Livestock Research for Rural Development

Volume 9 Number 1



Effect of dietary protein level and duckweed (Lemna spp) on reproductive performance of pigs fed a diet of ensiled cassava root or cassava root meal

Le thi Men, Bui Hong Van, Mai thi Chinh and T R Preston

 Cantho University, Cantho, Vietnam
*University of Tropical Agriculture, Thu Duc, Ho Chi Minh City, Vietnam


A trial was carried out during an 18 month period, from February 1995 to June 1996 at the experimental farm of Cantho University. The experimental animals were 16 local Baxuyen sows mated to Yorkshire boars. The trial was designed as a 2*2 factorial with two levels of protein in pregnancy (200g vs 150g/sow/day ) and two levels of duckweed (Lemna spp) (0 vs 50% substitution of the protein allowance) for pregnant and lactating sows. The treatments were applied during the first and second reproductive cycle (pregancy plus lactation)..

 The basal diet in the first cycle was ensiled cassava root, and in the second cassava root meal, as complete replacement for cereals with a protein supplement (50% fishmeal and 50% soya bean meal). On the duckweed treatments, the protein allowance (150 or 200 g/day during pregnancy and 400 g/day during lactation) was reduced to half and duckweed fed ad libitum.

 The parameters litter size, litter weight and total feed DM during lactation per unit weight piglet were not affected by the level of protein but were improved sisgnificantly by feeding duckweed.

 It is concluded that a diet of ensiled cassava root, or cassava root meal, with 75 g protein per day in pregnancy and 200 g/day during lactation, plus fresh duckweed ad libitum, can completely replace a conventional cereal-based diet for sows.

 Key words: Pigs, sows, reproduction, lactation, protein level, duckweed, cassava root


Duckweed (Lemna spp) as protein supplement in an ensiled cassava root diet for fattening pigs

Bui Hong Van, Le thi Men, Vo van Son and T R Preston*

Department of Animal Husbandry, Faculty of Agriculture,
Cantho University, Vietnam
*University of Tropical Agriculture, Thu Duc, Ho Chi Minh City, Vietnam


An experiment was carried out during 120 days in 1995 at the experimental farm of Cantho University using 24 pigs (Yorkshire X Landrace-Baxuyen) allotted in a completely randomized design with two treatments and three replications. The pigs had an average initial liveweight of 25.8 kg and were fed (ECR) ensiled cassava root and duckweed (Lemna spp) with a protein supplement or (control) a concentrate diet based on rice by-products.

 There were no significant differences in daily weight gain or feed conversion between treatments. The pigs fed ensiled cassava root and duckweed had thinner back-fat as compared with control pigs (P= 0.002).

 It is concluded that a diet based on ensiled cassava root and with duckweed (Lemma spp) replacing part of the protein supplement can replace the rice by-products traditionally used to fatten pigs in Vietnam.

 Key words: Pigs, ensiled cassava root, duckweed, fattening


Use of the nylon bag technique for protein and energy evaluation and for rumen environment studies in ruminants

E R  ěrskov and W J Shand

International Feed Resource Unit, The Rowett Research Institute,
Greenburn Road, Bucksburn, Aberdeen, AB21 9SB, UK


The nylon bag technique is a very robust and powerful tool with which to study several aspects of nutrition in ruminants. It is particularly useful in describing degradation characteristics of protein and roughages and also for rumen environment studies. For each purpose a slightly different approach has to be used. This article explains how this is best achieved.

Key words: Rumen, nylon bag, digestibility, degradation characteristics, gas production


Methods for establishing and evaluating a goat introduction project

Jennifer K Ketzis

Department of Animal Science,
Cornell University, Ithaca, New York 14853


While goat-introduction projects are gaining in popularity, they are not always appropriate. This paper outlines some of the issues to consider when determining if a goat project is appropriate. Also, basic issues to consider when establishing and evaluating the success of a goat introduction project are covered. Examples from a project in Honduras are presented to illustrate some of the key points.

