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Reproductive management in small ruminants Feb 2012 M.A. Driancourt, MSD AH, R&D Pharmaceuticals
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Backbone of the presentation 1.What are the main reproductive features of Middle East sheep and goat breeds? 2.What are the consequences on these physiological features on production? 3.What are the technical options to break seasonal anoestrus? 4.What are the technical options to synchronize estrus during the breeding season? 5.How can we improve fertility? 6.How can prolificacy be improved?
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3 What are the main reproductive features of Middle East sheep and goat breeds? Awassi sheep Display a seasonal pattern of reproduction Tend to display a late puberty Commonly produce a single lamb (low prolificacy) Are good milk producers
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4 What are the main reproductive features of Middle East sheep and goat breeds? Damascus goats Display a seasonal pattern of reproduction, with a variable breeding season (June to Oct in Jordan or Sept to Feb in Cyprus) Tend to display a late puberty Are mildly prolific (1.5 kid per litter) Are good milk producers (500kg/lactation)
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5 What are the main reproductive features of Middle East sheep and goat breeds? Links between month of the year and cyclicity in sheep and goats Month of the year % of females in estrus 100 50 0 Jan May Sept Dec Very seasonal breed or female Less seasonal breed or female anoestrus BS Transition
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6 What are the consequences on these physiological features on production? The seasonal pattern of reproduction does not allow to have reproduction timed to generate milk or lamb meat when prices are highest. The seasonal pattern of reproduction may not always fit with the periods when forage and feedstuffs are available to cover the production needs of the late pregnant and lactating ewes or the growth needs of the lambs Low prolificacy negatively affects the income of the farmers The random pattern of cyclicity between individual ewes of a flock does not allow to use AI (and the associated diffusion of genetic merit)
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7 What are the consequences on these physiological features on production? Breed during anoestrus (hence “break” anoestrus) Synchronize estrus during the breeding season (to use AI ) Increase prolificacy Technical needs triggered by these physiological features
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8 What are the technical options to break seasonal anoestrus? Use progestagen/progesterone impregnated vaginal devices Use the ram effect Use melatonin
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9 What are the technical options to break seasonal anoestrus? Use progestagen/progesterone impregnated vaginal devices Three types of devices are available: cronolone (20mg) impregnated sponges (Chronogest CR, MSD AH), MAP (60mg) impregnated sponges and CIDR(0.3g progesterone) Typical treatment schedule Day 0 Day 14 Day 17 Sponge insertion Sponge removal and PMSG injection AI or mating 55h SHEEP If mating is used, preparation of the rams (flushing, light treatment or melatonin) and a suitable ewe to ram ratio are needed
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10 What are the technical options to break seasonal anoestrus? Use progestagen/progesterone impregnated vaginal devices (+ 400IU PMSG and mating) in Awassi ewes SHEEP Ozyutlu et al 2010
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11 What are the technical options to break seasonal anoestrus? Use progestagen/progesterone impregnated vaginal devices Three types of devices are available: cronolone (20mg) impregnated sponges (Chronogest CR, MSD AH), and CIDR Typical treatment schedule Day 0 Day 11 Day 13 Sponge insertion Sponge removal AI or mating 44h GOAT Day 9 Prostaglandin injection and PMSG administration Bucks also need to be prepared!
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12 What are the technical options to break seasonal anoestrus? Use progestagen/progesterone impregnated vaginal devices GOAT Parity 1 55.3% Parity 2 73.7% Parity 3 55.9% Parity 4 75% Parity 5 58.8% 400UI PMSG 50.9% 500UI PMSG 62.9% 600UI PMSG 68.1% Prolificacy= 1.97+/- 0.8 Fertility Alpine & Saanen goats Intervet registration files
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13 What are the technical options to break seasonal anoestrus? Use the ram effect Pre-requisites: Target a breed with a light anoestrus or females during the transition period Ewes/goats need to be away from the rams/bucks for at least a month The rams/bucks need to be prepared (light treatment/melatonin)
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14 What are the technical options to break seasonal anoestrus? Use the ram effect Chemineau et al 2006 Estrus and formation of normal corpora lutea do not happen immediately!
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15 What are the technical options to break seasonal anoestrus? Use melatonin ear implants (18mg) ControlSponge + PMSG (450IU) Melatonin Fertility65%78% Prolificacy1.261.501.55 (Gomez et al 2006), Manchega ewes I Implants need to be inserted between 50 and 70 days before breeding
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16 What are the technical options to break seasonal anoestrus? Submission rate FertilityProlificacyAI use Progestagen sponges ++++++++Yes Ram effect+++No! Melatonin implant ++ No (no synchro) Take home message
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17 What are the technical options to synchronize estrus during the breeding season? Use progestagen/progesterone impregnated vaginal devices Use of Ovsynch type protocols Use of double prostaglandin protocols SHEEP
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18 What are the technical options to synchronize estrus during the breeding season? Use progestagen/progesterone impregnated vaginal devices Three types of devices are available: cronolone (20mg) impregnated sponges (Chronogest CR, MSD AH), MAP (60mg) impregnated sponges and CIDR (0.3g) Typical treatment schedule Day 0 Day 14 Day 17 Sponge insertion Sponge removal and PMSG injection AI or mating 55h SHEEP If mating is used, a suitable ewe to ram ratio needs to be respected
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19 What are the technical options to synchronize estrus during the breeding season? Use progestagen/progesterone impregnated vaginal devices SHEEP Dairy (Lacaune) Dairy (Manech) Meat (Texel, Vendeen) Fertility71%52.3%63.2% Prolificacy 1.69+/- 0.671.45+/- 0.77 1.62+/-0.68 Intervet registration files
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20 What are the technical options to synchronize estrus during the breeding season? Sponges allow to obtain improved reproductive performance in Awassi ewes managed in a “3 lambings in 2 years” management system (6 breeding periods) SHEEP Zarkawi et al 2011
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21 Use progestagen/progesterone impregnated vaginal devices Three types of devices are available: cronolone (20mg) impregnated sponges (Chronogest CR, MSD AH), and CIDR Typical treatment schedule Day 0 Day 11 Day 13 Sponge insertion Sponge removal AI or mating 44h GOAT Day 9 Prostaglandin injection and PMSG administration What are the technical options to synchronize estrus during the breeding season?
