scholarly journals Influence of Pre-Mating Plasma Prolactin Profile on Reproductive Performance of California Doe Rabbits

2021 ◽  
Author(s):  
Abdel-Khalek El-Sayed Abdel-Khalek ◽  
Zyad Mohamed Kalaba ◽  
Helmy Zaghloul ◽  
George Younan
Keyword(s):  
Body Weight ◽  
Pregnancy Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Reproductive Traits ◽  
Reproductive Efficiency ◽  
Average Weight ◽  
Plasma Prolactin ◽  
Live Body Weight

Abstract: Ovulation failure was associated with a reduction in pre-mating concentrations of oestradiol-17β and prolactin (PRL). The present study aimed to evaluate whether pre-mating PRL levels have a role on the reproductive efficiency of doe rabbits. A total of 78 multiparous California does (2nd parity) were divided, according to plasma pre-mating PRL, into five categories, >20-25, >25-30, >30-35, >35-40, and >40-45 ng/ml. Does in all categories were naturally mated and kindled, then their reproductive measurements and progesterone (P4) levels were determined. Results show that pre-mating PRL averaged 23.60±0.78, 28.00±0.83, 33.46±0.43, 38.17±0.49 and 41.98±0.68 ng/ml in five categories (p < 0.05), respectively, representing the highest distribution (38.5%) in the 3rd-category. Live body weight of doe rabbits, at mating, pregnancy, and parturition increased (p < 0.05) with increasing pre-mating PRL level. The number of services, litter size, and pregnancy rate increased (p < 0.05) by increasing PRL levels. Reproductive traits and P4 level at mid-pregnancy of does, and average weight of kits at birth increased (p < 0.05) by increasing PRL levels. The pre-mating PRL profile is important for the identification of reproductive performance in doe rabbits.

scholarly journals Effect of rebreeding interval on reproductive performance and body weight changes of does during pregnancy

2021 ◽  
Vol 32 (1) ◽  
pp. 142-152
Author(s):  
G. T. Iyeghe-Erakpotobor ◽  
E. O. Oyedipe ◽  
L. O. Eduvie ◽  
D. Ogwu
Keyword(s):  
Body Weight ◽  
Pregnancy Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Feed Intake ◽  
The Other ◽  
Weight Changes ◽  
Body Weight Changes ◽  
Tropical Conditions ◽  
Size At Birth

The effect of rebreeding interval on the reproductive performance and body weight changes of does during pregnancy was investigated using 24 multiparous crossbred (New Zealand White X California) does. The does were placed on three treatments comprising mating at 14, 21 and 28 days postpartum. The docs were served 250g-concentrate meal (23% CP und 2600 kcal ME/kg) daily, while water was given ad libitum. Parameters monitored were doe willingness to mate, doe weights during pregnancy, feed intake, pregnancy rate, litter size and weight at birth, alive at birth and up to 21 days postpartum and stillbirth rate. Kits were weaned at 4 weeks of age. Results obtained showed that does mated 14 days postpartum lost more weight in the second week of pregnancy than the other groups. Rebreeding interval did not significantly (P>0.05) affect doe weight gain in the 19, 3" and 4th weeks of pregnancy. Does mated 14-d postpartum had significantly (P<0.05) higher feed intake during the l", 2nd and 3rd weeks of pregnancy. Feed:guin ratio was higher for does mated 21 d postpartum than for other treatments. Pregnancy rate was higher in the 14-d group and lowest in the 28-d group. Willingness to mate also decreased with increasing rebreeding interval. Litter size at birth, number of kits alive at birth and up to 28 days postpartum were not affected (P>0.05) by rebreeding interval as was the case for litter birth weight and percent stillbirths. Does mated 14 days postpartum however, had numerically more kits alive at birth and up to 28 days postpartum than the other groups. Litter weights were slightly higher for does mated 14 and 21 days postpartum than 28 days. It is concluded from this study that mating does 14 days postpartum under tropical conditions could increase the number of kits weaned per doe and hence increase profitability of the rabbit production enterprise. 

