PHILIPPINE NATIONAL STANDARD        PNS/BAFS  143  :2014  
Corn Silage  
 
 
Foreword  
 
The Philippine National Standard for Corn Silage  intends to provide guidance on the 
composition and quality of Corn Silage as feeds intended for ruminants and other animals. It 
includes sections  on the  essential composition and quality parameters, contaminants, hygiene, 
packaging, labeling and methods of analysis and sampling.  
 
A Technical Working Group (TWG) for the crafting of the standard for corn silage  was 
organized and repr esented by several agencies of the Department of Agriculture-  Agri-Pinoy 
Corn Program, Bureau of Animal Industry, Bureau of Agricultural Research, Philippine Carabao 
Center and Philippine Center for Postharvest Development and Mechanization, University of 
the Philippines Los Baños – Institute of Plant Breeding (UPLB -IPB) and A gricultural Machinery 
Testing And Evaluation Center (AMTEC), National Corn Competitiveness Board, Ploughshares  
Incorporated and other  sectors.  
 
The Bureau in collaboration with the members of the TWG conducted a series of technical 
reviews and public consultations in General Santos  city, Dagupan city , Pangasinan  and Quezon 
city for the crafting of the Standard . Comments from the stakeholders on the draft were carefully 
assessed and d eliberated prior to its finalization and approval.  
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 PHILIPPINE NATIONAL STANDARD        PNS/BAFS  143  :2014  
Corn Silage  
 
 
Introduction  
 
 
According to Philippine Statistics Authority (PSA), t he corn -livestock sector accounts for 
approximately thirteen percent (13 .5%) of growth rate for the Gross Value Added (GVA) in 
Agriculture on the first quarter of 201 3. Some 600,000 farm household s depend on corn as a major 
source of livelihood, in addition to transport services, traders, processors and agricultural input 
suppliers who directly benefit from corn production, processing, marketing and distribution.  
 
Corn silage is popular forage for r uminant animals because it is high in energy and digestibility and 
is easily adapted to mechanization from the stand -crop to the time of feeding. 
Fortun ately, corn farmers earn higher from corn silage production. Net income from grain 
production more or less is doubled the net income for corn silage production. With corn silage, the 
cost for furrowing, shelling, drying, and hauling is omitted. The labor for harvesting is reduced as 
well.  
The creation of the Philippine National Standard for corn silage is one measure being done to promote corn silage competitiveness and ensure product safety in both domestic and foreign 
market.  
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
  
  
 
 
 
 
  
PHILIPPINE NATIONAL STANDARD        PNS/BAFS  143  :2014  
Corn Silage  
 
 
1 Scope  and Description  
 
The main purpose of this standard is to provide safe and high quality corn silage  intended
 for ruminants  and other animals  to promote its competitive ness to local and international
 trade.  
 
This Standard sh ould  be applied to  corn plants with intact corn ears harvested 25 mm to
 100 mm  length from the ground  with 60% to 70% moisture  content (MC)  wet basis  and
 approximately has 2/3 of the milk line or  has reached the soft dough stage . 
 
 
2 References  
 
The publications referred to in this s tandard are listed on the inside back cover.  
  
3 Definition  
 
For the purpose of this s tandard , the following definitions should  apply : 
 
3.1 aflatoxin  
group of toxic compounds which are carcinogenic (cancer causing), produced by strains of the 
fungi, Aspergillus flavus  and Aspergillus parasiticus  on suitable  substrates such as corn, peanut, 
copra, cassava and other oilseeds . 
 
3.2 anaerobic fermentation  
natural chemical changes brought abou t by enzymes produced by various  microorganisms 
in the absence of air . 
 
3.3 corn silage   
processed  feedstuff for ruminants and other animals produced by anaerobic fermentation 
of corn plant  as described in section 1 . 
 
3.4 feedstuff  
any single or multiple materials, whether processed, semi -processed or raw, which is 
intended to be fed dir ectly to food producing animals . 
 
3.5 putrefaction  
decomposition  of an organic matter  by microorganisms that produce  a foul smell  
 
3.6 ruminant   
any of a group of hoofed mammals that have a 4 -compartment stomach and that ruminate 
or chew a cud.  Examples are cattle,  carabao, buffalo,  goat, sheep  and deer.  
 
 
 
 PHILIPPINE NATIONAL STANDARD        PNS/BAFS  143  :2014  
Corn Silage  
 
4 Essential Composition and Quality Parameters  
 
4.1 The corn silage sh ould  conform to the  required quality parameters:  
 
4.1.1  Moisture content  
The required moisture content of corn , chopped f or silage sh ould  range from  
60% to 70%wet basis . 
 
4.1.2  pH 
   The pH of corn silage sh ould  range from  3.5to 4.7. 
 
