Practice on improving fattening local cattle production in Vietnam by increasing crude protein level in concentrate and concentrate level

Practice on improving fattening local cattle production in Vietnam by increasing crude protein level in concentrate and concentrate level

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Practice on improving fattening local cattle production

in Vietnam by increasing crude protein level

in concentrate and concentrate level

Dinh Van Dung&Nguyen Xuan Ba&Nguyen Huu Van&

Le Dinh Phung&Le Duc Ngoan&Vu Chi Cuong&

Wen Yao

Accepted: 21 March 2013

# Springer Science+Business Media Dordrecht 2013

Abstract Two experiments were conducted to determine

the effects of crude protein (CP) level in concentrate

(exper-iment 1) and concentrate level (exper(exper-iment 2) on feed

in-take, nutrient digestibility, nitrogen (N) retention, ruminal

pH and NH3-N concentration and average daily gain (ADG)

of Vietnamese local fattening cattle Animals (24 cattle,

initial live weight (LW) 150.3±11.8 kg in experiment 1

and 145.1±9.8 kg in experiment 2) were allotted based on

LW to one of four treatments in a randomised complete

block design In experiment 1, concentrate with four levels

of CP (10, 13, 16 and 19 %) was fed at 1.5 % of LW In

experiment 2, concentrate was fed at 1.0, 1.4, 1.8 and 2.2 %

of LW In both experiments, roughage was 5 kg/day native

grass and ad libitum rice straw (fresh basis) Results showed

that the CP level in concentrate significantly affected dry

matter (DM) intake (P<0.05), N retention, ADG and

rumi-nal NH3-N concentration (P<0.01), but it had no significant

effect on DM, organic matter (OM) and neutral detergent

fibre (NDF) digestibility (P>0.05), whereas CP digestibility

increased (P<0.001) along with the CP level DM intake, N

retention and ADG increased (P<0.001) linearly with

con-centrate intake DM and CP digestibility were not

signifi-cantly affected by concentrate intake (P > 0.05) OM

digestibility and NH3-N concentration increased linearly

(P<0.05), whereas NDF digestibility and ruminal pH de-clined linearly with increased concentrate consumption (P< 0.01) These results indicate that 16 % CP in concentrate and feeding concentrate at the rate of 2.2 % of LW are recommendable for fattening local cattle in Vietnam Keywords Crude protein Concentrate intake Digestibility Nitrogen retention Vietnam Local cattle Abbreviations

ADG Average daily gain

CP Crude protein

DM Dry matter

GE Gross energy

LW Live weight

N Nitrogen NDF Neutral detergent fibre

NH3-N Ammonia nitrogen

OM Organic matter

Introduction

Approximately 70 % of Vietnam’s population derives their income from agriculture, of which 25 % is earned from livestock In Vietnam, 90 % of cattle (the majority of which are local) are reared on small-scale farms, which are propi-tious for the utilisation of a variety of feeds, including the by-products of other agricultural businesses The rapid de-velopment of the national economy has led to rising living standards Consequently, intensive beef production is begin-ning to take shape in Vietnam, using a variety of concen-trates—including rice bran, maize, cassava powder, fish meal and urea, which have been fed to fattening cattle,

D Van Dung:W Yao (*)

College of Animal Sciences and Technology,

Nanjing Agricultural University, Nanjing, China

e-mail: yaowen67jp@njau.edu.cn

N X Ba:N H Van:L D Phung:L D Ngoan

Faculty of Animal Sciences and Veterinary Medicine,

Hue University of Agriculture and Forestry, Hue City, Vietnam

V C Cuong

National Institute of Animal Husbandry, Hanoi, Vietnam

DOI 10.1007/s11250-013-0407-2

generally 2.5–3.3 kg/day for individual cattle, irrespective

of weight, age or physiological condition These rations are

unformulated precisely according to the nutrient

require-ment and crude protein (CP) levels ranging from 6.2 to

12.1 % (Ngoan and Giang2008)

