Preface

Sheep farming is mainly important in the poorest regions of the world, particularly in those where the country itself has few economic resources. Thus, this activity serves as a livelihood for many families, ensuring their survival. As such, it is important that sheep farming develops in such a way as to improve economic conditions.

This book examines ways to use natural resources in sheep farming. Section 1 discusses sheep feeding and examines how sheep digest feeds in the Sahel countries. It also examines sheep grazing management in the mountain region of Serra da Estrela, Portugal. Sheep farming is vitally important in these regions and relevant for sustaining their environment, biodiversity, and culture. Section 2 discusses growth and carcass yield, which are relevant characteristics for meat production. It is true that the carcass yield varies with the animal's growth. If the animal expresses most of its genetic potential and increases its average daily weight gain, it reaches its slaughter weight earlier and is more likely to generate profits for the producer. The chapter uses an example in Ethiopia to illustrate how to improve the growth and yield of sheep carcasses. In addition, the chapter presents a case of using computed tomography and thermography to diagnose respiratory disorders in sheep. The production of these small ruminants can be improved or made more efficient using new technologies, leading to precision zootechnics. The use of these technologies is not intended only for intensive systems; in fact, there are many and varied examples of the use of new technologies in extensive systems improving production and the quality of life of farmers.

> **António Monteiro** Agrarian School of Polytechnic Institute of Viseu, Viseu, Portugal

**1**

Section 1

Feeding Sheep

Section 1 Feeding Sheep

**3**

**Chapter 1**

**Abstract**

**1. Introduction**

dairy and meat products [1].

Sheep Digestive Physiology and

Sheep have a gastrointestinal tract similar to that of other ruminants. Their stomach is made up of four digestive organs: the rumen, the reticulum, the omasum and the abomasum. The rumen plays a role in storing ingested foods, which are fermented by a complex anaerobic rumen microbiota population with different types of interactions, positive or negative, that can occur between their microbial populations. Sheep feeding is largely based on the use of natural or cultivated fodder, which is exploited in green by grazing during the growth period of the grass and in the form of fodder preserved during the winter period. Ruminant foods are essentially of plant origin, and their constituents belong to two types of structures: intracellular constituents and cell wall components. Cellular carbohydrates play a role of metabolites or energy reserves; soluble carbohydrates account for less than 10% dry matter (DM) of foods. The plant cell wall is multi-layered and consists of primary wall and secondary wall. Fundamentally, the walls are deposited at an early stage of growth. A central blade forms the common boundary layer between two adjacent cells and occupies the location of the cell plate. Most of the plant cell walls consist of polysaccharides (cellulose, hemicellulose and pectic substances) and lignin, these constituents being highly polymerized, as well as proteins and tannins.

Constituents of Feeds

*Samir Medjekal and Mouloud Ghadbane*

**Keywords:** cell wall, rumen microbiota, sheep feeding, tannins

Food is, in general, one of the main factors affecting animal production. Its effects can be noted on both the quantity and quality of animal products. Although this idea is easily accepted by technicians and breeders, especially aware of the negative effects of poor, inadequate or unbalanced nutrition. Ruminant farming depends mainly on the availability and the quality of the fodder. In developing countries, the low forage potential, linked to the limitation of water and arable area, has great difficulties in producing sufficient high-quality animal protein for the human population and involves a massive use of imports of animal products such as

Herbivores, and especially ruminants, occupy a prominent place in the world, among domestic animals bred for production. Their contribution to satisfying humanity's food needs through the milk and meat they are made to produce is of paramount importance. Ruminant animals have the advantage over monogastric animals of being able to extract and use the energy contained in a plant biomass which cannot be used directly by man because of its high lignocellulose content. As such, ruminant animals cannot be regarded as a direct competitor of man to his food biomass [2].

## **Chapter 1**
