TITLE:
Effect of mammary stimulation on dairy cows and heifers exposed to a lactation induction protocol
AUTHORS:
Reeza Ramgattie, Narendra Siew, Michael Diptee, Valerie Stoute, Marlon Knights
KEYWORDS:
Mammary-Stimulation; Lactation-Induction; Cows; Heifers
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.4 No.1,
January
6,
2014
ABSTRACT:
Cows (n = 21), dried off
for a minimum of 45 days, and nulliparous heifers (n = 26), at ages > 18 months
old, were placed on a 12-day Lactation Induction (LI) protocol. One group of animals
(including both cows and heifers) received 3-minute mammary gland stimulation, along
with the LI protocol. Another group, again including both cows and heifers, received
no stimulation only the LI protocol This consisted of two injections of prostaglandin
F2α (PGF2α; 25 mg) 11 days apart, followed by subcutaneous injections of 17β-estradiol
(0.1 mg/kg BW/d) and progesterone (0.25 mg/kg BW/d) beginning 1 day later and continuing
for seven (7) days. After this step, all animals received another injection of PGF2α on day 8, followed by intramuscular injections
of reserpine (5 mg/d) and dexamethasone (20 mg/d) on each of days 9 to 12. All animals
were milked, beginning on day 13, for a period of 154 days. For all animals, the
success rate for lactation induction was 78% ± 6.3% and the mean weekly milk yield
was 78.2 kg. Neither value was affected by mammary stimulation. Parity did not significantly
impact on the success rate but it did affect the mean weekly milk yield. Milk yield
varied significantly (p α =
0.05 level) affected by stimulation or by parity. However, heifers (at 8.2 weeks
± 1.0 week) tended (p = 0.1) to reach peak milk production earlier than cows (at
10.7 weeks ± 1.3). The milk produced was sold at a net profit per animal treated
of $2206.31 TT. Hence, one can conclude that a Lactation Induction protocol can
be a useful management tool to increase production and profitability of dairy operations
in the tropics.