Research has demonstrated that by maintaining the minimum dissolved oxygen (DO) concentration in earthen ponds at or above 3.0 ppm, feed intake and growth of Channel Catfish Ictalurus punctatus, Blue Catfish I. furcatus, and hybrid catfish (female Channel Catfish × male Blue Catfish) may be doubled relative to those achieved with the oxygen management regimes typically used on commercial catfish farms. In earlier studies using only emergency aeration or low levels of fixed aeration, the direct effect of stocking rate has been confounded by lower morning DO concentrations in ponds stocked at higher densities due to higher feed input and fish biomass. Although higher stocking rates in those studies did produce greater yields, individual fish growth and feed intake may have been impacted by lower DO levels while appearing to be a direct density effect. In this study, production of hybrid catfish, which were fed daily to satiation in earthen ponds with no water exchange, was compared at low (5,000 fish/acre) and high (20,000 fish/acre) stocking rates while using controlled intensive aeration to maintain a minimum DO over 3.0 ppm in all ponds through the study. We achieved an average net production of 27,704 lb/acre at the higher stocking rate compared to 10,176 lb/acre at the lower stocking rate. Although this is the highest yield reported thus far in traditional static‐water earthen ponds in the southern USA, it may not be the maximum production possible. The average weight of harvested fish was higher at the lower density (2.2 lb versus 1.6 lb), but the feed conversion ratio was identical (1.8) at the two densities. Our data indicate that when morning DO is maintained above limiting concentrations, other factors such as direct density interactions (aggression and/or inhibitory pheromonal feedback) and/or water quality variables unrelated to morning DO—specifically un‐ionized ammonia—may play a role in catfish feed intake and growth but not food conversion.

中文翻译：

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密度对溶解氧不是限制因素的强化曝气土池中Cat鱼生产的影响

研究表明，通过将土池中的最低溶解氧（DO）浓度保持在3.0 ppm或更高，可使intake鱼Ictalurus punctatus，蓝Cat I. furcatus的饲料摄入量和生长速度提高。，和杂交hybrid鱼（母海Cat鱼×蓝Blue鱼）相比，通常在商业cat鱼养殖场采用的氧气管理方案可实现的翻倍。在较早的研究中，仅使用紧急曝气或低水平的固定曝气，由于较高的饲料投入和鱼类生物量，以较高密度放养的池塘中早晨溶解氧浓度较低，从而影响了放养率的直接影响。尽管在这些研究中较高的放养率确实产生了更高的产量，但降低的溶解氧水平可能会影响个体鱼的生长和饲料摄入，而这似乎是直接的密度效应。在这项研究中，对杂交hybrid鱼的产量进行了比较，该产量在低水位（5,000英亩/英亩）和高水位（20英亩）的情况下，每天在没有水交换的土塘中饱食。通过该研究，在使用受控密集通气的同时，在所有池塘中将最小溶解氧保持在3.0 ppm以上，同时保持000英亩/英亩的放养率。高放养率下的平均净产量为27,704磅/英亩，而低放养率下的平均净产量为10,176磅/英亩。尽管这是迄今为止在美国南部传统的静水土池中报道的最高产量，但可能不是最大的产量。在较低密度下（2.2磅对1.6磅），收获鱼的平均重量较高，但在两种密度下，饲料转化率相同（1.8）。我们的数据表明，当早晨的溶解氧保持在极限浓度以上时，