Corrigendum: Feed conversion efficiency in aquaculture: do we measure it correctly? (2018 Environ. Res. Lett. 13 024017)

Jillian P Fry1,2,3,6 , Nicholas A Mailloux1 , David C Love1,2 , Michael C Milli1 and Ling Cao4,5 1 Johns Hopkins Center for a Livable Future, Johns Hopkins University, 111 Market Place, Baltimore, MD, United States of America 2 Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe Street, Baltimore, MD, United States of America 3 Department of Health, Behavior and Society, Bloomberg School of Public Health, Johns Hopkins University, 624 N Broadway, Baltimore, MD, United States of America 4 Center on Food Security and the Environment, Stanford University, 616 Serra St, Stanford, CA, United States of America 5 Institute of Oceanography, Shanghai Jiao Tong University, Shanghai, People’s Republic of China 6 Author to whom any correspondence should be addressed. OPEN ACCESS

The published article used dressed weight (i.e. head, guts, and other body parts removed) as the edible portion (i.e. yield) values for terrestrial species. This was an error, and instead we should have used yield values based on retail cuts of meat, which is consistent with the values used for farmed aquatic species. Therefore, we have replaced the dressed weight values with retail cut values for beef cattle and pigs, including bone-in and boneless values, similar to yield values used for aquatic animals. Chickens are commonly sold in a dressed form (i.e. dressed weight is a retail cut for chickens), so a combination of dressed weight and other retail cut values were used for chickens. We recalculated the protein and calorie efficiencies for these terrestrial species, and the following tables and figure below are corrected for beef cattle, pigs, and chickens: tables 1 and 2 and S4; figure 2. These revisions do not pertain to any data or calculations for aquatic animals.
These changes result in the following text revisions: 1. In the abstract, the sentence: Comparing all terrestrial and aquatic animals in the study, chickens are most efficient using these measures, followed by Atlantic salmon. Revision: Comparing all terrestrial and aquatic animals in the study, chickens and Atlantic salmon are most efficient using these measures.
2. In the first paragraph of section 3, the following text: Protein retention means ranged from 14%-28% for the nine aquatic species, and 13%-37% for livestock. Calorie retention means ranged from 6%-25% for the aquatic species, and 7%-27% for livestock. Chickens performed best for both protein and calorie retention, followed by Atlantic salmon.

Revision:
Protein retention means ranged from 14%-28% for the nine aquatic species, and 10%-34% for livestock. Calorie retention means ranged from 6%-25% for the aquatic species, and 5%-25% for livestock. Chickens and Atlantic salmon performed best for protein and calorie retention.

4.
In the third paragraph of section 3, the following sentence: Similar to above, chicken and Atlantic salmon have the highest mean calorie retention: 27 and 25%, respectively. Pigs have an FCR (3.9) that is less efficient than chicken and aquatic species, but high calories in edible flesh (211-304 kcal per 100 g) and the high edible portion (0.68-0.76) improves pig calorie retention (16%). Revision: Chicken and Atlantic salmon have the highest mean calorie retention: both 25%. Pigs have an FCR (3.9) that is less efficient than chicken and aquatic species, but high calories in edible flesh (211-304 kcal per 100 g) improves pig calorie retention (11%).     [18], National Pork Board [19], National Renderers Association [10], Oklahoma Department of Agriculture, Food, and Forestry [20], University of Kentucky Cooperative Extension Service [13].