EFFECTS OF EXPOSURE TO BULLS AND BODY WEIGHT ON REPRODUCTIVE PERFORMANCE IN BEEF HEIFERS

1985 ◽  
Vol 65 (1) ◽  
pp. 31-36 ◽  
Author(s):  
M. MAKARECHIAN ◽  
A. FARID ◽  
R. T. BERG
Keyword(s):  
Body Weight ◽  
Pregnancy Rate ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Control Group ◽  
Group Effect ◽  
Beef Heifers ◽  
Heavy Body ◽  
Breed Group ◽  
Calving Season

Calving records of 174 2-yr-old heifers from four breed groups; Hereford (HE), Beef Synthetic (SY), Dairy Synthetic (SD) and Crossbred Hereford (HX) were used in this study. Half of the heifers were exposed to three epididymectomized bulls for 6 wk before the start of the breeding season. While exposure to bulls had little influence (P = 0.51) on pregnancy rate, it advanced the calving date by 5.5 days compared with the control group (P < 0.05). Calving season in the exposed heifers was 2 wk shorter than that in the control group. Effect of heifer body weight at the start of breeding season on pregnancy rate differed (P < 0.05) among the four breed groups. Low body weight at mating was associated with lowered fertility in SY, SD and HE while very heavy body weight resulted in lowered fertility in SY and SD breed groups. Increase in body weight advanced calving date in the HX breed group only. Key words: Beef cattle, heifer reproduction, bull exposure, body weight

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 Difference in Body Weight at Breeding Affects Reproductive Performance in Replacement Beef Heifers and Carries Consequences to Next Generation Heifers

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2800
Author(s):  
Ramanathan K. Kasimanickam ◽  
Vanmathy R. Kasimanickam ◽  
Madison L. McCann
Keyword(s):  
Body Weight ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Production Traits ◽  
Next Generation ◽  
Beef Heifers ◽  
Balanced Diet ◽  
Reproductive Indices

Nutrition imprinting carries consequences across generations. The effect of 55% vs. 65% of mature cow body weight (MBW; 545 kg) at breeding on the reproductive performance of heifers and their offspring was investigated. Angus-cross dam heifers were randomly fed to attain 55% (n = 1622) vs. 65% (n = 1578) of MBW, and offspring (F1) heifers born to dam heifers [55% (n = 1285) vs. 65% (n = 1324)] were fed to attain 65% of MBW. Bodyweight and reproductive indices were recorded throughout the study. In dam heifers, puberty (44% vs. 53%), breeding season pregnancy (86.4% vs. 90.6%) and 21-day calving rates (55.2% vs. 65.4%) did vary, but dystocia rate (8.7% vs. 9.0%) did not differ between 55% and 65% MBW groups. Puberty (49.2% vs. 58.2%), breeding season pregnancy (87.2% vs. 92.8%) and 21-day calving rates (53.8% vs. 64.1%) did differ (p < 0.05), but dystocia rate (8.4 vs. 9.2%) did not differ between F1 heifer groups. In conclusion, 55% of MBW at breeding negatively affected the reproductive performance of heifers and its offspring heifers. The recommendation is to feed heifers a balanced diet to reach 65% of MBW at breeding with consideration of production traits.

scholarly journals VARIATIONS IN AND RELATIONSHIPS BETWEEN REPRODUCTIVE PERFORMANCE AND GROWTH PARAMETERS IN YEARLING BEEF BULLS IN SINGLE-SIRE MATING AT PASTURE

1989 ◽  
Vol 69 (1) ◽  
pp. 39-46
Author(s):  
A. FARID ◽  
M. MAKARECHIAN ◽  
R. T. BERG ◽  
M. A. PRICE
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Pregnancy Rate ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Growth Parameters ◽  
Reproductive Traits ◽  
Phenotypic Variance ◽  
Breed Group ◽  
Beef Bulls

