMS levels increased. Linear increases were recorded for slaughter [R2 = 0.197, p = 0.017] and breast weights [R2 = 0.197, p = 0.020] as OMS levels increased. Diet SMS0 promoted higher (p < 0.05) relative caeca weights than the CON and SMS treatment groups. Neither quadratic nor linear responses (p > 0.05) were observed for breast meat quality parameters. In conclusion, feeding brown seaweed SMS improved growth performance and slaughter weight, altered some blood parameters and internal organs, without affecting breast meat quality of Boschveld roosters. Based on the quadratic response for BWG, the optimum OMS level was deduced at 20% in a brown seaweed-based Boschveld rooster diet.

The effect of incorporating dietary green seaweed (Ulva sp.) on growth performance, blood parameters, and carcass and meat quality characteristics of Jumbo quail.

Seaweeds are functional aquatic plants that can be used in Jumbo quail (Coturnix sp.) feeds as sources of phytochemicals and nutrients. However, no studies have investigated the feed value of green seaweed (Ulva sp.) meal (SM) for the Jumbo quail. Thus, the impact of different dietary inclusion levels of SM on productive traits, serum biochemistry, haematology, visceral organ sizes, carcass features, and meat quality attributes in Jumbo quail was investigated. In a completely randomised design, one-week-old quail (n = 385; 67.7 ± 3.44 g body weight) were allotted to five treatments, with seven replicate pens (experimental unit). The treatments were produced by including 0 (SM0), 20 (SM20), 40 (SM40), 60 (SM60) and 80 g/kg (SM80) of green SM in a commercial grower diet. Regression results showed no linear or quadratic effects (P > 0.05) to different levels of SM for average weekly feed intake, overall weight gain, haematological indices, internal organs, carcass features, and meat quality characteristics of the birds. However, incorporating SM up to 80 g/kg in the diet linearly reduced overall gain-to-feed ratio (G:F) [R2 = 0.282; P = 0.0001] and slaughter weights [R2 = 0.159; P = 0.026]. Treatment SM80 promoted (P < 0.05) higher feed intake than diet SM60 in weeks 3, 4 and 5, but were comparable to the control treatment in weeks 4 and 5. Birds fed with diets SM0 and SM20 had higher (P < 0.05) overall weight gain than birds fed with diet SM60. Diet SM80 resulted in lower (P < 0.05) overall G:F (0.250) than diet SM0 (0.277). Higher slaughter weights were observed on SM0 and SM20 groups than the SM60 group. We concluded that the use of dietary green SM up to 80 g/kg in Jumbo quail feeds compromises gain-to-feed ratio and slaughter weights but not physiological and meat quality attributes.

Cultivating oyster mushrooms on red grape pomace waste enhances potential nutritional value of the spent substrate for ruminants.

The use of red grape pomace (GP; Vitis vinifera L. var. Shiraz) as a source of beneficial bioactive compounds in ruminant diets is limited by high levels of indigestible compounds in the grape skin matrix. This problem demands innovative, inexpensive, and easy-to-use strategies that improve the digestibility of GP. The bioconversion of GP using edible oyster mushrooms (Pleurotus ostreatus) is one such strategy that has not been previously explored. Therefore, this study evaluated the effect of cultivating oyster mushrooms on GP on chemical composition and in vitro ruminal fermentation parameters of the spent mushroom substrate. The GP was inoculated with oyster mushroom spawns at 0, 200, 300, 400, or 500 g/kg, and incubated for 4 weeks. Organic matter, acid detergent lignin, sodium, manganese, cobalt, and copper linearly declined (P < 0.05) as spawn rates increased. A quadratic trend was observed for crude protein, neutral detergent fibre, acid detergent fibre, magnesium, phosphorus, and calcium content in response to increasing spawn rates. Higher spawning rates (20-50%) had a positive effect (P < 0.05) on gas production from the immediately fermentable fraction (a), rate of gas production from the slowly fermentable fraction (c) and effective gas production. However, gas production from the slowly fermentable fraction (b) and potential gas production linearly declined in response to increasing spawning rates. There was a linear increase (P < 0.05) in the immediately degradable fraction (a), while quadratic effects were observed for partition factors, effective degradability, and in vitro organic matter degradability at 48 h in response to spawning rates. It can be concluded that inoculating GP with oyster mushroom spawn reduced fibre content while increasing crude protein content and in vitro ruminal fermentation efficiency of red grape pomace. Based on the quadratic responses of partition factors at 48 hours post-inoculation, the optimum spawning rate for maximum ruminal fermentation efficiency of GP was determined to be 300 g/kg.