Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias
Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias
Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias
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16 t h International Congress on Animal <strong>Reproduction</strong><br />
10 Workshop Abstracts<br />
ultrasonography has started to become more common <strong>in</strong> animal<br />
reproduction. This is an emerg<strong>in</strong>g technology that has the potential to<br />
<strong>in</strong>crease the diagnostic, monitor<strong>in</strong>g, and predictive capabilities of<br />
theriogenologists and research scientists. Transrectal color-, power-,<br />
and spectral-Doppler ultrasonography have been used <strong>in</strong> our<br />
laboratory to study ovarian and uter<strong>in</strong>e blood flow and perfusion <strong>in</strong><br />
mares. The technology is based on Doppler-shift frequencies, where<strong>in</strong><br />
the ultrasound frequency of the echoes from the mov<strong>in</strong>g red cells is<br />
<strong>in</strong>creased or <strong>de</strong>creased as the cells move toward or away from the<br />
transducer, respectively. Color-flow Doppler ultrasound superimposes<br />
color signals of blood flow on the B-mo<strong>de</strong> (gray-scale) image so that<br />
blood-flow velocities and perfusion can be assessed visually on an<br />
image plane. Blood perfusion to an organ or structure can be<br />
evaluated by scor<strong>in</strong>g the percentage of blood flow (color spots) or by<br />
count<strong>in</strong>g the number of color pixels. Us<strong>in</strong>g the spectral mo<strong>de</strong>,<br />
evaluations of blood flow velocities and <strong>in</strong>dices <strong>in</strong> an artery, which<br />
<strong>in</strong>clu<strong>de</strong> peak systolic velocity (PSV), end diastolic velocity (EDV),<br />
time-averaged maximum velocity (TAMV), resistance <strong>in</strong><strong>de</strong>x (RI), and<br />
pulsatility <strong>in</strong><strong>de</strong>x (PI), are computed and displayed for a selected<br />
cardiac cycle. Recently, our laboratory has used Doppler<br />
ultrasonography to test several biological hypotheses. These <strong>in</strong>clu<strong>de</strong><br />
the mechanisms <strong>in</strong>volved <strong>in</strong> follicle <strong>de</strong>viation, preovulatory follicle<br />
growth, and ovulation; oocyte maturity and competence; embryouter<strong>in</strong>e<br />
dynamics; corpus luteum <strong>de</strong>velopment, luteolysis, and PGFM<br />
pulses; uter<strong>in</strong>e cyst formation; and the effect of ag<strong>in</strong>g on preovulatory<br />
follicle and uterus blood perfusion. Although some limitations have to<br />
be consi<strong>de</strong>red, we have found this technology useful for our studies <strong>in</strong><br />
reproductive physiology. This presentation will focus on the ma<strong>in</strong><br />
f<strong>in</strong>d<strong>in</strong>gs of our experiments <strong>in</strong> mares that used Doppler<br />
ultrasonography to study the relationship between blood flow and<br />
perfusion to the reproductive organs and reproductive processes.<br />
Workshop 05 - Susta<strong>in</strong>able <strong>de</strong>velopment <strong>in</strong> care of<br />
reproduction <strong>in</strong> small rum<strong>in</strong>ants: efforts and perspectives<br />
Mo<strong>de</strong>rator: Dom<strong>in</strong>ique Blache (Australia)<br />
WS05-1<br />
Maximis<strong>in</strong>g survival of lambs: recent advances through<br />
mother-young bond<strong>in</strong>g<br />
Nowak, R 1 *, Bickell, SL 1 , Po<strong>in</strong>dron, P 2 , Chadwick, A 1 and Blache, D 1,2<br />
1UMR 6175 Physiologie <strong>de</strong> la <strong>Reproduction</strong> et <strong>de</strong>s Comportements INRA-<br />
CNRS-Université <strong>de</strong> Tours-Haras Nationaux, Nouzilly, France ; 2 School of<br />
Animal Biology, The University of Western Australia, Crawley, WA.<br />
In the reproductive process of ewes reared un<strong>de</strong>r extensive conditions<br />
