Effects of Feeding Pattern and Feeding Type on Occurrence of A flat oxen M, in Milk of High Producing Dairy Cows

Abstract

The dairy sector has been identified as the priority sector for the development among other livestock sub sectors in Sri Lanka as the country is currently in the process of achieving at least 50%» self-sufficiency in milk production by year 20 15. The demand for ruminant feeds, mainly roughages and concentrates is always increasing with the increase of milk production. As there is lack of suitable lands for enough roughage production and due to their poor quality, dairy producers tend to use higher amounts of concentrate feeds, such as rice by products, maize, coconut poonac, compound animal feeds, etc. The major problem associated with concentrate Needs is declining quality by contamination with fungal toxins called “Aflatoxins". Aflatoxins (AFs) are a group of mycotoxins produced mainly by common fungi Aspergillus flavus, A. parasiticus and A, nominus that present in Goods and feedstuffs such as in cereals, nuts, etc (Zinedine el at., 2007). Aflatoxin M1 (AFMi), shydroxylated metabolite of Aflatoxin B formed in the liver subsequently occurs in milk from lactating animals consuming AFBi contaminated feed. (Lin e/ o/. 2004). Aflatoxins are associated with various health and production problems in lactating animals. International Agency for Research on Cancer (IARC) classifies AFM as a possible human carcinogen that has comparable liver toxicity, which can reduce the immunity of infants. Humans get those toxins through AFM, contaminated milk and milk products. Several countries have established legislation to regulate the levels of AFB in feeds and AFM in milk because of their carcinogenicity (Liner «/. , 2004). Though considerable numbers of studies have been conducted internationally, research performed locally on this matter is very limited. Thus, Sri Lanka does not have standards for maximum aflatoxin levels to be allowed in animal feeds and milk. It is important to know the amount of AFM in locally produced milk having a special significance for infants and children. A recently conducted study by Pathirana et al(20I0) to evaluate the farm gate cow milk for AFM i, revealed that 33% of the locally collected milk contained aflacoxin M with 9.2%« exceeded the European Communities/Codex Alimentarius recommended limit of 50 ng L”', highlighting the significance of the problem. The study also states that the incidence of AFM / contamination is Oren high where cows are fed with high amounts of compound concentrate needs. The occurrence of AFM under various feeding praccices under Sri Lankan conditions should be investigated to understand the effects of feeding type on the incidence of AFMi in the milk as there is no such study available currently. Therefore, this research was conducted as a preliminary study for the objectives of investigating the relationship between feeding pattern and feed type on the occurrence of AFM in cow milk collected from the up country dairy farms.