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PubMed1997

Comparison of ketosis, clinical mastitis, somatic cell count, and reproductive performance between free stall and tie stall barns in Norwegian dairy herds with automatic feeding.

Differences in ketosis and clinical mastitis rates, mean somatic cell counts (SCC) and reproductive performance scores (fertility status index = FS-index) between herds housed in free stall (n = 533) and tie stall (n = 59) barns were measured in relation to management and environmental factors in a retrospective cohort study of Norwegian dairy farms with automatic grain feeding systems. Herds with tie stalls were found to have a higher clinical mastitis rate, (61.6 cases per 100 cow-years versus 46.4 cases per 100 cow-years (p < 0.01)); a significantly higher proportion of herds with ketosis, (relative risk = 1.59, (p < 0.01)); and a lower mean fertility status index, (67.3 versus 82.8 (p < 0.01)). No significant difference in mean SCC was found between the 2 groups of dairies (p = 0.32). Large herds had higher Loge geometric mean SCC than small herds (p < 0.01) and herds with high SCC had lower milk production than herds with low SCC (p < 0.01). Herds that scored "very good" on cow cleanliness had significantly lower adjusted mean SCC than herds with scores of "average" or "good" (p < 0.05). Herds in barns with a concrete floor had an adjusted mean number of cases of clinical mastitis of 51.4 per 100 cow-years, 14 per cent higher than herds in barns with rubber mats, litter bed or wood (45.2 cases per 100 cow-years) (p < 0.05). Herds with high milk production level had higher FS-index than herds with low milk production (p < 0.01). Lower disease rates and the higher fertility status measured in the present study favor free stall herds over tie stall herds.

Animal Husbandry↗

PubMed1979

Induction of puberty and subsequent reproductive performance.

A trial was conducted over 3 years to evaluate the success of inducing puberty in heifers of young age and light weight and to evaluate their subsequent reproductive performance at first calving. The control heifers and the young age heifers were grown at a rate of .56 kg/day compared to .23 kg/day for the light weight heifers. Eleven days prior to the start of breeding, heifers in the young age and light weight groups received the Synchromate B treatment. Implants were removed after 9 days. Average age and weight at breeding were 407, 334 and 406 days and 266, 239 and 243 kg for control, young age and light weight groups, respectively. After a 45-day breeding season 91, 47 and 81% of the heifers in the control, young age and light weight groups, respectively, (P<.05) had been in estrus. Pregnancy rates of the heifers that came into estrus were 67, 7 and 63% for the control, young age and light weight heifers, respectively, (P<.05) at the end of the 45-day breeding season. In the control and light weight groups 95 and 79% (P<.05) of the heifers that were diagnosed pregnant calved. Postpartum interval was 24 days shorter (P<.05) in the light weight heifers suckling calves and calf survival was 16% lower (P<.01) in the light weight group compared to the control heifers.

Journal Article↗

PubMed1982

Observations on the use of human chorionic gonadotrophin (HCG) during the post-insemination period on conception rates in synchronized beef cows with sub-optimum reproductive performances.

Oestrus was synchronized in 46 Afrikaner and Mashona beef cows by two injections of cloprostenol 11 days apart. All cows had a history of sub-optimum reproductive performance. Cows were inseminated up to three times after the second cloprostenol injection on the basis of observed oestrus and changes in the conductivity of cervical mucus. Half the cows received daily injections of 1000 i.u. HcG from days four to 19 after their last insemination; the other half received daily injections of 2 ml saline over the same period. Concentrations of progesterone in plasma was determined from samples taken on days 6, 8 and 22 after the last insemination. Treatment did not significantly affect conception rate and overall conception rate was 39 per cent. On day 8 after insemination none of the 8 cows that had progesterone levels of less than 1 ng/ml were pregnant when examined at day 70. Mean progesterone concentrations were not significantly different between treated and control cows on days 6 and 8, but were significantly higher (P<0,05) in treated cows by day 22. The practical significance of using HcG to stimulate luteal function in the early post-inseminaion period is discussed.

