Fat is an essential component in animal and human diets. The essential fatty acids are the critical components of fats and one very important fatty acid is the omega-3 derivative, docosahexaenoic acid (DHA).
Humans originally consumed a diet rich in omega-3 fatty acids and low in saturated fatty acids because pasture based animals had much higher contents of omega-3 fatty acids than do the present-day commercial livestock. In humans, DHA omega-3 is related to enhanced cognitive function and learning ability in children, including benefits for children with attention deficit and hyperactivity disorder (ADHD). In addition, DHA omega-3 improves the health of adults by lowering the risk of developing cardiovascular and Alzheimer’s diseases, and lessening severity of depression. Adequate supplies of DHA are required for infant development and the content of DHA in breast milk is influenced by the diet of the mother.
Today researchers are looking to increase the supply of beneficial omega-3 fatty acids to the human diet through feeding the animal and thus providing the DHA naturally. By adding DHA omega-3 in algal meal to the animal diet, we can also positively influence the health and wellbeing of the animal.
The metabolic demands for increasing milk production are significant and represent a major challenge to ensure optimum production while also facilitating reproduction. Dietary nutrients and nutrients from body tissues are directed to milk production. During this same time, the uterus, ovary, and hypothalamus/pituitary glands undergo a process of recovery and rebuilding for the establishment of subsequent pregnancy (Thatcher et al., 2011). Dietary formulations targeted for the benefit of reproductive performance represent a major challenge. Fat supplementation has been slowly developing a record of data for reproductive effects (Thatcher et al., 2011). The decrease in fertility of the lactating dairy cow is multi-factorial and often associated with high milk production (Lucy, 2001; Santos et al. 2008). The energy costs to synthesize and secrete hormones, ovulate a follicle, and sustain an early developing embryo are probably minimal compared to the energy needs for maintenance and lactation.
In recent years studies have examined the effects of feeding algal meal, high in DHA, on feed intake, enteric methane production and milk parameters (Boeckaert et al., 2008; Stamey et al., 2012; Moate et al, 2013). It has been demonstrated that feeding algal meal may inhibit voluntary dry matter intake and reduce milk fat concentrations (Moate et al., 2013).
In a recent trial in Italy, researchers examined the effects of feeding algal meal on milk production and milk composition of lactating dairy cows. The study was carried out with 36 Italian Friesian dairy cows in their average-late stage of lactation. Cows were allocated into two homogenous groups of 18 animals each, where the treated group received the supplementation (6 g/kg DMI) of the test product for 84 consecutive days mixed into one component of the TMR (corn meal), while the control group had received the same amount of corn meal without a test product.
The results of the study showed that the treatment with algal meal didn’t change the body condition scores and live weight tended to be a little higher for those cows, while milk yield increased during the trial period by 5.4 percent (1.19 kg/cow/day) and milk fat content and fat production was reduced.
Milk protein content and production, lactose content and production, urea and somatic cell count were unaffected. The algal meal significantly affected the milk fatty acid profile, increasing milk DHA (% of FA) from 0 to 0.37%. The researchers concluded that algal meal fed in a TMR to dairy cows enriched milk with beneficial DHA and increased conjugated linoleic acid. Milk yield increased; while milk fat and fat production declined without significant change in four percent fat corrected milk.
Current studies using DHA in lactating cows are aimed at enhancing the quality of the uterine epithelium, modifying and attenuating the release of prostaglandin F-2a and thus ensuring a higher pregnancy rate resulting from better maternal recognition of pregnancy and subsequent maintenance of pregnancy.
Supplementation using DHA-rich microalgae sources has been used successfully in monogastric livestock such as pigs and poultry to produce DHA-enriched meat and milk. Now attention is being directed to producing DHA-enriched foods from ruminants. It is anticipated that DHA inclusion in the diet will not only add benefits for animal and human health but also increase reproductive efficiency in the herd.