rBST Animal Health
Why did the Canadian dairy industry not support use of rBST?
Because of supply management and rejection from consumers
What has the USA allowed for labelling with rbST?
Consumer and activist groups have demanded labeling. FDA permits (does not require)labeling as "rBST-free" or "no added hormones" or "no synthetic hormones" but require the label also include a disclaimer statement that no significant difference has been shown between milk derived from rBST treated and non-rbST treated cows
How was reproduction affected by rBST use?
Slight increase in days open and substantial risk of non-pregnancy
Inconclusive results on cystic ovaries, abortion, and twinning
Most solved by treating after confirmed pregnancy
How is growth hormone seen in milk of BST treated cows?
No detectable increase in GH levels in milk of BST treated cows
GH is destroyed by pasteurization
Bovine GH is not active even when injected in humans - ruminant GH very similar (95-99% homologous), Porcine GH 79% similar to ruminants, chicken GH about 80% similar with ruminant, human GH about 70% similar to ruminant GH
How was lameness affected by rBST use?
Suggest up to 50% increase in incidence
Suggest management not able to reduce
related to high energy/protein dense diets
How does BST treated cows milk affect humans
IGF-I levels do not increase in bST milk
Bovine IGF-I is bioactive in humans
IGF-I is not destroyed by pasteurization
IGF-I is destroyed by process used for infant formulas
FDA concluded that the slight increase in IGF-I in bST milk is not a human health concern
How was mastitis affected by rBST use?
Suggest 25% increase in risk of clinical mastitis and increased sub-clinical
current management practice could reduce
Specifically rejected by monsanto with the argument of cows are producing more milk = more mastitis case; not due to rBST - argued there was a 40% increase in milk production over 15 years accompanied by only a small increase in mastitis
Consumers believe
= Increased antibiotics will be in milk because of increased incidence of mastitis - not true, treated milk is withheld from the bulk tank
= Milk will be full of puss - technically yes since neutrophils are puss, but like no
How did monsanto counter argue to health claims
repro problems are related to increased milk yield - same as response to genetic improvement, commercial use/recommendation is to treat post conception
lameness problem present but not significant - richer diet formulation required to support higher milk yield is associated with higher lameness
mastitis increase minor - production related, when compared against other factors impacting mastitis incidence, studies show GH increases immune function
much of the negative effects are considered related to higher milk production where genetically superior high producing cows which are not bST treated show similar increased incidence of health problems
What does milk being an ultrafiltrate of blood mean?
Nearly all components of blood are present in whole milk at some level in addition to components synthesized by the epithelium