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PubMed1976

An evaluation in rats of nutritional status and reproduction performance post oral contraceptive therapy.

Adult female rats were orally administered either 0.052, 0.26 mg of Enovoid E (OC) or the vehicle, propylene glycol. Thereafter they were mated six, thirteen or twenty-seven days after the discontinuation of the drug. Chemical analyses i.e. cholesterol levels in plasma, liver and adrenals; tocopherol levels in plasma and liver; fatty acid patterns of cholesteryl esters of plasma liver, and adrenals, and plasma lipoproteins distribution, were performed on the pre-breeding (post-OC) females, mothers (following weaning of the young) and young female progeny, 10 weeks after weaning. Weanlings derived from mothers previously exposed to OC weighed more than their counterparts from mothers who had not been given the drug. A slight decrease of the survival time of the young during lactation was also observed in groups treated with higher levels of OC. Liver weights were increased in mothers as a result of pregnancy and lactation. Observed elevations of plasma cholesterol levels and cholesteryl arachidonate in the livers of the progeny were probably due to prolonged exposure to the 15% corn oil diet. In addition, previously reported metabolic effects of OC, such as increases in liver cholesteryl oleate, decreases in plasma and adrenal cholesteryl arachidonate, decreases in the alpha/beta lipoprotein ratio and alpha-tocopherol levels in plasma were confirmed.

Adrenal Glands↗

PubMed1992

Etiologic factors of recurrent abortion and subsequent reproductive performance of couples: have we made any progress in the past 10 years?

OBJECTIVES: We hypothesize that the diagnostic yield and pregnancy outcomes of patients with recurrent abortion have improved over the past 10 years. STUDY DESIGN: The study was performed in an academic medical center. Diagnoses and outcomes for group A, a published series of 100 patients investigated for recurrent abortion in the section between 1968 and 1977, was compared with those for group B, the 131 patients seen between 1987 and 1991. A standardized protocol was followed, enhanced by new techniques and autoimmune investigations in the latter group. Results were compiled retrospectively. Descriptive statistics and chi 2 analysis were used. RESULTS: No cause could be found in 37% of patients in group A compared with 24% of couples in group B (p less than 0.05). No clear difference could be shown in the subsequent outcomes of pregnancies. CONCLUSIONS: Our ability to establish a cause of recurrent abortion has improved slightly over the past 15 years. The gain is not yet reflected in successful pregnancy rates. Multicenter trials are indicated.

Abortion, Habitual↗

PubMed2002

Effect of mating frequency on sow reproductive performance under field conditions and natural mating in large outdoor production units.

The effect of mating frequency on fertility and litter size of sows, kept in outdoor production systems was investigated. Sows that were mated once or twice during a single oestrus were included in the study to compare the effect of number of matings on farrowing rate and litter size. Natural mating was used during the study period. Four groups of sows of parity two or more were either mated once 28-30 h after the onset of oestrus or were mated 28-30 h after the onset of oestrus and again 24 h later. The farrowing rate did not differ significantly between single- and double-mated sows, although a noticeable but non-significant depression in farrowing rate was evident between the groups of single-mated and double-mated animals. With the exception of total-born litter size (p > 0.05), the total number born and number of live-born piglets per litter were significantly (p < 0.05) lower in the group of sows that received only one mating compared with the double-mated animals. The implication of these results is that the double mating by natural service of sows kept in an outdoor production systems may improve litter size.

Animals↗

PubMed2001

Reproductive performance of ewe lambs from ewes from different selection practices with or without induced estrus.