4.1.3  Processing Time  
The processing time of harvested corn plant should be within 24 hours  to 
avoid putrefaction.  
 
4.2 Other physical quality parameters : 
 
Table 1  - Quality Standard of Corn Silage  
 
Quality   Grain Content  
(%, wet basis)  
from 
Philippine 
Practice  Color  Odor  Cut Size  
Highly Acceptable  20 and above  Green  
 • Mild, pleasant 
pickle aroma with 
no indication of 
putrefaction  
 Small (10 mm and 
below) and 
uniformly cut  
Acceptable  12 to 19  Yellow to light 
brown  • Fruity, yeasty, 
musty, indicating 
poor fermentation.  
• Slight burnt sugar 
odor.  
• Sharp vinegar odor  Silage uniform 
with longer cut 
size (11mm - 50 
mm), but slightly 
stringy with some 
large pieces of 
shucks, cobs, and 
stalks  
Not A cceptable  
 Below 12  White, gray, 
dark brown or 
black due to 
mold  
 • Strong burnt odor 
indicating 
excessive heating.  
• Putrid, indicating 
improper 
fermentation.  
• A very musty odor indicating 
excessive mold 
which is readily 
visible throughout 
thesilage.  Silage largely 
stringy, puffy with 
variable sized 
pieces (longer  
than 50 mm)   
PHILIPPINE NATIONAL STANDARD        PNS/BAFS  143  :2014  
Corn Silage  
 
4.3 Additional Quality Parameters are set at Annex A of the standard  
 
5 Contaminants  
 
5.1 Aflatoxin  
The maximum allowable level sh ould be 50ppb . 
 
5.2 Microorganisms  
  Harmful microorganisms that thrive under aerobic condition.  
 
6 Hygiene  
 
6.1 It is recommended that the produce covered by the provisio ns of this standard
 should  be prepared  and handled in accordance with  Code of Practice on Good
 Animal  Feeding (CAC/RCP 54 -2004) specifically Section 5.4 (Annex B).  
 
7 Packaging  
 
7.1 Corn silage sh ould  be properly packed in  an airtight container  that will ensure
 anaerobic condition (e.g. high density polyethylene  (HDPE) bag with thickness of at
 least 0.002 mm , plastic barrels or drums ).  
 
8 Labeling  
 
8.1  The product covered  by this S tand ard should  conform to the descri ption given  in 
  section 1. 
 
Corn silage sh ould  be directly bagged  and properly labeled with the following  minimum
 information : 
 
8.1.1  Name of the product;  
8.1.2  Name and Address of Trader/Processor/Packer;  
8.1.3  Net Weight in kilogram; and  
8.1.4  Date of Production  and/or Batch Code . 
 
8.2 Additional information may also be indicated : 
 
8.2.1  Advice/s on proper handling  
8.2.2  Logo of the processor/company  
8.2.3  Nutritional composition  
 
9 Methods of Sampling and  Analysis  
 
9.1 The grain content of the entire feedstuff sh ould  be determined using percent by  
  weight  analysis  wet basis .  
 
9.2 For claims regarding nutrient composition, the samplin g and analytical procedure  
  should  conform to the Volume 13 Codex Alimentarius Methods of Analysis and  PHILIPPINE NATIONAL STANDARD        PNS/BAFS  143  :2014  
Corn Silage  
 
  Sampling by Codex Alimentarius  Commission/ PNS /ISO 874 and Cereals and Cereal  
  prod ucts – Sampling ISO 24333:2009.   
PHILIPPINE NATIONAL STANDARD        PNS/BAFS  143  :2014  
Corn Silage  
 
References:  
BAI Administrati ve Order No. 35.  1975 .  Rules a nd Regulations Governing t he Manufacture, 
Importation, Labeling, Advertising, Distribution and Sale Of Livestock and Poultry Feeds a nd 
Feeding Stuffs.  
Bates, G. (2009 ).Corn Silage.Agricultural Extension Service, University of Tennessee.  
 
Bureau of Agriculture and Fisheries Standards. PNS/BAFPS 27: 2008. Code of Practice for the 
Prevention and Aflatoxin Contamination in Corn.  
 
Codex Alimentarius Commission. 2004. Code of Practice on Good Animal Feeding.  
 
Codex Alimentarius Commission. 199 9. Recommended Methods of Analysis and Sampling.  
 Food and Agric ulture Organization of the United Nations.Silage Making for Small Scale Farmers.  
 
International Organization for Standardization (ISO) 874. 2009. Fresh fruits and vegetables - 
Sampling.  
 
International Organization for Standardization (ISO) 24333. 2009.  Cereals and cereal products - 
Sampling.  
 