Protein or nitrogen is the key component in ruminant

ration and an appropriate CP level is of utmost importance

(Bailey et al.2008) The CP levels of concentrate are

deter-mined in large part by the quality of forage consumed and

concentrate resources, although the National Research

Council (NRC) (1996) has suggested that the CP

require-ment of beef cattle with a body weight under 250 kg should

exceed 16 % CP However, Vietnamese local cattle have

smaller frames and a lower growth rate than temperate beef

cattle Consequently, the CP requirement of Vietnamese

local cattle may not be the same as those recommended by

the NRC Furthermore, in Vietnam, crop residues and

by-products are widely used to fatten cattle Therefore, there is

an obvious need to determine the CP level of concentrates

based on low-quality feed to facilitate rapid cattle

produc-tion and the effective use of local feed resources

In addition, previous studies have reported that cattle have

increased average daily gain (ADG) when concentrate

sup-plementation increased (Marino et al 2006; Manni et al

2013) The organic matter (OM) digestibility and nitrogen

(N) retention of cattle tend to rise with increased intake of

concentrate (Wanapat and Khampa2007) Previous studies

have established that feeding beef cattle with concentrate and

increasing the amounts of cassava powder and urea

supple-ment improve the ADG of cattle (Ba et al.2008a,b) But no

study to date has reported the effects of different concentrate

levels on feed intake, diet digestibility and the ADG of

finishing local cattle in Vietnam

The objectives of this study were to evaluate the effects

of CP levels in concentrate and concentrate intake levels on

feed intake, diet digestibility, N retention, pH and NH3-N

concentration in rumen fluid and ADG of finishing cattle,

with a view to provide useful data about the fattening of

cattle

Materials and methods

Animal, diet, and experimental design

Twenty-four male local cattle of approximately 15 to

18 months of age, with live weight of 150.3±11.8 kg

(ex-periment 1) or 145.1±9.8 kg (ex(ex-periment 2), were included

in a randomised complete block design Cattle were blocked

into six blocks by live weight (LW) (four cattle per block)

and then allotted randomly within a block to one of four

treatments (six cattle per treatment) In experiment 1, the

treatments consisted of CP levels in concentrate of 10, 13,

16 and 19 % In experiment 2, treatments contained con-centrate feeding levels at 1.0, 1.4, 1.8 and 2.2 % of LW (dry matter (DM) basis) The cattle were housed in individual stalls and underwent feeding management for 14 days in both experiments Both experiments were conducted at Hue University of Agriculture and Forestry farm in Thua Thien Hue Province (16°00′ to 16°48′ N, 107°48′ to 108°12′ E)

In both experiments, the native grass was harvested daily along the banks of the Huong River and chopped prior to feeding The rice straw was bought and reserved for the duration of the experiments All roughage fed to each cattle consisted of ad libitum rice straw at night and 5 kg of native grass (fresh basis) at 0730 and 1315 hours, twice daily, in two equal amounts

Table1 presents the feed ingredients and nutrient com-position of experiment 1 Concentrate allowance for each cattle was 1.5 % of live weight (DM basis) daily and was adjusted weekly in accordance with any changes to the body weight of the cattle Table2shows the nutrient composition

of concentrate, grass and rice straw, as well as the chemicals used in experiment 2 Concentrate was fed in three equal amounts at 0715, 1300 and 1630 hours When residue was left the next morning, it was weighed and subtracted from concentrate intake Drinking water was freely accessible All animals were treated for internal parasites and liver fluke with Bioxinil (Bio Pharmachemie, Ho Chi Minh) and vaccinated for pasteurellosis with P15 vaccine (NAVETCO,

Ho Chi Minh City) 14 days prior to experiments Cattle were weighed between 0630 and 0730 hours before feeding

on three consecutive days at the start and end of the exper-iments and at least once per week, including at the start and end of the digestibility and N balance periods

Data collection and sampling procedures From days 25 to 31 of experiment 1 and days 22 to 28 in experiment 2, the intake of roughage and concentrate for each cattle was recorded daily and sampled to test DM and nutrient digestibility Faeces were also quantitatively col-lected, thoroughly mixed, subsampled (5 % of mixed fae-ces) and stored at −20 °C for later chemical analyses

In addition, to test nutrient metabolism in the above period, urine was collected daily from each animal using a plastic bag attached to a tube with a tap, which was fixed by

a harness under the cloaca Whenever an animal urinated, the sample was immediately collected and added to a con-tainer holding 100 ml of 20 % H2SO4 The pH was regularly measured and acid was added to keep the pH below 4.0 At the end of each day, the total amount of urine was measured

