Sosimo Ma. Pablico
Duck raisers may now profitably extend the egg production period of their stock by adding ascorbic acid to feeds for ducks.
Dr. Jovita M. Datuin, agricultural center chief of the DA [Department of Agriculture] in the Ilocos, made this observation on more than one year old female Mallard ducks that were already past their productive period but ascorbic acid was added to their feeds.
Normally, duck raisers already dispose their flocks after one year because it is no longer profitable to continue raising them. Female ducks like these are called “spent” ducks. The volume of eggs they produce has declined by 50 percent and could barely pay for the feeds they consume.
In this study, Datuin was assisted by undergraduate students of the Virgen Milagrosa University Foundation and Pangasinan State University and a researcher of the DA in the Ilocos.
Results of the study showed that duck raisers could be saved from six months of waiting for a new batch of layers to produce eggs after disposing their spent ducks. They can start raising a new batch of chicks to become layers while they prolong the productive life of their present stock and, hence, egg production would be continuous.
The findings also showed that the productive life of female Mallard ducks could be prolonged to 93 weeks (741 days) by giving them 750 mg [milligrams] ascorbic acid per kilogram weight of the ducks.
The duck layers used in the study (160) were tested in three production periods: 58 to 69 weeks old, 70 to 81 weeks old, and 82 to 93 weeks old. Four levels of supplementation were tested in each group: 0, 250, 500, and 750 mg ascorbic acid per kilogram bodyweight. The birds were under total confinement.
The 58 to 69 week-old ducks have laid eggs for almost one year already; the 70 to 81 week-old, one year and three months; and the 82 to 93 week-old, one year and six months.
Ascorbic acid supplementation did not significantly affect the weight of the ducks during the three production periods. In fact, after 12 weeks of ascorbic acid supplementation the weight of 69 week-old ducks decreased by 180 grams. Since their egg production at 58 to 69 weeks old was high at 80 to 86 percent, this result suggest that the birds convert feed nutrients more efficiently for egg production rather than for meat production.
Earlier, other researchers noted no beneficial effect of supplementing Vitamin C (ascorbic acid) on the growth of broilers.
Datuin also observed that 58 to 69 week-old ducks given 250 mg AA/kg and 750 mg AA/kg had the highest percentage of hens that laid eggs everyday, 86.2 percent and 85.7 percent. In contrast, those not given ascorbic acid only had an average 82.7 percent.
Overall, the percentage of hens that laid eggs everyday decreased over time. At 82 to 93 weeks old, however, 50.9 percent to 60.4 percent of the ducks with ascorbic acid supplementation were still laying eggs everyday, while those without supplementation had an average 47.3 percent. This result shows that more ducks lay eggs everyday by giving them ascorbic acid.