The aim of this paper was to systematically reviewing the selected feed factors. A worldwide food demand, including animal-derived food is highly predictable to increase at 60% by 2050, particularly in developing countries. By 2030, an annual meat consumption is also estimated to grow from 25.5 to 37 kg per person. In some parts of the world; however, such a growing demand isn’t currently matching with a comparable growth in the local production. For example, by 2050, around 40% of an animal-sourced food could be imported by African countries. Although such insufficiency of an animal-sourced food is generally due to that of the farm-animals’ low productivity, this is specifically believed to be because of the poor quality and inadequacy of the feeds. Both anti-nutritional factors (ANFs) and mycotoxins are the main factors that can contribute to the low quality and less efficiency of the feeds. Although some have beneficial effects, at their low concentrations, anti-nutrients are generally accountable for the harmful effects on the nutrient absorption. For example, up to 50, 23 and 10% of proteins and amino acid digestibility, in non-ruminant animals are reduced by the presence of trypsin inhibitors (TI), tannins and phytates, respectively. Feeds that are toxic for the mono-gastric animals may not be toxic to the ruminants. Soaking/roasting followed by pressure cooking is one of the best treating mechanisms to reduce those of the harmful effects of ANFs. Supplementation of the feeds with typical microbial enzymes, particularly when they are in a combined state enables also to reduce the negative effects of ANFs. A quarter of the world’s crops are being contaminated by the molds and fungi, and hence aflatoxin is an inevitable contaminant. Consequently, when animals eat these contaminated feeds, with aflatoxins the milk, eggs and meat could have the safety concerns to the human consumers. Due to that of some weak regulatory standards, the South-East Asian and sub-Saharan Africa (SSA) countries remain at a high risk of aflatoxin contaminations. In addition to that of the carrying-over impacts of aflatoxins, ANFs and mycotoxins are the main factors that are reducing the feed quality and efficiency, in animal production.