Effects of drenching soybean oil and fish oil on intake, digestibility and performance of cattle fattening in the Mekong Delta, Vietnam

Nguyen Thi Hong Nhan, Nguyen Trong Ngu, T R Preston* and R A Leng**

College of Agriculture, Cantho University, Cantho, Vietnam
nthnhan@ctu.edu.vn ; ntngu@ctu.edu.vn
^*UTA Colombia, AA48 Socorro, Santander, Colombia
trpreston@mekarn.org
^**PO Box 814, Coolum Beach 4573, Australia
rleng@ozmail.com.au

Abstract

Three Sindhi-Yellow cattle were fed a basal diet of rice straw ad libitum and para grass (1% of LW on DM basis) and given a single drench of 6 ml/kg LW of either soybean oil or fish oil. The experiment was carried out according to a 3*3 Latin square design, beginning with 20 days of adaptation followed by 21 days of data collection, in which three sub-periods of 7-days were divided to measure feed intake and digestibility. In a second experiment, 15 Sindhi-Yellow growing cattle (136-143 kg) at a cooperative farm were arranged into 3 treatments with 5 replicates. The cattle were fed on the same diets as in experiment 1 and kept for 90 days after being given a single dose 6 ml/kg LW of soybean oil or fish oil.

In both oil treatments, apparent digestibility was improved from 54.4 (control) to 61.3 and 60.9% for soybean and fish oils. In the on-farm trial, growth rate increased to 383 and 387g/day in cattle given the oil drench compared to the control animals (338 g/day). Feed conversion ratio tended to be better in cattle given the oil drench.  There were no differences between fish oil and soybean oil in the degree of beneficial effects on the cattle. Both can be applied for fattening cattle under farm conditions.

Key words: defaunation, feed conversion, grass, growth, on-farm, protozoa, rice straw

Introduction

The first research published on this subject (Nguyen Thi Hong Nhan et al 2001) was stimulated by observations of farmer practice in Central Vietnam. Subsequent experiments in Cambodia (Mom Seng et al 2003), in An Giang province of South Vietnam (Nguyen Thi Hong Nhan et al 2003) and in Cantho University (Nguyen Thi Hong Nhan et al 2007a), confirmed that soybean oil eliminated the protozoa from the rumen resulting in faster growth rate of the cattle.. In addition to soybean oil, fish oil is also used by farmers in An Giang province for fattening their cattle about 3 months before slaughtering. The use of fish oil originated from the fact that catfish oil is abundant in the region and it is less competitive with human needs.

In all the trials done so far, there has been no detailed comparison between vegetable oil and fish oil. It is not known if cattle responses are similar for both these sources of long chain fatty acids. In the Mekong Delta (MD), many farmers have specialized in cattle fattening; they purchase lean cattle, often from Cambodia, and fatten them with a combination of grass, rice straw and rice bran. It is therefore of considerable interest for these farmers to know the relative advantages of the two sources of oil as a means of improving the efficiency of their fattening system.

The objectives of this research were therefore to determine the effects of the two sources of oil on digestibility and growth performance of cattle fed on rice straw and grass. .
 

Materials and methods  

Experiment 1

Treatments and design

Three growing crossbred Sindhi-Yellow cattle (145-160 kg) were allocated to three treatments according to a Latin square design. The treatments were:

RG: Rice straw ad libitum plus natural grass (1% LW, DM basis)

RGSO: Similar to RG with a single dose drench of soybean oil at 6ml/kg LW

RGFO: Similar to RG with a single dose drench of fish oil drench at 6ml/kg LW

All cattle were given a rumen supplement containing 1.5% sulphur, 5% salt, 5% bone meal, 73.5% rice bran. The oil was given orally (Photo 1).

Experimental procedures

The animals were vaccinated against foot and mouth disease and de-wormed before the initiation of the experiment. After 20 days of adaptation, the cattle were given a single dose of soybean oil or fish oil (Photos 2 and 3) followed by three sub-periods of 7 days each to measure feed intake and digestibility.

Data collection

Feeds offered and refused were recorded daily during each consecutive 7 day period. Feces were collected daily and frozen at –18C for later analysis. The determination of dry matter (DM) was by drying at 65ºC for 24 h. Analysis of crude protein (CP), ether extract, ADF and NDF were according to AOAC (1990). 

Experiment 2

Fifteen young beef cattle with initial live weight from 136 to 143 kg on a cooperative farm were allotted to the same 3 treatments and the same basal diet as in Experiment 1. The cattle fed for 90 days after being drenched orally with the oil During this period, they were totally confined in a shed; drinking water and rumen supplement  were available all the time.

The cattle were weighed in 2 consecutive mornings at the beginning, and after 30, 60 and 90 days of the trial. Feed intake and residues were measured daily and representative samples were collected and bulked weekly for chemical analysis including DM, CP, NDF, ADF and ash.

Statistical analysis

Data on feed intake and digestibility were subjected to analysis of variance using the least squares General Linear Model (GLM) procedure of the Minitab Statistical Software Release 13.2 (2000). Sources of variation were treatment and error.

Results and discussion  

Experiment 1

The composition of the rice straw and grass is in Table 1.

There was a very slight indication (P=0.30) that intakes appeared to be depressed during the first 7 days following the oil drench (Table 2). Coefficients of apparent digestibility of DM and crude protein were increased in days 8-15 and 16-21 by some 7 percentage units by both types of oil drench (an overall increase of 16%).  

