Grazing in Livestock: Definition and 4 Key System Types

Grazing is a fundamental practice in livestock production that involves allowing animals to directly consume the growing forage, including grasses, legumes, and forbs, in a pasture or rangeland.

This article aims to provide clarity on various grazing systems and terms commonly used in livestock production while emphasizing the importance of maintaining a balance between forage and livestock production, biodiversity, and ecosystem services.

Types of Grazing Systems:

1. Continuous Grazing: Under this system, livestock continually graze on a large section of land without rotation.
2. Deferred Rotational Grazing: In deferred rotational grazing, livestock are moved periodically between different sections of land to allow forage regrowth.
3. Rest Rotational Grazing: Rest rotational grazing involves resting a section of land for an extended period to allow forage to fully recover before grazing livestock return to that area.
4. Management-Intensive Grazing: Management-intensive grazing is a more intensive system that involves dividing land into smaller paddocks and carefully managing livestock movements for optimal forage utilization.

Key Terms in Grazing:

Stocking Rate:

The stocking rate refers to the number of animals per unit area of land. It is essential to strike a balance between understocking, which leads to land and herbage wastage, and overstocking, which results in low animal production, overgrazing, and soil erosion. Recommended stocking rates vary depending on the type of grazing area.

Recommended stocking rates are:

1. Well-fertilized ley: 3.5-5.0 adult beasts/ha
2. Average ley: 2.5-3.5 adult beasts/ha
3. Permanent rough grazing: 0.5–1.0 adult beasts/ha

Grazing Pressure:

Grazing pressure refers to the intensity of animal grazing on the available forage in a grazing area. Higher grazing pressure occurs when more animals graze in a given area, which can affect pasture health and animal productivity. It is crucial to monitor and manage grazing pressure to maintain a sustainable balance.

Specific Grazing Techniques:

a). Night Paddocking:

Night paddocking is a method in which cattle graze freely across a large area during the day but are confined to a smaller space during the night. Extensive research conducted in different regions of East Africa has demonstrated that Zebu cattle engage in approximately 25 percent of their grazing activities at night, primarily between 2.00 and 5.00 a.m. Conversely, exotic cattle exhibit an even higher proportion of nocturnal grazing.

Implementing night paddocking offers several benefits. Firstly, it enhances the overall well-being of the animals. This practice may serve as a deterrent against theft and wild animal attacks since the cattle remain near their home base during the night.

b). Strip Grazing:

Under this approach, animals are confined to small, enclosed plots of land where they are encouraged to consume nearly all of the vegetation within those limited areas before being moved to another location. The grazing strips are intentionally small, requiring the animals to graze intensively.

After one or two days, a new grazing strip is used, and the fence is moved forward. During the rainy season, approximately one adult animal can be accommodated on a quarter hectare. This method of grazing has proven to be highly effective.

c). Tethering:

In East Africa, tethering is a commonly used method to graze goats, sheep, and occasionally cattle. This practice involves tying the animals to ropes that are securely anchored to the ground. By using tethering, the animals are confined to a specific area, preventing them from wandering off. It is often employed when there is a scarcity of grazing land or to prevent animals from accessing certain locations.

Tethering serves as a means to manage animal movement and mitigate overgrazing in certain regions. However, it is important to consider the welfare of the animals by ensuring they have access to an adequate supply of food, water, and shelter while they are tethered.

d). Zero Grazing:

Animals are confined within pens, and their feed is prepared and brought directly to them. Among the varieties of fodder used, elephant grass and Guatemala grass (Trisacum laxum) are occasionally provided to cattle using this approach. This practice is predominantly observed in Africa, where it offers several advantages.

It minimizes the need for animals to extensively wander in search of water and pasture, thus preventing potential crop damage, soil erosion, and destruction of farm structures. Nonetheless, it should be noted that this method requires significant labor investment.

Fodder Crops

Fodder crops are cultivated specifically to provide herbage for silage or hay, and they can also be used for grazing during the dry season. Common fodder species include elephant grass, Guatemala grass, lucerne, sorghum, maize, bullrush millet, and soybeans. Harvesting these crops before the stems become woody and fibrous ensures optimal nutritional quality.

Descriptions of Selected Grass Varieties:

a). Rhodes Grass (Chloris gayana):

The grass thrives in regions situated between 610 and 1525 meters above sea level. As a stoloniferous perennial, it can reach a height of up to 1.5 meters. The grass reproduces by utilizing stolons, which carry two to four leaves at each node.

It is native to East Africa and exhibits robust growth during the initial 1 to 1.5 years. However, its yield gradually diminishes over time. The grass can be established either by sowing seeds at a rate of 2.2 kg per hectare or through the use of splits or rooting stolons.

b). Kikuyu Grass (Pennisetum clandestinum):

The plant is indigenous to East Africa and thrives in elevated areas, specifically at altitudes ranging from 1525 to 3050 meters above sea level. It exhibits exceptional productivity, offers excellent taste, and is highly nutritious. As a persistent crop, it serves as a valuable resource for long-term grazing purposes. Notably, it does not propagate through seeding but rather through slips for establishment.

c). Guinea Grass (Panicum maximum):

It reaches a maximum height of 3 meters and thrives in warm climates. This plant exhibits excellent drought resistance and is occasionally cultivated for hay production. While it can be propagated through either seeds or splits, the latter method is not commonly employed. Remarkably, it has the potential to yield an impressive 4.5 metric tons of herbage per hectare.

Varieties of Guinea grass, such as Likoni, Tengeru, Makueni, and Sabi, have been specifically developed or selected for their desirable characteristics. Each variety possesses certain traits that make it suitable for various purposes or environments. For instance, some varieties exhibit improved yield, disease resistance, or adaptability to specific climatic conditions.