there are several po<strong>in</strong>ts where lamb output can be <strong>in</strong>creased, amongst<br />
which the most important is tw<strong>in</strong>n<strong>in</strong>g rate and lamb survival.<br />
However, improvement <strong>in</strong> tw<strong>in</strong>n<strong>in</strong>g rate is seen as unethical if<br />
management systems are <strong>in</strong>a<strong>de</strong>quate for maximiz<strong>in</strong>g the survival of<br />
tw<strong>in</strong> lambs. Despite four <strong>de</strong>ca<strong>de</strong>s of worldwi<strong>de</strong> research, lamb<br />
mortality has not improved and recent data confirms that mortality is<br />
still higher <strong>in</strong> tw<strong>in</strong> than <strong>in</strong> s<strong>in</strong>gle lambs. Both genetic and<br />
environmental factors contribute to neonatal mortality. There are 3<br />
opportunities for <strong>in</strong>creas<strong>in</strong>g lamb survival. The first <strong>in</strong>volves breed<strong>in</strong>g<br />
of ewes that provi<strong>de</strong> high levels of maternal care – this is effective but<br />
direct measurements of maternal behaviour are impossible for largescale<br />
operations. A better alternative is genetic selection for ‘calm’<br />
temperament, for which practical on-farm tests are currently be<strong>in</strong>g<br />
evaluated across Australia. The second opportunity for reduc<strong>in</strong>g lamb<br />
mortality <strong>in</strong>volves improvement of colostrum production. Feed<strong>in</strong>g<br />
supplements to tw<strong>in</strong>-bear<strong>in</strong>g ewes dur<strong>in</strong>g the last week of pregnancy<br />
almost double the amount of colostrum available at birth. In addition,<br />
the colostrum that is produced by these ewes is less viscous and seems<br />
to be easier for the lamb to suck. Boost<strong>in</strong>g the colostrum <strong>in</strong>take by<br />
newborn lambs is of particular <strong>in</strong>terest because colostrum is essential<br />
for provid<strong>in</strong>g nutrients, for conferr<strong>in</strong>g immunity to disease, and for<br />
shap<strong>in</strong>g the early ewe-lamb bond. Successful suck<strong>in</strong>g at birth<br />
facilitates attachment to the mother through a comb<strong>in</strong>ation of the<br />
reward<strong>in</strong>g effect of colostrum <strong>in</strong>take and a neurophysiological effect<br />
of gastric distension. Delays <strong>in</strong> the provision of colostrum, or the<br />
provision of only small amounts, will thus be <strong>de</strong>trimental to the ewelamb<br />
relationship. The third opportunity for reduc<strong>in</strong>g lamb mortality<br />
<strong>in</strong>volves better management of ewe flocks dur<strong>in</strong>g lamb<strong>in</strong>g. Most<br />
importantly, we need to ensure that shelter, feed and water are nearby,<br />
and that there is a calm lamb<strong>in</strong>g environment. This will promote,<br />
rather than disrupt, the formation of the ewe-lamb bond by ensur<strong>in</strong>g<br />
that the mothers do not leave the birth site too soon after parturition<br />
and thus <strong>de</strong>ny sufficient access to the ud<strong>de</strong>r for the newborn. Any loss<br />
of mother-young contact early after birth is likely to lead to the <strong>de</strong>ath<br />
of tw<strong>in</strong> lambs. Recent research <strong>in</strong>to reproductive physiology and<br />
behaviour has allowed to <strong>de</strong>velop new strategies for <strong>in</strong>creas<strong>in</strong>g tw<strong>in</strong>lamb<br />
survival.<br />
WS05-2<br />
Towards better welfare for small rum<strong>in</strong>ants<br />
Blache, D<br />
UWA Institute of Agriculture M082, University of Western Australia, Crawley<br />
6009, Australia<br />
Farmed animals are exposed to many and varied sources of stress<br />
(stressors) <strong>in</strong> their life, and those stressors may impact on their<br />
capacity for reproduction. However, to be able to <strong>de</strong>velop strategies<br />
that lead to more susta<strong>in</strong>able animal care, it is important first to <strong>de</strong>f<strong>in</strong>e<br />