Yearling bull fertility, measured as pregnancy rate, percentage of calves born during the first 4 and 6 wk of calving and mean and median of calving date distribution, were studied in 109 single-sire breeding herds of two breed groups over a 10-yr period. The breed groups were Herefords bulls mated to purebred and crossbred Hereford cows, and Beef Synthetic bulls mated to Beef Synthetic cows. The bulls averaged 14 mo old at the start of breeding. The average bull-to-cow ratio was approximately 1:22, and the breeding season started on 1 July each year and extended for 60 d. Two out of 109 bulls (1.8%) were subfertile (less than 50% pregnancy of the herd). The Beef Synthetic, which had crossbred foundation, had significantly higher fertility, calved earlier, had smaller phenotypic variance, and lower year-to-year fluctuation in the reproductive traits than the Hereford. Variations in reproductive performances of bulls of the same breed group used in the same year were much larger than those among different years, the former comprised over 75% of phenotypic variance of the traits in the two breed groups. Relationships between fertility of bulls and their weight and growth parameters were negligible, but bull fertility tended (P < 0.10) to improve with age. Bulls that were heavy at weaning, end of feedlot test and breeding settled their mates earlier during the breeding season. Key words: Beef cattle, yearling bull, fertility

110 EFFECT OF MELATONIN TREATMENT ON LIBIDO AND ENDOCRINE FUNCTION OF DROMEDARY CAMEL BULLS OUT OF THE BREEDING SEASON

2017 ◽  
Vol 29 (1) ◽  
pp. 163 ◽  
Author(s):  
A. Swelum ◽  
I. Saadeldin ◽  
H. Ba-Awadh ◽  
A. Alowaimer
Keyword(s):  
Breeding Season ◽  
Reproductive Performance ◽  
Repeated Measures ◽  
Endocrine Function ◽  
Gland Secretion ◽  
Control Group ◽  
Dromedary Camel ◽  
Testosterone Levels ◽  
Significant Difference ◽  
Length Changes

The reproductive performance of camels is poor and has remained a major obstacle to the growth of dromedary populations. The limited breeding season is one of the most important causes of the poor reproductive performance. In seasonal animals, melatonin is the chemical messenger that allows the perception of daylight length changes. Commercial melatonin products have been developed for the manipulation of seasonal breeding in animals. The present study aimed to evaluate the influence of melatonin implantation on libido, serum melatonin, and testosterone concentrations in dromedary camels during the non-breeding season (June and July). Ten camel bulls were used in the 35-day-long trial; 5 of them were implanted with 30 Melovine® implant (Ceva, Libourne, France) subcutaneously on Day 0, whereas the other 5 camel bulls remained untreated as a control. Libido was evaluated weekly in response to oestrous-induced female camels treated with oestrogen (1 mL Oestrocon; oestradiol benzoate 5 mg mL−1) 2 days before assessment of libido. Libido was scored as follows: 0 = not interested: the male did not show any libido; 1 = low interested: the male went near the female and showed low frequency of sniffing and flehmen; 2 = interested: the male went near the female, it showed sniffing, flehmen, grinding of teeth/whistling, yawning; 3 = high interested: the male went near the female and was very agitated, it showed sniffing, flehmen, grinding of teeth/whistling, yawning, urination, and tail raising. It stood with open legs, and poll gland secretion and neck rubbing were observed; 4 = excited, like 3, but the male showed blatering and dulaa extrusion, was very excited, stood with open legs, high poll gland secretion and neck rubbing were observed. Blood samples were collected weekly. Serum melatonin and testosterone concentrations were evaluated using commercial ELISA kits. Comparisons among groups were evaluated using repeated-measures ANOVA, using SAS software (SAS Institute Inc., Cary, NC, USA). A difference was considered significant at the P < 0.05 level. The results revealed that at Day 0, all camel bulls in 2 groups had no libido and there was no significant difference in the melatonin or testosterone levels in the 2 groups. The libido increased gradually in the melatonin group and reached the maximum (3–5) at week 4 and week 5. The control group had low libido (0–1) along the trial. Statistically, the libido was significantly higher in the melatonin group than control group. Additionally, testosterone levels were significantly higher in melatonin group than control group, especially in the fourth week of the present trial (565.07 ± 33.04 pg mL−1 and 458.49 ± 25.36 pg mL−1, respectively). In conclusion, melatonin implantation in the non-breeding season significantly improved the libido and the reproductive performance of dromedary camel bulls. Therefore, it may be possible to improve the reproductive efficiency of camels by extending the breeding season through treatment with melatonin during the non-breeding season.

