Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

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16 t h International Congress on Animal Reproduction 10 Workshop Abstracts ultrasonography has started to become more common in animal reproduction. This is an emerging technology that has the potential to increase the diagnostic, monitoring, and predictive capabilities of theriogenologists and research scientists. Transrectal color-, power-, and spectral-Doppler ultrasonography have been used in our laboratory to study ovarian and uterine blood flow and perfusion in mares. The technology is based on Doppler-shift frequencies, wherein the ultrasound frequency of the echoes from the moving red cells is increased or decreased as the cells move toward or away from the transducer, respectively. Color-flow Doppler ultrasound superimposes color signals of blood flow on the B-mode (gray-scale) image so that blood-flow velocities and perfusion can be assessed visually on an image plane. Blood perfusion to an organ or structure can be evaluated by scoring the percentage of blood flow (color spots) or by counting the number of color pixels. Using the spectral mode, evaluations of blood flow velocities and indices in an artery, which include peak systolic velocity (PSV), end diastolic velocity (EDV), time-averaged maximum velocity (TAMV), resistance index (RI), and pulsatility index (PI), are computed and displayed for a selected cardiac cycle. Recently, our laboratory has used Doppler ultrasonography to test several biological hypotheses. These include the mechanisms involved in follicle deviation, preovulatory follicle growth, and ovulation; oocyte maturity and competence; embryouterine dynamics; corpus luteum development, luteolysis, and PGFM pulses; uterine cyst formation; and the effect of aging on preovulatory follicle and uterus blood perfusion. Although some limitations have to be considered, we have found this technology useful for our studies in reproductive physiology. This presentation will focus on the main findings of our experiments in mares that used Doppler ultrasonography to study the relationship between blood flow and perfusion to the reproductive organs and reproductive processes. Workshop 05 - Sustainable development in care of reproduction in small ruminants: efforts and perspectives Moderator: Dominique Blache (Australia) WS05-1 Maximising survival of lambs: recent advances through mother-young bonding Nowak, R 1 *, Bickell, SL 1 , Poindron, P 2 , Chadwick, A 1 and Blache, D 1,2 1UMR 6175 Physiologie de la Reproduction et des Comportements INRA- CNRS-Université de Tours-Haras Nationaux, Nouzilly, France ; 2 School of Animal Biology, The University of Western Australia, Crawley, WA. In the reproductive process of ewes reared under extensive conditions there are several points where lamb output can be increased, amongst which the most important is twinning rate and lamb survival. However, improvement in twinning rate is seen as unethical if management systems are inadequate for maximizing the survival of twin lambs. Despite four decades of worldwide research, lamb mortality has not improved and recent data confirms that mortality is still higher in twin than in single lambs. Both genetic and environmental factors contribute to neonatal mortality. There are 3 opportunities for increasing lamb survival. The first involves breeding of ewes that provide high levels of maternal care – this is effective but direct measurements of maternal behaviour are impossible for largescale operations. A better alternative is genetic selection for ‘calm’ temperament, for which practical on-farm tests are currently being evaluated across Australia. The second opportunity for reducing lamb mortality involves improvement of colostrum production. Feeding supplements to twin-bearing ewes during the last week of pregnancy almost double the amount of colostrum available at birth. In addition, the colostrum that is produced by these ewes is less viscous and seems to be easier for the lamb to suck. Boosting the colostrum intake by newborn lambs is of particular interest because colostrum is essential for providing nutrients, for conferring immunity to disease, and for shaping the early ewe-lamb bond. Successful sucking at birth facilitates attachment to the mother through a combination of the rewarding effect of colostrum intake and a neurophysiological effect of gastric distension. Delays in the provision of colostrum, or the provision of only small amounts, will thus be detrimental to the ewelamb relationship. The third opportunity for reducing lamb mortality involves better management of ewe flocks during lambing. Most importantly, we need to ensure that shelter, feed and water are nearby, and that there is a calm lambing environment. This will promote, rather than disrupt, the formation of the ewe-lamb bond by ensuring that the mothers do not leave the birth site too soon after parturition and thus deny sufficient access to the udder for the newborn. Any loss of mother-young contact early after birth is likely to lead to the death of twin lambs. Recent research into reproductive physiology and behaviour has allowed to develop new strategies for increasing twinlamb survival. WS05-2 Towards better welfare for small ruminants Blache, D UWA Institute of Agriculture M082, University of Western Australia, Crawley 6009, Australia Farmed animals are exposed to many and varied sources of stress (stressors) in their life, and those stressors may impact on their capacity for reproduction. However, to be able to develop strategies that lead to more sustainable animal care, it is important first to define and understand ‘stress’ and ‘welfare’. There is no universal definition for animal welfare and no quantitative method for measuring it. It is not intrinsic to animals but it is brought on by the careers as they meet the needs of their animals. The ideal state, where all needs are provided for, is summarized in the “five freedoms framework” – freedom from hunger and thirst, from discomfort, from pain and diseases, from fear and distress, and freedom to express natural behaviours. Maximum welfare, on a subjective scale, will be achieved when the animal supervisors do all they can to prevent or reduce suffering or harm by providing enough care to fulfill the five freedoms. Generally, the level of animal welfare is related to the level of stress experienced by the animals. Stress can be physical, such as inadequate nutrition, fatigue, heat or cold, or it can be psychological, such as fear of isolation in flocking animals. Stress can be acute or chronic, and it can be cumulative, and one stressor can have a potentiating effect for another. Stress is not necessarily bad for animals and the boundary between ‘good stress’ and ‘bad stress’ is also difficult to define. One useful criterion for assessing the consequences of stress on welfare is the measurement of the ability of animals to cope, physiologically and behaviourally, with challenges. How do we go towards better welfare for small ruminants As described above, bad or good stress can be seen as a deviation from the ‘norm’ and the amount of deviation can be assessed by animal careers who have a deep knowledge of the biological ‘norms’ of their animals. This means that animal carers or welfare officers need education in husbandry, behavior and physiology if we are to assess and then improve welfare. At the producer level, good stockman skills are essential because stockmanship assumes respect, understanding and empathy for animals, as well as dedication to the livestock. A trained stockman will be able to read the behaviour of the animal and will know how to handle a particular species. For example, instead of using fear of noise and pain to make animals move, we can use their flight zone and flocking behaviour. At the specialist level, training in stress physiology, regulation of core temperature and behavioural adaptation to environmental stress, will be necessary for conducting in-depth welfare assessments. As a complement to these human changes, selection of animals that are physiologically and behaviourally better adapted to the farming environment will also improve their welfare. Improving animal welfare by reducing stress is obviously beneficial for the animal but, equally as importantly, it is beneficial for producers in two ways: i) the quantity and quality of product will increase; ii) low stress animals are easiest to manage and will lead to an improvement of the producer’s quality of life and job satisfaction. Moreover, there is an urgent need for animal production to be ethical by ensuring that animal welfare reaches the best possible standards –
16 t h International Congress on Animal Reproduction Workshop Abstracts 11 this will improve the image and the public attitude towards animal industries, so the intensity of the public scrutiny, extant already in industrialised countries and growing in the rest of the world, will be relaxed. WS05-3 Seasonality of reproduction and MT1 receptor gene polymorphism in Awassi sheep Faigl, V 1 *; Árnyasi, M 2 ; Keresztes, M 1 ; Kulcsár, M 1 ; Reiczigel, J 1 ; Dankó G 2 ; Jávor, A 2 ; Cseh, S 1 ; Huszenicza, G 1 1Szent István University Department and Clinic of Reproduction, Budapest, Hungary; 2 University of Debrecen, Institute of Animal Sciences, Debrecen, Hungary In three consecutive experiments seasonal pattern of ovarian activity was investigated in lactating, non-suckled dairy awassi sheep. In Experiment 1. (Exp. 1.) resumption of postpartum (pp) ovarian cyclicity was studied in autumn lambing (AL;n=27) and spring lambing (SL;n=38) ewes. Cyclicity was monitored by means of individual progesterone (P4) profiles (milk P4 was assayed trice weekly from day (d) 5 to d100 pp). 89% of AL dams ovulated before d 35 and became cyclic thereafter. Incidence of persistent corpus luteum (CLP n=5) and short luteal phases (sCL n=8; CLP and sCL together n=4) was frequent among non-conceiving dams. In contrast only 39% of SL ewes ovulated before d70. P4 levels during luteal phase in cyclic animals were lower, and length of cycle was longer in SL compared to AL. No CLP or sCL was detected in SL. 61% of SL remained acyclic till the end of trial. In Exp.2. influence of additional lighting on the time of first ovulation was investigated in 48 AL ewes. Long-day photoperiod (LD) group (n=23) was exposed to artificial light from sunset till midnight (approx 16 hours light/8 hours dark). Control group (n=25) received no treatment (natural photoperiod). Sampling protocol was similar to Exp. 1. Time of first pp ovulation tended to delay in LD animals compared to Control (average 25.87±1.63 vs 21.5±1.72 d pp; surv analysis P=0.093). In Exp.3. interaction between melatonin receptor 1a (MT1) gene polymorphism and out-of-season cyclicity was evaluated in 395 dams. Milk P4 level was determined 3 times 7 days apart between 10-12 weeks pp. If P4 level was >4 nmol/L in at least one of the samples, animals were judged cyclic. 10 weeks pp plasma leptin and insulin-like growth factor I were measured, and MT1 polymorphism was determined. Proportion of out-of-season cycling animals was depending on age (P=0.003) and leptin level (P
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Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

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