The positive effects of soybean oil on apparent digestibility of DM and crude protein are similar to what was reported by Nhuyen Thi Hong Nhan et al (2007b) for a similar basal diet of rice straw and natural grass. There are no reports on the use of fish oil as a defaunating agent but the results are similar to those obtained with soybean oil. Doreau and Chilliard (1997) concluded that fish oil decreased feed intake and increased OM and fiber digestibility in dairy cows fed on maize silage. Recently, Wistuba et al (2006) stated that supplementation of fish oil decreased feed intake of steers consuming high concentrate diets. It is, however difficult to compare these results as in these latter experiments the fish oil was fed continuously as a supplement.

Experiment 2

The oil drench depressed growth rates in the first 30 days but steadily increased them in subsequent periods of 30-60 and 60-90 days (Table 3; Figure 1).

DM intake was lower from 0 to 30 days, in the cattle drenched with both types of oil (Table 4). In the subsequent sub-periods intake was higher for the oil drench treatments with no differences between types of oil. 

Overall, there was a tendency (P=0.10) for a higher intake due to the oil treatment. DM feed conversion in the first 30 days was worse on the soybean oil drench compared with fish oil and the control (Table 4). In the next 30 days there were no differences among treatments, while from 60 to 90 days conversion was better for the oil drench than the control. Over the overall 90 period there were no differences among treatments.

The results of the on-farm growth study confirmed the efficacy of both soybean oil and fish oil in enhancing the nutritive value of the basal diet of rice straw and para grass for growing cattle.  There is now a considerable body of evidence for the beneficial effects of a single oil drench on growth performance of cattle (Mom Seng et al 2003; Nguyen Thi Hong Nhan et al 2003, 2007a; Sypraseuth Khonglalien et al 2008) and that this is mediated through the oil drench causing a reduction in the population of the large protozoa (Nguyen Thi Hong Nhan et al 2001; Mom Seng et al 2003;  Nguyen Thi Hong Nhan et al 2007a;  Sypraseuth Khonglalien et al 2008) and increasing the population of bacteria (Nguyen Thi Hong Nhan et al 2007b).  .

Conclusions 

• A single dose of either soybean or fish oil at 6 ml/kg live weight improved DM digestibility and growth rates in Vietnamese Yellow cattle

  
  

• The effects of soybean oil and fish oil on feed intake, digestibility and daily weight gain in cattle were similar.
   

Acknowledgements 

The authors are grateful to the MEKARN project , financed by SidaSAREC, for funding this study.

References 

Doreau M and Chilliard 1997 Effects of ruminal or postruminal fish oil supplementation on intake and digestion in dairy cows. Reproduction Nutrition Development  37: 113-124 http://rnd.edpsciences.org/index.php?option=article&access=standard&Itemid=129&url=/articles/rnd/pdf/1997/01/RND_0926-5287_1997_37_1_ART0012.pdf

Mom Seng, Preston T R, Leng R A and ter Meulen U 2001 Effect of a single drench of cooking oil on the rumen ecosystem and performance of young local "yellow" cattle fed rice straw and cassava foliage. Livestock Research for Rural Development. Volume 13, Article # 134 http://www.lrrd.org/lrrd13/4/seng134.htm

Nhan N T H, Hon N V, Ngu N T, Von N T, Preston T R and Leng R A 2001 Practical application of defaunation of cattle on farms in Vietnam: response of young cattle fed rice straw and grass to a single drench of groundnut oil. Asian-Australasian Journal Animal Science 14 (4): 485-490

Nguyen Thi Hong Nhan, Nguyen Van Hon, Nguyen Trong Ngu, Nguyen Thi Thu Hong, Preston T R and Leng R A 2003 Effect of drenching with cooking oil on performance of local “Yellow” cattle fed rice straw and cassava foliage. Livestock Research for Rural Development 15 (7) http://www.lrrd.org/lrrd15/7/nhan157.htm

Nguyen Thi Hong Nhan, Nguyen Trong Ngu, Vo Van Son, Preston T R and Leng R A 2007a  Effects of oil drench on growth rate of cattle fattened on grass, supplemented with molasses, rice bran or rice straw. Livestock Research for Rural Development. Volume 19, Article #133. http://www.lrrd.org/lrrd19/9/nhan19133.htm

Nguyen Thi Hong Nhan, Nguyen Trong Ngu, Nguyen Thiet, Preston T R and Leng R A 2007b Determination of the optimum level of a soybean oil drench with respect to the rumen ecosystem, feed intake and digestibility in cattle. Livestock Research for Rural Development. Volume 19, Article #117 http://www.lrrd.org/lrrd19/8/nhan19117.htm

Sypraseuth Khonglalien, Bounlieng Khoutsavang, Phonepaseuth Phengsavanh and Preston T R 2008 Measuring growth responses to an oil drench and cassava foliage in local (Yellow breed) cattle fed rice straw and a rumen supplement. Proceedings MEKARN Regional Conference 2007: Matching Livestock Systems with Available Resources (Editors: Reg Preston and Brian Ogle), Halong Bay, Vietnam, 25-28 November 2007

http://www.mekarn.org/prohan/seuth.htm

Wistuba T J, Kegley E B and Apple J K 2006 Influence of fish oil in finishing diets on growth performance, carcass characteristics, and sensory evaluation of cattle. Journal of Animal Science 84: 902-909 http://jas.fass.org/cgi/reprint/84/4/902

Received 18 April 2008; Accepted 15 May 2008; Published 3 July 2008

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