Journal Article↗

PubMed1995

The effects of low dietary copper intake during pregnancy on physiological fluids and reproductive performance of first-litter gilts.

Seven pairs of first littermate gilts were used to study the influence of low copper supply and pregnancy on physiological fluids and reproductive performance of first-litter gilts. They were fed semi-purified diets containing either 2.13 or 12.25 micrograms/kg of Cu from 30 days of gestation through two weeks of lactation. Low-Cu gilts had lower plasma Cu in early- and mid- gestation and farrowed piglets with lower plasma Cu and higher plasma Zn concentrations (p < 0.05). Plasma Fe and Mn concentrations were not affected by Cu supply (p > 0.05). Plasma Cu and Fe levels of newborn piglets were lower than those of their dams (p < 0.05) but this was not true for plasma Zn and Mn (p > 0.05). Low-Cu gilts had lower Cu and higher Zn content in colostrum and also lower Cu in milk than control gilts (p < 0.05). No significant differences were found in Fe and Mn levels in colostrum and milk between the two treatments (p > 0.05). Colostrum was richer in Cu and Zn than milk (p < 0.05) but not in Fe and Mn (p > 0.05). The low-Cu diet did not affect (p > 0.05) weight changes during pregnancy. The duration of parturition was shorter for low-Cu than for control gilts (3.19h vs. 5.71h, p < 0.05). Control gilts farrowed larger litters than low-Cu gilts (9.71 vs. 7.57 piglets, p < 0.05). There were no significant differences in live litter weights at birth, one wk. or two wks. of age (p > 0.05). The results indicated that a low-Cu diet and pregnancy had some effect on plasma, colostrum and milk mineral concentrations, as well as on litter size of gilts. An interaction between Cu and Zn was found.

Animals↗

PubMed1998

Influence of mating frequency on sow reproductive performance.

Gilts and sows were bred one, two, or three times during a single estrous period in a commercial herd for evaluating the effect of mating frequency on reproductive performance. Estrus detection started at approximately 0630 daily by applying back pressure to females with the presence of a mature boar. Natural mating was used. Gilts detected in estrus were mated in the morning of d 1 (AM), the morning of d 1 and 2 (AM-AM), and the morning and afternoon of d 1 and morning of d 2 (AM-PM-AM) for mating frequencies 1, 2, and 3, respectively. Sows were bred in the AM, AM-AM, AM-PM-AM (1), and morning of d 1 and morning and afternoon of d 2 [AM-AM-PM (2)] for mating frequency 1, 2, 3 (1), and 3 (2), respectively. Breeding events in the morning and afternoon started at approximately 0730 and 1530. Females were randomly assigned to a mating frequency. Boars were randomly assigned to each breeding event. In total, 256 gilts and 766 sows were involved in the study. Gilts with a single mating (76.5%, P = .06) and triple matings (80.4%, P < .05) had higher farrowing rates than those with double matings (65.3%). No differences (P > .1) in the farrowing rates of sows were observed between mating frequencies 1, 2, 3 (1), and 3 (2). Double-mated gilts had more (P < .03) total born (9.7 vs 8.6) and pigs born alive (9.3 vs 8.2) than did single-mated gilts. There were no differences (P > .3) in total born and pigs born alive in sows between mating frequencies. We concluded that triple-mating gilts and sows did not improve farrowing rate and litter size compared with single and double matings. There were no differences in farrowing rate and litter size between double- and single-mated sows. Gilts with double matings had a larger litter size than those with a single mating.

Animals↗

PubMed2002

Defining and diagnosing postpartum clinical endometritis and its impact on reproductive performance in dairy cows.

