APPLICATION OF CONTROLLED REPRODUCTION TO SHEEP FLOCKS IN NEWFOUNDLAND

1982 ◽  
Vol 62 (3) ◽  
pp. 679-687 ◽  
Author(s):  
J. N. B. SHRESTHA ◽  
L. AINSWORTH ◽  
D. P. HEANEY ◽  
A. N. SMITH
Keyword(s):  
Key Words ◽  
Reproductive Performance ◽  
Field Conditions ◽  
Spring Season ◽  
Fall Season ◽  
Controlled Reproduction

A 3-yr study demonstrates that commercially acceptable reproductive performance can be achieved in breeding sheep following the application of a fluorogestone-acetate- (FGA-) impregnated intravaginal sponge and pregnant mare's serum gonadotrophin (PMSG) treatment to induce a synchronized estrus under field conditions. Overall fertility, prolificacy and fecundity levels of 76%, 1.92 and 148%, respectively, resulted from breeding at the synchronized estrus, and 94%, 1.86 and 175%, respectively, due to breeding at the synchronized and subsequent estruses in the breeding (fall) season. In the nonbreeding (spring) season, these responses were 51%, 1.73 and 88%, respectively, at the synchronized estrus, and 63%, 1.61 and 109%, respectively, due to breeding at the synchronized and subsequent estruses. Significant farm-to-farm variation was observed with reproductive performance ranging from 77 to 100% for fertility, 1.45 to 2.74 for prolificacy, and 134 to 274% for fecundity in the estrous season. There were no significant differences among farms after synchronization and breeding during the anestrous season. Key words: Sheep, synchronization, fluorogestone acetate, pregnant mare's serum gonadotrophin, season, farm flocks.

INFLUENCE OF BREED ON THE REPRODUCTIVE PERFORMANCE OF EWES TREATED WITH FLUOROGESTONE-ACETATE-IMPREGNATED INTRAVAGINAL SPONGE AND PREGNANT MARE'S SERUM GONADOTROPHIN DURING THE BREEDING SEASON

1983 ◽  
Vol 63 (1) ◽  
pp. 1-6
Author(s):  
J. N. B. SHRESTHA ◽  
L. AINSWORTH ◽  
D. P. HEANEY
Keyword(s):  
Key Words ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Field Conditions ◽  
Reproductive Outcome ◽  
The North ◽  
Single Location ◽  
Significant Difference

The influence of breed on the reproductive performance of 454 mature ewes treated with fluorogestone acetate (FGA)-impregnated intravaginal sponges and pregnant mare's serum gonadotrophin (PMSG) to induce synchronized estrus during the breeding season was studied from 1978 to 1980 at a single location under field conditions. Fertility and fecundity after breeding at the synchronized estrus were, respectively, 79 and 145% for Polled Dorset, 51 and 94% for Suffolk, and 65 and 113% for North Country Cheviot breeds. The fertility and fecundity of the Polled Dorset were significantly higher than those of the Suffolk, but the North Country Cheviot was not significantly different from Polled Dorset and Suffolk breeds. There was no significant difference among the breeds with respect to prolificacy. Significant year-to-year variation in fertility and fecundity, but not in prolificacy, was observed among breeds with respect to FGA-PMSG treatment at the synchronized estrus. We conclude that the use of FGA-impregnated intravaginal sponge and PMSG treatment with appropriate breeds of sheep may further enhance the reproductive outcome of breeding at the synchronized estrus during the breeding season. Key words: Breeds, sheep, FGA sponge, PMSG, reproduction

EFFECT OF CANOPY AND INCORPORATION ON METRIBUZIN PERSISTENCE IN SOILS

1989 ◽  
Vol 69 (3) ◽  
pp. 711-714 ◽  
Author(s):  
K. I. N. JENSEN ◽  
E. R. KIMBALL ◽  
J. A. IVANY
Keyword(s):  
Key Words ◽  
Half Life ◽  
Field Tests ◽  
Soil Surface ◽  
Bare Soil ◽  
Field Conditions ◽  
Row Width ◽  
Sampling Zone

The half-life of metribuzin applied to a bare soil surface was calculated to be 3–7 d over four field tests. An artificial cover erected after application or a shallow incorporation increased the half-life of metribuzin approximately 2.5- to 3-fold. Leaching out of the 0- to 5-cm-deep sampling zone could not account for loss of metribuzin. It was concluded that metribuzin persistence may be affected by volatility and/or photodecomposition losses under field conditions, especially shortly after application. Key words: Metribuzin half-life, volatility, photodecomposition, row width

THE ACCUMULATIVE EFFECT OF FINNSHEEP BREEDING IN CROSSBREEDING SCHEMES: REPRODUCTIVE PERFORMANCE

1988 ◽  
Vol 68 (1) ◽  
pp. 69-81 ◽  
Author(s):  
MOHAMED H. FAHMY ◽  
JACQUES J. DUFOUR
Keyword(s):  
Body Weight ◽  
Mortality Rate ◽  
Key Words ◽  
Litter Size ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Ovulation Rate ◽  
Genetic Groups ◽  
Linear Regressions ◽  
Size At Birth

