REPRODUCTIVE PERFORMANCE OF HAMSTERS WITH POLYACRYLAMIDE IMPLANTS CONTAINING ETHINYLOESTRADIOL

1972 ◽  
Vol 70 (2) ◽  
pp. 385-395 ◽  
Author(s):  
B. K. Davis ◽  
I. Noske ◽  
M. C. Chang
Keyword(s):  
Reproductive Performance ◽  
Mature Female ◽  
Pregnancy Rates ◽  
List Type ◽  
Pathological Changes ◽  
Apparent Effect ◽  
Tissue Sections ◽  
Main Target

ABSTRACT Mature female hamsters bearing subcutaneous polyacrylamide (PAA) implants, with ethinyloestradiol (EO), for at least 10 days prior to mating revealed: 0.5 and 2.5 mg EO in 7% PAA significantly disturb the timing of oestrus and mating, but have no apparent effect on rate of pregnancy, ovulation and implantation. 2.5 mg EO in 20 and 40% PAA conspicuously reduces the likelihood of pregnancy, although the occurrence of oestrus and mating are affected only slightly. Fertility in these hamsters was virtually restored, judging from pregnancy rates, when they were remated 11 days, or more, following removal of their implants (37 days after implantation), but significantly more foetuses were resorbed in these litters. From tissue sections of skin and muscle at the implant site, ovary, uterus, pituitary, adrenals and liver, PAA implants, without EO, cause no overt pathological changes in the bearer. Effects characteristic of oestrogen are present when these implants contain EO, and these include a conspicuous thickening of the epidermis and dermis; haemorrhagic lesions were also noted in the maternal placenta of animals with EO implants. There is an association between reproductive performance and the rate of EO release by an implant. A 7% PAA implant with 2.5 mg EO can release most of it within 2 days, and principally influences events (oestrus and mating) that precede the main target (pregnancy) of a 20% PAA implant, which releases the steroid over the longer interval of 7 days.

scholarly journals Effects of management system on beef heifer growth and reproductive performance

2020 ◽  
Author(s):  
Parker A Henley ◽  
Frank A Ireland ◽  
Igor F Canisso ◽  
J Lannett Edwards ◽  
Daniel W Shike
Keyword(s):  
Development Strategy ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Pregnancy Rates ◽  
Fescue Toxicosis ◽  
Soybean Hulls ◽  
Randomized Design ◽  
Condition Score ◽  
Calf Performance

Abstract This study evaluated the effect of heifer development system on body weight (BW), body condition score (BCS), fescue toxicosis symptoms, reproductive performance, and subsequent calf growth of fall-calving beef heifers. Angus × Simmental heifers [n = 399; 240 ± 20.0 kg initial BW; age = 252 ± 20 d] were stratified by BW and BCS and assigned to 1 of 12 groups in each of the 2 production years. The study utilized a stratified randomized design. Pens were randomly assigned to 4 treatments: drylot (DL) development (fed ad-libitum diet consisting of 90% hay and 10% DDGS on a dry matter basis), grazing endophyte-infected fescue supplemented daily (2.3 kg as-fed/heifer/d; 50:50 mix of soybean hulls and DDGS; E+/S), grazing endophyte-infected fescue and supplemented from the midpoint of treatment period until breeding (4.5 kg as-fed/heifer/d; 50:50 mix of soybean hulls and DDGS; E+/LS), and grazing novel endophyte-infected fescue with no supplement (NE+/NS). Treatments ceased on d 168 [time of artificial insemination (AI)] and heifers were commingled and managed as a group through second breeding season. Heifers in DL had greatest (P ≤ 0.05) BW and BCS from d 28 until d 254. Furthermore, E+/S heifers had greater (P ≤ 0.05) BW and BCS than both E+/LS and NE+/NS from d 28 until d 168. On d 56 and 84, E+/LS heifers had lower (P ≤ 0.05) BW and BCS compared to NE+/NS, but on d 148 treatments reranked and E+/LS remained at a greater (P ≤ 0.05) BW and BCS compared to NE+/NS through the first breeding season. Drylot heifers had greatest (P ≤ 0.05) percentage cycling and percentage of mature BW at AI (66.6%) and had greater (P ≤ 0.05) AI and overall pregnancy rates compared to E+/LS and NE+/NS. The E+/S (55%) and E+/LS (53.7%) heifers were developed to a greater (P < 0.01) percentage of mature BW than NE+/NS (49.3%). A greater (P ≤ 0.02) percentage of DL and E+/S heifers were pregnant at the end of the first breeding season (89.3 and 85.1%; respectively) compared to NE+/NS (61.5%). In summary, DL heifers had the greatest BW and BCS at AI, percentage cycling, and AI pregnancy rate. However, this strategy did not result in differing overall pregnancy rates between DL, E+/S, and E+/LS and there were no differences in milk production, rebreeding reproductive performance, and calf performance between all treatments. Finally, the poorest AI and overall pregnancy rates of the NE+/NS heifers suggests this is not a viable development strategy for fall-born heifers.