The objectives of this study were to validate diagnostic criteria for clinical endometritis in postpartum dairy cows and to measure the impact of endometritis on reproductive performance. Data were collected from 1865 cows in 27 herds, including history of dystocia, twins, retained placenta, or metritis. All cows were examined once between 20 and 33 d in milk (DIM) including external inspection, vaginoscopy, and transrectal palpation of the cervix, uterus, and ovaries. All cows were followed for a minimum of 7 mo or until pregnancy or culling. Survival analysis was used to derive a case definition of endometritis based on factors associated with increased time to pregnancy. The significance of clinical findings depended on the interval postpartum when examination took place. The presence of purulent uterine discharge or cervical diameter > 7.5 cm after 20 DIM, or mucopurulent discharge after 26 DIM identified cows with clinical endometritis. Given vaginoscopy, no diagnostic criteria based on palpation of the uterus had predictive value for time to pregnancy. The prevalence of clinical endometritis was 16.9%. Vaginoscopy was required to identify 44% of these cases. Accounting for parity, herd, and ovarian status, cows with clinical endometritis between 20 and 33 DIM had a hazard ratio of 0.73 for pregnancy (took 27% longer to become pregnant), and were 1.7 times more likely to be culled for reproductive failure than cows without endometritis.

Animals↗

PubMedDate not supplied

Cadmium chronic administration to lactating ewes: reproductive performance, cadmium tissue accumulation and placental transfer.

20 lactating ewes were allotted to two groups: 10 subjects received orally 100 mg/day of CdCl2 for 108 consecutive days, and the remaining 10 acted as control. Reproductive performance in ewes and cadmium tissue accumulation, both in ewes and their lambs, were investigated. The results showed that in ewes: 1) the regular cadmium intestinal intake negatively influences all reproductive parameters; 2) cadmium is particularly accumulated in kidney and liver, but also in mammary gland, although at a distinctly lower level; 3) chronic administration does not increase cadmium placental transfer in lactating pregnant subjects.

Animals↗

PubMed1992

Influence of low birth weight on subsequent reproductive performance of female rats.

Female rats which were born underweight had lower absolute body mass throughout the whole experimental period than female litter mates with normal birth weight (controls). Their reproductive performance observed during three consecutive pregnancies was not different from that of controls except for lower litter size in the 1st pregnancy. Thus at least for rats, low spontaneous birth weight of females does not indicate subsequent poor pregnancy outcome.

Aging↗

PubMed1980

Effects of season, lactation and plane of nutrition on the reproductive performance and associated plasma LH and progesterone profiles in hormonally treated ewes.

Two experiments were designed to determine the effects of duration of lactation and plane of nutrition on the reproductive performance of Finn x Dorset Horn ewes mated at a hormonally induced oestrus 9 weeks after lambing. In Exp. 1, ewes were mated on 4 December or 19 March and lactation was terminated at 35 or 15 days before mating or 7 or 35 days after mating. The fertility of ewes lactating at the time of mating was reduced, particularly in ewes mated in March. This was not attributable to differences between lactating and non-lactating ewes for the incidence of oestrus, ovulation rate, litter size or the pattern of LH production. Indirect evidence based on progesterone profiles and returns to service suggest that reproductive failure was due to failure of fertilization and to embryonic death. In Exp. 2 ewes were mated on 1 July or 15 October. Lactation was terminated 15 days before or 7 days after mating and the ewes in each group were subjected to a high or low plane nutrition. Lactation depressed fertility in ewes mated in July but not in those mated in October. While the fertility of non-lactating ewes was independent of nutritional treatment, lactating ewes on a low plane and mated in July had a higher lambing rate than those on a high plane of nutrition. Nutritional effects on fertility appeared to be mediated through changes in milk production and reproductive failures were attributed to failure of fertilization and embryonic death. Seasonal and treatment effects on the incidence of oestrus and on ovulation rates, litter sizes and LH production were small and of little importance.

Animal Nutritional Physiological Phenomena↗

PubMed1986

Reproductive performance of lactating Holstein cows fed supplemental beta-carotene.

