The âgold standardâ mammalian safety toxicopathological tests are very sensitive and reproducible examinations used by veterinary pathologists in the pharmaceutical industry and regulatory agencies to detect sublethal toxic effects of candidate drugs, pesticides and other chemicals in laboratory animals to determine the safe dose range of these medications/chemicals for humans and animals. However, comparable toxicopathological approaches using histopathology have not been developed for honey bees.
Feather pecking (FP) in egg-laying hens, where individuals peck repetitively and excessively at other birds to pull out and eat their feathers, is a challenge for the industry with large economic and welfare implications. High prevalence of FP is reported (60-80%) and this is associated with mortality rates of up to 20-40%, which translates to hundreds of millions of birds dying due to FP every year.
Pork producers in Canada are in the process of transitioning from stall housing to group housing systems for gestating sows. The greatest concern with this change is the problem of aggression when pregnant sows are mixed. Mixing frequently results in aggressive interactions among sows, and can affect reproduction and cause welfare problems. Typically sows are held in stalls for several weeks after insemination to minimize stress during embryo implantation, however there is increasing pressure to reduce the time that sows are kept in stalls.
A parasite present in the Bras dâOrs Lake in Cape Breton, NS has closed the oyster aquaculture and wild fishery in Cape Breton since the initial outbreak in 2002. This parasite has also affected oysters in the Eastern US. The industry in the US has survived and is stable in part due to the production of triploid oysters. Triploid oysters grow to market size faster and this fast growth rate reduces the time the oyster spends in the wild and therefore reduces the timeframe that the oyster may become infected with the parasite.
This research will investigate use of calcium oxide treated straw (CaOS) to increase fibre levels in wheat-based feedlot cattle finishing diets. In vitro total gas production will be measured to determine the ideal treatment protocol for creation of CaOS. Further in vitro work will compare fibre digestibility of CaOS to untreated straw, barley silage and corn silage as an indicator of nutritional quality. A feeding trial using yearling steers will measure changes in animal performance when 10% silage is replaced with 12% CaOS in finishing diets.
Sub-clinical disease results in reduced growth and less efficient use of nutrients, resulting in substantial impact on profitability of pork producers. With the elimination of in-feed antibiotics for growth promotion it is increasingly important to understand the interaction between nutrition and health and nutrient requirements during disease challenge events. Feeding high-fibre feedstuffs reduces the efficiency of utilization of dietary threonine for growth in pigs due to an increase in endogenous threonine loss as a result of increased mucin production.
The B vitamin requirements of cattle were traditionally satisfied via rumen microbial synthesis. However, the B vitamin demands of the modern high producing dairy cow now exceed the synthesis rate by rumen microbes, leading to sub-optimal milk production and efficiency. An increased understanding of dietary factors driving ruminal synthesis and use of B vitamins will help identify when supplementation will benefit the cow. Although B vitamin kinetics in the dairy cow have not previously been modelled, data on concentrations and flows are available from extant sources.
Feed restriction in gestating sows is required to prevent excessive body weight gain and the associated negative consequences on lactation, locomotion, farrowing, and feed intake during lactation. Aggression and stereotypies associated with restricted feeding become a welfare and production concern when the sows are housed in groups.
A new revolution in life science research is ongoing since the discovery of the CRISPR/Cas system. With this technology is now possible to specifically and efficiently manipulate the genome of cultured cells, embryos and animals. The technology has many applications in agriculture including the dairy genetic industry to generate the next generation of elite animals having improved traits. For example, using the CRISPR/Cas technology it is now possible to produce dairy cows of any bloodline having improved traits for health, welfare, production and management. L'Alliance Boviteq Inc.
Transition cows (3 wk before calving until 3 wk after calving) often suffer from negative energy and protein balances due to reduced feed intake, but increased nutrient demands for milk production. In Canada, up to 50% of transition cows may be affected by a metabolic (ketosis, hypocalcemia, and milk fever) or infectious (retained placenta, displaced abomasum, and uterine infection) disease. These diseases lead to production losses, infertility, animal welfare problems, and high culling rates of transition cows.