Three groups of ewe lambs born in May (experiment 1; n=211) or April (experiment 2; n=174) were used to evaluate the effects of selection line and induction of estrus on pregnancy rate. Experiment 1 was a single factor experiment with induction of estrus as the main effect. In early December, May-born Targhee (n=82) and Rambouillet x Targhee (n=129) ewes were randomly assigned within body weight to one of two treatment groups: control or induction of estrus. Experiment 2 was designed in a 2x2 factorial array with the main effects of induction of estrus or selection line. In early November, April-born Targhee lambs (n=174) from two distinct selection lines were either treated as controls or received an estrus induction treatment. The two lines included an unselected control line of randomly bred ewes and a line that had been selected since 1976, based on the weight of lamb weaned. Ewes from each line were randomly assigned within body weight to one of the treatment groups. In experiments 1 and 2, estrus was induced using MAP pessaries. Pessaries were inserted for 12 days. At the time of pessary removal, ewe lambs received 400 IU eCG i.m. All ewe lambs were bred in multi-sire pens. Pregnancy rate and fetal numbers were determined either by lambing data or real-time ultrasound. Body weight, lambing date and fetal numbers were analyzed by GLM, and remaining variables were analyzed by CATMOD. For experiment 1, estrus induction increased (P<0.01) pregnancy rates (61 versus 31%) and number of fetuses estimated by real-time ultrasound (79 versus 35%) compared to control ewe lambs. Pregnancy rate and fetal number were increased (P<0.01) for the 1st year compared to the 2nd year. For experiment 2, estrus induction tended to increase (P<0.07) pregnancy rate, and pregnancy rate differed (P<0.01) between selection lines. Estrus induction increased (P<0.05) fetal numbers (0.96) compared to controls (0.77). Fetal numbers were greater (P<0.01) for the selected line (1.06) compared to random bred controls (0.67). Average date of lambing was earlier in both experiments for the estrus-induced ewe lambs compared to controls. These results indicate that induction of estrus can be recommended if increased reproduction is desired for ewe lambs.

Administration, Intravaginal↗

PubMed1990

Effect of feeding on reproductive performance in Finnish dairy cows.

The effect of 2 types of feeding on the involution of the genital tract and on the fertility was studied in 79 Finnish dairy cows on a research farm. The cows were fed twice a day with home-produced feed in accordance with the Finnish feeding standard. The cows were divided according to the type of feed into a hay-urea group and a silage group. The cows were examined clinically by rectal palpation 3 times a week during 8 weeks postpartum. The time required for the complete involution of uterus and cervix was recorded. The cows in the silage group had a significantly longer time in uterine involution, a lower fertility rate at first insemination and a longer interval from calving to conception than those in the hay-urea group. The pregnancy rate in the first insemination was in the hay-urea group 91% and in the silage group 57%. The interval between calving and the first insemination was shorter in the hay-urea group than in the silage group: 71.4 +/- 10.6 and 74.0 +/- 10.3 days, respectively. The interval between calving and conception was in the hay-urea group significantly (p less than 0.01) shorter than in the silage group; 74.8 +/- 15.1 and 89.5 +/- 24.4 days, respectively.

Animal Feed↗

PubMed1975

Thyroxine-induced hyperthyroidism upon the reproductive performance of female rats.

L-Thyroxine (L-T4) was injected into mature rats daily at levels of 0, 3, 6, 12, 24, 48 and 96 mug/100 g body weight through estrous cycling, conception, pregnancy, parturition and 20 days of lactation. Mothers which lactated to 20 days were killed and mammary glands measured for DNA and RNA content. Those which were not able to maintain their pups were killed on the day when all pups died. Estrous cycling and pregnancy were not markedly effected by exogenous L-T4 at levels 3-96 times the normal thyroxine secretion rate in rats. After parturition the mothers on L-T4 above 12 mug did not allow the pups to suckle. As a result the pups died within 2-7 days after birth. Levels of L-T4 from 3 to 12 mug allowed lactation to progress, but survival of pups to day 20 of lactation was significantly lower than in the normal control group. The results of this study indicate that high levels of L-T4 inhibit mammary growth and mild secretion. This, in turn, results in the loss of pups, probably through depletion of prolactin as a result of higher metabolic rate due to hyperthyroidism.

Animals↗

PubMed1999

Growth hormone gene polymorphism and reproductive performance of AI bulls.