Fifty-six Holstein cows were used in a replicated study to determine whether supplemental beta-carotene improved reproductive performance. Each of two replicates was of completely randomized design with 2 X 2 factorial arrangement of two diets with or without beta-carotene supplementation. On a dry matter basis, diet 1 was 5% hay, 20% haylage, 25% corn silage, and 50% concentrate. Diet 2 was 7.5% hay, 42.5% corn silage, and 50% concentrate. The diets contained adequate amount of vitamins A, D, and E. From 10 d postpartum until pregnancy was confirmed by rectal palpation, half the cows on each diet received a supplement of 400 mg beta-carotene per head daily. The remaining cows on each diet received a supplement of 160,000 IU vitamin A per head daily. Supplemental beta-carotene increased plasma beta-carotene throughout the trials. Median days to first ovulation, first service, days open, and mean services per conception were: 22, 77, 97, and 1.6 for cows receiving beta-carotene supplement compared with 19.5, 73, 82, and 1.9 in controls. Supplementation did not affect first service conception rate, uterine involution, or milk yield. Incidence of follicular cysts, luteal cysts, pyometra, and endometritis in cows fed beta-carotene were 11, 7, 0, and 7% compared with 8, 21, 4, and 13% in control cows. Supplemental beta-carotene did not improve the fertility of Holstein cows.

Animals↗

PubMed1994

Effect of bulky diets based on wheat bran or oat hulls on reproductive performance of sows during their first two parities.

The aim of the present study was to determine the effect of different degrees of bulkiness in the gestation diet on reproductive performance of sows during their first two parities. The density of the diets was modified by incorporating a high proportion of fibrous ingredients (wheat bran and corn cobs in Diet 2 and oat hulls and oats in Diet 3). A diet without fibrous ingredients was used as a control (corn and soybean meal in Diet 1). Although all the gestation diets were formulated to provide the same daily intake of the major nutrients, sows fed Diet 3 were the lightest and had the lowest backfat thickness (P < or = .05) during both parities, and those fed Diet 2 were the heaviest and the fattest (P < or = .05) during the second parity. These results seem to indicate an overestimation of the calculated nutritive value of Diet 3, whereas those obtained with Diet 2 seemed to be linked to its marked effect on behavior of sows during the second parity. There was no marked effect (P > .11) of treatments on the number of pigs born alive, on preweaning mortality, or on the weaning-to-estrus interval. At parturition, total litter weight was similar among treatments in the first parity, whereas in the second parity it was greater (P < or = .05) in sows fed Diet 2 than in those fed Diets 1 and 3. In both parities, feed intake of the common lactation diet given during lactation was 5% higher (P < or = .05) for sows fed Diet 3 during gestation than for sows fed the other diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

PubMed1996

Reproductive performance and changes in blood lipids in breeding females and in growing Watanabe heritable hyperlipidaemic and New Zealand White rabbits.

The aim of the study was to compare the reproductive performance of homozygous and heterozygous WHHL and NZW females, to record the changes in blood lipids due to gestation and lactation in the heterozygous WHHL and NZW females, and to investigate the changes in blood lipids from 4 to 11 weeks of age in homozygous and heterozygous WHHL and NZW rabbits. The conception rate of homozygous WHHL females was 14% lower than that of NZW and heterozygous WHHL females. The litter size and the weaning rate of homozygous WHHL females were significantly lower than in NZW and heterozygous WHHL females. In heterozygous WHHL and NZW females the total cholesterol was lower during the gestation and lactation while the triglycerides were higher during the gestation and were the lowest during lactation when compared to the levels at mating. In growing homozygous WHHLs of both sexes the total cholesterol did not change from 4 to 11 weeks of age. The triglycerides remained unchanged in males but decreased in females at 11 weeks of age. At this age the triglycerides were significantly lower in females than in males. In growing heterozygous WHHLs of both sexes the total cholesterol and triglycerides decreased with age. At 11 weeks of age the blood lipids were significantly higher in females than in males. The triglyceride levels in homozygous and heterozygous WHHL males and females were comparable at 4 and 6 weeks of age but significantly lower in heterozygous WHHLs at 11 weeks of age. In growing NZW rabbits of both sexes the blood lipids decreased significantly with age but no sex difference was recorded. The blood lipids in the heterozygous WHHLs of both sexes were higher than in NZWs during weaning. At 11 weeks of age the blood lipids of the males and triglycerides of the females of both strains were comparable. Only the total cholesterol remained higher in heterozygous WHHL females. The decrease with age in blood lipids in growing rabbits should be kept in mind when designing experiments beginning in animals younger than 3 months of age.

