Reproductive performance in the Sheep CRC Information Nucleus using artificial insemination across different sheep-production environments in southern Australia

2014 ◽  
Vol 54 (6) ◽  
pp. 715 ◽  
Author(s):  
K. G. Geenty ◽  
F. D. Brien ◽  
G. N. Hinch ◽  
R. C. Dobos ◽  
G. Refshauge ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Artificial Insemination ◽  
Reproductive Rate ◽  
Industry Standards ◽  
Frozen Semen ◽  
Production Environments ◽  
Natural Mating ◽  
Sheep Production ◽  
Reproductive Rates ◽  
Birth Type

The present paper covers reproductive performance in an artificial-insemination (AI) program of the Sheep CRC Information Nucleus with 24 699 lambs born at eight locations in southern Australia across five lambings between 2007 and 2011. Results from AI with frozen semen compared well with industry standards for natural mating. Conception rates averaged 72%, and 1.45 lambs were born per ewe pregnant for Merino ewes and 1.67 for crossbreds. Lamb deaths averaged 21% for Merino ewes and 15% for crossbreds and 19%, 22% and 20% for lambs from ewes that were mated to terminal, Merino and maternal sire types, respectively. Net reproductive rates were 82% for Merino ewes and 102% for crossbreds. From 3198 necropsies across 4 years, dystocia and starvation-mismothering accounted for 72% of lamb deaths within 5 days of lambing. Major risk factors for lamb mortality were birth type (single, twin or higher order), birthweight and dam breed. Losses were higher for twin and triplet lambs than for singles and there was greater mortality at relatively lighter and heavier birthweights. We conclude that reproductive rate in this AI program compared favourably with natural mating. Lamb birthweight for optimum survival was in the 4–8-kg range. Crossbred ewes had greater reproductive efficiency than did Merinos.

scholarly journals The effects of natural mating and artificial insemination using cryopreserved buck semen on reproductive performance in Alpine goats

2018 ◽  
Vol 61 (4) ◽  
pp. 459-461 ◽  
Author(s):  
Dehouegnon Jerry Agossou ◽  
Nazan Koluman
Keyword(s):  
Chorionic Gonadotropin ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Live Weight ◽  
Mortality Rates ◽  
Breeding Methods ◽  
Frozen Semen ◽  
Natural Mating ◽  
Equine Chorionic Gonadotropin

Abstract. This study compared the effects of natural mating and artificial insemination using frozen buck semen on reproductive performance in Alpine goats. Sixty reproductive Alpine goats were grouped according to natural mating (n=30) and artificial insemination (n=30) breeding methods. Oestrus was synchronised in experimental goats using a vaginal sponge impregnated with 20 mg of progestogen FGA (fluorogestone acetate) for 11 days. At the time of sponge insertion, 150 µg of prostaglandin F2α (PGF2α) analogue was injected intramuscularly. Forty-eight hours prior to vaginal sponge withdrawal, 500 IU equine chorionic gonadotropin (eCG) was injected into the animals. At the end of synchronisation protocol, goats were fertilised using frozen semen or mated with a well-performing buck (ratio: 1 male to 5 females). The pregnancy (pregnant/synchronised goats) and mortality rates (P<0.05) were higher (93 % vs. 70 %; 2 % vs. 4 %) in the naturally mated goats than the artificially inseminated group. Kids' live weight at birth was similar (3.83±0.23 and 3.15±0.11 kg) in both groups. The oestrus synchronisation followed by natural mating achieved better reproductive performance than the goats artificially inseminated using frozen semen. However, the artificially inseminated animals displayed an acceptable twinning rate.

The effect of method of breeding on reproductive performance in indigenous goats (Capra prisca) mated at the beginning of the breeding season

1989 ◽  
Vol 49 (2) ◽  
pp. 291-297 ◽  
Author(s):  
D. Zygoyiannis ◽  
N. Katsaounis ◽  
G. Karatzas
Keyword(s):  
Breeding Season ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Gestation Length ◽  
Mating Group ◽  
Natural Pasture ◽  
Frozen Semen ◽  
Natural Mating ◽  
Natural Service ◽  
Fresh Semen