Relationships between the growth hormone gene RFLP polymorphism and bull sperm characteristics were the objects of the present study. DNA was extracted from blood or sperm samples collected from 113 AI bulls and submitted for polymerase chain reaction (PCR) followed by digestion with Alu I restriction enzyme. The bGH genotypes were visualized on 10% polyacrylamide gel. The analyzed population of AI bulls consisted of dairy (Holstein Fresian [HF] crossbred [HF x Polish Black and White]) and beef breeds (Limousine, Charolaise, Piemontese, Angus and Hereford). The frequency of the Leu allele was 0.86 among dairy bulls and 0.38 in beef bulls (0.14 and 0.62 for the Val allele, respectively). Eight sperm characteristics and Day 60 non-return rates (NRR) were analyzed. The 3 genotype groups (LL, VV and LV) and the effect of production type (dairy or beef) on sperm characteristics were considered. None of the traits showed significant variability in relation to the bGH genotype, although a tendency was observed for LL bulls to have a lower ejaculate volume and VV bulls higher NRR. Moreover some statistically significant associations with production type were noticed: beef bulls were superior in sperm concentration and non-return rate, whereas dairy bulls excelled in individual fresh sperm motility.

Animals↗

PubMed1993

Randomized field trial to determine the effects of oral selenium supplementation on milk production and reproductive performance of Holstein heifers.

A field trial was conducted to measure differences in performance between selenium-supplemented and nonsupplemented heifers on a 1,200-cow California dairy. One hundred seventeen 19- to 27-month-old Holstein heifers were randomly assigned to treatment (n = 59) and control (n = 58) groups. A federally approved, commercially available, sustained-release intraruminal selenium bolus was administered to each heifer in the treatment group. Blood samples were taken from treated and control animals to assess selenium values before and after bolus administration and again after introduction to the milking ration. Production data were obtained from an on-farm computerized record system for each heifer during her first lactation. Mean blood selenium concentrations in treated heifers were higher than those in control heifers from posttreatment day 30 until after calving. Data analyzed in midlactation and late lactation indicated no significant differences between treated and control groups in somatic cell count, days not pregnant, total milk produced, or times bred.

Administration, Oral↗

PubMed1985

Reproductive performance and mutagenic response of the wasp Bracon hebetor following treatment with the antibiotic bleomycin.

Bleomycin (BM) induced dominant-lethal genetic lesions in the gametes of both sexes of adult Bracon hebetor wasps following ingestion. This effect was demonstrated by decreased fertility in the unfertilized eggs of treated females as well as in eggs fertilized by mature sperm derived from treated males. Death in the unhatched eggs occurred prior to blastoderm formation indicating BM caused chromosome breakage. Affected ovarian cells were limited to those exposed to BM between the developmental stages of vitellogenesis and early metaphase I. Sperm-associated fertility reductions were temporary in duration with substantial reductions being observed starting on the second day following the initiation of oviposition. BM lowered general egg-formation capacity in treated females but, unlike the fertility effects, decreased fecundity was caused by somatic debility. Although the BM-induced genetic damage observed in B. hebetor was radiomimetic in nature, the time of appearance and duration of the effects did not correspond with previous patterns found when B. hebetor adults were exposed to X-rays. While the differences could be due to the BM detoxification or the repair of BM-induced chromosome damage, further investigation would be required to demonstrate the presence of such systems in this hymemopteran.

Animals↗

PubMed2005

Oregano improves reproductive performance of sows.