A subsample (3 % of total urine) was obtained and stored at

−20 °C for later analysis of nitrogen content

The pH value and NH3-N concentration in rumen fluid were measured daily from day 64 to 70 (experiment 1) or

day 54 to 60 (experiment 2) A vacuum-pump machine

(MEDI-PUMP, USA) collected rumen fluid via a stomach

tube at 0 and 4 h, after the morning feeding of concentrate

Each time, 250–300 ml of rumen fluid was collected and the

pH value was measured immediately by a pH meter (Schott,

Germany) Rumen fluid was then filtered through four

layers of muslin cloth and a 50-ml subsample of each animal

was used to analyse NH3-N concentration

Analytical procedures

Samples of feeds and faeces were dried at 60 °C and ground

through a 1-mm screen in a Retsch grinder (Retsch,

Germany) and analysed using the standard methods of the Association of Official Analytical Chemists (AOAC) (1990) for DM and ash The gross energy of feeds and faeces was determined by bomb calorimetry (Bomb Calorimeter 6300, Parr Instrument Company), and neutral detergent fibre (NDF) was determined as described by Van Soest et al (1991) with the addition of α-amylase but without sodium sulphite and results were expressed with residual ash Total

N was determined according to AOAC (1990) and the concentration of CP was calculated as N×6.25

Rumen fluid was immediately measured for pH using a

pH meter (Schott, Germany) The NH3-N concentration of rumen fluid was measured by the Kjeldahl method (AOAC

Table 1 Ingredients and

chemi-cal composition of diets in

experiment 1

DM dry matter

a Premix vitamins–minerals:

vita-min A 3,600,000 UI/kg, vitavita-min

D 3 300,000 UI/kg, vitamin

E 4,000 mg/kg, vitamin

B 1 500 mg/kg, vitamin

B 2 1,000 mg/kg, vitamin

B 6 650 mg/kg, vitamin

B 12 6 mg/kg, vitamin

C 12,000 mg/kg, vitamin

K 3 300 mg/kg, biotin 16 mg/kg,

folic acid 100 mg/kg, vitamin

B 5 2,500 mg/kg, niacin

5,000 mg/kg, choline chloride

(Fe, Zn, Cu, Mn, Mg)

40,000 mg/kg

Ingredient (% fresh basis)

Chemical composition (%DM)

Table 2 Composition of

con-centrate, grass and rice straw

used in experiment 2

DM dry matter

a

Premix vitamins–minerals:

vita-min A 3,600,000 UI/kg, vitavita-min

D 3 300,000 UI/kg, vitamin E

4,000 mg/kg, vitamin B 1

500 mg/kg, vitamin B 2

1,000 mg/kg, vitamin B 6

650 mg/kg, vitamin B 12 6 mg/

kg, vitamin C 12,000 mg/kg,

vitamin K 3 300 mg/kg, biotin

16 mg/kg, folic acid 100 mg/kg,

vitamin B 5 2,500 mg/kg, niacin

5,000 mg/kg, choline chloride

(Fe, Zn, Cu, Mn, Mg)

40,000 mg/kg

Ingredient (% fresh basis)

Chemical composition (%DM)

1990) Urine sample was analysed for total N according

AOAC (1990)

Statistical analysis

Statistical analyses were performed using the general linear

model procedure of SPSS 16.0 Data were analysed using the

model Yijk= μ + Pi+Kj+eijk,where Yijkis the observation from

animal k, receiving treatment i, in block j, μ is the overall of

mean, Piis the effect of the crude protein level in concentrate

in experiment 1 or the effect of concentrate level in experiment

2 (i=1, 2, 3, 4), Kjis the effect of block (j=1, 2, 3, 4, 5, 6) and

eijkis the residual effect The differences between means were

compared using a least significant difference method

Statistical difference was declared at P<0.05

Results

Experiment 1

Feed intake and digestibility

The CP levels in concentrate significantly affected (P<0.05)

DM intake (in kilograms per day) CP intake increased with

increasing CP levels (P<0.001) and ranged from 0.42 to

0.72 kg/day Increasing CP in concentrate had no significant

effect (P>0.05) on the digestibility of DM, OM or NDF A

significant effect on CP digestibility was discernible

be-tween treatments (P<0.001) The CP level in concentrate

affected (P<0.05) GE digestibility (Table3)

Apparent nitrogen retention and average daily gain

The N intake had a positive relationship with CP levels in

concentrate (P<0.001) Faecal N excretion was low in low

dietary CP level However, no significant difference was

found (P>0.05) between cattle fed with 10 and 13 % CP

and with 13 and 19 % CP in concentrate Apparent N retention

(in grams per day) was inclined to increase linearly (P<0.01)

with increasing CP levels in concentrate The ADG of cattle in

this trial had a positive linear relationship with the CP level in

concentrate; however, significant effects could only be found

between 10 % compared to other CP levels (Table3)

pH and NH3concentration in rumen fluid

The CP levels in concentrate had no significant effect (P>

0.05) on pH value both at 0 and 4 h Ruminal NH3-N

concentration at 0 and 4 h after morning feeding with

concentrate of different CP levels was significantly different

(P<0.01) among treatments and raised in accordance with

the increased CP level in concentrate (Table3)

