The present study was conducted to observe the seasonal variation in aflatoxin M1 and nutritional quality of milk along informal marketing chains. Milk samples (485) were collected from three different chains over a period of one year. The average concentrations of aflatoxin M1 during the autumn and monsoon seasons (2.60 and 2.59 ppb) were found to be significantly higher (standard error of the difference, SED = 0.21: p = 0.003) than in the summer (1.93 ppb). The percentage of added water in milk was significantly lower (SED = 1.54: p < 0.001) in summer (18.59%) than in the monsoon season (26.39%). There was a significantly different (SED = 2.38: p < 0.001) mean percentage of water added by farmers (6.23%), small collectors (14.97%), large collectors (27.96%) and retailers (34.52%). This was reflected in changes in milk quality along the marketing chain. There was no difference (p = 0.178) in concentration of aflatoxin M1 in milk collected from the farmers (2.12 ppb), small collectors (2.23 ppb), large collectors (2.36 ppb) and retailers (2.58 ppb). The high levels of contamination found in this study, which exceed the standards set by European Union (0.05 ppb) and USFDA (0.5 ppb), demand radical intervention by regulatory authorities and mass awareness of the consequences for consumer health and safety.

Improving both quality and quantity of food available is a pressing need especially when one eighth of the world’s population consumes less energy than is required for maintenance and is exposed to contaminated food, both of which lead to greater susceptibility to diseases. The Pakistani population depends heavily on milk for nutritional needs and 10% of household income is spent on milk. This commodity requires continuous monitoring and care from its site of production by smallholder dairy producers through to urban consumers along tradition milk marketing chains. Feed ingredients used as concentrate feed to enhance milk production are often contaminated with mycotoxins, which, after ingestion, are transferred into milk. Aflatoxins can contribute to the causation of liver cancers, immune system disorders, and growth-related issues in children. Moreover, deaths in both humans and animals have also been reported after ingestion of aflatoxin-contaminated food. Studies have shown contamination of food and feed ingredients with mycotoxins, especially aflatoxins. This review places the dairy industry into context, summarizes how milk and milk products are contaminated with aflatoxins, and discusses the present legislative regulation of milk quality implemented in Pakistan. There is a need to eliminate fungus-susceptible animal feed ingredients, which are the source of mycotoxins so prevalent in the milk marketed to the consumer in Pakistan.

The production performance of multiparous lactating Sahiwal cows (n = 24) was evaluated according to both milking frequency and method. Selected animals were randomly divided into four groups containing six animals each under a completely randomized design. Cows in groups A & B were milked by the hand milking method three times per day, respectively. Similarly, cows in groups C & D were milked by the machine milking method two and three times per day, respectively. All animals were maintained under uniform feeding and management conditions. Dry matter intake was high in animal groups milked three times per day, and it remained unchanged between the hand and machine milking methods. Milk yield was higher (P < 0.05) in cows milked three times compared to those milked twice per day, and it did not differ between hand and machine milking methods. Milk fat percentage was higher (P < 0.05) in cows milked twice per day compared to those milked three times using both machine and hand milking methods. The percentage of total solids showed a similar pattern as the fat percentage. However, percentages of protein, lactose, and non-fat solids in milk were not significantly different (P > 0.05) among the treatment groups. Collectively, the results show that milking three times per day instead of twice at 8-hour intervals can enhance milk yield in Sahiwal cows using both hand and machine milking methods.

The objectives of the present study were (1) to monitor the pattern of excretion of aflatoxinM1 in urine after its conversion from aflatoxinB1 and (2) to observe the effects of different levels of aflatoxinB1 in feed on serum concentrations of key metabolites glucose, total protein, cholesterol and urea as indicators of metabolic status. Nili-Ravi buffalo heifers (n = 12) of similar age and weight were randomly distributed to four groups. Animals in Groups A, B and C were offered a contaminated cottonseed cake-based concentrate ration at 0.5%, 1.0% and 1.5% of bodyweight, respectively. Control animals in Group D were fed with aflatoxinB1-free green fodder. Based on the level of contamination of the concentrate ration with aflatoxinB1 (554 µg/kg), Groups A, B and C consumed 953, 2022, 3202 µg of aflatoxinB1 daily. Feed samples were analysed at Romer Laboratories Pty Ltd, Singapore by high performance liquid chromatography. AflatoxinM1 quantification in urine samples was conducted using a competitive enzyme-linked immunosorbent assay with kits supplied by Helica Biosystems, Inc., USA. Serum samples were analysed for concentrations of glucose, total protein, cholesterol and urea using clinical chemistry kits provided by Human diagnostics (HUMAN, Biochemica und Diagnostica mbH, Germany). Carry-over rate of aflatoxinM1 in urine for Groups A, B and C was 15.51%, 15.44% and 14.04% of aflatoxinB1 while there was no detectable aflatoxinM1 in the urine of the control group (D). There was no significant difference in the concentrations of serum glucose, total protein and cholesterol between treatment groups. However, the concentration of serum urea was significantly higher (P < 0.05) in the group offered the highest level of aflatoxinB1-contaminated concentrate. This result suggests that mycotoxicosis may compromise protein metabolism and accretion in affected animals. This leaves open the possibility that high concentrations of aflatoxins in milk may ultimately affect the health status of human milk consumers.