Reproductive performance and body weight were studied on 361 ewes, representing Finnsheep (F), DLS (a population of 1/2 Dorset, 1/4 Leicester, 1/4 Suffolk) and seven combinations ranging from 1/8 to 7/8 Finnsheep breeding. Conception rate in yearlings was 61.5% for DLS compared to 89.0% for F with the crosses being intermediate. Conception rate in older ewes was similar in the different genetic groups (avg. 94%). Ovulation rate and litter size at birth of DLS ewes were 1.72 and 1.44 lambs, which was less than half those of F ewes (3.51 and 2.86 lambs, respectively). Both traits increased progressively with an increase in F breeding in crosses and with advances in age. DLS ewes weaned 1.22 lambs compared to 2.03 lambs for F ewes and 1.84 lambs for 4/8 F ewes. The heaviest litters at weaning (31.7 kg) were raised by 4/8 F ewes, followed by 7/8 F (30.8 kg) while those raised by DLS ewes weighed 23.0 kg and F ewes 29.1 kg. Percentage of ova lost per ewe mated averaged 24% and ranged between 18% (DLS and 1/8 F) and 29% (6/8 F). About 3.6% of lambs were born dead and a further 13.8% died before weaning. Preweaning mortality rate was highest in F (22.9%) and lowest in 3/8 F (9.4%). Average kilograms of lambs weaned per ewe exposed was highest in 4/8 F (27.6 kg) followed by F (26.0 kg), whereas that of DLS was the lowest at 18.1 kg. The 4/8 F cross showed 25% heterosis in kg of lambs weaned per ewe exposed and 52.5% increase over DLS. Significant positive linear regressions were calculated for ovulation rate, litter size and preweaning mortality rate on proportion of Finnsheep breeding in crosses. The relation was quadratic for percent ova lost and lamb mortality at weaning. Yearling DLS females weighted 36 kg compared to 44 kg for F yearlings. However, at 5 yr of age DLS ewes weighed 62 kg, 5 kg heavier than F ewes. The heaviest ewes at all ages were the 4/8 F (45 kg at 1 yr, 65 kg at 5 yr). Key words: Reproduction, DLS sheep, Finnsheep, crossbreeding, heterosis, repeatabilities

scholarly journals The influence of adding estradiol to semen on reproductive performance of sows

1991 ◽  
Vol 71 (2) ◽  
pp. 589-591 ◽  
Author(s):  
R. N. Kirkwood ◽  
P. A. Thacker
Keyword(s):  
Key Words ◽  
Litter Size ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Pregnancy Rates ◽  
And Control ◽  
Estradiol 17Β

One hundred gilts and one hundred mixed-parity sows of Yorkshire and Landrace breeding were inseminated with semen with or without an additional 10 μg estradiol-17β. Pregnancy rates of gilts receiving estradiol-supplemented and control semen were 90 and 79%, respectively (P < 0.09). The estradiol supplementation of semen did not improve the pregnancy rates or litter size in sows. Key words: Swine, artificial insemination, estradiol

Temporal Dynamics and Severity of Cucurbit Downy Mildew Epidemics as Affected by Chemical Control and Cucurbit Host Type

Plant Disease ◽  
2021 ◽  
Author(s):  
Isaack Kikway ◽  
Anthony P. Keinath ◽  
Peter S. Ojiambo
Keyword(s):  
Downy Mildew ◽  
Disease Severity ◽  
Temporal Dynamics ◽  
Parameter Estimates ◽  
Spring Season ◽  
Fall Season ◽  
Fungicide Treatment ◽  
Cucurbit Downy Mildew ◽  
Disease Progress ◽  
Host Type

Cucurbit downy mildew caused by the oomycete Pseudoperonospora cubensis is an important disease that affects members of Cucurbitaceae family globally. However, temporal dynamics of the disease have not been characterized at the field scale to understand how control strategies influence disease epidemics. Disease severity was assessed visually on cucumber and summer squash treated with weekly alternation of chlorothalonil with either cymoxanil, fluopicolide or propamocarb, during the 2018 spring season and 2019 and 2020 fall seasons in North Carolina, and the 2018 and 2020 fall seasons in South Carolina. Disease onset was observed around mid-June during the spring season and early September during the fall season, followed by a rapid increase in severity until mid-July in the spring season and late September or mid-October in the fall season, typical of polycyclic epidemics. The Gompertz, logistic and monomolecular growth models were fitted to disease severity using linear regression and parameter estimates used to compare the effects of fungicide treatment and cucurbit host type on disease progress. The Gompertz and logistic models were more appropriate than the monomolecular model in describing temporal dynamics of cucurbit downy mildew, with the Gompertz model providing the best description for 34 of the 44 epidemics examined. Fungicide treatment and host type significantly (P < 0.0001) affected standardized area under disease progress curve (sAUDPC), final disease severity (Final DS) and weighted mean absolute rates of disease progress (ρ), with these variables, in most cases, being significantly (P < 0.05) lower in fungicide treated plots than in untreated control plots. Except in a few cases, sAUDPC, Final DS and ρ were lower in cases where chlorothalonil was alternated with fluopicolide or propamocarb than in cases where chlorothalonil alternated with cymoxanil or when chlorothalonil was applied alone. These results characterized the temporal progress of cucurbit downy mildew and provided an improved understanding of the dynamics of the disease at the field level. Parameters of disease progress obtained from this study could serve as inputs in simulation studies to assess the efficacy of fungicide alternation in managing fungicide resistance in this pathosystem.