scholarly journals Comparison of the effects of Presynch-Ovsynch, Presynch- Ovsynch+CIDR, and G6G protocols on the reproductive performance of lactating Holstein cows in the postpartum period

2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Hesam Kohsari ◽  
Khatereh Berenjian
Keyword(s):  
Serum Concentration ◽  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Dairy Farm ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Holstein Cows ◽  
Treatment Protocols ◽  
Ovulatory Follicle

This study was performed on an industrial dairy farm near Tehran province, Iran, on 666 lactating Holstein cows from September 2019 to June 2020 in order to eliminate the harmful effects of heat stress on the reproductive performance of the cows. The hypothesis of the recent study was that by increasing the serum concentration of progesterone (P4) in the luteal phase before insemination in the form of Presynch-Ovsynch+CIDR (POC) and G6G protocols, the pregnancy rate of cows would be increased compared to the Presynch-Ovsynch (PO) protocol. The aim of the present study was to evaluate the effects of Presynch-Ovsynch (PGF2α-14d- PGF2α-12d-Ovsynch (OVS: GnRH(GnRH1)- 7d-PGF2α(PG)-2d-GnRH)-18h-Fixed-time artificial insemination (FTAI), n=212), Presynch-Ovsynch+CIDR (similar to the PO protocol, plus the use of a CIDR for 7 days, from the start of the OVS+FTAI protocol to the time of PG injection, n=230), and G6G (PGF2α- 2d-GnRH-6d-OVS+FTAI, n=224) protocols on the reproductive performance and pregnancy rate of lactating Holstein cows. The average body condition score (BCS) for the cows was about 2.5 at the time of the onset of the OVS+FTAI program. The average daily milk production for cows at the time of the start of the OVS+FTAI program was 38.3 kg/day. On average, the studied cows were inseminated 86 days postpartum. Implementation of the G6G protocol in comparison to the PO and POC protocols increased the serum concentration of P4 at GnRH1 (P=0.04). The cows that received the G6G protocol had a greater number of corpuses luteum (CL) on their ovaries at PG in comparison to the cows in the PO and POC protocols (P=0.03 and P=0.05, respectively). For all treatment protocols, the pregnancy rate of cows with >2 CLs on their ovaries at PG was significantly higher than for cows with ≤2 CLs on their ovaries at this time. The overall pregnancy rate for all cows studied was 42%. Separately, pregnancy rates for cows in PO, POC, and G6G protocols were calculated at 36.7%, 41.7%, and 47.3% respectively. The highest and the lowest pregnancy rates were obtained in the G6G and PO protocols, respectively (P=0.03). It can be concluded that the G6G protocol increased the pregnancy rate of cows in comparison to the PO but not to the POC protocol. This result can be attributed to the increase in serum concentration of P4 at GnRH1 and the greater number of CLs at PG following implementation of the G6G compared to the PO protocol. Although CIDR administration in the POC protocol led to an increase in the pregnancy rate of cows compared to the PO protocol, possibly by increasing the synchrony rate and the quality of the ovulatory follicle, this increase was not statistically significant (P=0.09).

