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The impact of exposing semen and doe rabbits to heat stress on heat tollerance of their offsprings
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Abstract: A total number of 630 sexual mature New Zealand White (NZW) rabbits of five months of age (560 nonparous does and 70 bucks) was used in this study. The study included two experiments.
First experiment (in vitro part) was planned to evaluate effects of heat exposure (sudden) on diluted physical semen quality, sperm enzymatic activities, the ability of sperm penetration into estrus cow cervical mucus and total bacterial counts, during conservation at different high temperatures for 30 minutes. Heat exposure temperatures were 37 (control group), or 40, 45 and 50°C (heat shock groups).
Second experiment (in vivo work) was designed to study effects of pre-mating heat exposure (sudden) on .fertility traits of NZW rabbit does inseminated naturally or artificially. Heat exposure of rabbit does were at temperature humidity index (THI) < 72 (absence heat stress); 72 to < 73 (moderate heat stress); 73 to < 74 (severe heat stress) and over 74 (very severe heat stress) for up to 30 minutes pre-coitus. Rabbit does which exposed to heat stress pre natural mating or artificial insemination were tested for .fertility traits during the next parity under normal conditions. The experiment also evaluated the tolerance of offspring housed in severe heat stress conditions which produced from heat stressed semen or/ and rabbit does.
The results obtained revealed that, values of each of physical semen quality, spermatozoa storagability, sperm penetration into estrus cow cervical mucus and total bacterial counts significantly (P<0.01) decreased in descending order, while values of AST; ALT; ACP and ALP enzymes in diluted NZW rabbit semen increased significantly (P<0.01) in ascending order, due to temperatures of heat exposing at 40, 45 and 50 °e, respectively, compared with conservation at 37 °C (control). Physical semen quality and spermatozoa storagability decreased significantly (P<0.01) and sperm penetration into estrus cow cervical mucus, total bacterial counts and enzymatic activities significantly (P<0.01) increased by advancement of diluted semen preservation at different temperatures for 30 minutes.
Ovulation and kindling rates and litter size and weight at birth of NZW rabbit does showed highly significant variation (P<0.01) in descending order due to expose to heat stress pre natural mating or artificial insemination. for up to 30 minutes at absence heat stress, moderate heat stress, severe heat stress and very severe heat stress, respectively. Re-mated rabbit does which exposed to different levels of heat stress pre previous mating did not record any significant in fertility traits. Mortality rate of growing rabbits produced from semen or rabbit does exposed to heat stress were significantly (P<0.01) lower descendingly as recorded with very severe heat stress; severe heat stress; moderate heat stress and absence heat stress, respectively, during the period from weaning till sexual maturity and housing at very severe heat stress condition. Kindling rates and libido and physical semen quality of female and male rabbits housed at very severe heat stress conditions and produced from semen or does exposed to heat stress were significantly (P< 0.01) superior and in descending order due to very severe heat stress; severe heat stress; moderate heat stress and absence heat stress, respectively.
In general the study concluded that, exposing rabbit semen and does to very severe heat stress produced offspring have more tolerance and adaptation to heat stress.
Keywords: Rabbits; heat stress; semen quality; fertility traits; natural mating; AI.
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| Publication year |
2010
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| Pages |
427-441
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| Availability location |
معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى - الجيزة
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| Availability number |
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| Organization Name |
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| City |
اسيوط
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| serial title |
The 6th International Conference on Rabbit Production in hot climate
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| Author(s) from ARC |
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| Agris Categories |
Animal physiology - Reproduction
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AGROVOC
TERMS |
Fertility.
Heat stress.
Rabbits.
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| Proposed Agrovoc |
semen quality;fertility traits;natural mating;
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| Publication Type |
Conference/Workshop
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