When selecting the appropriate variety of Guinea grass for a specific location or farming system, it is crucial to consider factors such as the local climate, soil type, and intended use. Seeking guidance from local agricultural experts or extension services can provide further assistance in determining the most suitable variety for a particular area.

d). Congo Signal Grass (Brachiaria ruziziensis and Brachiaria brizantha):

Brachiaria ruziziensis is a perennial grass that grows up to 1 meter in height. It originates from the Congo and is established through seed propagation. This grass responds well to nitrogen fertilization. It is recommended to provide cover when the grasses and legumes have been depleted through grazing.

e). Jaragua Grass or Thatching Grass (Hyparhenia rufa):

Jaragua grass is a tufted perennial that can reach a height of 4 meters. It is commonly found in dry regions with low fertility. It dominates grassland communities in savanna areas and thrives at elevations between 1525 and 1830 meters above sea level.

Jaragua grass is well-suited for poor soils, but it cannot withstand poor management or heavy grazing. Establishing this grass from seed can be challenging due to the long awns on the seeds. It mixes well with Chloris gayana and Stylosanthes gracilis, and it has good seed production.

f). Nandi Setaria (Setaria anceps):

Formerly known as Setaria sphacelata, Nandi setaria is a tufted perennial that can grow up to 2 meters tall. Its leaves are succulent when young. It thrives from sea level up to 2135 meters above sea level and is a highly persistent grass. It provides good nutrition and palatability during its young stage.

In Kenya, only one cultivar of Setaria, called Nandi, is cultivated, and it mixes well with Louisiana clover and Desmodium species. The establishment of Nandi Setaria is done through seed propagation, and it has good seed production.

g). Molasses Grass (Melinis minutiflora):

Molasses grass is a creeping perennial with sticky, aromatic leaves. Its creeping nature allows it to provide good ground coverage. It is widely cultivated in Kenya. The best ecological habitat for this grass is 1830 meters above sea level. It tolerates acid soils but is susceptible to the small-leaf virus. Propagation is done through seeds.

h). Guatemala Grass (Tripsacum laxum):

Guatemala grass is a tall perennial fodder grass known for its broad leaves. It can thrive in waterlogged areas, making it suitable for cultivation in wet or swampy regions. Livestock farmers often use Guatemala grass as a forage crop due to its high productivity and nutritional value. It provides ample grazing material and can be used for hay or silage. Its tolerance to waterlogged conditions makes it a valuable choice for areas with poor drainage.

i). Elephant Grass or Napier Grass (Pennisetum purpureum)

Elephant grass, also known as Napier grass (Pennisetum purpureum), is a tall perennial grass that thrives in areas receiving 640 to 760 mm of rainfall. It can grow to a height of 5 to 7 meters, with the top two meters being succulent, leafy, and highly nutritious, making it suitable for silage production or stall feeding.

The grass can be established using whole canes, cane cuttings, or rooted shoots. When using cane cuttings, it is important to ensure that each cutting has about four nodes. The canes or cuttings are buried in furrows created by plows or hand hoes, with overlapping placements or sometimes inserted upright into the ground.

The spacing of Elephant grass varies depending on the rainfall and soil type. In Uganda, row widths typically range from 1 to 2 meters, with narrower rows resulting in better stand density. Wider row widths, on the other hand, are suitable for poor soils or dry conditions. In Kenya, row widths can range from 1 to 3 meters.

Elephant grass is known for its high yield potential, with production reaching 112 to 135 tons of green material per hectare per year. At the Entebbe Experimental Station under irrigation, yields of up to 225 tons per hectare per year have been achieved.

One of the key benefits of Elephant grass is its ability to improve soil fertility. By providing a substantial amount of organic matter, the grass facilitates the release of nutrients from the lower layers of the soil.

However, there are some challenges associated with establishing Elephant grass. It can be difficult to manage, as it tends to die out under heavy grazing pressure. The grass becomes woody quickly and is most nutritious when it is at a height of 1 to 2 meters. There is also a risk of grazing animals getting injured by the sharp leaves. Moreover, due to its high water content, cattle may not consume sufficient bulk if fed fresh, necessitating wilting to increase dry matter intake.

Conclusion

In conclusion, grazing is a fundamental practice in livestock production, and understanding the various grazing systems and terms is essential for maintaining a sustainable balance between forage and livestock production, biodiversity, and ecosystem services. By implementing appropriate grazing systems such as continuous grazing, deferred rotational grazing, rest rotational grazing, and management-intensive grazing, farmers can optimize forage utilization while ensuring the long-term health of pastures and animal productivity.

Key terms like stocking rate and grazing pressure play a crucial role in managing grazing systems effectively. Striking the right balance in stocking rates prevents wastage of land and herbage or overgrazing and soil erosion. Similarly, monitoring and managing grazing pressure help maintain a sustainable balance in pasture health and animal productivity.

Specific grazing techniques like night paddocking, strip grazing, tethering, and zero grazing offer innovative approaches to maximize the benefits of grazing while addressing specific challenges. These techniques provide benefits such as enhanced animal well-being, theft and predator deterrence, intensive forage utilization, and reduced environmental impact.

Incorporating fodder crops into the grazing system can ensure a consistent supply of high-quality forage throughout the year. Cultivating suitable fodder crops like elephant grass, Guatemala grass, lucerne, sorghum, and soybeans can provide herbage for silage, hay, and grazing during the dry season. Selecting appropriate grass varieties such as Rhodes grass, Kikuyu grass, Guinea grass, Congo signal grass, Jaragua grass, Nandi setaria, Molasses grass, Guatemala grass, and Elephant grass is crucial for optimizing productivity and adaptability to specific environmental conditions.