Natural herbs are being explored as alternatives to antimicrobials. The objective of the present study was to determine the effect of strategic addition of oregano to prefarrowing and lactation diets of sows under field conditions. Alternate farrowing groups were given diets containing 1000 ppm oregano (dried leaf and flower of Origanum vulgare, enriched with 500 g/kg of cold-pressed essential oils of O. vulgare) in prefarrowing and lactation diets. Overall, 801 oregano-treated sows, including 601 primiparous and 1200 multiparous (parity 2.99 +/- 0.43, mean +/- S.E.) and 1809 untreated control sows (705 primiparous and 1104 multiparous; parity 3.04 +/- 0.38), were used. Sows fed oregano had lower annual sow mortality rate (4.02 +/- 0.4% versus 6.92 +/- 1.11%, mean +/- S.E.; P = 0.003), lower sow culling rate during lactation (8.01 +/- 1.11% versus 14.02 +/- 1.33%, P = 0.02), increased farrowing rate (77.02 +/- 2.31% versus 69.91 +/- 2.32%, P = 0.01), increased number of liveborn piglets per litter (10.49 +/- 1.5 versus 9.95 +/- 1.22, P < 0.05), and decreased stillbirth rate (0.909 +/- 0.01 versus 0.807 +/- 0.01, P = 0.05). In addition, multiparous sows fed oregano had higher (P = 0.04) daily voluntary feed intake compared to non-treated sows (7.7 +/- 0.32 kg versus 7.0 +/- 0.42 kg, P = 0.04). Additional studies are needed to elucidate the effects of oregano on the gastrointestinal, immune and urogenital system in swine and to determine if it has any adverse effects.

Abortion, Veterinary↗

PubMed1991

Seasonal influence on the reproductive performance of swine in the humid zone of Ghana.

Relationships between month and climatic factors (ambient temperature, relative humidity, RH, and rainfall) with litter size, conception rate, days from weaning to conception and mortalities at birth and preweaning were studied in large white pigs under research station (RS) and commercial farm (CF) conditions. In RS and CF 868 and 572 farrowing records, respectively, were involved. Litter size was almost evenly distributed in all months of the year, at both farms, despite significant (P less than 0.05) negative but low correlations between litter size and maximum (r = -0.272, RS) and minimum (r = -0.233, CF) temperatures in the month after conception. There were no significant differences in conception rate between months. However under RS conditions there were significant (P less than 0.05) correlations between minimum temperature and conception rate in the months prior to (r = -0.362) and at conception (r = -0.221). Days from weaning to conception were bimodally distributed with peak values occurring between January and June and October and December. Significant mortality at birth (P less than 0.05) and preweaning was generally highest in the cold rainy months of May to October. However, only under CF conditions were there significant correlations between minimum temperature in the month of birth and percentage mortalities at birth (r = -0.217) and preweaning (r = -0.250). Rainfall and RH had no significant (P greater than 0.05) correlation with birth and preweaning mortalities.

Animals↗

PubMed1997

Reproductive performance of cows mated to and preweaning performance of calves sired by Brahman vs alternative subtropically adapted breeds.

Comparisons involving Brahman and Brahman-derivative (Brangus, Santa Gertrudis, Beef-master, Simbrah, Braford) sires indicate the following: 1) cows mated to Brangus and Santa Gertrudis bulls had a shorter gestation length than cows mated to Brahman bulls, 2) calves sired by Brangus and Beefmaster bulls were lighter at birth and weaning than calves sired by Brahman bulls, and 3) birth and weaning weights were similar for calves sired by Santa Gertrudis and Brahman bulls and for calves sired by Simbrah and Brahman bulls. Comparisons involving Brahman and other Zebu (Sahiwal, Nellore, Gir, Indu-Brazil, Boran, Romana Red) sires indicate that gestation length was slightly longer for cows mated to Sahiwal and Nellore bulls and that, relative to the Brahman, birth and weaning weights were similar to or lighter for calves sired by bulls of the other Zebu breeds. The only exception to this pattern was birth weight of Indu-Brazil-sired calves, which were heavier than calves sired by Brahman bulls. Comparisons involving Brahman and non-Zebu subtropically adapted (Tuli, Senepol) sires indicate that cows mated to Tuli bulls had a slightly shorter gestation length than cows mated to Brahman bulls and that birth and weaning weights of calves sired by Tuli and Senepol bulls were lighter than those of calves sired by Brahman bulls.

Adaptation, Physiological↗

PubMed2004

Heterogeneity in stable isotope profiles predicts coexistence of populations of barn swallows Hirundo rustica differing in morphology and reproductive performance.

