Anestrus is a major reproduction problem in pasture-based dairy operations that results in poorer reproductive outcomes than herdmates detected in estrus before the start of the seasonal breeding program. The objective of the current study was to assess a combined progesterone and estradiol benzoate treatment program including resynchrony with no ...

We previously reported that ovulation rate, but not pregnancy rate or litter size at d 30 after mating, was enhanced by treatment with P.G. 600 (400 IU of PMSG and 200 IU of hCG, Intervet America, Inc., Millsboro, DE) in gilts fed the orally active progestin, altrenogest (Matrix, Intervet America, ...

Pregnancy is associated with significant, but reversible changes in thyroid function studies, which are among the most profound seen as a result of a normal physiologic state. The present study was carried out to find out alterations in thyroid function tests in each trimester in normal pregnant women as compared ...

Anal incontinence (AI) is a significant problem that causes social and hygienic inconvenience. The true prevalence of AI is difficult to estimate due to inconsistencies in research methods, but larger studies suggest a rate of 2-6% for incontinence to stool. There is a significant association between sonographically detected anal sphincter ...

OBJECTIVE: To determine the effect of intrauterine administration of ceftiofur sodium on fertility and the risk of culling in postparturient cows with retained fetal membranes (RFM), twins, or both. DESIGN: Single-blind randomized clinical trial and prospective cohort study. ANIMALS: 2442 cows that calved from January 1, 2000, to May 31, ...

Hostein cows (n=141) in five commercial dairy herds in central New York were examined for endometritis by examination of endometrial aspirates for presence of inflammatory cells, principally neutrophils, by endometrial cytology at 40-60 days postpartum. The prevalence of cytologically-diagnosed endometritis was 53%; within herds the prevalence varied from 37 to ...

Environmental effects on fertility measures early in lactation, such as the interval from calving to first luteal activity (CLA), proportion of samples with luteal activity during the first 60 days after calving (PLA) and interval to first ovulatory oestrus (OOE) were studied. In addition, traditional measurements of fertility, such as ...

This study investigated the relationship between follicle size (FS) and developmental competence of calf oocytes. Cumulus-oocyte-complexes (COCs) from follicles>8 (L-COCs; n=19), 4-8 (M-COCs; n=54), and 2-3 mm (S-COCs; n=155) were recovered from non-stimulated 1-4 months old dairy calves post mortem and ex vivo (laparoscopy), and in parallel from slaughtered adult ...

The objective of this study was to determine whether administration of hCG approximately 5 d after AI would increase plasma progesterone concentrations and conception rates in beef heifers. Heifers from two locations (Location 1: n = 347, BW = 367 +/- 1.72 kg; Location 2: n = 246, BW = ...

OBJECTIVE: To determine the distribution of drying times of umbilical cords of dairy calves and to determine if cord dryness is a reliable indicator of age. DESIGN: An observational study was undertaken in a spring calving herd in Victoria, of the umbilical cords of 188 calves (82 Friesian bulls, 82 ...

The behavior of pyrethrins and piperonyl butoxide (PB) on peaches has been studied after field treatment. Three experiments were carried out at 1, 5, and 10x the concentration recommended by the manufacturer. In all experiments, the initial deposition was below the maximum residue level (MRL), and the half-life time calculated ...

The aim was to determine the factors that contribute to embryonic mortality in buffaloes mated by AI during a period of increasing day length which corresponds to a natural decline in reproductive activity. Italian Mediterranean buffalo cows (n=243) showing regular estrous cycles were synchronized using the Ovsynch-TAI program and mated ...

Twin pregnancies are undesirable in dairy cattle as they increase the risk of abortion and have many negative effects on the profitability of the herd. The purpose of this study was to evaluate manual reduction of a twin embryo in dairy cows bearing unilateral twins. On day 34 of gestation, ...

The overall objective was to compare the efficacy of GnRH, porcine LH (pLH) and estradiol cypionate (ECP), in a modified Ovsynch/fixed-time AI (FTAI) protocol that included a controlled internal drug [progesterone] release (CIDR) device. In Experiment 1, heifers received a CIDR on Day -10, and PGF (25mg) on Day -3. ...

In the study, the relationship of follicular growth waves, oestradiol and pregnancy rates were investigated during oestrus cycle in cows. A total of 22, Brown Swiss cows (3-5 years old) were used for the study. The ovaries of animals were examined from sixth day of cycle to next oestrus by ...

The present study aimed to relate feed intake of red deer hinds in the later stages of gestating wapitixred deer crossbred foetuses on dam body condition, gestation length, birth weight and calf growth. Multiparous hinds (N=18) conceiving at known dates to either wapiti (n=12) or red deer (n=6) sires were ...

The possible direct relationship between climate variations and abortion in Neospora caninum-infected cows has not been studied. The objective of this study was to determine whether climate changes could be a risk factor for abortion in N. caninum-infected cows, and was based on yearly serological screening for neosporosis and on ...