ABSTRACTNinety-nine indigenous Greek goats (Capra prisca) on natural pasture were used to study reproductive performance as affected by method of breeding. At the beginning of the breeding season oestrus was induced with 45 mg fluorogestone acetate-impregnated vaginal sponges and 300 to 500 i.u. PMSG, given on day 15. The animals were separated into groups of 33 for mating: (i) by natural service (natural mating); (2) by artificial insemination with fresh semen (AI fresh); and (3) by insemination with frozen semen (AI frozen). Alpine bucks and Alpine semen were used for natural mating and AI of does.No effect of method of breeding was found on gestation length and sex ratio. Reproductive performance was significantly affected by method of breeding; at 21 days after insemination, fertility of does bred with fresh semen (69·7%) was comparable with that obtained with natural mating (72·7%) but the fertility of does bred with frozen semen (48·5%) was much lower. This difference was statistically significant at kidding (P < 0·05). Litter size was 2·14 and 1·86 (P < 0·05) for the AI fresh and AI frozen groups, respectively, and was 1·96 for the natural mating group. More multiple litters were obtained with the AI fresh group (P < 0·05). It is concluded that, induction and synchronization of oestrus and ovulation at the beginning of the breeding season gave reproductive performance with fresh semen comparable to that obtained with natural service, but use of frozen semen gave unsatisfactory results.

COMPARISON OF ARTIFICIAL INSEMINATION AND NATURAL MATING ON REPRODUCTIVE PERFORMANCE OF FIVE STRAINS OF SHEEP DURING THE ANESTROUS SEASON IN AN INTENSIVE SYSTEM

1979 ◽  
Vol 59 (4) ◽  
pp. 675-683 ◽  
Author(s):  
A. J. HACKETT ◽  
H. A. ROBERTSON ◽  
E. K. INSKEEP ◽  
J. N. B. SHRESTHA ◽  
M. S. WOLYNETZ
Keyword(s):  
Reproductive Performance ◽  
Artificial Insemination ◽  
Hormone Treatment ◽  
Corpora Lutea ◽  
Blood Samples ◽  
Natural Mating ◽  
Main Effects ◽  
Mating Method ◽  
Intensive System

Synchronized estrus and ovulation were induced during the anestrous season (April–May 1974) in 373 ewes of three synthetic (one sire and two dam) strains and two unselected (Suffolk and Finnish Landrace) purebred strains by treatment with 30 mg fluorogestone acetate (FGA) impregnated in polyurethane intravaginal sponges for 12 days. Following sponge removal each ewe received 500 IU pregnant mares’ serum gonadotrophin (PMSG) IM. Of these, 167 were bred by artificial insemination (AI) at 48 and 60 h post sponge removal with 0.2 ml raw unextended semen collected by electroejaculation (EE). Five days after AI, ewes were exposed to a follow up ram for 16 days for subsequent mating if a second estrus occurred. The remaining 206 were exposed to rams for a period of 22 days for natural mating. Blood samples were collected from 69 ewes, 9, 19 and 27 days post sponge removal and analyzed for progesterone to ascertain if corpora lutea were formed and whether the ewes recycled. The age of ram by mating method interaction significantly affected both fertility and fecundity mainly because some of the younger rams lacked libido and experience for natural mating. There were no significant differences in prolificacy due to any of the main effects tested. Among the 69 ewes examined for progesterone levels, 93% had formed corpora lutea after hormone treatment and 16% recycled. Only 16 of the 255 ewes that did not conceive to the synchronized estrus lambed to the subsequent estrus.

The influence of purified porcine relaxin on the reproductive performance of sows following artificial insemination with fresh or frozen semen

1991 ◽  
Vol 71 (1) ◽  
pp. 237-239 ◽  
Author(s):  
P. A. Thacker ◽  
A. D. Gooneratne ◽  
R. N. Kirkwood
Keyword(s):  
Key Words ◽  
Pregnancy Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Pregnancy Rates ◽  
Frozen Semen

Pregnancy rates and litter sizes following insemination of sows with fresh-extended and frozen-thawed semen averaged 71 vs. 53% and 10.6 vs. 4.4, respectively, and was not affected by the addition of 12.5 μg relaxin to semen. These results indicate no relaxin mediated effect on either pregnancy rate or litter size when sows are artificially inseminated with relaxin-supplemented semen. Key words: Artificial insemination, relaxin, sows

