Soil fertility

The results of soil characteristics in treatments are presented in Table IV. The data show a marked improvement in soil fertility as a result of fertilizing to grass with cattle manure treated by new way. Concentration of N (N), K (in K₂O form) (K), P (in P₂O₅ form) (P) were higher in the soil fertilized with cattle manure treated with absorbents and kept in the hole with plastic roof during storing time. There was a decrease of N, P, K concentration in the soil from the first to the second harvesting time.

TABLE IV: EFFECT OF FERTILIZING CATTLE SOLID MANURE TREATED IN DIFFERENT WAYS ON VARIATION OF SOLID COMPOSITION

T1

Under farmers’ conditions in the Red river delta (RRD) of North Vietnam, commonly used feedstuffs for ruminants are crop residues. It is widely recognized that major limitations to the utilization of fibrous crop residues as a feedstuff for ruminants are associated with their low digestibility, low intake and low content of essential nutrients such as N and minerals. In this study improvement of growth performance of cattle in new group may be due to contribution of the urea treated rice straw and UMMB.

Many reports show that treatment of rice straw with urea and other chemicals improved nutritive value of rice straw. Vu Duy Giang [9] reported that treatment of rice straw with urea and Ca(OH)2 improved organic matter digestibility in cattle compared to untreated rice straw and concentration of NDF tended to reduce and voluntary feed intake in cattle

increased when they were fed urea treated rice straw. Other workers also reported positive responses of cattle in growth performance and feed utilization efficiency when they were given urea treated rice straw compared to un treated rice straw such as [5, 10].

In this study, one of reasons for improving performance of the animals in the new group is addition of UMMB to diet for cattle. UMMB supplied cattle with some essential nutrients such as by-pass protein and minerals. So with supplementation of UMMB to the ration together with urea treated rice straw improved cattle performance. These results agree with results in research of Badudeen et al., [1] and Ghebrehiwet et al., [2].

Methane production in animals during the process of fermentative digestion and metabolism represents a loss of food energy. It was observed that methanogenic energy loss is high particularly on low quality roughages such as straw-based diet [3]. In this study, lower methane production was found in the animals at the new feeding strategy group. This may due to quality of roughages for animals in these groups was improved by treatment of rice straw with urea and due to contribution of UMMB supplementation.

Leng [4] reported that 2 kg of methane produced per kg meat when animals fed mainly with straw. However, methane production can be reduce to 0.36 kg to produce kg meat by offering straw with urea and by-pass protein which may be due to the efficient fermentative digestion. The results of this study agree with statement of Saadullah [7]

that the methane production per unit of product can be reduced by 25 to 75% allowing urea molasses block, fishmeal, oil cakes etc.

In rural areas in RRD in Vietnam, farmyard manure commonly applied to the soil when it is fresh or it can be stored. Fresh manure contains large amount of easy available nutrients, but these nutrients may be easier lost under poor management. The data in Table 2 indicate that with traditional management way N loss is highest during storing time and it is a main reason for low biomass production of grasses fertilized with manure treated in traditional way.

5. CONCLUSION

The new feeding strategy improved growth performance, feed utilization efficiency and reduced methane production in local cattle. Applying to the soil solid cattle manure absorbed with rice straw ash and stored in the hole with plastic roof for three weeks before planting improved biomass yield of elephant grass and soil fertility.

REFERENCES

[1] BADUDEEN. A. N, IBRAHIM. M. N. M, S.S.E. RANAWANA, Methods to improve utilization of rice straw III. Effect of urea ammonia treatment and urea molasses blocks supplementation on intake, digestibility, rumen and blood parameters. Asian-Australasian Journal of Animal Science, 7 (1994) 363-372.

[2] GHEBREHIWET. T, P. WANGDI, M.N.M. IBRAHIM, Feeding rice straw supplemented with urea-molasses lick block to lactating cows in Bhutan. Asian-Australasian Journal of Animal Science, 6 (1997).

[3] ISLAM. M. R.,J. BEGUM, Short Review of Global methane Situation and of Facilities to Reduce in Ruminants in Third World Countries. Asian-Australasian Journal of Animal Science, 10 (1997) 157-163.

[4] LENG. R. A., Muscle metabolism and nutrition in working animals. In. Draught Animal Power for Production. J.W. Copland. (Ed). ACIAR Proceeding Series.

No. 10. Canberra (1985).

[5] PHAM KIM CUONG, VU CHI CUONG, LE VIET LY, JAN BERG, Effects of cottonseed meal and fish meal supplemented to the basal diets of untreated or urea

treated rice straw on the ruminant characteristics, in sacco, DM, CP degradability, apparent digestibility of feed and performance of growing cattle. Workshop on Improved Utilization of By-products for Animal Feeding in Vietnam. The Agricultural Publishing House. Hanoi. 2002. 124-145 p.

[6] RICHARD. T. L., Eliminating Waste. Strategies for Sustainable Manure management. Proceedings Pre-conference Symposia. The 8^th World Conference on Animal Production. June 28-July 4. 1998. Seoul National University. Korea.

1998. 488-196 p.

[7] SAADULLAH. M., Livestock – its importance, problems and potential and its linkage with agriculture and energy. Proceeding of the Bangladesh Animal Husbandry Association, 4 (1992) 106-129.