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

scholarly journals Fertility parameters in German dairy herds: Associations with milk yield and herd size

2019 ◽  
Vol 64 (No. 11) ◽  
pp. 459-464
Author(s):  
Jörn Rethmeier ◽  
Michael Wenzlau ◽  
Martin Wagner ◽  
Steffi Wiedemann ◽  
Lisa Bachmann
Keyword(s):  
Pregnancy Rate ◽  
Milk Yield ◽  
Reproductive Performance ◽  
Dairy Farms ◽  
Herd Size ◽  
Pregnancy Rates ◽  
Conception Rate ◽  
Service Rate ◽  
Dairy Herds ◽  
Key Factor

Fertility in dairy cows has decreased over the last fifty years while milk production per cow has increased. Furthermore, dairy herds become larger resulting in fewer employees per cow, which might also influence reproductive performance. To elucidate the situation in Germany, selected parameters (conception rate, service rate, pregnancy rate, days to first insemination and days open) were studied using data on 148 herds. For statistical analysis the herds were categorized concerning milk yield: (1) &lt; 30 kg, (2) 30‒35 kg, and (3) &gt; 35 kg/cow/day as well as concerning herd size: (1) &lt; 200, (2) 200‒400, (3) 400‒1000 and (4) &gt; 1000 milking cows. There was no difference in conception rate among herds. That means on dairy farms of larger size or with high milk yield the chance of an inseminated cow to become pregnant is the same as in small herds or in herds with low milk yield. Small herds (&lt; 200 cows) had lower pregnancy rates than larger herds (200–400 cows). The pregnancy rate in herds with different milk yield was not statistically different. Though there was a trend that dairy farms with higher milk yield (&gt; 30 kg) had higher pregnancy rates. The statistical differences and trends of pregnancy rates are due to higher service rate in larger herds as well as in herds with high milk yield. Therefore, service rate is the key factor for high reproductive performance on dairy farms. Poor fertility is not associated with high milk yield on herd basis or large herd size but may represent inappropriate farm management.

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

Improving reproductive performance in lactating dairy cows by synchronising ovulation or inducing oestrus

2002 ◽  
Vol 50 (2) ◽  
pp. 231-234 ◽  
Author(s):  
Gy. Gábor ◽  
J. P. Kastelic ◽  
S. Pintér ◽  
Keyword(s):  
Dairy Cows ◽  
Reproductive Performance ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Preliminary Trial ◽  
Lactating Cows ◽  
Lactating Dairy Cows ◽  
Considerable Promise ◽  
Holstein Friesian ◽  
Prostaglandin F

Lactating crossbred Holstein-Friesian dairy cows (n = 331) were started on an Ovsynch regimen 68 ± 8.2 days after calving; 200 µg GnRH intramuscularly (i.m.) on Days 0 and 9, and 35 mg prostaglandin F2a i.m. on Day 7. Thirty-eight and 31 cows (11.5 and 9.4%, respectively) were in oestrus on Days 0 to 6 and 7 to 8, respectively, and inseminated, and the remainder were fixed-time inseminated (on Day 10). For these three groups, pregnancy rates (60-65 days after breeding) were 31.6, 38.7 and 34.0%, respectively (P = 0.82) and calving rates were 100, 100 and 89.9% (P = 0.23). In a preliminary trial, twelve lactating cows (45 to 60 days postpartum) with inactive ovaries were given 1500 IU eCG i.m.; 10 were in oestrus within 10 days after treatment (and inseminated) and eight of these were pregnant (30 days after breeding). The Ovsynch program resulted in acceptable reproductive performance in cyclic cows and eCG treatment has considerable promise for inducing oestrus in anoestrous cows.