The present study aimed to relate feed intake of red deer hinds during late pregnancy to dam body condition, foetal development and calf growth. Across 3 years, multiparous (n=33) or primiparous (n=18) hinds with known conception dates were housed in individual pens from days 150-220 of pregnancy, during which time ...

The aim of this study was to use a Weibull proportional hazards model to explore the impact of type traits on the functional survival of Canadian Jersey and Ayrshire cows. The data set consisted of 49,791 registered Jersey cows from 900 herds calving from 1985 to 2003. The corresponding figures ...

The objective of this study was to examine the feasibility of implementing routine national calving ease (CE) genetic evaluations of Brown Swiss (BS) and Jersey (JE) sires that include records of crossbred calvings. Records were available for 11,793 BS calvings, 3431 BS-sired crosses, 65,293 JE calvings, and 7090 JE-sired crosses. ...

Pregnancy rates were compared in lactating dairy cows (n = 1083) assigned to protocols for resynchronization of ovulation based on stages of the estrous cycle, or presence of ovarian cysts or anestrus. Cows were detected not pregnant by ultrasonography 30 d after a previous AI (study day 0) and classified ...

The objective was to compare pregnancy rates and pregnancy losses in lactating dairy cows that were diagnosed not pregnant and re-inseminated following either the Ovsynch or Heatsynch protocols. Also evaluated were the effects of stages of the estrous cycle, ovarian cysts and anestrus on pregnancy rates for both treatments. Non-pregnant ...

Our objectives were to compare: (1) conception rates (in early postpartum Japanese Black beef cows) to timed-artificial insemination (timed-AI) among Ovsynch and Ovsynch plus CIDR protocols, and a protocol that used estradiol benzoate (EB) in lieu of the first GnRH of the Ovsynch plus CIDR; and (2) the effects of ...

Poor detection of estrus, still a major problem in the dairy industry, has prompted the development of electronic estrous detection technologies. One of the features of estrous behavior is a marked increase in walking activity. The objectives of the present study were to evaluate the effects of various management factors ...

Ovulation failure and double ovulation rates were examined in 1917 inseminations performed in high-yielding dairy cows under standard commercial conditions. The ovulation rate was determined 11 days post-insemination by ultrasound detection of at least one corpus luteum in the ovaries. Analyzing the double ovulation and pregnancy rates, the study population ...

The objective of this study was to determine the effect of GnRH (100 microg i.m.) treatment 5 and 15 days after timed insemination (TAI) on pregnancy rate and pregnancy loss in lactating dairy cows subjected to synchronization of ovulation. The study included 831 lactating dairy cows subjected to a Presynch-Ovsynch ...

The aim of the present study was to investigate the ovulation rate and its relationship to number of total piglets born in purebred gilts under tropical climatic conditions. This study was conducted in two swine breeding herds (A and B) in the northeastern part of Thailand. The sources of swine ...

In the last few years, the detection of free radical damage and the body's defences against it have become increasingly important in clinical medicine as a complementary tool in the evaluation of metabolic status. The aim of this study was to evaluate, under field conditions, the anti-oxidant status of healthy ...

Our objectives were to determine pregnancy rates after altering times of the second GnRH injection, insemination, or both in a combined Presynch + Ovsynch protocol, to accommodate once-daily lockup of dairy cows. Lactating dairy cows (n = 665) from 2 dairy herds in northeastern Kansas were studied. Cows ranged from ...

There is an evidence that the epidemiology of neosporosis differs in dairy and beef cattle, such that beef cattle carry a lower risk of abortion. The aim of the present study was to establish whether artificial insemination using semen from beef bulls could reduce the risk of abortion in dairy ...

This present study, was designed to establish whether Neospora caninum infection affects the fertility of high-producing dairy cows, and was based on yearly serological screening for neosporosis and on the confirmation of N. caninum infection in aborted foetuses. Assessment was made of 7518 artificial inseminations (AI) (applied to parous cows) ...

AIM: To describe the reproductive performance of beef cow herds in New Zealand and to develop reference ranges for assessing the reproductive performance of individual herds from in-calf rates, that take into account variation in the length of mating periods. METHODS: Veterinary practices throughout New Zealand involved in beef cattle ...

The objectives of this study were to evaluate the effects of flunixin meglumine (FM), an inhibitor of PGF(2alpha) synthesis, and insertion of an intravaginal progesterone-releasing device (CIDR), on pregnancy rates in beef cattle embryo transfer (ET) recipients, and to examine the effect of a CIDR after embryo transfer on the ...

Anestrous and lactating Bos taurus by Bos indicus crossbred cows with minimum body condition were studied to determine the efficacy of GnRH+PGF 2alpha combinations for induction of estrus and/or ovulation on pregnancy rate during the months of the year when temperatures are greater. On day 0 (start of treatment), cows ...