and un<strong>de</strong>rstand ‘stress’ and ‘welfare’.<br />
There is no universal <strong>de</strong>f<strong>in</strong>ition for animal welfare and no quantitative<br />
method for measur<strong>in</strong>g it. It is not <strong>in</strong>tr<strong>in</strong>sic to animals but it is brought<br />
on by the careers as they meet the needs of their animals. The i<strong>de</strong>al<br />
state, where all needs are provi<strong>de</strong>d for, is summarized <strong>in</strong> the “five<br />
freedoms framework” – freedom from hunger and thirst, from<br />
discomfort, from pa<strong>in</strong> and diseases, from fear and distress, and<br />
freedom to express natural behaviours. Maximum welfare, on a<br />
subjective scale, will be achieved when the animal supervisors do all<br />
they can to prevent or reduce suffer<strong>in</strong>g or harm by provid<strong>in</strong>g enough<br />
care to fulfill the five freedoms. Generally, the level of animal welfare<br />
is related to the level of stress experienced by the animals. Stress can<br />
be physical, such as <strong>in</strong>a<strong>de</strong>quate nutrition, fatigue, heat or cold, or it<br />
can be psychological, such as fear of isolation <strong>in</strong> flock<strong>in</strong>g animals.<br />
Stress can be acute or chronic, and it can be cumulative, and one<br />
stressor can have a potentiat<strong>in</strong>g effect for another. Stress is not<br />
necessarily bad for animals and the boundary between ‘good stress’<br />
and ‘bad stress’ is also difficult to <strong>de</strong>f<strong>in</strong>e. One useful criterion for<br />
assess<strong>in</strong>g the consequences of stress on welfare is the measurement of<br />
the ability of animals to cope, physiologically and behaviourally, with<br />
challenges.<br />
How do we go towards better welfare for small rum<strong>in</strong>ants As<br />
<strong>de</strong>scribed above, bad or good stress can be seen as a <strong>de</strong>viation from<br />
the ‘norm’ and the amount of <strong>de</strong>viation can be assessed by animal<br />
careers who have a <strong>de</strong>ep knowledge of the biological ‘norms’ of their<br />
animals. This means that animal carers or welfare officers need<br />
education <strong>in</strong> husbandry, behavior and physiology if we are to assess<br />
and then improve welfare. At the producer level, good stockman skills<br />
are essential because stockmanship assumes respect, un<strong>de</strong>rstand<strong>in</strong>g<br />
and empathy for animals, as well as <strong>de</strong>dication to the livestock. A<br />
tra<strong>in</strong>ed stockman will be able to read the behaviour of the animal and<br />
will know how to handle a particular species. For example, <strong>in</strong>stead of<br />
us<strong>in</strong>g fear of noise and pa<strong>in</strong> to make animals move, we can use their<br />
flight zone and flock<strong>in</strong>g behaviour. At the specialist level, tra<strong>in</strong><strong>in</strong>g <strong>in</strong><br />
stress physiology, regulation of core temperature and behavioural<br />
adaptation to environmental stress, will be necessary for conduct<strong>in</strong>g<br />
<strong>in</strong>-<strong>de</strong>pth welfare assessments. As a complement to these human<br />
changes, selection of animals that are physiologically and<br />
behaviourally better adapted to the farm<strong>in</strong>g environment will also<br />
improve their welfare.<br />
Improv<strong>in</strong>g animal welfare by reduc<strong>in</strong>g stress is obviously beneficial<br />
for the animal but, equally as importantly, it is beneficial for<br />
producers <strong>in</strong> two ways: i) the quantity and quality of product will<br />
<strong>in</strong>crease; ii) low stress animals are easiest to manage and will lead to<br />
an improvement of the producer’s quality of life and job satisfaction.<br />
Moreover, there is an urgent need for animal production to be ethical<br />
by ensur<strong>in</strong>g that animal welfare reaches the best possible standards –