Experiment 2 Feed intake and digestibility The amount of concentrate intake increased from 1.53 to 3.49 kg DM/day when concentrate supplementation increased from 1.0 to 2.2 % of LW Total DM intake increased linearly

as the amount of concentrate consumed increased and ranged from 4.42 to 5.70 kg/day for 2.69 to 3.17 % of body weight (P<0.001), respectively The digestibility of DM, CP or GE was not significantly affected by concentrate intake (P>0.05)

OM digestibility increased linearly (P<0.05), whereas NDF digestibility declined linearly (P<0.01) as the amount of concentrate consumed increased (Table4)

Apparent nitrogen retention and average daily gain Nitrogen intake was significantly affected by different con-centrate levels and increased linearly with the amount of concentrate consumed (P<0.001) Nitrogen excreted in urine did not vary significantly with concentrate levels (P>0.05), whereas nitrogen excreted in faeces differed between treat-ments and increased (P<0.001) linearly with concentrate in-take The ADG increased (P < 0.001) linearly with the increased amount of concentrate consumed (Table4)

pH and NH3-N concentration in rumen fluid Different levels of concentrate intake did not affect the rumen pH at 0 h, whereas pH at 4 h post concentrate feeding declined linearly with the amount of concentrate consumed (P<0.01) Rumen NH3-N concentration at 0 and 4 h after concentrate feeding with different concentrate levels was significantly different (P < 0.05) among treatments and tended to increase linearly as the amount of concentrate consumed increased (Table4)

Discussion Our results indicated that DM intake was improved by an increase in the protein level of beef cattle This observation was in agreement with Paengkoum and Tatsapong (2009), Chen et al (2010) and Yuangklang et al (2010) Similarly, the positive relationship between dietary CP levels and DM intake in dairy cows was affirmed (Broderick 2003; Promkot and Wanapat 2005) In swamp buffaloes, Chanthakhoun et al (2012) reported that the level of CP in concentrate mixture supplementation improved rumen de-gradability and, as a consequence, improved DM intake However, other studies (Chantiratikul et al 2009; Norrapoke et al.2011; Danes et al.2013) reported that CP levels had no significant effect on DM intake These

variations might have been caused by the different feed

resources used in the respective experiments, such as the

types of roughage and the ingredients of concentrate The

results of our experiment confirmed that a moderate increase

(from 16 to 19 %) of the CP level in concentrate could help

enhance the feed intake of fattening cattle However, protein

is expensive, so for tropical conditions as in Vietnam, where

cattle are reared on a crop residue-based feeding system

with limited supplemental concentrate, 16 % CP in

concen-trate is the recommended optimal level Concenconcen-trate intake

with 16 % CP had positive effects on DM intake

(experi-ment 2) These observations are similar to those of Ba et al

(2008b), who studied Vietnamese local growing cattle, and

Manni et al (2013), who studied growing dairy bull

Sairanen et al (2005) and Arriola et al (2011) reported that

daily feed intake increased with increasing levels of

con-centrate in dairy cows Based on this result, 2.2 % of LW

concentrate intake is recommendable

The digestibility of DM and OM was not significantly

different in terms of CP levels These results are in

agreement with previous studies of Thai indigenous heifers (Chantiratikul et al.2009; Chumpawadee et al.2009), Thai beef cattle (Chen et al.2010), Brahman cattle (Yuangklang

et al.2010) and dairy cow (Ghorbani et al.2011; Norrapoke

et al.2011) However, these observations did not agree with other researches of cattle (Paengkoum and Tatsapong2009) and buffalo (Shahzad et al 2011; Chanthakhoun et al

2012) NDF digestibility was not significantly affected by dietary CP levels, as per the findings of Chantiratikul et al (2009) and Chen et al (2010) In contrast, Ghorbani et al (2011) and Chanthakhoun et al (2012) reported that increas-ing dietary CP levels resulted in a significant increase in NDF digestibility The effects of CP levels on the digest-ibility of nutrients varied, depending on factors such as protein sources, dietary CP levels, the animal condition and breed (Milis and Liamadis 2007; Chantiratikul et al