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

The effect of deworming naturally infected heifers on liveweight gain, reproductive performance and fecal egg counts

1993 ◽  
Vol 73 (2) ◽  
pp. 287-293
Author(s):  
S. L. Boyles ◽  
L. J. Johnson ◽  
W. D. Slanger ◽  
B. J. Kreft ◽  
J. D. Kirsch
Keyword(s):  
Key Words ◽  
Reproductive Performance ◽  
Fecal Sample ◽  
Average Daily Gain ◽  
Treated Group ◽  
The Other ◽  
Control Group ◽  
Age At Puberty ◽  
Daily Gain

Twenty-six of 52 heifers with an average liveweight of 318 kg were dewormed by intraruminal injection of oxfendazole and placed in drylot on 31 January. The other 26 animals served as controls. All heifers were pastured starting on 14 June and the treatment heifers were dewormed in the same manner as at the start of the experiment (31 January) on 1 July and 31 July. The groups started out with similar total worm eggs per gram of fecal sample, but the dewormed heifers had fewer counts each month thereafter. The drylot average daily gain of the treated heifers was higher (P = 0.01) and less variable (P = 0.12) and by 29 May these animals were heavier by 11.7 kg (P = 0.10). The treated animals did not gain as fast on pasture (P = 0.20), but the gain continued to be less variable (P = 0.09). Age at puberty was not different. Number of open heifers in the treated group was 4 vs. 15% for the control group (P = 0.18). Deworming by intraruminal injection resulted in faster feedlot gains, more uniform gains during both drylot and pasture, reduced parasites and no abscess at injection sites. Key words: Anthelmintics, oxfendazole, cattle, heifers

EFFECT OF FORCED EXERCISE DURING GESTATION ON REPRODUCTIVE PERFORMANCE OF SOWS

1985 ◽  
Vol 65 (4) ◽  
pp. 851-859 ◽  
Author(s):  
S. L. FERKET ◽  
R. R. HACKER
Keyword(s):  
Key Words ◽  
Reproductive Performance ◽  
Key Words Exercise ◽  
Birth Intervals ◽  
Blood Samples

A trial was conducted to determine the effect of forced exercise during gestation on the reproductive performance of sows. On day 35 of gestation, 48 first parity Yorkshire sows were randomly allocated to one of four groups of 12: control-cannulated, control-noncannulated, exercised-cannulated, exercised-noncannulated. Exercised sows were forced to walk 2 km daily until day 108 of gestation when appropriate sows were cannulated in the ear vein. From day 109 on, all sows were in farrowing crates, and blood samples were taken twice daily from cannulated sows except during parturition, when samples were taken every 15 min. Serum was assayed for progesterone, estradiol and cortisol. Cannulation had no effect on any of the parameters measured. Exercised sows (ES) farrowed faster and had shorter birth intervals than control sows (CS) (P = 0.06). Several of the CS took longer than 12 h to complete farrowing whereas all ES farrowed within this time. The stillbirth rates did not differ between the two groups but a higher percentage of piglets from CS (P < 0.001) than ES died before suckling. The hormone profiles and interval from weaning to first estrus were similar between the groups but estradiol/progesterone ratios tended to be higher in exercised sows from 24 h prepartum to onset of parturition. Prepartum levels of cortisol started to increase sooner in control than exercised sows (P < 0.05). It is concluded that exercise during gestation can improve the farrowing performance of first parity sows through shorter farrowing times and more viable piglets at birth. Key words: Exercise, reproductive performance, farrowing, sows, steroids

Influence of Postpartum Cloprostenol Treatment in Sows on Subsequent Reproductive Performance under Field Conditions

2008 ◽  
Vol 43 (4) ◽  
pp. 484-489 ◽  
Author(s):  
C Vanderhaeghe ◽  
J Dewulf ◽  
A Daems ◽  
A Van Soom ◽  
A de Kruif ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Field Conditions

EFFECT OF DOSE OF PREGNANT MARES' SERUM GONADOTROPHIN ON THE REPRODUCTIVE PERFORMANCE OF EWES SYNCHRONIZED FOR ESTRUS AND HOUSED IN TOTAL CONFINEMENT

1982 ◽  
Vol 62 (1) ◽  
pp. 291-294 ◽  
Author(s):  
A. J. HACKETT
Keyword(s):  
Key Words ◽  
Reproductive Performance

Ewes housed indoors year round were treated with 40 mg of fluorogestone acetate followed by 0, 250, 500 or 750 IU pregnant mares' serum gonadotrophin (PMSG). PMSG did not enhance fertility, prolificacy or fecundity in ewes bred at the synchronized estrus. Key words: Sheep, PMSG, synchronization, fertility, prolificacy, fecundity

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