RESULT OF ADVANCED TECHNIQUES FOR ARTIFICIAL INSEMINATION IN EWES WITH FROZEN-THAWED SEMEN

2015 ◽  
Vol 13 (2) ◽  
pp. 43-47
Author(s):  
P Myagmarsuren ◽  
U Myagmardulam ◽  
Ts Haliunaa
Keyword(s):  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Intrauterine Insemination ◽  
Animal Husbandry ◽  
Pregnancy Rates ◽  
Luminal Diameter ◽  
Physical Size ◽  
Domestic Species ◽  
Breeding Station

In all domestic species, acceptable pregnancy rate with frozen-thawed semen is 20-30% through simply cervical and vaginal insemination. Researchers have proved that achievable high results can be expected only from intrauterine insemination in ewes. Unlike the cow, and goat, the cervix of ewes is a formidable barrier to penetrate for transcervical intrauterine insemination. It is not only due to the physical size of the canal and a narrow luminal diameter (even at estrus), but also due to its caudally facing eccentric series of four to eight funnel-like rings. The major aim of this study was to evaluate a comparison of transcervical and laparoscopic intrauterine artificial insemination techniques with frozen –thawed semen on the reproductive performance of ewes.58ewes of 3-4 years of age, so called Altanbulag subspecies of breed were selected and equally divided into 2 groups for the AI methods from October 15-20, 2013 in the breeding station of Research Institute of Animal Husbandry in Hongor sum, Darhan uul province. The estrus was synchronized with EAZI-BREED TMCIDR in which the progesterone content was 0.3 g. After 12 days, the CIDR were removed, PMSG of 400 and 200 IU were administrated intramuscularly per ewe. The total success of synchronization rate was 93.3%. The results has shown the possibilities of laparoscopic and transcervical AI techniques in 55.17%, 41.37% (p>0.05) of pregnancy rates respectively, with frozen-thawed semen in ewes by ultrasonography diagnosis.Mongolian Journal of Agricultural Sciences Vol.13(2) 2014: 43-47

scholarly journals Effects of Polyunsaturated Fatty Acids (PUFA) Supplementation on Reproductive Performance of Beef Heifers Submitted to Fixed-time Artificial Insemination (FTAI) Protocol

2019 ◽  
Vol 47 (1) ◽  
Author(s):  
João Batista Souza Gorges ◽  
Andressa Varella Gonsioroski ◽  
Eduardo Pradebon Da Silva
Keyword(s):  
Reproductive Performance ◽  
Reproductive Function ◽  
Pregnancy Rates ◽  
Beef Heifers ◽  
Pufa Supplementation ◽  
Group 2 ◽  
Ovulatory Follicles ◽  
Dietary Treatments ◽  
And Control ◽  
Group 1

Background: More recently, polyunsaturated fatty acids (PUFA) supplements have been used in grazing beef herds in attempt to influence specific metabolic pathways and hormones that directly modulate reproductive function. Supplementation of calcium salts of PUFA can positively influence ovarian follicular growth, luteal function, and improve reproductive performance in dairy and beef females. The aim of this experiment was to evaluate strategies of dietary treatments using PUFA supplementation for 30 days before or after FTAI protocol and its effects on of ovulatory follicle size, ovulation, pregnancy and gestational losses rates in beef heifers.Materials, Methods & Results: One hundred and ninety-nine Brangus heifers (24 ± 3 months-old; BW= 320 ± 15 kg; BCS= 2.85 ± 0.17) were randomly assigned in three different groups to receive dietary treatments. Group 1 (n = 70) was fed with 0.5 kg/day of a protein-mineral mixture supplement containing 0.2 kg/day PUFA (Mix A)during 30 days before FTAI, Group 2 (n = 68) received the same supplement 30 days after FTAI and Control (n = 61) only the supplement without PUFA (Mix B) during all period. Heifers were submitted to estrous synchronization treatment using progesterone (P4), estradiol benzoate (E2) and prostaglandin F2a  (PGF). Ultrasound exams were done to measure ovulatory follicle diameter and to determinate ovulation and pregnancy rates on Day 30 and 60 after FTAI. Daily gain (DG) was higher (P < 0.05) only when heifers received supplement containing PUFA (Group 1= 30 days prior FTAI) and (Group 2= 30 days after FTAI). PUFA supplementation before FTAI also resulted in larger ovulatory follicles diameter (P < 0.05) in Group 1 (11.2 ± 2.5 mm) compared to Group 2 (9.9 ± 2.3 mm) and Control (10.0 ± 2.07 mm). Ovulation rates were similar (P > 0.05) in Group 1 (90%), Group 2 (75%) and Control (67%). Pregnancy rates were higher (P < 0.05) in Group 1 (Day 30= 67.1% and Day 60= 64.2%) when compared with Group 2 (Day 30= 48.5% and Day 60= 44.1%) and Control (Day 30= 49.2% and Day 60= 45.9%). Gestation losses were similar (P > 0.05) among Groups 1 (6.6%), 2 (9%) and Control (6.6%).Discussion: Rumen-protected supplemental lipids have been used to increase energy density and to determine direct positive effects on reproduction in dairy and beef herds.  There is evidence that feeding moderate amounts of PUFA supplements can improve energy status and result in significant differences in DG as it was observed during experimental period. Thus, heifers that received 0.2 kg/day of PUFA supplement 30 days before FTAI protocol had also a positive effect on ovulatory follicles size, but ovulation rates were similar in groups. Beneficial effects of pre-breeding PUFA supplementation were observed on pregnancy rates on Days 30 and 60 after FTAI, but pregnancy loss was not different among dietary treatments in beef heifers. Based on this study, PUFA supplementation before FTAI protocol had a positive effect on reproductive performance of beef heifers by directly improving ovarian function, uterine environment and early embryonic development. Results indicate that pre-breeding PUFA supplementation to beef heifers is a suitable strategy to increase pregnancy rate in FTAI programs. Therefore, for a better understanding of interactions of nutritional strategies and utero-ovarian functions more evaluations are needed to understand the mechanisms by which feeding PUFA may improve reproductive function in beef heifers.