Aging↗

PubMed1980

Effects on reproductive performance of administration of GnRH to early postpartum dairy cows.

Three-hundred and thirty-five lactating dairy cows from two herds were used to compare the effects on reproductive performance of intramuscular injections of 100 micrograms gonadotropin-releasing hormone (GnRH), 250 micrograms GnRH or saline given on day 13, 14 or 15 postpartum. The incidence of ovarian cysts or uterine infections was not reduced after GnRH injection. Culling rate for infertility did not differ in either herd between GnRH- and saline-treated control cows. In the herd in which breeding began earlier in the postpartum period (Herd B), injection of 250 micrograms GnRH resulted in a better (P < .05) calving to conception interval (81 vs 96 days), better first service conception rate (74.5 vs 56.0%), better overall conception rate (70.6 vs 51.1%) and a lower number of services per conception (1.23 vs 1.74) than in the controls. In reproductively well-managed herds, injections of 250 micrograms GnRH, given to lactating dairy cows 2 weeks after calving, may increase fertility.

Animals↗

PubMed1999

The reproductive performance of sows raised by smallholder farmers in the Philippines.

We conducted a cross-sectional study at two sites in the Philippines to obtain baseline information about the reproductive performance of smallholder sows, and to identify important constraints and opportunities for smallholder pig raisers. Using an interview-based questionnaire, we collected data about 99 (with 128 sows) and 123 (144) herds at the northern and southern study sites, respectively. A range of animal- and herd-level measures of sow productivity were assessed, including average interfarrowing interval (9.7 and 6.6 mo in herds at the northern and southern sites, respectively), number of liveborn piglets (8.5 and 8.4) and preweaning mortality (19.0% and 12.8%). We have identified a number of animal- and herd-level factors associated with the productivity of smallholder sows in the Philippines, including aspects of breeding and piglet management and nutrition.

Animal Husbandry↗

PubMed1978

Effect of chlorinated hydrocarbons on reproductive performance of adult White Leghorn male chickens.

Two experiments of 20 and 40 weeks duration were conducted to determine the effects of feeding dieldrin or PCB (Aroclor 1254) on the reproductive performance of adult White Leghorn males. Dieldrin at the levels used (0, 25, and 50 ppm) produced no significant changes in semen volume, semen concentration, fertility, and hatchability of fertile eggs. Mortality increased with increased levels of dieldrin and appeared related to duration of exposure to the pesticide. A significant reduction (P less than .05) in feed consumption was observed at the 25 ppm level. No significant differences in body weights were observed except shortly before death when marked reductions in both feed consumption and body weight were noted. PCB at the levels used (0, 10, 20, and 40 ppm) produced no differences in fertiluty, hatchability of fertile eggs, body weights, feed consumption, or mortality. However, over a period of 40 weeks, PCB significantly (P less than .05) reduced semen volume, semen concentrations, and testes weights,

Animal Feed↗

PubMed1987

Effect of feeding fungal endophyte (Acremonium coenophialum )-infected tall fescue seed on reproductive performance in CD-1 mice through continuous breeding.