EVALUATION OF BULL AND COW FERTILITY AT PASTURE IN SINGLE-SIRE MATING

1985 ◽  
Vol 65 (4) ◽  
pp. 799-809 ◽  
Author(s):  
M. MAKARECHIAN ◽  
A. FARID ◽  
R. T. BERG
Keyword(s):  
Body Weight ◽  
Pregnancy Rate ◽  
Average Daily Gain ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Low Fertility ◽  
Scrotal Circumference ◽  
Semen Volume ◽  
Calving Season ◽  
Daily Gain

Pregnancy rates and calving dates of beef cows in 27 single-sire breeding herds mated to yearling or 2-yr old bulls were used in this study. The breed groups of bulls were Hereford and Beef Synthetic and cow herds were Hereford, Hereford cross and Beef Synthetic, respectively. A week before the start of the breeding season the bulls were scored for libido, their scrotal circumferences were measured and semen samples were collected. Semen volume, sperm motility and percent normal cells were evaluated. The average bull to cow ratio was 1:20. Pregnancy rate increased as age and body weight of cows increased, but it was independent of the previous calving date. Calving date was not related to body weight or age of cow, but it was influenced by the previous calving date. Each day delay in calving after the first 5 wk of calving season resulted in a 0.7-day delay in the date of calving during the next calving season. The Beef Synthetic-sired herds had higher pregnancy rates (P < 0.05) than the Hereford-sired herds, but the average calving dates of the two groups were similar. Cows mated to 2-yr-old bulls had 5% higher (P = 0.12) pregnancy rate than those mated to yearling bulls. Five of the herds showed low fertility and late calving, probably due to low fertility of the bulls. Yearling weight and feedlot average daily gain were positively (P < 0.05) related to bull fertility. The number of services performed by a bull during a 10 min libido test and total libido score were also found to be useful in assessing bull fertility, but scrotal circumference or semen traits were not related to fertility of bulls when used in single-sire mating at pasture. Key words: Beef cattle, bull fertility, single-sire mating

The effect of zeranol implants on growth and pregnancy loss in beef heifers

1994 ◽  
Vol 74 (1) ◽  
pp. 73-76 ◽  
Author(s):  
B. D. King ◽  
R. N. Kirkwood ◽  
C. L. Guenther ◽  
R. D. H. Cohen ◽  
G. A. Bo ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Pregnancy Loss ◽  
Average Daily Gain ◽  
Fetal Loss ◽  
Live Weight ◽  
Fetal Mortality ◽  
Beef Heifers ◽  
Calf Survival ◽  
Daily Gain

Live weight, average daily gain (ADG) and reproductive performance were compared between heifers implanted with zeranol at birth, 100 and 200 d of age (n = 54) and those not implanted (n = 50). Zeranol implantation resulted in increased (P < 0.05) ADG from birth to weaning, weaning weight, ADG from weaning to breeding, breeding weight and calving weight but did not affect (P > 0.05) calf birth weights, incidence of dystocia, calf survival or gestation lengths. Zeranol implants did not affect (P > 0.05) the incidence or magnitude of the pre-ovulatory LH surge or the number of heifers that ovulated between 48 and 168 h after cloprostenol injection. Pregnancy rate 42 d after bull entry did not differ between the two groups (P > 0.10), tended toward a difference at 72 d (P < 0.10), and was different at 133 d (P < 0.05), with implanted heifers having a lower pregnancy rate than non-implanted heifers. Between day 72 and day 133 after bull entry there was a 10% embryonic or fetal mortality rate in zeranol-implanted heifers, which differed from the 0% loss in non-implanted heifers (P < 0.05). We conclude that serial implants of zeranol from birth reduced the pregnancy rate in heifers and that this effect was due to early fetal loss. Key words: Zeranol, embryonic/fetal mortality, bovine, pregnancy rate, ultrasonography

scholarly journals The reproductive performance of dairy cows with anovulatory anoestrus that were injected with either gonadotrophin-releasing hormone or oestradiol benzoate as part of a re-treatment process after insemination

2007 ◽  
Vol 78 (1) ◽  
Author(s):  
B.V.E. Segwagwe ◽  
J. Malmo ◽  
K.L. Macmillan ◽  
P.D. Mansell
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Control Group ◽  
Releasing Hormone ◽  
Start Date ◽  
Oestradiol Benzoate ◽  
Conception Rates ◽  
Gonadotrophin Releasing Hormone

