**Abstract**

Intensive livestock farming systems are vital for sustaining the growing world population by providing several goods and services. However, the increased livestock operations cost, particularly related to animal feeding, compromises the expansion of this industry, especially in developing countries. One way to reduce the feeding costs without compromising the nutritional quality would be the use of protein-rich food waste discarded by the industries that otherwise would pollute the environment. This chapter presents an overview of the intensive livestock farming systems in developed and developing countries and discusses the use of agro-industrial by-products as alternative sources of nutrients to improve livestock productivity, as well as the key nutritional components that are likely involved to improve the reproductive performance of animals. Our results showed that diets containing 30 to 45% of coconut meal, rich in ether extract and protein, may improve sperm progressive motility, sperm concentration per mL, total sperm per ejaculate, and total viable sperm per ejaculate of beef goats, compared with diets with no or lower coconut meal content. Diets with coconut meals may also enhance the semen quality of sheep.

**Keywords:** goats, lipid and protein resources, semen quality, sheep, testicular parameters