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 Biological efficiency of Charolais beef cows of different body sizes

2018 ◽  
Vol 39 (4) ◽  
pp. 1737
Author(s):  
Gustavo Duarte Farias ◽  
Liliane Cerdótes ◽  
Ricardo Zambarda Vaz ◽  
João Restle ◽  
Marcia Ferreira Bitencourt ◽  
...  
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
Reproductive Period ◽  
Productive Efficiency ◽  
The Body ◽  
Biological Efficiency ◽  
Average Weight ◽  
Pregnancy Diagnosis ◽  
Cow Calf ◽  
Weight Groups

This study aimed to evaluate the production, reproductive performance, and productive efficiency of predominantly Charolais cows and their calves (Straightbred, ¾ C, ¼ N) according to body size at calving. Sixty-three cow-calf pairs were used and classified into three weight groups: Light (331.3±5.8 kg), Moderate (385.9±5.3 kg), and Heavy (424.4±6.2 kg). The classes were formed using half standard deviations above or below the average weight of the cows at calving. For each pair, the body weight was evaluated at calving, at weaning (63 days), at the beginning and at end of the reproductive period, and at 9 months for the calves. Pregnancy rates were similar (P > 0.05) between weight groups. The calves did not differ (P > 0.05) in terms of body weight and weight gain from calving until pregnancy diagnosis (210 days). The heavy cows had greater weight variations from 210 days to 270 days than the light cows. The calf production rate (kg calf/cow kept in herds) did not differ between weight groups. However, in relation to the weight of the cows at 210 days, light cows were 11.28% and 13.02% more productive (P < 0.05), than moderate and heavy cows, respectively. Light cows were more efficient than the other classes of cows at calving and at 210 days old. Our simulations showed that there were more kilograms for sale in herds of light cows (53.085 kg) than moderate and heavy cows (52.310 and 52.870 kg, respectively), while maintaining the structures of the herd constant. The size of the Charolais cow did not influence the weight of calves from calving until 7 months of age or their reproductive performance provided they were weaned early. The need for space for the maintenance of the cow-calf pair increased as the weight of the cows increased. In herds with smaller cows, higher numbers and a higher production of weight for sale are observed than in herds with moderate and heavy cows. Light cows were the most efficient at calving and during pregnancy diagnosis at 210 days.

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

Using blup to estimate responses est a sheep flock selected for litter size

1993 ◽  
Vol 1993 ◽  
pp. 105-105
Author(s):  
G.E. Pollott
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Reproductive Traits ◽  
Phenotypic Variance ◽  
Sheep Flock ◽  
Sheep Population ◽  
Important Contributor ◽  
Selection Experiments ◽  
Genetic Trends

The reproductive performance of ewes is an important contributor to flock profitability in many different situations. Although the heritability of reproductive traits is low there is often enough phenotypic variance to make a consideration of selection a possibility for improvement in litter size. Genetic trends in selection experiments have traditionally been monitored using a control flock which should be kept as an unseletced group. The recent availability of user friedly BLUP programs have added an extra method for estimating genetic trends. This paper reports the use of BLUP to estimate the genetic trends in a sheep population selected for litter size.

Estrous length, pregnancy rate, gestation and parturition lengths, litter size, and juvenile mortality in the domestic cat

1995 ◽  
Vol 31 (5) ◽  
pp. 429-433 ◽  
Author(s):  
MV Root ◽  
SD Johnston ◽  
PN Olson
Keyword(s):  
Pregnancy Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Domestic Cat ◽  
Gestation Length ◽  
Juvenile Mortality ◽  
Induction Of Ovulation ◽  
Percent Mortality

Reproductive performance in a feline research colony of 14 queens is reported. Average estrous length in 38 cycles was 5.8 +/- 3.3 days, with a range of two to 19 days. Estrous length in 23 bred cycles was not shorter (p greater than 0.05) than in 15 nonbred cycles, suggesting that induction of ovulation does not decrease estrous length. Pregnancy rate in 23 bred cycles was 73.9%. Gestation length averaged 66.9 +/- 2.9 days with a range of 62 to 71 days (n = 15). Average parturition length was 16.1 +/- 14.3 hours (n = 7), with a range of four to 42 hours. Litter size ranged from one to five kittens, with an average of 3.7 kittens per litter (n = 15). Percent mortality by eight weeks of age was 29.1%, with 4.7% stillbirths.