scholarly journals Economics of Improved Reproductive Performance in Dairy Cattle

EDIS ◽  
2019 ◽  
Vol 2005 (9) ◽  
Author(s):  
Albert De Vries ◽  
Jessika Van Leeuwen ◽  
William W. Thatcher
Keyword(s):  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Economic Value ◽  
Economic Benefits ◽  
Cooperative Extension Service ◽  
Pregnancy Rates ◽  
Dairy Herds ◽  
University Of Florida ◽  
Fact Sheet ◽  
The Cost

This fact sheet provides some estimates of the economic benefits of improved reproductive performance through increasing pregnancy rates in dairy herds. After a short literature review, the fact sheet focuses on estimates under conditions in Florida. At the herd level, the economic value of an improvement in pregnancy rate and the cost of an additional day open are estimated. This is done for both an overall increase of pregnancy rate and an increase of first service pregnancy rate. In addition, the fact sheet presents some estimates of the maximum that can be spent on a reproductive program to obtain increases in first service pregnancy rates. At the cow level, the values of a new or established pregnancy are discussed. Results show the maximum that can be spent to get specific cows pregnant. This document is AN156, one of a series of the Department of Animal Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published August 2005.

scholarly journals COVID-19. Liver damage – visualization features and possible causes

2020 ◽  
Vol 24 (3) ◽  
pp. 26-36
Author(s):  
A. S. Vinokurov ◽  
M. V. Nikiforova ◽  
A. A. Oganesyan ◽  
O. O. Vinokurova ◽  
A. L. Yudin ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Liver Damage ◽  
Biochemical Markers ◽  
Ct Imaging ◽  
Acute Stage ◽  
Pathological Changes ◽  
Main Target ◽  
The Central Nervous System ◽  
Damage Visualization

Item. To evaluate the features of CT imaging of the liver and the possible causes of pathological changes in COVID-19.Materials and methods. An analysis of the literature and our own data on the features of CT imaging of the liver in combination with biochemical analyzes in patients with COVID-19 was performed. The main possible causes of changes in the liver, as well as symptoms with CT, are examined.Results. The main target of the new SARS-CoV-2 coronavirus is the respiratory system. But among patients with COVID-19, along with damage to the central nervous system, myocardium, and intestines, cases of liver damage or dysfunction have been reported. This is expressed in an increase in biochemical markers of liver damage, as well as in a diffuse decrease in its density during CT, which is usually observed in the acute stage of the disease.

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