|
| |
Controversy about rBST
Use of rBST has been held in controversy for a variety of reasons, including:
animal health concerns, human health concerns, and the encroachment on small
farmers by large corporations.
Animal health concerns
In 2003, a meta-analysis on rBGH's effects on bovine health was published in The
Canadian Journal of Veterinary Research. The article states that rBGH "was found
to increase the risk of clinical mastitis by approximately 25% during the
treatment period." "Use of rBST increased the risk of a cow failing to conceive
by approximately 40%." Treated cows had a "an estimated 55% increase in the risk
of developing clinical signs of lameness (moving with pain or difficulty on
account of injury, defect, or temporary obstruction of a function) ."
The movie The Corporation has a segment on rBGH. This includes video of cows
suffering from mastitis. According to The Corporation's website: "Because of the
increased production, the cows suffer from mastitis, a painful infection of the
udders. Antibiotics must then be injected, which find their way into the milk,
and ultimately reduce people's resistance to disease ."
"Dairy records demonstrate an association between milk yield and incidence of
mastitis. This association suggests that incidence of mastitis would increase in
BST-treated cows because they produce more milk. This has been observed in some
BST studies. However, BST does not appear to increase the incidence of mastitis
above that expected from the greater milk yield ."
"Although increased milk yield is associated with an increased incidence of
mastitis, proper management practices can minimize the frequency and impact of
mastitis. Not every mastitis case requires treatment of the cow with
antibiotics. All milk is tested for the presence of antibiotics before it is
marketed and dairy producers realize they must not ship milk contaminated with
antibiotics. Producers incur significant financial penalties if they ship
antibiotic-contaminated milk. Dairy producers have considerable incentive to
follow established guidelines for antibiotic use. Use of BST will not increase
the incidence of antibiotic contamination of the milk supply if producers use
antibiotics as directed ."
In other words, mastitis is not caused specifically by treatment with BGH or
rBGH, but is caused in general by the increased levels of milk production,
whether promoted by rBGH or other methods. Cows that naturally produce more milk
are more likely to experience mastitis. Similarly, cows that produce more milk
require more services (fertilization attempts) than cows that produce less milk.
Selective breeding of dairy cows has greatly improved milk yield over the years,
but has also increased incidence of mastitis and other health problems in dairy
cattle.
rBGH has been associated with an increased risk of mastitis in cows. The warning
label on Monsanto’s Posilac explicitly states, "Cows injected with Posilac are
at increased risk for clinical mastitis." The EU Scientific Committee on Animal
Health and Animal Welfare (SCAHAW) was asked to report on the incidence of
mastitis and other disorders in dairy cows and on other aspects of the welfare
of dairy cows. The Committee stated
"bST (Bovine somatotropin) use substantially increases foot problems, mastitis
and injection site reactions in dairy cows. These conditions are painful and
debilitating, leading to significantly poorer welfare of the animals. bST also
causes reproductive disorders. Therefore, from the point of view of animal
welfare and health, this substance should not be used."
Health Canada, like the SCAHAW, banned rBST because of its effects on cows .
Health Canada cited this reason for its ban
"The veterinary experts cited an increased risk of mastitis of up to 25%, of
infertility by 18%, and of lameness by up to 50%. These increased risks and
overall reduced body condition lead to a 20-25% increased risk of culling from
the herd."
IGF-1
Monsanto's studies show use of rBGH in cows increases bovine insulin growth
factor 1 (IGF-1) in milk. Human and bovine IGF-1 are almost completely identical
and indistinguishable by available immune assay methods.
| |
|