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22 What are the technical options to synchronize estrus during the breeding season? Use progestagen/progesterone impregnated vaginal devices Damascus goats GOAT Al Merestani et al (2003)
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23 What are the technical options to synchronize estrus during the breeding season? Use of Ovsynch type protocols (Deligiannis et al 2005, Titi et al 2010) SHEEP Day 0 5 6.5 7 AI GnRH PGF2 a 50% fertility in Greek ewes 60% fertility in Awassi ewes Day 0 5 6 GnRH PGF2 a Rams in
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24 What are the technical options to synchronize estrus during the breeding season? Use of Ovsynch type protocols (Holtz et al 2008) Boer goats GOAT N=24/groupSponge + prostaglandin and 250IU PMSG 48h before sponge removal (AI 43h later) Ovsynch ( 4µg Buserelin on d0, prostaglandin on d 7 and 4µg buserelin on d 9 with AI 16h later) % goats in estrus 100%96% Fertility (day 30post AI) 50%56% Prolificacy 1.83 +/- 0.231. 86 +/- 0.14
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25 What are the technical options to synchronize estrus during the breeding season? Use of double prostaglandin protocols ( 7 to 11 days apart) SHEEP controlDouble PG Conception (% US positive 30 days post AI) 88%63% Prolificacy1.581.27 Fierro et al 2011
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26 What are the technical options to synchronize estrus during the breeding season? Vaginal sponges are the best approach Ovsynch may be an alternative in goats Double prostaglandin treatment reduces fertility Take home message When a successful synchronization is obatined, 1.Diffusion of genetic merit becomes possible (AI) 2.Breeding can be focussed on a narrow part of the year (labor efficiency) 3.Lambing is limited to a narrow time period (labor efficacy) 4.An homogeneous lamb crop is ready to be sold at a set time every year
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27 How can we reach optimal prolificacy? What is optimal prolificacy? An homogeneous crop of twins! (no triplets) If 1. maternal behavior of the ewe is OK! 2. Milk production of the ewe is adequate!
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28 How can prolificacy be improved? Use PMSG at removal of progestagen/progesterone impregnated vaginal devices Use Androvax, a vaccine against an ovarian steroid Use genetic introgression of a prolificacy gene (such as Fec B) into your sheep breed
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29 How can prolificacy be improved? Use PMSG at removal of progestagen/progesterone impregnated vaginal devices Dose of PMSG (IU) Ovulation rate Quirke et al 1986
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30 How can prolificacy be improved? Use Androvax, a vaccine against an ovarian steroid The recommended vaccination schedule is First vaccination (2ml): 8 to 10 weeks before joining Booster (2ml): 4 to 6 weeks before joining The antibodies reduce negative feedback of the steroids on LH secretion. The increased frequency of LH pulses increases the proportion of double ovulations (by around 20%) Not affecting seasonality (not inducing ovulation in anoestrous ewes) Not synchronizing ovulation, hence compatible with mating by rams A booster is needed every year to obtain the prolificacy increase, but may be skipped if the environment is too harsh A vaccine against a steroid (androstenedione coupled to a carrier (bovine lactalbumin) in a DEAE adjuvant), applied as a primary and a booster on the first year of treatment.
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31 How can prolificacy be improved? Use Androvax, a vaccine against an ovarian steroid Prolificacy data from 27 farms in NZ
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32 How can prolificacy be improved? Use genetic introgression of a prolificacy gene (such as Fec B) into your sheep breed The Booroola gene (Fec B) is a major gene that has large effects on prolificacy (but not on seasonality). Homozygous ewes and heterozygous carrier ewes display over 5 and around 3 ovulations (vs 1 for the non carriers) This gene acts by interfering with the signalling of bone morphogenic proteins Its position in the sheep genome is known By crossing a specific breed with homozygous rams and then backcrossing to the initial breed, it is possible to introgress the Fec B prolificacy gene in that breed, while keeping all the production features of the breed (was done with Awassi)
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33 How should fertility problems be analysed? Questions to be asked when fertility is lower than expected 1.Is the problem physiological or pathological? 2.What evidence do I have that low fertility is only a female problem? 3.What evidence do I have that the ewes were indeed ready to be bred (i.e. cycling) 4.Was body condition of the ewes adequate for initiation and maintenance of pregnancy? 5.What were the climatic conditions in the days around ovulation and early embryonic development?
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34 Conclusion : the tools to work from… Efficient breeding at all times of the year Improving prolificacy Allowing early breeding of ewe lambs Allows easy diffusion of genetic merit by AI Allows matings by rams Sponges YesYes( 10- 40%) (depending on amount of PMSG) Yes Yes (ram to ewe ratio adapted to the season) Melatonin implants No?Yes (15%)No Yes Androvax NoYes (25%)No Yes Genetics Not yet If prolificacy genes are introgressed No Yes Improved nutrition NoYes (10%)No Yes
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35 Conclusion: how to implement these tools according to your needs There are many tools that are available to move from extensive production systems towards more intensive ones (provided the farm technical management and food availability allow it) Several steps of intensification are possible (from mild such as the use of Androvax or melatonin implants to a more “European” production system using sponges to obtain three lambings in 2 years with increased prolificacy)
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36 Questions?
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