PROJECT RESULTS

Hulless Barley in Laying Hen Diets

Applicant: 

Dr. W. Guenter
Department of Animal Science
University of Manitoba
Winnipeg, Manitoba  R3T 2N2  Canada

Table of Contents:

• Background and Objectives
• Procedure and Project Activities
• Results and Discussion
• Conclusions

ARDI Project:

#98-089

Total Approved:

$63,500

Date Approved:

Project Status:

Completed February, 2001

Background and Objectives:

Hulless barley has recently become available as an alternative feed source for use in livestock and poultry diets. While hulless barley is gaining acceptance as a quality feedstuff for use in swine diets, there is limited information available regarding its use in laying hen diets. Dietary exogenous enzymes have been shown to be necessary for the effective use of hulless barley in diets of growing poultry but there is limited information available regarding the use of enzymes in laying hen diets. The use of dietary enzymes could be more critical if the apparent differential among varieties experienced with broilers is also a factor for laying hens.

The major objective of this research was to demonstrate the efficacy of hulless barley as a feedstuff in laying hen diets. Secondary objectives were to determine if the productivity of laying hens fed hulless barley could be enhanced by the use of exogenous enzymes and to demonstrate that nitrogen and phosphorus pollution can be minimized through the use of dietary enzymes to enhance productivity.

Procedure and Project Activities:

Four varieties of hulless barley (Falcon, Silky, Dawn and Gainer) were each planted in 10 acre plots at the Glenlea Research Station in May of 1998, 1999 and 2000. The harvested grain was utilized in the following research trials. For the determination of True Metabolizable Energy (TME) and True Digestible Amino Acid (TDAA) availability determination a fifth variety (Bacon) was purchased to ensure that the overall evaluation of hulless barley would encompass the potential variability in the crop that may exist. 

The TME and TDAA content of the hulless barley varieties were determined using the adult rooster bioassay. The TDAA values were determined for 16 of the amino acids present.

In the second phase of the research four hulless barley varieties were used in three types of laying hen feeding trials. The first trial was a 5-28 d period feeding trial with two strains of birds and five dietary treatments: wheat control and Silky, Falcon, Gainer and Dawn hulless barley diets formulated to meet the requirements of the birds. Each diet was fed to 8 replicates of 16 hens per strains or 252 hens per dietary treatment.

The second experiment was designed to determine if feeding hulless barley based diets plus exogenous enzymes to laying hens will result in equal performance compared to wheat diet control birds. 1280 SCWL hens of the Shaver White strain at 26 wks of age were subdivided into replicate groups of 4 adjacent cages (16 birds per replicate group). Each group was randomly assigned to one of 10 dietary treatments (8 replicates per treatment). The dietary treatments were: wheat control, and four hulless barley diets (Silky, Falcon, Gainer, Dawn). The diets were fed with and without enzyme supplementation for 9-28 d periods.

The third laying hen trial was a 5-28 d period feeding trial with two strains of hens equally distributed to each dietary treatment. 576 hens (288 hens/strain) were equally divided into 36 replicates of 16 hens and each replicate was randomly assigned to one of three dietary treatments (12 replicates or 192 hens per treatment). The dietary treatments were as follows: a mixed barley (equal parts of Gainer, Silky and Dawn) control diet without enzymes and two mixed barley diets where the nutrients of the barley, canola and soybean meal were uplifted by either 5% or 10% with an enzyme supplement added to the diet. The uplift of the nutrients was based on the positive effect observed in our second trial. Concurrent with this trial a nutrient availability study was superimposed, to determine the enzyme affect on nitrogen and phosphorus excretion and amino acid availability.

The production parameters collected daily in all three laying hen trials were: egg production, feed consumption, initial and final body weights, mortality as it occurred, egg weight over 3 consecutive days for each period, observation of stained, cracked and shell-less eggs. From the data also calculated were egg mass per day and feed efficiency as g feed per g egg produced.

Results and Discussion:

On average the amino acid content of the five hulless barley varieties expressed as a percent of protein varied less than 6% whereas the true metabolizable energy variation was about 3%. The average true digestibility of the amino acids was 78.5% with a low of 55% for lysine and medium of 72% for methionine and 79% for threonine. These values are of great significance for formulating diets on the basis of amino acid availability. On average the hulless barley diets without enzymes resulted in a slight reduction (1.5%) in hen-day production and a 2% reduction in daily egg mass whereas other parameters were not affected. Of interest is to note that there was a differential response to the hulless barley diets by the two strains of birds, which might be worth investigating further.

Supplementing hulless barley diets with a cocktail of enzymes significantly improved performance of laying hens in general but the magnitude of the response varied with the hulless barley variety, with Silky and Falcon yielding the overall greatest response.   However the use of enzymes with all hulless barley varieties resulted in performance equal to or better than the wheat control diet plus enzymes. This suggests that the use of enzymes in hulless barley diets removes the variability in response to different varieties. Similarly based on the balance trial the amino acid availability was significantly improved which may explain the improved performance. Contrary to common belief that hulless barley diets when fed to laying hens increases the incidence of soiled eggs, we did not experience this problem.

Uplifting the nutrient content of diets by 5 or 10% when supplemental enzymes were fed reduced the feed intake by 7.5% but maintained production at 88.6%, however egg size and egg mass were slightly reduced (1.5%).More research is required to accurately determine the uplift required to maintain all production parameters. Although no change in excreta nitrogen content was observed the phosphorus content was significantly decreased (15%) when enzymes were fed with hulless barley diets.

Table 1. Performance of SCWL Hens Fed a Wheat Control Diet and Four Hulless Barley Varieties With and Without Enzymes (9-28 d periods) 

¹(-) no enzyme added, (+) enzyme supplementation

Conclusions:

Hulless barley when used in combination with exogenous enzymes can effectively  replace feed wheat in rations for laying hens.

The research results will be of direct benefit to grain producers as laying hens represent a significant source of demand for cereals and will be a good market for hulless barley. The feed industry should also benefit in that they have an alternative grain source to use in laying hen diets.

The reduction in phosphorus excretion will certainly be of benefit to the environment.

Acknowledgments:

This project was made possible due to the funding from the Governments of Manitoba and Canada through the Canada-Manitoba Agri-Food Research and Development Initiative (ARDI).  Matching funds were received from the Manitoba Egg Producers, Canadian International Grains Institute, the Alberta Barley Commission and the Western Grains Research Foundation.

ARDI Home - Contact ARDI