Lee, C., Herbek, J., Lacefield, G., and Smith, R. (2005).Producing Corn for Silage.Department of Plant 
and Soil Sciences.College of Agriculture, University of Kentucky.  
 
Perry., T.W., A.R.. Cullison and R.S.  Lowrey.  1999.  Feeds and Feeding. 5
th Edition.Prentice Hall.  
Upper Saddle River, New Jersey 07458.  
 
Department of Agriculture – Philippine Carabao Center. 2013. Extension Bulletin No. 2 - Wastong  
Paggawa at Pagpapakain  ng Burong  Damo (Silage) para  sa mga  Kalabaw.  
 
Winconsin Corn Agronomy.  Silage Quality and Feeding. Retrieved March 24, 2014 from 
http://cornagronomy.wisc.edu/Silage/S006.apx  
 PHILIPPINE NATIONAL STANDARD        PNS/BAFS _____  :2014  
Corn Silage  
 
ANNEX A  
(Informative)  
Additional Quality Parameters  
 
Table 1- Nitrate concentrations and feeding instructions1 
 
Corn silage sh ould  conform to the nitrate concentration as specified below.  
 
Nitrate (NO 3) in 
dry matter  
(ppm)  Nitrate nitrogen 
(NO 3-N) in dry 
matter  
(ppm)  Potassium Nitrate 
(KNO 3) in dry matter  
(ppm)  Feeding instructions  
0 – 4000  0 – 1000  0- 7200  Safe to feed.  
4400 -6600  1000 – 1500  7200 - 10800  Safe to non -pregnant animals.  
 
Limit to 50% of total dry ration 
for pregnant animals.  
6600 – 8800  1500 – 2000  10800 – 14400  Limit to 50% of total dry ration  
 
Avoid feeding pregnant animals.  
  14400 – 25200  Limit to 33 % of  total dry ration.  
8800 – 17600  2000 – 4000  25200 – 28800  Limit to 25% of total dry ration.  
> 17600  > 4000  > 28800  Toxic. Do not feed to animals.  
 
 
 
 
 
 
 
 
 
 
  
  
 
 
 
 
 
 
 
1Lee, C., Herbek, J., Lacefield, G., and Smith, R. (2005).Producing Corn for Silage.Department of Plant 
and Soil Sciences.College of Agriculture, University of Kentucky.  
                                                             
PHILIPPINE NATIONAL STANDARD        PNS/BAFS  143  :2014  
Corn Silage  
 
Department of Agriculture  
Bureau of Agriculture and Fisheries Standards  
 
Technical Working Group for the  
Philippine National Standard of Corn Silage  
 
Chairperson  
1 Mr. Salvador D. Umengan  
National Corn Competitiveness Board  
 
Vice Chairperson  
2  Mr. Milo D. Delos Reyes  
Department of Agriculture- Agri -Pinoy Corn Program  
 
Members  
 
3   Dr. Antonio G. Gerundio  
      Agri -Pinoy Corn Program  
      Department of Agriculture  8 Mr. Adolfo M. Buenviaje  
National Corn Competitiveness 
Board  12   Mr. Leonardo Arceta  
  Ploughshares  Inc.,  Pangasinan  
4  Engr. Darwin C. Aranguren  
    Agricultural Machinery Testing And  
    Evaluation Center  (AMTEC)  
University of the Philippines Los Baños  9 Ms.Marivic M. De Vera  
Bureau of Animal Industry  
Department of Agriculture  13  Dr. Daniel L. Aquino  
 Philippine Carabao  Center  
 Department of Agriculture  
5 Ms.Apolonia A. Mendoza  
      Bureau of Agricultural Research  
      Department of Agriculture  10    Mr. Hernando F. Avilla  
         Bureau of Animal Industry  
         Department of Agriculture  14   Dr. Ofero A. Capariño  
Philippine Center for 
Postharvest Development and 
Mechanization  
Department of Agriculture  
6 Dr. Rhea D. Desalesa  
     Bureau of Agricultural Research  
     Department of Agriculture  11   Dr. Eric P. Palacpac  
        Philippine Carabao  Center  
        Department of Agriculture  15 Engr . Andres M. Tuates  Jr. 
Philippine Center for Postharvest  
Development and Mechanization  
       Department of Agriculture  
                                                                                   16   Dr. Artemio M. Salazar  
     Institute for Plant Breeding  
                           Univer sity of the Philippines Los Baños  
 
Secretariat  
Bureau of Agriculture and Fisheries Standards  
 
Team Leader  
17  Mr. Israel Q. Dela Cruz  
 
Assistant Team Leader  
18  Dr. Alpha P. Mateo 
 
Members  
19  Ms.Farlash D. Pancho 
20  Mr.Jerson Raphael A. Bontogo n