[8] SINGH. G. P., New Methane Measurement Technique Using Sulphur Hexaflouride Tracer Technique. Unpublished Report. National Dairy Research Institute. India (1993).

[9] VU DUY GIANG, NGUYEN XUAN TRACH, Effects of treatment with lime and/or urea on rice straw chemical composition, intake and degradability.

Workshop on Improved Utilization of By-products for Animal Feeding in Vietnam. The Agricultural Publishing House. Hanoi. 2002. 162-175 p.

[10] VU VAN NOI, PHAM KIM CUONG, DINH VAN TUYEN, VU CHI CUONG, USE of urea treated rice straw as one of fibre components in finishing diet of cattle. Workshop on Improved Utilization of By-products for Animal Feeding in Vietnam. The Agricultural Publishing House. Hanoi. 2002. 104-109 p.

[11] León-Velarde, C., Quiroz, R.A., Cañas, R., Osorio, J., Guerrero, J. and Pezo, D., LIFE - SIM: Livestock Feeding Strategies Simulation Models. Working Paper No. 2006-1. International Potato Center, Lima, Perú. 37 p (2006).

[12] Minitab Statistical Software (Version 13.31), Minitab Inc., Pennsylvania, USA (2000).

INTEGRATION OF FEEDING STRATEGIES AND MANURE MANAGEMENT FOR IMPROVING MILK PRODUCTION OF DAIRY COWS AND CONSERVING THE ENVIRONMENT UNDER FARMER’S CONDITIONS IN SOUTH VIETNAM

DOAN DUC VU, NGUYEN VAN TRI Ruminant Research Department,

Institute of Agricultural Sciences for Southern Vietnam, Ho Chi Minh City, Vietnam

Abstract

Six farms with 4 dairy cows (75% of Holstein Friesian) each in Hoc Mon district, Ho Chi Minh City, Vietnam were selected and divided into two groups (three farms; 12 cows each). In group 1, animals were fed using traditional feeding system verses a new feeding strategy in group 2. The diet in the traditional feeding system was composed of grasses, untreated rice straws, cassava waste, brewery waste and concentrate. In the new feeding system, rice straw was treated with 4% urea and animals were supplemented with urea molasses multi-nutrient blocks (UMMB).

In each group, the animals were further divided into two groups for manure collection. In one group, the traditional manure storage method i.e. sun-drying was used whereas in the other, manure was stored roofed and covered and the manure from the different storage methods subsequently used as fertilizer for grasses. The results showed that the new feeding system with urea treated rice straw and UMMB improved milk production and reduced methane production.

Roofing and covering manure reduced N loss from the manure and improved soil fertility and biomass yield of the test grasses.

1. INTRODUCTION

Livestock production is a traditional sector, which is developing rapidly in Vietnam. The population of ruminants in 2007 was 6.8 million heads of cattle, 3.0 million buffaloes and 1.8 million goats and sheep. Ruminant production in Vietnam is different from those in developed countries in that it is mainly composed of small farms with two to 4 heads of cattle/buffaloes and/or 10 to 15 sheep and goats. Coupled with the small farm sizes is low knowledge and skill of farmer implying most livestock is reared in a semi-intensive systems, which combines grazing, and supplementation of crop residues such as rice straw and peanut hay at cattle sheds after grazing.

Most of dairy farms are concentrated around Hochiminh City and Hanoi the capital for close proximity to the milk processing factories. Currently, the dairy cattle population is approximately 100,000 with almost 70,000 of the cattle around Hochiminh City. As the land size for dairy farmers is gets smaller and smaller and the increasing population of dairy cattle around the cities, the issue of roughage shortage and environmental pollution becomes of great concern.

Furthermore, as a hot and humid tropical country, the quality of forages and crop residues is low. This leads to low animal productivity and high methane production from the animals due to inefficient fermentation in the rumen. Low quality roughage and the nutritionally imbalanced diets, especially energy and protein are the main factors effecting methane production. Thus, treating of roughages with urea, feed supplementation, balancing the ration and improving the environmental condition of

cattle sheds are basic methods to decrease methane production and improve the efficiency of feed utilization and therefore increase the overall productivity of the animals.

Additionally, because Vietnam is an agriculture country, people have always used manure for crop production. However, the management and utilization of manure are still very simple resulting in considerable losses of N and P into the environment. The traditional methods are composting manure with others waste such as straw, grasses, tree leaves. For a faster composting process, farmers normally add lime to the compost and this causes more losses of nutrients from the manure. Another method for treatment manure is sun-drying, but it also leads to nutrient losses especially N. Recently, farmers have started making manure compost with yeast or using red worms (perionyx excavatus) to treat the manure which shorten the time required to cure the compost as well as to reduce the loss of nutrients. In small pig or dairy farms, biogas production is also normally used for manure treatment. Solid waste, urine and wastewater from stable are gathered into plastic bags or concrete pool for biogas production. The waste product after fermentation has a high nutrient value and is used to fertilize grasses.

The overall objective of this project was to improve livestock productivity through better nutritional strategies while conserving the environment. The specific objectives were to improve milk production and decrease methane, N and P pollution into the environment in dairy farms.

2. MATERIALS AND METHODS