Effect on Nutrient Digestibility and Nitrogen Balance in Grower Pigs fed

Three Forms of Blended Cassava Roots

Michael Dom, Workneh Ayalew, Phil Glatz, Roy Kirkwood & Paul Hughes

Outline of seminar

• Introduction - feeding value of cassava to grower pigs

• Metabolic Experiment

• Results & Discussion

• Key findings & Conclusion

• Implications & Recommendations for R,D&E

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INTRODUCTION

Metabolic trial on the feeding value of cassava roots to grower pigs Experiment conducted at Labu Livestock Station Wau-Bulolo Road, Lae Morobe Province PNG National Agriculture Research Institute

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Cassava as animal feed(1)

• Roots are readily available & common pig feed

• Low dry matter content 18-40%

– >80% starch, low fibre, <3% protein, imbalance of essential amino acids (EAA) particularly methionine (Ravindran, 1993)

– Used as a dry or wet feed, leaves for protein but are less palatable and used in smaller proportions

– Also contain several anti-nutritional factors and dietary fibre, require some processing to prepare feed

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Cassava as animal feed(2)

• Processing to remove anti-nutrients

– Grating and milling is most effective root processing (Teka et al, 2013)

– Drying at <100°C may not be effective for reducing HCN and protease inhibitors (Teka et al, 2013; Cardoso et al,

2005; Marfo et al, 1990)

– Fermenting and boiling significantly reduces HCN, phytates, tannins and oxalates (Teka et al, 2013; Cardoso et al, 2005; Marfo et al,

1990)

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Metabolic experiment on grower pigs

• Feeding cassava as boiled, ensiled & milled roots Objective: Evaluation of feeding value of three nutritionally balanced, blended diet formulations in commercial crossbred grower pigs (Large White-Landrace x Duroc) compared to a standard grower feed

Hypothesis: There are no significant differences between diets for digestibility of nutrients and energy and performance in grower pigs

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Experiment feeding value cassava roots to grower pigs

Experimental procedures: • Used a Latin Square Design as 4 Treatments x 4 Replicates and with

x 4 Feeding periods this affords n = 64 experimental units • Four castrate male pigs at 25kg (8 weeks old) • Fed ad libitum for 24 hours • Clean fresh piped water available at all times • 5 days adaptation, 3 days collection by four periods (32 days) • Sampling at 24 hour intervals on three days and were pooled for

chemical testing • Chemical analysis of feed, faeces & urine • Proximate nutrients & nitrogen balance • Urine samples were stored at <10°C after collection • Faeces were oven dried at 105°C and stored in sealed bags in a dry

shed

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Large White-Landrace x Duroc crossbred pigs

Milled cassava

Grated cassava Peeled & chopped cassava

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Experimental set-up • Fed 2000g DM, blended as fresh

weight and topped-up twice daily • Water available from nipple drinkers • Temperature monitored and cages

aerated by floor fans • Faeces trapped on sliding trays

beneath each cage then collected into buckets

• Urine drained and filtered into sealed, dark glass bottles for measuring volume and sampling

Blended diets

Metabolic cage (back) Metabolic cage (front)

Pigs released from cages

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Table 1: Feed components, processing and particulars for making each Treatment-diet

Feed Components Processing Particulars Label

Pig

concentrate1 Meal

Mixed in factory -

meal

See Table B; blended at 45%

DM of 2000g daily ration 45

Standard pig

grower

~10 mm

Pellets

Pellets, rolled to <

5mm size

Manufactured feed, 16% crude

protein, 14MJ/kg ME STDPG

Cassava Roots Milled and dried Grated then sun/oven dried

105°C to ~80% moisture loss CAMR45

Cassava Roots Ensiled wet

Grated then ensiled by

standard methods (+0.5% w/w

Na)

CAER45

Cassava Roots

Five days curing,

2-3 weeks

storage, boiled

Chopped, placed in boiling

water for 45-60 minutes (+0.5%

w/w Na), drained

CABR45

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Nutrients (%) Components Treatments

CABR CAER CAMR PigConc1 CABR45 CAER45 CAMR45 STDPG

Dry Matter 38.8 35.4 88.8 87.9 51.5 48.1 88.4 88.0

Ash 1.00 0.92 2.30 8.80 4.58 4.53 5.28 6.39

Fiber 0.61 0.56 1.40 4.10 2.21 2.19 2.64 5.64

Ether Extract (fats)

0.26 0.24 0.60 4.40 2.16 2.14 2.34 3.78

Crude Protein 0.74 0.68 1.70 32.9 15.4 15.4 15.9 16.5

NFE† 36.2 33.0 82.8 37.7 37.4 35.7 63.2 55.7

Total N 0.12 0.11 0.27 5.26 2.47 2.47 2.55 2.64

Lysine* - - - 2.03 0.89 0.90 0.89 0.86

Methionine* - - - 0.82 0.36 0.36 0.36 0.24

Meth+Cyst* - - - 1.26 0.56 0.56 0.55 0.53

DE (MJ/kg)** 16.8 16.9 16.1 15.6 16.3 16.3 15.9 14.8

Lys:DE (g/MJ)*** - - - - 0.57 0.57 0.58 0.60

Table 2: Nutrient composition of the feed components and experimental treatments

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RESULTS & DISCUSSION

Metabolic trial on the feeding value of cassava roots to grower pigs

Experiment conducted at Labu Livestock Station

Wau-Bulolo Road, Lae Morobe Province

PNG National Agriculture Research Institute

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Digestibility (%)