Population studies assume that individuals belonging to a study population are homogeneous for natal and breeding origin, although this assumption is rarely tested. We tested for heterogeneity in stable-isotope profiles (delta15N, delta13C, deltaD) of feathers grown in the African winter quarters from a Danish breeding population of adult barn swallows, Hirundo rustica. Deuterium isotope values did not provide useful information on population segregation of wintering swallows in Africa. However, both delta15N and delta13C values showed a clearly bimodal distribution with 6% belonging to one category and the remaining birds belonging to another category, resulting in this population comprising three categories of birds. Adults belonging to the two categories of delta13C isotope profiles differed weakly in morphology for several different characters. The frequency and the size of second broods differed between categories of delta13C isotope profiles. Phenotypes of nestlings from the first brood in terms of tarsus length, body mass and T-cell response differed significantly between the two delta15N isotope categories, suggesting that conditions during winter carried over to the breeding season at least as late as the first brood. Polymorphism can be maintained only if fitness is similar for birds from categories of isotope profiles. We suggest that fluctuating selection or migration-selection balance may maintain the observed polymorphism.

Analysis of Variance↗

PubMed2005

A cross-sectional study of reproductive performance of smallholder dairy cows in coastal Tanzania.

A retrospective cross-sectional study was conducted on 200 randomly selected smallholder farms from a mixed dairy farming system in Tanga, Tanzania, between January and April 1999. We estimated the frequency and determinants of long calving interval (LCI), retention of fetal membrane (RFM), dystocia, and abortion in smallholder crossbred cattle and explored birth trends. The mean calving interval was 500 days and birth rate was 65 per 100 cow-years. Dystocia was reported to affect 58% of calvings, and 17.2% of animals suffered RFM. Using mixed effect models, the variables associated with LCI, RFM and dystocia were breed, level of exotic blood and condition score. Zebu breeding was associated with LCI (odds ratio (OR) = 2.3, p = 0.041) and Friesian breeding with lower odds for RF (OR = 0.26, p = 0.020). Animals with higher levels of exotic blood had lower odds for evidence of dystocia (OR = 0.45, p = 0.021). Evidence of dystocia was significantly associated with poor condition score (p = -1.10, p = 0.001). Our observations suggest that LCIs are common in smallholder dairy farms in this region and a likely source of economic loss. Dystocia, RFM, poor condition score and mineral deficiency were common problems and were possibly linked to LCI.

Animal Husbandry↗

PubMed1984

Reproductive performance in dairy cows following postpartum treatment with gonadotrophin releasing hormone and/or prostaglandin: a field trial.

Three hundred and five Holstein Friesian cows were given either 250 micrograms gonadotrophin releasing hormone (GnRH) or saline on day 15 postpartum followed by 500 micrograms cloprostenol or saline on day 24 postpartum. Four treatment groups were formed using random allocation: Group I -- placebo (Day 15)/placebo (Day 24), Group II -- GnRH (Day 15)/placebo (Day 24), Group III -- placebo (Day 15)/cloprostenol (Day 24), Group IV -- GnRH (Day 15)/cloprostenol (Day 24). Double blind techniques were used during the follow-up period. Rectal palpation, to assess uterine involution and ovarian activity was performed just prior to each treatment and again at 28 days postpartum. In addition blood samples were collected at 15, 24 and 28 days postpartum for measurement of plasma progesterone. There were no significant differences among treatment groups with respect to services per conception, number of heats detected before first service and culling for infertility. Cows treated only with GnRH had an increased calving to first estrus and calving to first breeding interval, and tended to have an increased calving to conception interval. Treatment with cloprostenol significantly decreased calving to conception and calving to first observed estrus intervals. Treatment with GnRH on day 15 postpartum resulted in a significant increase in the subsequent incidence of pyometra and prebreeding anestrus. On the other hand, cloprostenol treatment on day 24 postpartum resulted in a decreased incidence of pyometra, regardless of GnRH treatment and a decreased incidence of prebreeding anestrus in GnRH treated cows compared to cows receiving only GnRH at day 15 postpartum.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2005

Within-farm variability in age structure of breeding-female pigs and reproductive performance on commercial swine breeding farms.

