Evaluating Hemp Seed in Layer Diets

The commercial production of hemp (Cannabis sativa L.) in Canada was permitted in 1998 following a long period of discontinuation. The development of industrial hemp varieties with low levels of tetrahydrocannabinal (THC), a psychoactive found in other cannabis plants, has led to the reintroduction of this plant into Canadian production systems. The oil content of hemp seeds is approximately 33-35 per cent, and the oil is approximately 19 per cent alpha-linolenic acid (ALA), an omega-3 fatty acid. Since the bulk of the oil is extracted through cold-pressing/extrusion-based processing, the remaining seed cake or meal has significant oil content (approximately 10 per cent) and a high (greater than 30 per cent) protein content, making it an attractive supplement for use in poultry diets.  

However, hemp seed and hemp seed products are not registered as approved feed ingredients by the Canadian Food Inspection Agency (CFIA). Therefore, with a goal to establish data to support safety and efficacy claims for hemp products for use in poultry diets, Dr. James House and his research team at the University of Manitoba conducted a study to determine the impact of adding hemp seed or hemp oil to diets of laying hens.

Forty eight 19-wk old Bovan White laying hens were fed one of five diets containing either hemp seed (HS) or hemp seed oil (HO). The level of HO was four, eight, or 12 per cent whereas it was 10 and 20 per cent for the HS. A set of eight birds fed wheat-, barley- and corn oil-based diets served as the control. Performance was monitored over 12 weeks, and researchers measured feed intake, egg production, feed efficiency, egg quality, egg yolk fatty acid composition, aroma, and flavour.

Their findings?  Average egg production was not affected upon feeding of either HS or HO diets. Egg weight was higher than controls for hens consuming the 20 per cent HS diet. Feed intake was lower than controls for birds consuming the four per cent HO diet, but similar across other treatments.  Final body weights were not affected by diet, with the exception of being lower than controls in hens consuming the 12 per cent HO diet. The total egg yolk omega-3 fatty acid content increased with increasing dietary ALA provision with the HS- or HO-based diets. While total omega-3 fatty acids increased in a linear fashion, the content of the long chain omega-3 fatty acid, docosahexaenoic acid (DHA), increased but then reached a plateau at higher levels of hemp inclusion.  

When assessing smell and flavour, panelists could find no significant differences between the cooked eggs.  The one observation that was made related to yolk colour: the inclusion of higher rates of hemp seed or hemp oil led to the production of more intensely coloured yolks. It is suggested that inclusion of the hemp products HS or HO in the diets of laying hens up to a maximum level of 20 per cent and 12 per cent, respectively, does not adversely impact the performance of laying hen and leads to the enrichment of the omega-3 fatty acid content of eggs.  In total, the data from the current study support the use of hemp seed and hemp oil as safe and efficacious ingredients for use in the diets of laying hens. 

To read more, please visit www.poultryindustrycouncil.ca.