Grand mean

Treatment means sed lsd F pr. cv%

CABR45 CAER45 CAMR45 STDPG

Dry matter 78.7 81.0a 82.5a 82.4a 68.7b 2.12 5.18 0.002 3.8

Ash 40.6 36.0 44.5 50.1 31.9 7.03 17.20 0.137 24.5

Fats 58.9 57.9 56.2 67.2 54.2 4.80 11.75 0.127 11.8

Fiber 28.0 21.7a 20.8a 31.0a,b 38.5b 5.24 13.46 0.055 26.5

Protein 75.7 73.1 75.8 75.9 78.0 2.13 5.22 0.258 4.0

NFE† 82.1 82.9a 82.4a 89.9b 73.2c 2.76 6.74 0.006 4.7

Energy 87.0 88.7a 89.0a 89.1a 81.1b 1.31 3.21 0.002 2.1

Table 3: Apparent total tract digestibility in grower pigs fed blended cassava root diets

Means with different superscripts are significantly different at p<0.05. † NFE is Nitrogen free extracts, a calculated estimate of carbohydrate content.

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N balance (g/d)

Grand mean

Treatment means sed lsd F pr. cv%

CABR45 CAER45 CAMR45 STDPG

Intake 54.4 59.2 47.3 52.4 58.6 4.60 11.25 0.116 12.0

Feces 13.0 15.3 11.4 12.4 13.0 1.32 3.24 0.108 14.4

Digested 41.3 43.9 35.9 39.9 45.6 3.93 9.61 0.162 13.4

Urine 17.3 18.0 15.8 16.1 19.5 4.67 11.43 0.839 38.1

Retained 27.0 29.9 25.9 24.6 27.6 1.88 4.60 0.119 9.8

Retention as % of:

N-intake 48.9 50.0 56.0 44.3 45.1 4.89 11.96 0.163 14.1

N-digested 64.7 68.3 74.7 58.4 57.4 6.85 16.75 0.121 15.0

Table 4: Nitrogen balance in grower pigs fed blended cassava root diets

Means with different superscripts are significantly different at p<0.05.

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Table 5: Performance of Crossbred Grower Pigs fed Cassava Blended with Protein Concentrate (Treatments)

Treatment means

Parameter Grand

mean CABR45 CAER45 CAMR45 STDPG sed lsd F pr. cv%

DMI

(g/day) 2080 2382a 1776b 2083c 2080c 73.8 180.6 0.001 5.0

ADG

(g/day) 890 865a 800a 1072b 823a 51.4 125.9 0.006 8.2

FCR

(kg/kg) 2.54 3.06a 2.37b 2.12b 2.59b 0.157 0.384 0.005 8.7

Values with different superscripts are significantly different at P < 0.05.

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Fig. 1: Lysine:DE ratios vs ADG and FCR for commercially bred growing pigs fed for cassava blended diet compared to the standard Pig Grower ration (Control) and reference values (Dom et al., 2014)

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Key findings

• Apparent Total Tract Digestibility of nutrients was similar between three cassava blends and improved against the standard feed, while N-retained was similar (156.25 to 187.5 g/day CP)

• Agreement with literature values (e.g. Ospina et al., 1995; Phuc et al., 2000; An et al., 2004)

• It is surmised that processing effectively reduced anti-nutritional factors (Dietary fibre, TI’s, phytates, tannins, oxalates )

• Feed intake, efficiency and growth performance of cassava blended diets was equal or better than standard pig grower feed

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Conclusions

• Cassava roots blended at 55% of the diet improved the nutrient and energy utilization to grower pigs regardless of the mode of preparation

• Test diets demonstrated their suitability to high performing genotypes compared against a wheat based standard feed

• This feed should be tested on the local mixed genotype pigs farmed in PNG

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Implications & Recommendations

• Pig Grower uses 91.2% wheat while Pig Conc.1 uses 47.8%, which is 43.4% less wheat

• Blended at 45% DM in the cassava root diets this means that wheat use was effectively reduced to only 21.5% wheat

• Compared to the Pig Grower this means a total reduction of wheat use by 69.6% in the improved cassava ration

• Boiled cassava – for village extensive farming, informal, customary market (Several farmers to test feed)

• Ensiled cassava – for small-scale intensive piggeries, that serve dual customary/fresh meat markets (Test at 3 farm locations)

• Milled cassava – for intensive commercial piggeries serving formal markets (Integrate with feed mills activities)

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ACKNOWLEDGEMENTS Charlie, Arthur, Elly, Labu Pig section, Margaret & Collin Cargill

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