This study investigated relationships between herd age structure and herd productivity in breeding herds; it also investigated a pattern in parity proportions of females over 2 years and its relationship with herd productivity in commercial swine herds. This study was based on data from 148 commercial farms in North America stored in the swine database program at the University of Minnesota. The primary selection criterion was fluctuations in breeding-female pig (female) inventories over a 2-year interval. Productivity measurements and parity proportions of females were extracted from the database. A 24-month time-plot in proportions of Parity 0 and Parities 3-5 females (mid-parity) was charted for each farm. Using these charts, a change in proportions of Parity 0 and mid-parity for each farm was categorized into patterns: FLUCTUATE (Parity 0 and mid-parity proportion lines crossed) or STABLE (the two proportion lines never crossed). Higher proportions of mid-parity sows were correlated with greater pigs weaned per female per year (PWFY; P < 0.01). Farms with a FLUCTUATE (73% of the 148 farms) pattern had lower PWFY than those with a STABLE pattern (P < 0.01). The STABLE farms had higher proportions of mid-parity sows, higher parity at culling, higher frequency of gilt deliveries per year, and lower replacement rate than the FLUCTUATE farms (P < 0.01). In conclusion, maintaining stable subpopulations with mid-parity and Parity 0 are recommended to optimize herd productivity.

Aging↗

PubMed1984

Effect of low and high fill diets on dry matter intake, milk production, and reproductive performance during early lactation.

Feedstuffs analyzed for rate and extent of ruminal neutral detergent fiber disappearance were used to formulate two diets that differed for predicted time required for ruminal clearance of neutral detergent fiber. Diets with slow and fast estimated disappearance rate of neutral detergent fiber were termed and high and low fill, respectively. For both diets, crude protein, acid detergent fiber, neutral detergent fiber, net energy of lactation, and soluble protein were similar. Twenty-eight lactating cows were limit fed the rations 2 wk prior to calving, then fed for ad libitum consumption until 8 wk after calving. Cows fed low fill produced more milk (30.3 vs. 26.3 kg) and milk protein (.97 vs. .78 kg) and had higher incidence of short estrous cycles and fewer acyclic cows by 8 wk postpartum than cows offered high fill. Dry matter intake, fat-corrected milk yield, daily fat production, and solids-not-fat did not differ between diets. Rumen fermentation measurements for pH and ammonia-nitrogen concentrations were also not different between diets. Cows fed low fill tended to have higher rates of solids and liquid turnover and lower total dry matter in the rumen compared with cows fed high fill. Low ruminal pH on both diets as well as other physiological mechanisms may have been responsible for failure of rates of neutral detergent fiber disappearance to affect intake of dry matter.

Animals↗

PubMed1996

Effects of dietary exposure to fumonisins from Fusarium moniliforme culture material (M-1325) on the reproductive performance of female mink.

Adult female mink (Mustela vison) were fed diets that contained Fusarium moniliforme culture material that provided low- or high-dose dietary concentrations of 86 or 200 ppm fumonisin B1, 22 or 42 ppm fumonisin B2, and 7 or 12 ppm fumonisin B3, respectively, from approximately two weeks prior to breeding through gestation and lactation. Breeding performance of the females was not affected by consumption of the fumonisin diets. However, 58% of the mated females fed the high-dose diet (254 ppm total fumonisins) whelped compared to 100% of those fed the control and low-dose diets (115 ppm fumonisins). There was a statistically significant, dose-dependent decrease in kit (young mink) body weights at birth and a notable, but non-significant, decrease in litter size. The percentage of stillborn kits was directly proportional to the concentration of fumonisins in the dams' diets. Fumonisin concentrations in milk collected from those fed the high-dose diets were approximately 0.7% of the dietary fumonisin concentrations. Lactational exposure to fumonisins did not significantly decrease kit survival from birth through three weeks of age. Hepatic cell vacuolation was present in 25% of the control and 80% of the high-dose adults. No treatment-related gross or histologic lesions were observed in the kit mink. Numerous differences in hematologic and serum chemical parameters were noted between the control and fumonisin-exposed mink.

Administration, Oral↗