The embryo transfer is becoming a
widespread practice. Most embryos are collected from spontaneous single
ovulating mares and result in 50% of embryo recovery, increasing the
costs of production. To illustrate, the price of a catheter for embryos
recovery range from US$ 194.00 to US$ 250.00 (R$ 350.00 to R$ 450.00).
Therefore, the aim of this work was to verify if catheter with damaged
balloon can be recuperated and reused without altering its efficiency.
For this study, two groups were used: a control group (GI, n=10), on
which the nonsurgical recovery of the embryos of mares was performed
with the catheter with original balloon; and another group (GII, n=20),
in which a restored catheter was utilized. The mares of GI had an
embryo recovery rate of 60%, and GII mares had an embryo recovery rate
of 55%. There was not statistical difference between groups I and II
(P>0.05). Considering that the material used to restore the catheter
costs US$16.66 (R$30.00), this data show that the recuperation of the
catheters for embryo recovery in mares may reduce costs without
compromising the rates of embryo recovery.
Keywords: equine, embryo transfer, catheter recycling, costs reduction
A transferência de embriões está se
tornando uma prática largamente utilizada. Apesar disso, na indústria
de equinos, a colheita dos embriões é realizada a partir de ovulações
simples, resultando em recuperação de, aproximadamente, 50%, o que
aumenta os custos de produção. Cite-se como exemplo o custo do cateter
para colheita do embrião, que varia de R$ 350,00 a R$ 450,00 (US$
194,00 a US$ 250,00). Assim, com este trabalho objetivou-se verificar
se cateteres com balão danificado podem ser recuperados sem alterar a
sua eficiência. Para o estudo utilizaram-se dois grupos: controle (GI -
n=10), em que a colheita não cirúrgica dos embriões das éguas foi
realizada com cateter original; e o tratamento (GII - n=20), submetido
à colheita do embrião com cateter recuperado. O custo do material
utilizado para recuperar os cateteres foi de R$ 30,00 (US$ 16,66). Para
as éguas do GI, obteve-se uma taxa de recuperação embrionária de 60% e
no GII de 55%, não havendo diferença (P>0,05) entre os grupos.
Considerando o baixo custo do material utilizado para recuperar os
cateteres, conclui-se que sua recuperação, visando à reutilização na
colheita de embrião de éguas, pode reduzir consideravelmente o custo
final da técnica, sem comprometer as taxas de recuperação embrionária.
PALAVRAS-CHAVES: Equino, recuperação de cateter, redução de custos, transferência de embrião.
INTRODUCTION
Mean embryo recovery from single ovulating mares in commercial embryo transfer (ET) programs is approximately 50% (SQUIRES
et al., 1999; CARVALHO
et al.,
2001), although, other rates ranging from 40 to 80% have been found
(RIERA & McDONOUGH, 1993; SQUIRES, 1993; TISCHNER & TISCHNER,
1996; FLEURY, 1998). There are many different reasons for this great
amplitude of results, such as age of the mare (SQUIRES
et al., 1999), fertility of the donor (KATILA
et al., 1989; SQUIRES
et al., 1999), day of embryo recovery (McKINNON
et al., 1988), number of ovulations (SQUIRES
et al., 1987a,b; ROSA
et al., 1998), stallion (DOUGLAS, 1979; CASTLEBERRY
et al., 1980; PASHEN
et al., 1993), quality of semen (SQUIRES
et al., 1999), and the occasion of the reproduction season (McKINNON
et al., 1988).
The maintenance of animals enrolled in the ET programs as well as the
material used in its procedures turns the ET in horses into a great
challenge, considering the high operational costs. Thus, only animals
with high genetic value should be used as donors (SQUIRES
et al., 1999).
The material used in the non-surgical procedure of embryo recovery
increases the costs of ET in horses, specially the catheter, whose
prices vary from US$ 209.375 to US$ 281.25 (R$ 350.00 to R$ 450.00)
each. The catheter is a very fragile equipment, and any puncture in its
balloon turns it useless. Therefore, the aim of this work was to verify
if recycled catheters could be used for embryo recovery in mares,
without altering the equipment efficiency and reducing the costs.
