Research Update – Alternative Feedstuffs

bonderic

Eduardo Beltranena1,2 and Ruurd T. Zijlstra2

Alberta Agriculture and Rural Development, #307 JG O’Donoghue Building, 7000 – 113

Street NW, Edmonton, AB T6H 5T6; Email: eduardo.beltranena@gov.ab.ca

Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton,

AB T6G 2P5; Email: ruurd.zijlstra@ualberta.ca

Introduction

Yearly, we come to Banff Pork Seminar to discuss what a hard year Prairie

pork producers have had and discuss what the coming year might bring.

Production of grains and oilseed in 2009 will be 59.5 vs. 72.6 Mt last year

because some areas of the Prairies received not enough rain and heat (Ag

Canada 2009). Feed prices were not as high in 2009 relative to 2007 – 2008,

but remained high relative to 5 – 10 years ago. Similar feed commodity pricing

trends are expected for 2010 (Ag Canada 2009). Crude oil prices remain low,

while the Canadian:US dollar exchange rate continues narrowing. The latter

suggests cheaper ethanol supported by mandates of ethanol inclusion,

implying greater upcoming opportunities to reduce feed cost by feeding

distillers’ dried grains with solubles (DDGS). This paper summarizes our latest

research findings regarding feeding corn, wheat and triticale DDGS to pigs.

Feeding High Levels of Corn DDGS

At writing, there was a $2 benefit per hog for feeding corn DDGS in Alberta.

The currency exchange keeps narrowing, so we expect to see more American

corn DDGS in western Canada. We also have an outstanding Alberta dataset

to share with you. Corn DDGS is high in unsaturated oil that may soften the

pork fat if fed at high levels to finishing hogs, potentially affecting pork quality.

In a commercial trial, we fed corn DDGS, no corn DDGS or implemented three

strategies to remove or withdraw corn DDGS out of the finishing diets. The

goal was to optimize the use of DDGS in hog diets to reduce feed costs for

producers while mitigating possible pork quality concerns for packers.

One-fifth of the barrows or gilts were fed a control diet over 5 growth phases

until market weight (Figure 1). We implemented 3 corn DDGS withdrawal

strategies during the last 2 finisher phases. Four-fifths of the barrows or gilts

were offered diets containing 30% corn DDGS replacing soybean meal for the

first 3 grower phases. These hogs were then fed 20 and 20%, 20 and 10% or

20 and 0% corn DDGS in the last 2 finisher phases, respectively, until

reaching market weight. Our results showed that feeding 30% corn DDGS or

implementing a withdrawal strategy did not affect hog growth performance,

feed cost per hog, income over feed cost, or cost per kg gained. However, the

rate of withdrawal of corn DDGS out of the finishing diets improved carcass

dressing percent and estimated carcass pork yield (Beltranena et al. 2009a).

Figure 1. Withdrawal strategies tested for corn DDGS .

Agriculture and Agri-Food Canada – Lacombe Research Centre conducted

the primal cut outs and extensive pork quality work. We found that feeding

30% corn DDGS or implementing a DDGS withdrawal strategy reduced the

dissectible intermuscular fat in the picnic, butt, loin and ham. Implementing the

DDGS withdrawal strategies also increased the weight of the squared and

trimmed belly, proportionally reducing the weight of the spare ribs. Retail

appearance, marbling scores and objective colour measurements were

diminished by feeding 30% vs. 0% DDGS, but were enhanced by

implementing the 3 DDGS withdrawal strategies. Most importantly, sensory

panellists were unable to practically detect differences in texture and flavour

attributes in cooked chops and burger patties from hogs fed 30% or no corn

DDGS. So, in contrast to a minor impact on retail appearance, there were

benefits of feeding 30% vs. no corn DDGS on primal cuts tissue composition,

loin quality and no effects on sensory results (Beltranena et al. 2009b).

