According to Nova Scotia Agricultural College (NSAC) graduate student Michelle Daniel, the secret to obtaining a good quality egg shell is sufficient calcium. Laying hens need a certain amount of calcium in order to prevent a soft shell or cracks in the shell. To meet the calcium requirement for shell quality, bird diets generally contain powdered limestone or a mixture of limestone and oyster shell. However, one of the biggest issues with oyster shell is that it costs approximately three times that of limestone. Hence, an alternative calcium source is warranted.

Michelle’s research program was funded by the Graduate Research Training Initiative Scholarship Program under the federal-provincial-territorial Agricultural Policy Framework (APF), 2003-2008. The APF is funded by Agriculture and Agri-Food Canada and the Nova Scotia Department of Agriculture. The purpose of this initiative is to provide financial support to graduate students at NSAC whose research will benefit the Nova Scotia agriculture and agri-food industry. This initiative is intended to encourage qualified students to undertake graduate studies thus building a professional capacity to meet the future needs of Nova Scotia's agri-food industry.

Michelle, a native of Herman’s Island, NS, says that previous studies evaluating shellfish by-products as calcium sources for laying hens in Atlantic Canada are very limited. Her current project investigates the use of local by-products from the Atlantic shellfish industry as possible feed ingredients for laying hens under the supervision of Dr. Derek Anderson, Professor of Nutrition at NSAC.

A regional company in New Brunswick provided Michelle with the shellfish by-products for her experiment. One of her main objectives was to determine the effectiveness of crab and lobster meal as alternative feed ingredients for laying hens by evaluating their effects on productive performance and egg quality; specifically the composition and structural integrity of the eggs, and calcium utilization by the hen.

Barn trials were conducted that involved a full-cycle production study that finished in August 2006 and took approximately 32 weeks. The control hens were fed a regular diet of oyster shell and limestone, and the others were fed a diet supplemented with either lobster meal, crab meal or a combination of the both. In this trial, Michelle specifically investigated egg yolk pigmentation and egg specific gravity. The specific gravity test is an indicator of egg shell quality and Michelle found no difference between the control diet and test diets. The egg yolk colour yielded some interesting results, as the crab and lobster meal have red pigments which showed up in the yolk.

“One of the more interesting results discovered was the red pigment astazanthin that is present in lobster and crab meal which was transferred to the egg yolk,” says Michelle. “The red pigment is also an anti-oxidant, so it would be interesting to test the levels to see if these anti-oxidant properties were transferred to the egg yolk. There could be an opportunity to produce value-added eggs.”

Michelle also conducted an in vitro solubility study for calcium utilization, testing different types of shells of various local by-products of the Atlantic shellfish industry as potential feed ingredients for laying hens. Other calcium sources were analyzed for their calcium solubility, including commercial oyster shell, commercial ground limestone, surf clam shells, blue mussel shells, scallop shells, and soft shell clams.

“The solubility study basically mimicked the bird’s digestive system,” says Michelle. “We weighed the shells before placing them in a hydrochloric acid solution, and weighed them after a 24-hour period. From here, we evaluated the percentage of calcium that disappeared and relate it to how well we think the hen will utilize these ingredients as sources of calcium for egg shell deposition.”

Results from the solubility test showed that many of the shells were in fact comparable to the conventional oyster shell. However, Michelle says that more research with production trials are necessary in order to determine if there is a similar in vivo degradation pattern throughout the laying cycle of the hen.

Having completed her undergraduate degree in Animal Science at the University of Guelph, Michelle decided to return to the Maritimes to do her graduate program. “I worked with monograstrics during my studies at Guelph, and I found this project interesting and relevant.”

When asked about NSAC, Michelle had a lot of praise for the institution. “Since I’ve arrived at NSAC, I’ve had the opportunity to attend various conferences within Canada where I was able to interact with industry and communicate my research. I was awarded second place in the poster presentations in the graduate student research presentation at the Annual meeting of the Canadian Society of Animal Science held in Halifax in August 2006.”

The research facilities provide another incentive for attending NSAC. The opening of the Atlantic Poultry Research Centre, slated for May 30th, is a multi-million dollar centre that will provide a world-class facility for poultry research. While Michelle has already finished her lab work, she says “Some of my results are already being formulated into new projects, which will benefit from this facility.”

For now, Michelle is busy working on her statistical analysis and preparing to write her thesis. When asked about her future plans, Michelle replied that she would love to stay in Atlantic Canada and continue working in this field: “My goals are to apply my nutrition expertise in the feed industry and continue research in the area of specialty ingredients for improved productivity.” She is currently preparing to present her data at the Canada Nutrition Congress in Winnipeg in mid June.