 Key words: Goats, development


Sugar cane tops as a feed for goats;
Effect of harvest season

Nguyen Thi Mui, Dinh Van Binh, Le Viet Ly and T R Preston*

Goat and Rabbit Research Centre, Son Tay, Hatay, Vietnam
* University of Tropical Agriculture, Finca Ecologica, Thu Duc, Ho Chi Minh City, Vietnam


Two feeding trials were done to compare sugar cane tops with guinea grass as the main forage source for weaned goats in both the wet (July-December 1995) and dry seasons (January-May 1996). There were six groups (wet season) and five groups (dry season), each of 2 goats, on each forage source. The rest of the diet consisted of leaves of Trichanthera gigantea and Acacia mangium (wet season) or of Jack fruit (dry season). In both seasons there were additional supplements of a molasses/urea block and concentrate. For the wet season the trial began 25 July 1995 and ended December 1995; for the dry season the trial began in January 1996 and ended in May 1996.

 There was no significant difference in liveweight gain in the wet season between goats fed sugar cane tops and guinea grass. In the dry season, the growth was significantly higher for goats fed the sugar cane tops . Data for feed conversion showed a similar pattern with significant improvements in goats fed sugar cane tops compared with guinea grass in the dry season. Growth rates on sugar cane tops were 49% higher in the dry than in the wet season. The improvement for guinea grass in the dry season compared with the wet season was 25%. Feed conversion was better in the dry than in the wet season for sugar cane tops but the opposite was the case for the guinea grass.

Key words: Sugar cane tops, goat, guinea grass, growth, season


Chemical composition of cashew apple and cashew apple waste ensiled with poultry litter

La Van Kinh, Vu Van Do and Dang Duc Phuong

Institute of Agricultural Sciences, Ho Chi Minh City, Vietnam


The aims of this study were to examine the possibility of using whole cashew apple and cashew apple waste (a residue from fruit processing) as feed for dairy cows by ensiling them with poultry litter. The basic material was either the waste` (after juice extraction) or the whole cashew apple. Four treatments (combinations with poultry litter) with each product were compared. as follows: 100% cashew apple waste (CAW) or cashew apple (CA), 90% CAW (or CA) +10% poultry litter (PL), 80% CAW (or CA) + 20% PL and 70% CAW (or CA) + 30% PL based on fresh weight. The materials were ensiled in glass jars (2.5 litres capacity). There were 3 replications (jars) of each treatment of whole fruit and waste and of each of the sampling times, which were at 0, 3, 7, 15 and 30 days after ensiling.

 The pH fell rapidly in the first three days and continued to fall until the 7th day to a constant value of around 4.45. Total sugars also were reduced dramatically in the first three days (from 12.2 to 1.9% in DM). The sensory evaluation showed that the silages from 100% CAW or 90% CAW and 10% PL were of acceptable quality (yellow colour, nice smell) and those from 80% and 70% CAW were not acceptable (dark colour, bad odour).

 It is concluded that cashew apple fruit and cashew apple waste (after juice extraction) can be preserved for long term use by anaerobic ensiling and that there appeared to be little advantage in mixing them with poultry litter before ensiling. The conversion of the soluble sugars into organic acids and alcohol may have negative effects on nutritive value. Feeding trials are necessary to evaluate this.

Key words: Cashew apple fruit, waste, ensiling, composition


Use of Trichantera gigantea leaf meal and fresh leaves as livestock feed

Nguyen Thi Hong Nhan, T R Preston* and Frands Dolberg**

Department of Animal Husbandry, Faculty of Agriculture, Cantho University, Vietnam
*University of Tropical Agriculture, Thu Duc, Ho Chi Minh City, Vietnam
**Department of Political Science, University of Arhus, Denmark


Studies were done to detemine the optimum inclusion rates in poultry diets of meals made from sun dried leaves of Trichantera gigantea meals, and of the fresh leaves in diets for ducks, as locally available sources of carotene and plant protein. Three trials were made in collaboration with smallholder farmers in Cantho City.

 In trial 1 a randomized block design was used with three levels (0, 2 and 6% air dry basis) of Trichantera leaf meal with 180 laying hens. The second trial lasted 10 weeks and evaluated 0 or 6% Trichantera leaf meal in the diet of 300 laying quails. The results for mean egg production and egg quality of laying hens and quails were similar for the control and experimental diets. The cost of production tended to be lower for diets with Trichantera leaf meal.

 In the third trial, 200 ducks were fed from 21 to 60 days of age to evaluate fresh leaves of Trichantera and water spinach in fattening diets. There were no significant differences between treatments for daily weight gain and feed conversion ratio. Carcass parameters were not affected by treatments, except that breast muscle percent increased with increasing intake of Trichantera.