We determined that feeding 30 vs. 0% corn DDGS to market weight reduced

backfat hardness. Reducing to 20%, followed by entirely removing corn DDGS

from the last finisher diet, 2 weeks prior to hogs reaching market weight

improved, but did not entirely restore backfat hardness. When bellies were

draped over a bar to rate belly fat hardness, feeding 30% corn DDGS to

market weight or reducing the dietary inclusion from 30 to 20% over the last 2

finisher phases prior to market weight, reduced the distance between the two

hanging ends and the angle formed at the bar compared to bellies of control

pigs. Reducing corn DDGS in the diet to 20%, followed by complete removal

two weeks prior to hogs reaching market weight (i.e., 20, 0% strategy)

increased belly thickness, the distance between ends and improved

(increased) the angle, but did not entirely restore belly fat hardness to that of

the 0% DDGS control hogs (Beltranena et al. 2009c).

Feeding 30% corn DDGS to market weight increased polyunsaturated fatty

acids, omega-6, omega-3, and reduced saturated and monounsaturated fatty

acids in belly fat compared to control hogs (Figure 2). From a human health

perspective, this would have mixed implications because increases in the

omega 6:omega 3 ratio and reductions in monounsaturated would be viewed

as negative, while decreases in saturated fats would be positive.

Implementing the three corn DDGS dietary withdrawal strategies for the last

two finisher phases prior to market weight resulted in mostly intermediate

content (between the 30 and 0% DDGS) of these fatty acids; the 20, 0%

strategy was mostly different from the 20, 20 or 20, 10% corn DDGS feeding

strategies, closer to controls (Beltranena et al. 2009c). Reducing to 20%,

followed by entirely removing corn DDGS from the last finisher diet lowered

the iodine value to 67 (Beltranena et al. 2009c).

Figure 2. Feeding 30% corn DDGS increased polyunsaturated fatty acids,

n-6, n-3, and reduced saturated and monounsaturated fatty acids in belly

fat compared to controls.

Our recommendation, therefore, is to maximize inclusion of corn DDGS in

grower diets when the high oil content of corn DDGS will return the most by

contributing extra dietary energy. If bellies are the MOST important cut to

packers, corn DDGS should be withdrawn sooner (e.g., 4 weeks prior to

market weight) if hogs were previously fed diets with ≥30% DDGS compared

to hogs previously fed up to 20% DDGS, where withdrawing DDGS 2 weeks

prior to market weight would be sufficient. Although the 3 corn DDGS

withdrawal strategies tested improved fat hardness, not even the most

aggressive withdrawal strategy (20, 0%) restored fat hardness to that of

controls. But is there a need to reach ‘zero’ impact on fat hardness by

withdrawing corn DDGS? The extent and length of withdrawal should

therefore be a compromise between impact on fat hardness and benefits on

pork quality. The effects of feeding corn DDGS were more pronounced in gilts

compared to barrows.

Feeding Increasing Levels of Wheat DDGS

Wheat DDGS is locally produced in the Prairies, and there are more

Saskatchewan plants in operation now than previously (Terra Grain Fuels in

Belle Plains, Norwest Terminals in Unity). The quality of wheat DDGS from the

new ethanol plants might be superior to that of older plants, but wheat DDGS

is as variable a co-product as American corn DDGS. Co-fermenting of wheat

and corn continues (Husky Energy, Lloydminster) without the buyer being

advised in what proportions or when these change. Therefore, assigning

nutrient values for formulation is a moving target. We have recently conducted

two studies, one with weaner pigs; the other with growout hogs.

Figure 3. Growth performance of weaned pigs fed diets with increasing

levels of wheat DDGS in substitution for soybean meal (Avelar et al. 2009,

submitted)

We evaluated increasing levels of wheat DDGS (0, 5, 10, 15, or 20%)

substituting soybean meal and wheat in the diet fed to weaner pigs starting

one week post-weaning for four weeks. The diets were formulated to provide

2.39 Mcal net energy (NE) per kg and 4.80 g standardized ileal digestible

lysine per Mcal NE. Increasing the levels of wheat DDGS in the nursery diet

quadratically reduced feed intake, weight gain and feed efficiency (Figure 3).

At d 28, weaner pigs fed 10 and 20% wheat DDGS were 0.15 and 5.6 kg

lighter than controls. We concluded that weaned pigs can be fed up to 15%

wheat DDGS without reducing performance (Avelar et al. 2009).

