Fermentation Characteristics and Nutritional Value of Opuntia Ficus-indica Silage
CHAPTER 1 GENERAL INTRODUCTION
Agricultural drought may be defined as a deficiency of rainfall in respect to the median or to the mean that seriously impairs agricultural production for a period of several months to several years, extending over a large geographical area (WMO,1975).
difficult to find more widespread and better exploited plant, particularly in the subsistence economy of arid and semi-arid zones
drought resistance, high biomass yield, palatability and adaptability to a range ofsoils and climatic regions (Zeeman & Terblanche, 1979; Ben Salem et al., 1996; Batista et al., 2003)
The voluntary dry mater (DM) intake by sheep of fresh spineless cactus pears is less than their maintenance requirements and the animals will loose body mass. The voluntary intake of dried and ground spineless cactus cladodes, with a much lower water content than other physical forms of spineless cactus pears, was markedly higher and consequently the loss in body mass was also much less (Jacobs, 1977).
a supplement of any roughage or the adding of 3% feed lime to the ration will counteract the laxative effect (De Kock, 1998)
lucerne hay is regarded as an exceptionally suitable supplement to spineless cactus in any form (De Kock, 1980)
Besides the income from fruit production it has tremendous potential as regards job creation and small-scale farming. Fruit production necessitates the yearly pruning of the plant to get rid of diseases infected parts and to facilitate the harvesting of fruits. This available fresh plant material is mostly used as feed for sheep and beef cattle.
CHAPTER 2 LITERATURE REVIEW
Barbera (1995) stated that the presence of Opuntia was first reported in 1772 in South Africa.
According to Brutsch & Zimmermann (1995) as cited by Zeeman (2005) there issome evidence to suggest that originally (at least 250 years ago) only spineless varieties of Opuntia ficus-indicawere introduced in South Africa and that these have reverted back to the spiny form over a period of nearly 200 years
Since 1980, the first intensive and specialized plantations have been set up [in S Africa]
During 2003 more than 465 000 kg of fresh fruits were exported by sea and air from South Africa (Anonymous, 2003).
commonly used as fencing around farms and small villages, and as a windbreak [Morocco, Algeria]
In Mexico, Nopalitos are cladodes of less than one month old, are widely used in traditional Mexican cooking. The breeding of Dactylopius coccus costais also economically important for the production of carmine dye (Barbera, 1995).
Experiments have shown that sheep kept in pens can do without water for more than 500 days if they have daily access to sufficient quantities of spineless cactus (Potgieter, 2004). The research results show clearly that water intake is zero when cactus intake by sheepis about 300g of dry matter. Sheep fed for a long period (400 to 500 successive days) with large amount of cactus stopped drinking (Roussow, 1961). Woodward et al. (1915) with Jersey cows made the same observation. However, Cottier (1934) as cited by Felker (1995) suggested that it is not possibleto suppress completelywater for cattle fed on cactus.
energy requirement for the survival of a 35 kg sheep is approximately 350g of total digestible nutrients (TDN) to supply its energy needs for maintenance. Such sheep would thus have to ingest 538g of dry spineless cactus pads to obtain sufficient energy. This means that 5 to 6 kg of fresh spineless cactus must be ingested. According to De Kock (1998) a sheep can however only consume an average of 4 kg fresh cactus leaves per day. De Kock (1980) stated that the daily TDN requirements for a 400 kg beef cattle are 2 850g. Therefore, such an animal will require approximately 4 385 g of dry cactus to meet its requirements. That means a daily ingestion of 44 to 45 kg of fresh cactus cladodes. The animal only consumes an average of 40 kg of fresh cactus cladodes per day (De Kock, 1980).
high moisture content of fresh cactus is thus an important limiting factorof cactus intake by sheep.
De Kock (1980) that any ration for non-reproductive sheep and cattle should contain at least 8% of crude protein, sheep with a live weight of 35 kg requires approximately 50 g of crude protein per day. An average daily intake of 500 g from of cactus cladodes contains only 20 g of crude protein.
Potgieter (1995) mentioned that another noticeable deficiencies ofcactus pear are the low phosphorus and sodium contents, which can be supplemented with an inexpensive lick consisting of 60 % bone meal and 40 % salt.
high calcium, carbohydrate (energy) and digestibility (above 70%).
Large losses occur during grazing due to wastage Direct browsing needs very tight grazing control, otherwise wastage may reach 50 %
[cut and carry] ideal size of cubes is approximately 30 mm x 30 mm. It is in fact sufficient if the pads are chaffed in strips approximately 20 to 30 mm wide (De Kock, 1980). [little to no loss, higher labor] mobile chaff-cutter
[can be dried and hammer seived to 6 mm][feeds easier as animals don't fill up on water, but doesn't help water animals in drought either, no need for either/or use dry and fresh]
supplementation of 100g of alfalfa in summer and 200g in winter per sheep with spineless cactus meal ad libitum is recommended. Any other legume hay with reasonably high protein content can be used instead of alfalfa
CHAPTER 3 CHEMICAL COMPOSITION OF DIFFERENT OPUNTIA FICUS-INDICA CLADODES VARIETIES
no significant differences (P>0.05) in ash content between different Opuntia varieties.
CHAPTER 4 THE FERMENTATION CHARACTERISTICS OF OPUNTIA FICUS-INDICA var. FUSICAULIS
fresh cladodes to be available as feed when the plants are pruned to stimulate fruit production
cladodes contains a high water content. Therefore it is also not economical and practical to transport this bulk material
This problem could be solved by drying the cladodes. This is however a time consuming process if sunlight is used or expensive when artificially dried
[good silage] 84 parts mass of cactus cladodes and 16 parts of roughage, with the addition of molasses
When cladodes bearing fruit are used for silage, the addition of molasses is not necessary.
[cut into 20 mm squares, place on wire net in glasshouse to dry, turn to prevent mold]
CHAPTER 5 THE DIGESTIBILITY OF OPUNTIA FICUS-INDICA var. FUSICAULIS CLADODE SILAGE
200 litre plastic bag in metal drums, tightlypacked and air tightly sealed
The inclusion of molasses at ensiling however influenced DMI by sheep favourably (P=0.054). It probably increased the palatability of the silage
CHAPTER 6 GENERAL CONCLUSIONS
cactus cladode silage with less than about 30% DM will result in badly preserved silage irrespective of the inclusion level of molasse
The inclusion of 24% molasses at ensiling increased the palatability and DMI of cladode silage.
cladodes could be classified as a high moisture energy source with an energy level between that of roughages and concentrates with a low CP and high Mg, K and Ca content.