Ewe culling and retention strategies to increase reproductive rates in Merino sheep

2018 ◽  
Vol 58 (8) ◽  
pp. 1545 ◽  
Author(s):  
S. Hatcher ◽  
S. Dominik ◽  
J. S. Richards ◽  
J. Young ◽  
J. Smith ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Reproductive Rate ◽  
Retention Strategies ◽  
Marginal Benefit ◽  
Selection Strategies ◽  
Single Strategy ◽  
Scan Data ◽  
Reproductive Rates ◽  
Breeding Efficiency ◽  
The Impact

The present empirical study of data from three Merino resource flocks of varying genetic backgrounds run in different environments investigated the impact of various selection strategies aimed at culling poor performers (‘passengers’) or retaining good doers (‘performers’) longer, or both, on the flock reproductive performance. Four strategies were investigated and applied either individually or in combination, to quantify their impact on the litter size, rearing type and breeding efficiency (number of lambs weaned per ewe per year) of the whole flock. The main benefit from implementing any of the strategies was a decrease in the proportion of dry ewes in each flock (1–7%). There was little difference between the single strategies of culling twice-dry ewes or culling ewes that twice lambed and lost their lambs. When retaining a cohort of older ewes, it was more efficient to select these on the basis of their lifetime reproductive performance. There was only a marginal benefit gained by combining strategies and, in some cases, a single strategy was still better in terms of breeding efficiency. Commercial producers can improve the reproductive rate of these flocks by culling twice-dry ewes on the basis of their pregnancy scan data.

A COMPARISON OF FRESH AND FROZEN SEMEN IN THE INSEMINATION OF CONFINED SHEEP

1979 ◽  
Vol 59 (4) ◽  
pp. 685-691 ◽  
Author(s):  
G. A. LANGFORD ◽  
G. J. MARCUS ◽  
A. J. HACKETT ◽  
L. AINSWORTH ◽  
H. F. PETERS ◽  
...  
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Embryonic Mortality ◽  
Frozen Semen ◽  
Serum Gonadotropin ◽  
Early Embryonic Mortality ◽  
The Difference ◽  
Natural Service ◽  
Fresh Semen

The reproductive performance of crossbred sheep maintained in total confinement was compared after artificial insemination with fresh or frozen semen. Estrus was synchronized with progestagen-impregnated vaginal sponges and pregnant mares’ serum gonadotropin. Inseminations were performed 54 and 60 h after sponge removal. The fertility of ewes inseminated with fresh semen was significantly higher than of ewes inseminated with frozen semen. Conception rates, lambing rates and litter size were 83%, 78% and 2.2 using fresh semen and 65%, 43% and 1.8 using frozen semen. In a group of similar ewes bred by natural service, the lambing performance was comparable to that obtained with fresh semen. The difference between conception and lambing rates suggests an increase in early embryonic mortality when breeding with frozen semen and confirms the need for improved frozen semen technology.

Factors affecting reproductive performance of white-tailed deer subjected to fixed-time artificial insemination or natural mating

2013 ◽  
Vol 25 (3) ◽  
pp. 581 ◽  
Author(s):  
Miguel Mellado ◽  
Claudia G. Orta ◽  
Eloy A. Lozano ◽  
Jose E. García ◽  
Francisco G. Veliz ◽  
...  
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Fixed Time ◽  
Arid Environment ◽  
Factors Affecting ◽  
Litter Weight ◽  
Subsequent Period ◽  
Natural Mating ◽  
Game Hunting

The objectives of this study were to examine the effects of several factors affecting fawning rate, litter size, litter weight and neonatal fawn mortality in white-tailed deer inseminated either transcervically or by means of laparoscopy. Oestrus synchronisation with a controlled internal drug release (CIDR)-based protocol and fixed-time artificial insemination (FTAI) was conducted in 130 white-tailed deer (Odocoileus virginianus texanus) during three reproductive seasons (2007–2009; 271 services) in a game-hunting ranch in a hot–arid environment (26°4′ N, 101°25′ W). Ninety additional non-treated does were exposed to bucks for natural mating. Fawning rate did not differ between AI methods (40.0 vs 45.0% for transcervical and laparoscopic AI, respectively). Overall fawning rate (proportion of all does fawning after FTAI and a subsequent period of buck exposure) did not differ between transcervical (89.5%), laparoscopic (80.3%) or natural (88.9%) insemination. Litter size per fawning doe was higher (P&lt;0.05) in naturally-served does (1.65±0.48) than in transcervically-inseminated does (1.40±0.51) or in laparoscopically-inseminated does (1.48±0.50). The main conclusion was that no enhancement of fawning rate or litter size occurred as a result of intrauterine deposition of semen by laparoscopy compared with the transcervical insemination technique.