In a commercial-scale study, 550 gilts and 550 barrows (30 kg) penned

separately were fed diets with increasing levels (0, 7.5, 15, 22.5 or 30%) of

wheat dried distillers’s grain with solubles (DDGS) to market weight (118 kg).

The 5 growth phase study diets were formulated to provide 2.4, 2.4, 2.35, 2.35

and 2.30 Mcal/kg NE and 4.0, 3.7, 3.3, 3.0 and 2.8 g SID Lys/Mcal NE.

Overall, feed intake increased (130 g/d) to 22.5% DDGS, but declined 20 g/d

at 30% inclusion (Figure 4).

Figure 4. Growth performance of grower-finisher pigs fed diets with

increasing levels of wheat DDGS (Beltranena et al. 2009, unpublished)

Weight gain increased 40 g/d at 15% DDGS, but decreased 10 g/d at 22.5

and 30% inclusion. Pigs consumed 42 g/d more feed per kilo gained for every

7.5% increase in dietary wheat DDGS inclusion. Dressing percentage

decreased 0.45 %-unit and backfat thickness decreased 0.23 mm for each

7.5% increase in wheat DDGS inclusion. Estimated pork yield increased 0.13

%-units and index increased 0.25 units for each 7.5% increase in dietary

wheat DDGS inclusion. Due to increased feed intake, reduced weight gain

and days to market, income over feed cost decreased linearly with increased

wheat DDGS inclusion. The results of this study indicate that the NE content

of wheat DDGS was overestimated. It appears that 20% inclusion rate should

be the maximum commercial inclusion rate of wheat DDGS for grower-finisher

pigs after which reduced performance should be expected.

Feeding Increasing Levels of Triticale DDGS

The Canadian Triticale Biorefinery Initiative has the goal of promoting triticale

as a bioindustrial crop, including production of ethanol for gasoline and DDGS

for livestock feeding. To validate the effect of feeding increasing dietary

inclusion levels of triticale DDGS on growth performance and carcass

characteristics, 48 barrows and 48 gilts were fed 0, 10, 20 or 30% triticale

DDGS in the grower, developer and finisher diets from 25 to 125 kg. Pigs

were weighed and feed intake established every 14d and for the entire trial.

Real time ultrasound was conducted at the grading site at market weight (125

kg) to measure backfat thickness and loin depth instead of the planned

carcass grading. Over the entire trial, feed intake increased 60g/d and pigs

required 72 g more feed per kg gained for every 10% inclusion of triticale

DDGS in the diet, but daily weight gain was not affected (Figure 5).

Figure 5. Growth performance of grower-finisher pigs fed diets with

increasing levels of triticale DDGS (Beltranena et al. 2009, unpublished)

Live backfat thickness and loin depth at market weight were not affected by

DDGS inclusion level either. We concluded that previous digestibility work

likely overestimated the NE value of triticale DDGS; yet hogs can be fed up to

20% triticale DDGS in the growout diets.

Extrusion of DDGS to Enhance Nutrient Digestibility

To enhance the nutrient digestibility of DDGS and assess the feeding

opportunity for growing pigs, 9 ileal-cannulated pigs (27.6 kg) were used to

characterize the effect of extrusion processing on energy and amino acid

digestibility of wheat and corn DDGS, and to compare single- vs. twin-screw

extrusion. One wheat and 1 corn DDGS sample were processed using a

single-screw InstaPro 2500 or a twin-screw Werner & Pfleiderer ZSK-57

extruder. In a 7 x 9 Youden square design, 7 diets (wheat DDGS, single-screw

extrudate, twin-screw extrudate, corn DDGS, single-screw extrudate, twin-

screw extrudate, N-free) were fed to 9 pigs at 2.8 x maintenance over 7

periods consisting of a 5-d diet adaptation, a 2-d collection of feces, and a 2-d

collection of ileal digesta.