Reproductive performance over repeated parities of lines of mice selected for appetite, lean growth and fatness

1986 ◽  
Vol 42 (3) ◽  
pp. 397-410 ◽  
Author(s):  
F. D. Brien ◽  
W. G. Hill
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Lean Mass ◽  
Reproductive Performance ◽  
Late Pregnancy ◽  
Reproductive Rate ◽  
Lean Growth ◽  
Implantation Sites ◽  
Average Total Number ◽  
Post Implantation

ABSTRACTFemale reproductive performance over four parities was studied for lines of mice selected for one three criteria: appetite (A), total lean mass (P), or proportion of fat (F). Female mice were first bred 8 weeks of age, and thereafter at intervals of about 7 weeks until fourth parity when they were dissected in late pregnancy to measure components of litter size.The high A lines had higher litter sizes at the first three parities and higher ovulation rates, numbers of implantation sites and live foetuses at the fourth parity than the low A lines. The high P lines were also higher than the low P lines for each of these traits. In contrast, litter sizes and ovulation rates differed little between the high and low F lines. Fitting body weight as a covariate removed the high-low differences in ovulation rate and litter size between the P lines, but not all the differences between the A lines.Pre-implantation survival at the fourth parity was slightly lower in the high than in low A and in high than in low P lines. Differences in post-implantation survival were very small. No component of prenatal survival differed substantially at fourth parity between the high and low F lines.Differences in fertility at each parity and the percentages of females surviving to the end of the study were small. At each litter, dams of the high A lines produced heavier total weights of litters at 12 and 21 days than dams of the low A lines and the corresponding high-low differences in the P lines were larger. There were only small differences in these traits between the F lines. When litter size, fertility and survival were summed over parities, the average total number of young produced per female was substantially higher in the high than in the low A lines (5·0 young born alive or dead) and the P lines (7·2), but the high-low difference was small in the F lines (2-0). For all lines, litter size at first parity gave a reliable indication of reproductive rate during a major portion of the reproductive lifespan.

Effect of vitamin E on reproductive function in the mice treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin*

2008 ◽  
Vol 24 (9) ◽  
pp. 595-601 ◽  
Author(s):  
JP Xu ◽  
YP Yin ◽  
XQ Zhou
Keyword(s):  
Body Weight ◽  
Vitamin E ◽  
Survival Rate ◽  
Sex Ratio ◽  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Control Group ◽  
Group Iii ◽  
Group I ◽  
Experimental Group

The study was conducted to determine the effects of vitamin E on reproductive performance in mice treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The 75 female and 40 male mice were randomly assigned into five groups. The levels of both TCDD and vitamin E given by gavage were 0 and 0 (Control group), 100 and 0 (experimental group I), 100 and 20 (experimental group II), 100 and 100 (experimental group III), and 100 ng/kg/day and 500 mg/kg/day (experimental group IV), respectively. Males and females were mixed to mate at the ratio of 1:2 after 4-week experiment. The gavage treatments were continued until the end of gestation in female mice after mating. The results showed that the litter number, survival rate, and body weight at birth of offspring in experimental group I had significantly decreased, and the females’ pregnancy rate and pup sex ratio in experimental group I had the decreasing tendencies when compared with the control group. The litter number in experimental group III, survival rate in experimental group II and III, body weight at birth in experimental group III and IV exhibited significant increase compared with experimental group I. The female pregnancy rate in both experimental group III and IV recovered to 100%, but there were no significant differences when compared with experimental group I. The pups’ sex ratio had a gradually increasing tendency with increase of vitamin E level, but there was no significant difference among experimental group I–IV. The results suggest that TCDD could induce reproductive toxicity in mice, whereas vitamin E alleviated adverse effects on reproductive performance in mice caused by TCDD.