This experiment compared the reproductive performance of synchronised anoestrous dairy cows that were treated initially with a combination of progesterone and oestradiol benzoate and then with either gonadotrophin-releasing hormone (GnRH) or oestradiol benzoate to resynchronise returns to service. It was hypothesised that injecting anoestrous dairy cows with GnRH 12-15 days after insemination and coinciding with the time of insertion of a controlled intravaginal progesterone-releasing (CIDR) device would increase conception rates to the preceding 1st insemination compared with oestradiol benzoate treated cows; both GnRH and oestradiol benzoate would resynchronising the returns to service of those cows that did not conceive to the preceding insemination. Groups of cows in 11 herds were presented for a veterinary examination after they had not been seen in oestrus postpartum. Those cows diagnosed with anovulatory anoestrus (n = 1112) by manual rectal palpation and / or ultrasonography were enrolled in the trial. Each enrolled cow was injected with 2mg oestradiol benzoate i.m. on Day -10, (where Day 0 was the 1st day of the planned insemination) concurrently with vaginal insertion of a CIDR device. The device inserted was withdrawn on Day -2 and then each cow injected i.m. with 1 mg of oestradiol benzoate on Day -1 unless it was in oestrus. Observation for oestrus preceded each insemination. Every cow that had been inseminated on Days -1,0,1 or 2 was presented for treatment for resynchrony on Day 14 (n=891). They were divided into 2 groups; those with an even number were each injected i.m. with 250 µg of a GnRH agonist (Treatment group n = 477); each of the cows with an odd number injected i.m. with 1mg of oestradiol benzoate (control group, n = 414). Each GnRH or oestradiol benzoate injection preceded reinsertion of a CIDR device previously inserted from Days -10 to -2. It was withdrawn on Day 22, 24 hours before injecting 1mg oestradiol benzoate. Cows observed in oestrus were submitted for a 2nd insemination. Every enrolled cow still present in the herd was pregnancy tested by palpation of uterine contents per rectum about 6 weeks later and again at the end of a herd's seasonal breeding programme. The alternative use of GnRH instead of oestradiol benzoate did not affect the percentage of cows conceiving within 3 days of the mating start date (MSD) (35.6 %vs 35.3 %, P=0.90), resubmission rates for a 2nd insemination among cows not pregnant to the 1st insemination (81.6 % vs 83.5 %, P=0.41), 6-week pregnancy rate (59.3 % vs 60.6 %, P=0.65), 21-week pregnancy rate (86.6 vs 85.0, P=0.36), mean interval from MSD to conception (32.5 + 1.8 days vs 29.9 + 1.8 days, P = 0.26) or conception rate of cows reinseminated by Day 28 (43.3 % vs 38.8 %, P=0.39). When GnRH conception rate of cows reinseminated by Day 28 (43.3% vs was compared with oestradiol benzoate, it did not increase conception rates to the 1st service; it was as effective as oestradiol benzoate in synchronising returns to service in previously treated anoestrous cows that did not conceive to the 1st service. Its use affected neither conception rates to the preceding 1st inseminations nor to the following 2nd inseminations.

Effects of melatonin implantation on the fertility potentials of Kivircik and Charollais ewes and rams during the non-breeding season

2017 ◽  
Vol 20 (3) ◽  
pp. 501-506 ◽  
Author(s):  
M. Cevik ◽  
C. Yilmazer ◽  
A. Kocyigit
Keyword(s):  
Pregnancy Rate ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Reproductive Potential ◽  
Testicular Volume ◽  
Melatonin Treatment ◽  
Scrotal Circumference ◽  
Estrus Response

AbstractThis study examined the effect of melatonin implantation during the non-breeding season on the reproductive performance of ewes and the testicular dimensions of rams. In seasonally anestrus Kivircik and Charollais ewes and rams were subjected to melatonin. Estrus response was significantly higher in treated than control ewes of both breeds (p<0.001). The pregnancy rate was significantly lower (p<0.001) in the control than in the treated animals. The twinning rate was significantly lower in melatonin implanted Kivircik than Charollais ewes (p<0.05). The testicular dimensions after 42 days of melatonin treatment increased in both breeds. Scrotal length (SL) increased in Kivircik and Charollais rams (p<0.01). The increase in scrotal circumference (SC) was more marked in the Charollais (P<0.01) than in the Kivircik rams. There was a large increase in testicular volume (TV) in both Kivircik (p<0.01) and Charollais (p<0.001) rams. This study shows that melatonin implants can be applied to induce estrus in ewes approximately four months earlier than breeding season. Melatonin implantation in the non-breeding season significantly increased testicular dimensions in Kivircik and Charollais rams thus increasing their reproductive potential.