Single- and twin-screw extrusion increased the apparent total tract digestibility

(ATTD) of gross energy by 5.0 and 4.5%, and the DE value of DDGS by 6.1

and 5.9%, respectively. There was a DDGS grain by extrusion interaction on

the standardized ileal digestibility (SID) of 8 out of 10 and the mean of all 10

indispensable AA, glutamine and tyrosine. Single- and twin-screw extrusion

processing increased the SID of the mean of all 10 indispensable AA in corn

DDGS by 7 and 5%, respectively; twin- but not single-screw-extrusion did so

by nearly 3% for wheat DDGS. Extrusion increased the SID of lysine by 11%

(Figure 6), tryptophan by 8 %, valine and isoleucine by 7%, methionine,

phenylalanine histidine, leucine, glutamine and tyrosine by 5% in corn DDGS.

Figure 6. Effect of extrusion on the standardized ileal digestibility of

amino acids in corn and wheat DDGS for growing pigs (Beltranena et al.

2009d)

There was no effect of single- or twin-screw extrusion on wheat DDGS, except

for twin-screw extrusion on the SID of methionine and tyrosine and both

single- and twin-screw extrusion on the SID of leucine. The results of this

study indicated that single- and twin-screw extrusion is an effective processing

method to increase the dietary energy digestibility of DDGS. More so for corn

than wheat DDGS, extrusion also increased the AA digestibility of the main

co-product of ethanol production in diets for growing pigs (Beltranena et al.

2009d).

Conclusions

The results of these studies indicate that unless packers express concern

regarding fat and belly quality, corn DDGS can be included in western

Canadian hog diets up to 30%. A two week withdrawal was sufficient to

reduce iodine value to 67, mitigating the impact in fat and belly quality. Until

we have additional information, we suggest prudence limiting the inclusion of

wheat and triticiale DDGS to 15% in late nursery diets and 20% in growout

hog diets. Identifying the proper NE value for high protein and fibre wheat and

triticale DDGS has been a challenge. Extrusion of corn and wheat DDGS

increased the energy and amino acid digestibility for young pigs.

Acknowledgments

The authors wish to acknowledge the following organizations for in-kind or

cash contributions towards the research projects summarized in this paper:

Agriculture & Agri-Food Canada

Alberta Livestock Industry Development Fund

Alberta Agricultural Research Institute

Government of Alberta

U.S. Grains Council

Canadian Bio-Systems Inc

O&T Farms

References

Agriculture and Agri-Food Canada. 2009. Canada: Grains and Oilseeds

Outlook: 2009-10. Aug 28, 2009

Avelar, E., E. Beltranena, M. Cervantes, and R. T. Zijlstra. 2009. The effect of

feeding wheat distiller’s dried grain with solubles on growth

performance and nutrient digestibility in weaned pigs. Can. J. Anim.

Sci. (submitted).

Beltranena, E., M. Young, N. Campbell, J. Aalhus, M. Dugan, M. Oryschak

and R. T. Zijlstra. 2009a. Corn DDGS withdrawal rates for hogs.

Effects on animal performance, carcass traits, and cost variables.

Western Hog Journal, Vol. 30, No. 5 pp. 46 - 48.

Beltranena, E, J. Aalhus, M. Dugan, M. Young, N. Campbell, M. Oryschak and

R. T. Zijlstra. 2009b. Corn DDGS withdrawal rates for hogs: Tissue

composition, loin quality, retain appearance and sensory results.

Western Hog Journal, Vol. 31, No. 1 pp. 48 – 52.

Beltranena, E, M. Dugan, J. Aalhus, M. Young, N. Campbell, M. Oryschak and

R. T. Zijlstra. 2009c. Corn DDGS withdrawal rates for hogs: Backfat

and Belly Quality. Western Hog Journal, Vol. 31, No. 2 pp. 49 - 52.

Beltranena, E., J. Sánchez-Torres, L. Goonewardene, X. Meng and R. T.

Zijlstra. 2009d. Effect of single- or twin-extrusion on energy and amino

acid digestibility of wheat or corn distillers dried grain and solubles

(DDGS) for growing pigs. 42nd meeting of the Midwestern Section,

American Society of Animal Science, Des Moines, IA. J. Anim. Sci.

87, e-Suppl. 3, Abstr. 166.

wwjkinghoo

全英文的，下来看一下

sunshoulei

看不懂什么意思呢能翻译过来吗

bonderic

用google慢慢翻译着看。