This study was designed to assess the effect of endophyte-infected (Acremonium coenophialum ) tall fescue (KY-31) seed (80% infected) on reproductive performance in CD-1 mice by continuous breeding. Twenty-four pairs of 70-d-old CD-1 mice were randomly allocated to four diets: 1) mouse chow ad libitum; 2) 40% infected fescue seed and 60% chow (w/w); 3) reduced intake (100% chow) similar to the intake, adjusted daily, in Diet 2; and 4) 60% infected fescue seed and 40% chow. Males and females were randomly paired (six pairs/treatment) and placed on the above diets. The mice were fed the corresponding diets for 80 d, although the pairs were separated on Day 60 (prior to the birth of the 3rd litter) and the females were monitored for one additional gestation period (20 d). The pregnancy data (litters produced) among the four treatments were 100.0 (18), 77.8 (14), 100.0 (18) and 80.0% (12) respectively. Similarly, the average number of pups born per litter among the four treatments was 11.8, 9.3, 10.1, and 9.8. When the chow treatment (1 and 3) and the fescue treatments (2 and 4) were pooled and compared, the percent pregnancy was 100.0 (n = 36) and 78.8 (n = 26), and the pups born per litter (means +/- SEM) were 11.0 +/- 0.5 and 9.5 +/- 0.6, respectively. Also the intervals between the three litters born during the 60-d cohabitation period were 21.6 +/- 1.1 and 24.5 +/- 0.9 d for the chow and fescue treatments, respectively. The results point out that 40 and 60% infected fescue seed in the diet of mice does influence (P < 0.05) their reproductive capacity as measured by percent pregnancy and litter size.

Journal Article↗

PubMed2006

Reproductive performance of high growth rate gilts inseminated at an early age.

The aim of this work was to determine if gilts, which have a high growth rate (GR) could be mated earlier without reducing the reproductive performance or increasing the culling rate up to the third parity. Gilts of Camborough 22 (C22, n=568) breeding were mated and allocated into three groups according to weight and age on the insemination day. G1 (n=164)-gilts with a GR>or=700 g/d and inseminated at <210 d. G2 (n=165)-gilts with a GR>or=700 g/d and inseminated at >or=210 d. G3 (n=239)-gilts with a GR<700 g/d and inseminated at >or=210 d. All females were fed ad libitum from 150 d on and were inseminated at their second estrus or later. The minimum weight at mating was 127 kg. Three parities were studied, with farrowing rate, litter size and culling rate being compared. At the first parity, G2 gilts produced, on average, one more piglet than the other groups (P<0.05). However, when analyzing three parities, there were no differences in total born (11.6 x 12.3 x 11.7), farrowing rate (87.1% x 88.7% x 89.8%) and culling rate (30.2% x 25.3% x 28.2%) among G1-G3 groups, respectively (P>0.05). In conclusion, gilts, which had a minimum weight of 127 kg can be inseminated at their second or greater estrus, between 185 and <210 d of age, without impairing their productive performance over three parities.

Aging↗

PubMed1985

Management factors affecting reproductive performance of dairy cows in the northeastern United States.

Dairy herds (476) in seven states in the northeastern United States were surveyed to determine effects of various management factors on reproductive performance. Error of estrus detection (greater than 1 ng/ml of milk progesterone) on the day of service was 5.1% for 4558 cows but was as high as 60% in some herds. Error was not affected by herd size but was greater in freestall (6.8%) than in conventional (5.2%) housing. "Standing" and "riding other cows" were the most accurate signs of estrus. Of cows in or near estrus when serviced, 28.1% were open 3 wk later, 12.9% were probably open, and 59% were probably pregnant based on analysis of milk progesterone. Conception rate, not affected by herd size or housing type, was greater for cows in estrus during the morning and serviced the same afternoon (52.2%) than for cows observed in the afternoon and serviced the next morning (47.1%). Fifty-five percent of cows open to first service were serviced again within 3 days of expected return to estrus. Days to first service and conception rates were correlated positively. Milk progesterone concentration 21 to 24 days after service predicted a cow will calve with 88.6% accuracy and that she will not with 93.9% accuracy. Veterinarians predicted a calf with 92.5% accuracy by rectal palpation.

Animal Husbandry↗