**1. Introduction**

Ensilage is the method of forage conservation based on conversion of water‐soluble carbohy‐ drates in organic acids by the activity of lactic acid bacteria, which reduces the pH and preserve the fresh forage [1].

The ensiling process show advantages such as conservation of large quantities of forage in short time and forage conservation is less weather dependent. However, a disadvantage of the ensiling process is the relative reduction of feeding value of the silage when compared to the

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

original crop [2]. Although, correct management of silages and use of additives may stimulate the intake of silages and improve the digestibility of silages.

organic acid concentration is variable and it is influenced by management of the ensilage process, use of additive and principally by forage characteristics. This variation is recognized

> **BA (g/kg DM)**

**Ethanol (g/kg DM)** 

3.7 38.6 14.3 1.4 2.0 3.5 10.1 17.5 Hassanat et al.

3.9 63 14.4 2.8 0.71 – 48 – Dos Santos et al.

4.0 20.4 5.85 0.15 0.38 – 43.5 17.99 Ridwan et al.

4.2 74.2 26.1 2.4 0.9 2.2 27.7 18.3 Hassanat et al.

4.1 37.6 12.7 0.1 12.1 – 100.1\* 21.2 Rong et al. [16]

3.81 80.2 22.5 8.1 05 – 9.0 20.4 Nogueira [17]

Restle et al. [9] evaluating the performance of feedlot calves receiving grass silage (*Brachiaria plantaginea*) and corn and sorghum silages, found that corn and sorghum silage promoted higher intake and better performance than the animals fed grass silage. Although the authors justify the higher dry matter intake of animals fed with corn and sorghum silage was due to an increasing difference in weight, which interfere directly in the intake values, the result may have also occurred because the fermentative characteristics and different end‐products of

The dry matter intake (DMI) is determinant to ingress of nutrients to cater to the requirements for animal maintenance and production, principally the intake of protein and energy [10]. The DMI is the factor that affects the animal productive performance, since 60–90% variation in

3.66 61.5 16.7 0.1 0.4 18 6.68 – Santos [13]

**NH3‐N (mM/g DM)**

**WSC (g/kg DM)**

[12]

Intake and Digestibility of Silages http://dx.doi.org/10.5772/65280 103

[14]

[15]

[12]

**Crop Ensiling characteristics Author**

**PA (g/kg DM)** 

and search object of researchers worldwide (**Table 1**).

**AA (g/kg DM)** 

**pH LA (g/kg DM)** 

Corn silage (*Zea mays*

Sorghum silage (*Sorghum bicolor* L. Moench)

Pearl millet silage (*Pennisetum glaucum*

Calliandra silage (*Calliandra calothyrsus*)

Napiergrass silage (*Pennisetum purpureum*

Cactus palm silage (*Opuntia ficus indica*)

**Table 1.** Fermentative characteristics of silages.

fermentation concentration.

**3. Factors that interfere on the silage intake**

Alfafa silage (*Medicago sativa*)

Schum)

\*NT.

L.)

LR)

The forages may have changes in the nutritive value due to the procedures during production, conservation and post‐opening management and biochemical and microbiology phenomena [3]. Besides the conversion of carbohydrates in organic acids occurs by the partial breakdown of proteins, which gives the non‐protein structures. These changes depend on the interaction between microorganisms on the material to be ensiled and amount and type of the substrate [4].

The silage quality affects the intake and digestibility of ruminants. Basically, the main factors that can interfere with the fermentation of the silage is the dry matter (DM) content, water‐ soluble carbohydrate (WSC) concentration and microorganism populations present in the forage. Forage with low DM and WSC concentrations may show undesirable fermentation and forage with excessive WSC content may generate acidic silages, which reduces silage intake.

Some end‐products of fermentation, such as acetic and butyric acids and ammonia, are associated with the decrease in the intake of silages. Poorly fermented silages have large concentrations of undesirable compounds that explain the low silage intake.

Some changes resulting from the ensiling process influence the digestibility of silages. High concentration of ammonia, for example, can interfere in digestibility of the silage, and enter the N recycling cycle and increase the animal energy costs.

The objective of this chapter is to explain how end‐products of fermentation of the silage and changes in the structure of forage resulting from the ensiling process can affect the intake and digestibility of silages.