Key words : Trichantera gigantea, water spinach, laying hen, laying quail, ducks.


Effect of management practices and fertilization with biodigester effluent on biomass yield and composition of duckweed

Nguyen Duc Anh and T R Preston

University of Agriculture and Forestry, Ho Chi Minh City, Vietnam.


The experiments were done during a four-month period, from May to August 1996 at the "Finca Ecologica", situated in the Experimental Farm of the University of Agriculture and Forestry, Ho Chi Minh City.

Duckweed (Lemna spp) was grown in plastic bins of 100 litre capacity with a water surface area of 0.60 m. Four experiments were done. In the first, effluent from two biodigesters charged with cattle manure was added to tap water at rates of 0.25, 0.5, 0.75, 1.0 and 1.25 litres/bin/day. In the second experiment, five initial concentrations of N were obtained by mixing the effluent with water at rates (% of effluent) of 9, 18, 27, 36 and 45%. Fresh effluent was then added daily at the rate of 0.5 litres/bin. In the third experiment, a comparison was made of different amounts of inoculum (fresh duckweed returned as seed after harvesting the biomass). The fourth experiment compared harvest frequencies (every day, second, third, fourth or fifth day).

When N in bin water was in the range of 10-30 mg N/litre, fresh biomass yield was of the order of 100 g/m2/day and contained 5-6% dry matter and 37-40% protein in dry matter. The protein content of the duckweed was negatively related with the root length of the duckweed. Equivalent yields of protein ranged from 6 to 10 tonnes/ha/yr. Optimum level of inoculum was 200-300 g/m2. The optimum rate of harvesting was at two-day intervals.

Key words: Biodigester, effluent, duckweed, inoculum, harvest, nitrogen.


Effect of level of local supplements for fattening
Muscovy ducks by poor farmers in remote
villages in Mekong delta of Vietnam

Nguyen Thi Kim Dong, B Ogle and T R Preston*

Department of Animal Husbandry, Faculty of Agriculture
Cantho University, Cantho, Vietnam

*University of Tropical Agriculture, Thu Duc, Ho Chi Minh City, Vietnam

A trial was conducted with some of the poorest farmers in Phuong Binh village of Can Tho province to determine the performance of Muscovy duck raised with available local feed resources. Two hundred and sixty four Muscovy ducks at four weeks of age were allocated acording a 2*2 factorial arrangement in twelve farmer households as replications.The first factor was breed (the local Muscovy duck and F1 crosses of the local and French Muscovy duck). The second factor was supplementation level; duck scavenging supplemented (1-2 times/per week) with paddy rice, a little waste fish and the water plant Blyxa japenicey following the traditional habits of the farmers, and duck scavenging, supplemented with paddy rice and daily supplementation of waste fish and Blyxa japenicey.

After two months, it was found that growth rate of the F1 crosses was significantly higher (31.3 g/day) than that of the local Muscovy ducks (25.0 g/day)(P=0.001). The carcass weights were 1.71 vs 1.33 kg (P= 0.023); and the profit was 191,500 vs 133,000 VND/10 birds, respectively. For the irregular and daily supplementation the growth rates were 24.9 and 31.4 g/day (P= 0.0001); the carcass weights were 1.23 and 1.81 kg (P= 0.001); and the profit 137,900 and 186,500 VND.

It was concluded that by using efficiently the local feed resources for Muscovy duck production, the farmers could get a good profit.

Key words : Muscovy duck, growth rate, profit, paddy rice, waste fish, blyxa japenicey, poor farmers



Egg production and economic efficiency of Khaki Campbell ducks reared on locally available feedstuffs in the coastal land stretch of the Red River Delta

Luong Tat Nho and Hoang Van Tieu

National Institute of Animal Husbandry, Hanoi


An egg-type duck breed namely Khaki Campbell was imported from Thailand in 1990 and tested for egg production and economic efficiency under two management conditions: herding and confinement. The tested groups consisted of 6248 laying ducks, of which 3105 ducks for herding and 3143 ducks for confinement. Ducks were fully fed on local feedstuffs.

Khaki Campbell ducks showed normal physiological status and yielded high egg productivity under both management conditions tested. There were significant differences between ducks under two management conditions for age at first egg, egg productivity and feed consumption in favour of the herding system.

Key words: Ducks, scavenging, herding, confinement, local feed resources