scholarly journals OESTRUS SYNCHRONIZATION, ARTIFICIAL INSEMINATION AND EARLY REBREEDING IN YANKASA SHEEP

2021 ◽  
Vol 9 (2) ◽  
pp. 107-111
Author(s):  
O. A, OSINOWO
Keyword(s):  
Artificial Insemination ◽  
Production System ◽  
Post Treatment ◽  
Natural Mating ◽  
Sheep Production ◽  
Lambing Rate

COMPONENTS of an intensive sheep production system including oestrus synchronization, artificial insemination and early rebreeding were investigated in two trials with Yankasa sheep. Treatment of ewes with progrestagen pessaries for 12 days resulted in good synchronization of first and second post-treatment oestrus. In Trial I, (January–February, 1982) 33 ewes were treated, of which 81.8% showed oestrus within 4 days after the end of progrestagen treatment while 72.7% showed a second oestrus within 21 days. In Trial II, (August – September, 1982), 48 eyes were treated, of which 87.5 and 77.1% showed first and second oestrus respectively over the same periods as in Trial I. Mean interval (± s.e.m) between first and second induced oestrus in both trials was 16.4 ±0.1 days (n = 61). About 90% of ewes exhibiting oestrus were detected 2 to 4 and 17 to 20 days after progrestagen treatment for first and second oestrus respectively.  Lambing reates of ewes to artificial insemination or natural mating at the second induced oestrus in Trial I were 50.0 and 91.7% respectively, Corresponding lambing rates in Trial II were 65.0 and 86.70%.  Rebreeding interval in ewes which lambed in Trial I was 59.1 ±0.8 days following commencement of progestagen treatment approximately one month after lambing. Lambing rate in this group was 78.6%.

Comparison of laparoscopic and transcervical insemination with frozen semen in Sarda dairy ewes

1998 ◽  
Vol 66 (2) ◽  
pp. 369-373 ◽  
Author(s):  
P. Cappai ◽  
S. R. Sanna ◽  
A. Branca ◽  
A. Fraghì ◽  
G. Bomboi
Keyword(s):  
Reproductive Performance ◽  
Plasma Cortisol ◽  
Breeding Scheme ◽  
Return Rates ◽  
Frozen Semen ◽  
Before And After ◽  
Cortisol Levels ◽  
Natural Mating ◽  
Suitable Technique ◽  
Body Condition Scores

AbstractLaparoscopic insemination with frozen-thawed semen is currently used for planned matings in the Sarda breeding programme. In order to find a fast and less intrusive artificial insemination (AI) method that could replace laparoscopic insemination, a field comparison of laparoscopic and transcervical techniques was carried out on 200 mature Sarda ewes. After AI, ewes were assigned to teaser and fertile rams for 2 months. Return rates and cumulative (AI + natural mating) lambing rates were recorded over three subsequent 23-day periods. Lambing rates to AI were significantly different (P < 0·01), and were 62% and 7% respectively for laparoscopic and transcervical AI. Cumulative lambing rates after two further 23-day periods of natural mating were no longer significantly different (P > 0·05) and reached 82% and 74% respectively. Ewes with body condition scores at AI higher than 2·75 showed better overall reproductive performance, but not higher pregnancy rate to AI. Plasma cortisol concentrations, sampled twice, before and after AI, were higher (P < 0·01) in the last sample, suggesting a stress response to insemination. Cortisol levels after AI were lower (P < 0·01) for ewes submitted to transcervical rather than laparoscopic insemination (P < 0·01). However, cortisol levels after AI were no greater than those recorded when ewes were restrained in a milking yoke different from that usually employed. Laparoscopic AI was confirmed as the most suitable technique for insemination offrozen semen in the Sarda breeding scheme.

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