In the present study, somatic cell cloning technology was used to produce eight newborn calves from an aged, infertile bull. Average birth weight of these calves was significantly higher than that of calves produced using AI. Four of the cloned calves died during the peripartum period; the remaining four (Clones ...

Twin pregnancies represent a management problem in dairy cattle since the risk of pregnancy loss increases, and the profitability of the herd diminishes drastically as the frequency of twin births increases. The aim of this study was to monitor the development of 211 twin pregnancies in high producing dairy cows ...

A controlled field study examined conception rates after 2 timed artificial insemination (TAI) breeding protocols conducted on 2 commercial dairy farms. Estrous cycles in postpartum lactating cows were presynchronized with 2 injections of PGF(2alpha) given 14 d apart (Pre-synch) and then, after 12 d, the standard Ovsynch protocol (injection of ...

In this study, we examined the concentration of bovine IL-18 in the sera of pregnant cows, their fetuses and newborn calves, and in colostrum in order to examine the role of IL-18 in bovine pregnancy and the neonatal period. A sandwich-ELISA to quantify bovine IL-18 was established using anti-porcine IL-18 ...

This study discriminated between 2 effects (birth date and presence of older calves) assessed jointly in previous studies. Birth date delay produced similar effects to those reported previously: reduced milk and milk nutrient production in late-calving hinds, concentration of milk, substitution of protein by fat, greater body weight losses of ...

The experimental objective was to compare pregnancy rates after fixed-time AI in postpartum suckled beef cows following administration of two progestin-based protocols to synchronize ovulation. Cows (n = 424) at three locations (n = 208, 122, and 92 per location) were stratified by age, BCS, and days postpartum (DPP) and ...

BACKGROUND: Recently, preservation using oxygenated perfluorocarbon (the two-layer method) has shown beneficial effects on islet yield and viability. In this paper, we apply this concept on isolation processes to examine the effectiveness of oxygenation. METHODS: Rat pancreata were digested using four different methods: (groups 1A, 1B, 2A, and 2B) with ...

The objective of the study was to compare three systems for estrus detection and combinations of these systems on a large commercial dairy (1075 lactating cows) during stress of summer heat. At 37-45 days in milk (DIM), 255 cows were fitted with a HeatWatch device (HW; DDx Inc., Denver, CO), ...

AIMS: To evaluate the effectiveness of treatment programmes that included controlled internal drug-releasing (CIDR) devices containing progesterone (P4) in improving synchrony of oestrus, and conception and pregnancy rates in cycling, anoestrous and inseminated dairy cows, using meta-analysis. To describe the difference in response between cycling and anoestrous cows to CIDR-based ...

The objectives of this study were to determine the effects of incorporating a progesterone intravaginal insert (CIDR) between the day of GnRH and PGF2alpha treatments of a timed AI protocol using estradiol cypionate (ECP) to synchronize ovulation on display of estrus, ovulation rate, pregnancy rate, and late embryonic loss in ...

A population of 300 F(3:4) lines derived from the cross between maize inbred lines F2 and F252 was evaluated for testcross value in a large range of environmental conditions (11 different locations in 2 years: 1995 and 1996) in order to study (1) the magnitude of genotype x environment and ...

A total of 799 Holstein cows from 3 herds were randomly assigned at 37 +/- 3 d in milk (DIM) to timed artificial insemination (AI) or insemination at detected estrus. Cows were presynchronized with injections of PGF(2alpha) at 37 and 51 DIM. At 65 DIM, cows received an injection of ...

The objectives of this observational study were to document ovarian and endocrine responses associated with the treatment of cystic ovarian follicles (COFs) in dairy cows, using gonadotropin releasing hormone (GnRH) and prostaglandin F2alpha (PGF) with or without exogenous progesterone. A secondary objective was to determine pregnancy establishment following synchronization of ...

The influence of sex hormones is a key proximate factor underlying male reproductive behavior in mammals. Effective conservation policies for the remaining purebred plains bison (Bison bison bison) herds require knowledge of the physiology underlying bison reproductive biology. We used fecal steroid analysis to characterize androgen levels in adult bison ...

It was hypothesized that sub-optimal progesterone concentrations during the late embryo and early fetal period may act to compromise conceptus development in dairy cattle. The aim of the present study was to test this hypothesis by supplementing pregnant cows with exogenous progesterone following pregnancy diagnosis. The study population consisted of ...

Two experiments were conducted to test 2 progesterone (P4)-based treatments that were applied to lactating dairy cattle of unknown pregnancy status to resynchronize estrus of nonpregnant cows. In experiment 1, cows were assigned randomly before a timed AI (TAI) to 1) treatment with a CIDR (controlled internal drug-releasing intravaginal insert ...