scholarly journals Correlated responses to selection for large body size in oMt1a-oGH transgenic mice: reproductive traits

2000 ◽  
Vol 75 (2) ◽  
pp. 199-208 ◽  
Author(s):  
K. R. PARKS ◽  
E. J. EISEN ◽  
I. J. PARKER ◽  
L. G. HESTER ◽  
J. D. MURRAY
Keyword(s):  
Body Weight ◽  
Transgenic Mice ◽  
Reproductive Performance ◽  
Large Body ◽  
Low Frequency ◽  
High Growth ◽  
Reproductive Traits ◽  
Correlated Responses ◽  
Term Selection ◽  
Transgenic Lines

Correlated responses in female reproductive performance were evaluated following short-term selection within full-sib families for increased 8-week body weight in two replicates of four lines of mice: two ovine metallothionein–ovine growth hormone (oMt1a-oGH) transgene-carrier lines, one from a high-growth background (TM) and one from a control background (TC), and two non-transgenic lines, one from each of these genetic backgrounds (NM and NC, respectively). A fifth line (CC), not containing the transgene, served as a randomly selected control. The initial frequency of the oMt1a-oGH transgene construct in the TM and TC lines was 0·5. The frequency of transgenic females sampled at generations 7 and 8 of selection was 84·0% and 6·1% in the TC and TM lines, respectively. No significant female infertility differences were detected between transgene-carrier and non-transgenic lines or between transgenic and non-transgenic mice within carrier lines, whereas high-growth background lines had a higher infertility than control background lines (P < 0·05). Correlated responses in the TC transgene-carrier line were suggestive of reduced reproductive performance as indicated by increased post-implantation mortality (P < 0·05), number of dead fetuses plus implants (P < 0·05), and loss of fetuses from day 16 to parturition (P < 0·001). For the first two traits, the negative correlated responses were accounted for by the reduced performance of transgenic compared with non-transgenic females. Embryos carrying the transgene may also have a lower viability. In contrast, the NC non-transgenic line did not exhibit reduced reproductive performance for these traits. The low frequency of the transgene in the high-growth background TM line was associated with reduced fitness and a lower additive effect for 8-week body weight compared with the control background TC line.

scholarly journals Effects of BF Gene Polymorphism on the Reproductive Performance of Hybrid Polish Landrace X Polish Large White Sows

2016 ◽  
Vol 66 (1) ◽  
pp. 125-131
Author(s):  
Dorota Napierała ◽  
Maria Kawęcka ◽  
Eugenia Jacyno ◽  
Beata Matysiak ◽  
Anita Kołodziej-Skalska
Keyword(s):  
Gene Polymorphism ◽  
Litter Size ◽  
Reproductive Performance ◽  
Reproductive Traits ◽  
Specific Primers ◽  
Large White ◽  
Potential Relationship ◽  
Pcr Rflp

AbstractThe aim of this study was to determine the potential relationship between variants of the BF gene and litter size in Polish Landrace x Polish Large White sows. To identify polymorphism within the BF gene, the PCR-RFLP method was applied, using specific primers and the SmaI enzyme. The researchers identified the presence of two alleles, T and C, with frequencies: 0.68 and 0.32, giving three genotypes with frequencies: 0.49, 0.37 and 0.14, respectively for TT, TC and CC. Analysis of relationships between the various genotypes of the BF gene and selected reproductive traits showed significant differences. Sows with TT genotype in the BF locus, gave birth to significantly more live piglets in the first litter (10.24) compared with sows with the CC genotype (7.13).

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