2009) Moreover, the digestibility of CP increased linearly with increases of the CP level This kind of relationship between the digestibility of CP and dietary CP levels has been reported by many recent studies (Chumpawadee et al

Table 3 Effects of crude protein

levels in concentrate on feed

intake, digestibility, nitrogen

retention, average daily gain, pH

and NH 3 -N concentration in

rumen fluid of Vietnamese local

fattening cattle

Values on the same row with

different lowercase letters differ

(P<0.05)

CP crude protein, ADG average

daily gain

a Treatment, linear and quadratic

effects of different crude

protein levels in concentrate

DM intake

Nutrient digestibility (%)

Nitrogen balances

Faecal outgo (g/day) 29.5a 31.6ab 35.2b 33.0ab 0.99 <0.01 <0.01 <0.05 Urinary outgo (g/day) 13.2a 19.9ab 24.3b 37.4c 3.03 <0.001 <0.001 0.307 Nitrogen retention

pH

NH 3 -N (mg%)

2009; Chantiratikul et al 2009; Yuangklang et al 2010;

Ghorbani et al.2011)

Ba et al (2008b) reported that the digestibility of DM

was not significantly affected by concentrate intake and that

OM digestibility increased with higher concentrate intake,

while NDF digestibility declined linearly as the amount of

concentrate intake increased Our results were comparable

to these findings Many studies have concluded that

in-creased concentrate intake contributes to a reduction of

rumen pH and cellulolytic bacterial activity, which

de-creases the digestion of fibre (Moorby et al.2006; Plaizier

et al.2009; Agle et al.2010) In a review by González et al

(2012), it was reported that a pH value over 5.6 of the rumen

fluid was necessary for normal rumen function, whereas a

pH below 5.0 is considered the benchmark for acute rumen

acidosis In the present study, rumen pH ranged from 6.56 to

7.17 (experiment 1), which was sufficient for the

mainte-nance of rumen function However, rumen pH reduction at

4 h post concentrate feeding (experiment 2) indicated that a

high amount of concentrate intake could contribute to

de-creased fibre digestion NH3-N concentration in rumen fluid

in our study appeared to confirm the conclusion of Preston

and Leng (1987) that the optimal NH3-N concentration in rumen fluid ranged from 5 to 25 mg% in order to improve rumen ecology, microbial protein synthesis, digestibility and voluntary feed intake

Increasing CP levels significantly affected apparent N retention This observation was consistent with that of Paengkoum and Tatsapong (2009), Chantiratikul et al (2009) and Chen et al (2010) However, our result did not concur with that of Vasconcelos et al (2009) Such discrep-ancies might be due to the use of a different type of cattle, type of protein and its degradability Moreover, N retention increases linearly with increasing CP levels, but N retention

as a percentage of N absorbed was almost similar in all treatments and lower in cattle fed with 19 % CP level compared to other CP levels; this might have resulted from

N outgo through urine in cattle fed with a 19 % higher level

of CP than other dietary CP levels Our results indicated that

CP levels exceeded 16 % in concentrate, which efficiently reduced utilisation of N N retention was significantly af-fected by concentrate levels and increased linearly as the amount of concentrate consumption increased This obser-vation was comparable to that of Wanapat and Khampa

Table 4 Feed intake, nutrient

digestibility, nitrogen retention,

average daily gain, pH and NH 3

-N concentration in rumen fluid

of Vietnamese local fattening

cattle fed with different

concen-trate levels

ADG average daily gain

a

Relationship between

concen-trate intake (CI) and different

parameters is given

DM intake

Nutrients digestibility (%)

Nitrogen balances

Nitrogen retention

pH

NH 3 -N (mg%)

(2007) ADG increased with increasing CP levels in

con-centrate or concon-centrate intake This result was consistent

with previous studies (Paengkoum and Tatsapong 2009;

Ba et al.2008b; Manni et al 2013) Increasing CP levels

in concentrate or concentrate intake contributed to increased

DM intake and N retention, which would be the causative

factors of a greater ADG of cattle

Conclusion

Increasing CP level in concentrate or concentrate intake

sig-nificantly increased DM intake, N retention, improved NH3-N

concentration in rumen fluid and ADG in Vietnamese local

fattening cattle These observations suggest that 16 % of CP

level in concentrate and 2.2 % of LW concentrate during the

fattening period are recommendable for local cattle production

in Vietnam

Acknowledgments The authors thank the Norwegian Program for

Development Research and Education project (NUFU) for financially

supporting this research.

Conflict of interest The authors declare that there is no conflict of

interest.

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