Effects of a growth implant and age of dam on growth and fertility in heifer calves

1994 ◽  
Vol 74 (2) ◽  
pp. 203-208 ◽  
Author(s):  
L. M. Rutter ◽  
P. A. Day
Keyword(s):  
Treatment Group ◽  
Pregnancy Rate ◽  
Field Trial ◽  
Average Daily Gain ◽  
Beef Heifers ◽  
Pelvic Area ◽  
Calving Season ◽  
Growth Implant ◽  
Calving Difficulty ◽  
Daily Gain

A field trial was conducted to determine the effects of a growth implant on growth, pregnancy rate, calving difficulty and calf weaning weight in replacement beef heifers. Heifers were assigned equally to either a control (n = 43; no implant), Ralgro (n = 43) or Synovex-C (n = 42) treatment group based on age of dam and age and weight at the start of the trial (implantation at 45–90 d of age). Neither Ralgro nor Synovex-C enhanced heifer weight or average daily gain (ADG) from the start of the trial to weaning (approximately 7 mo of age), breeding, or pregnancy determination. At breeding, Synovex-C implanted heifers had greater pelvic area than controls while Ralgro implanted heifers were intermediate (control = 149.7, Ralgro = 154.7 and Synovex-C = 157.4 pooled SE of 2.2 cm2; P = 0.05). Pelvic dimensions were similar among treatments at pregnancy determination and there were no treatment effects on calving difficulty. Age of dam affected heifer weight (P = 0.0005) and ADG (P = 0.001) to weaning, with heifers from mature cows weighing more at weaning and having a higher ADG from the start of the study to weaning than heifers from either first- or second-calf cows. Post-weaning performance of heifers from first-calf cows was similar to heifers from mature cows while heifers from second-calf cows were lighter at breeding (P = 0.04) and had a lower ADG from weaning to breeding (P = 0.04). Age of dam did not influence pregnancy rate (P = 0.10), but more heifers from second-calf cows calved late in the calving season (≥ 64 d) compared with heifers from either first-calf or mature cows (P = 0.04). It appears from this field trial that use of a growth implant between 45 and 90 d of age neither enhanced growth nor impaired fertility in beef heifers bred as yearlings. It also appears that second-calf 3-yr-olds may need to be managed separately from the mature cow herd in order to optimize replacement heifer development. Key words: Bovine, replacement heifers, growth implant, age of dam, weight, pregnancy rate

scholarly journals Effect of the Addition of Magnesium Salt to a Feed Mixture on Intestinal Microflora, Health, and Production of Sows

2013 ◽  
Vol 57 (1) ◽  
pp. 69-72 ◽  
Author(s):  
Beata Trawńska ◽  
Antoni Polonis ◽  
Jerzy Lechowski ◽  
Leszek Tymczyna ◽  
Ryszard Borowski ◽  
...  
Keyword(s):  
Body Weight ◽  
Survival Rate ◽  
Reproductive Performance ◽  
Intestinal Microflora ◽  
Alimentary Tract ◽  
Magnesium Salt ◽  
Control Group ◽  
Feed Mixture ◽  
E Coli ◽  
Newborn Piglets

Abstract The effect of feed mixture supplementation with MgCl2 on alimentary tract microflora, haematological markers, and selected parameters of reproductive performance of sows was investigated. The animals were divided into control group (K) and two experimental groups (E1 and E2). The sows from the experimental groups were receiving 1 g of MgCl2 6H20/100 kg b.w./day, which constituted 120 mg of pure magnesium, administered in a small portion of a feed mixture. The sows from group E1 were receiving MgCl2 every day for 30 d, whereas sows from group E2 for 60 d. A significant decrease in the count of E. coli, Providencia sp., and Proteus sp. was noted in faeces of the swine of both experimental groups. The study has also demonstrated a reduced number of lymphocytes and an increased number of granulocytes in blood of the sows receiving MgCl2. Feeding of pregnant sows with the addition of magnesium salt decreased the mortality rate of newborn piglets, increased the survival rate of piglets until 21 d of their life, and increased body weight values of litters originating from experimental sows, compared to the litters of control sows.

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