MATERIAL AND METHODS
In this experiment, Mangalarga 30 mares, raised on Tanzania and Pangola
pasture, were used. They also received mineral salt specialized for
equines
ad libitum. All
animals were treated with a specific vermifuge for horses with
ivermectine. All the animals came from a property in the city of Santo
Estevão, Bahia / Brazil, a semi-arid region, with rainfall of
approximately 800 milimeters per year and a low air humidity rate.
The experiment was carried out during the months of January and
February. The thirty mares were equally and collectively handled. The
handling system comprised daily oestrus notification, and group
teasing, in order to identify reproductive activity. All animals went
through the same pattern of treatment, which consisted of the
application of 250 μg of cloprostenol (Ciosin, Schering-Plough, São
Paulo, Brazil), oestrus detection and follicle development control by
palpation per rectum until the day of ovulation. All mares were
covered by the same stallion and the embryos were collected seven days
after the determination of ovulation.
The animals were randomly divided into two groups. In group I (n=10),
the embryo recovery was done with a brand new catheter with an original
balloon, and in group II (n=20), used catheters with recycled balloon
were used (Disposable Balloon, Ref. 006448, IMV, L’Aigle, France).
The procedure for recycling the catheter was performed as follows:
after finding a damaged balloon, it was manually removed from the
catheter, and was replaced by a new one, commercially available,
inserted with the help of pliers (IMV, Ref. 007799, L’Aigle, France).
The pliers should be moistened with distilled water to facilitate
their removal after inserting the new balloon, which is manufactured in
such a way that there is no need for glue after insertion. After the
procedure described above, the recycled catheter was packaged and
sterilized with ethylene oxide by a specialized company.
The recycled catheter was evaluated regarding the tolerance to pressure
with a volume of air (60mL), capacity of fixation to the mare’s uterus
(assessed by manual traction after fixation of catheter) and its
efficiency in recovering embryos, in comparison to catheters with the
original balloon.
The catheters to be used in both groups had their balloons inflated
with air for 30 minutes before initiating the procedure, in order to
verify any possible linkage.
The procedure to recover the embryos consisted of manually placing the
catheter into position through the cervix and injecting 60 mL of air to
inflate the balloon. After notifying that the catheter was properly
placed, one liter of ringer with lactate was injected and recovered.
This procedure was repeated three times totalizing three liters per
mare submitted to embryo recovery. The flushed material was filtered
and evaluated in order to verify the presence of an embryo.
Chi-square test was used to evaluate the difference of embryo recovery among groups I and II, with significance level of 5%.
RESULTS AND DISCUSSION
Most embryos recovered came from single ovulating mares. Similar
results were found by other studies about horses. The embryos were
recovered from day seven to day eight after ovulation (Day 0 =
ovulation day), as suggested by most authors (BATTUT
et al., 1997; SQUIRES
et al., 1999; FLEURY
et al., 2001).
The balloons were submitted to a pressure from 60 to 80 mL of air (FLEURY
et al., 2001; SQUIRES
et al.,
2003). Both new and recycled catheters demonstrated tolerance to this
kind of pressure, as well as good fixation to the uterus. The recycled
catheters were used up to three times each. A brand new catheter and a
recycled one are shown in the
Figure 1.
The mares from group I (new catheter) and group II (recycled catheter)
had an embryo recovery rate of 60% and 55%, respectively. There was no
statistical difference between groups I and II (p>0.05). The mean
rate of embryo recovery in mares in commercial programs of ET is
approximately 60% (LOGAN
et al., 2007; MORTENSEN
et al., 2009). Similar results were found in this experiment with the recuperated catheters.
The material used to recycle the catheter costs US$ 16.66 (R$ 30.00),
while the costs for purchasing of a new catheter may range from US$
194.00 to US$ 250.00 (R$ 350.00 to R$ 450.00) each. Both balloons and
the pliers can be purchased directly with the equipment manufacturer.
Figure 2
shows the proper material used to recycle the catheter. These figures
show a recycled catheter, the balloon used to restore it and pliers for
the insertion of the balloon.
CONCLUSIONS
Considering that the restored catheter possesses the same performance
as the new ones with original balloon, regarding tolerance to pressure,
capacity of fixation to the mare´s uterus and embryo recovery
efficiency, and that the material used to recycle it costs US$ 18.75
(R$ 30,00), this experiment demonstrated that the restored catheters
could be used as a tool for cost reduction on the recuperation of
equine flushing.
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Protocolado em: 14 jul. 2008.
Aceito em: 26 out. 2009.