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PubMed1978

Some clinical aspects of caprine reproduction.

Several clinical reproductive problems in the female dairy goat are considered, including estrus detection, artificial insemination, pregnancy diagnosis, abortions, and periparturient difficulties. Sexual behavior of the buck, onset of puberty, techniques for semen collection and evaluation, the production of teaser animals, and methods of castration are also discussed. Recognition of the intersex goat, which may have a masculine, feminine, or intermediate phenotype, is necessary in herds where naturally polled animals are bred.

Abortion, Veterinary↗

PubMed1989

A method of artificial insemination in captive White-tailed deer (Odocoileus virginianus ).

Production of fawns by artificial insemination in captive White-tailed deer (Odocoileus virginianus ) has been accomplished by using frozen-thawed spermatozoa. The purpose of this study was to determine if frozen-thawed semen deposited at the posterior face of the os cervix could produce conception. Five hand-raised female White-tailed deer and one hand-raised male White-tailed deer were used over two breeding seasons 1984-1985 and 1985-1986. The vasectomized buck was ued to detect estrus in the does. The does were inseminated with frozen-thawed semen containing at least 100 million live normal cells with a 60% or higher motility. The artificial insemination catheters used in this study worked well, but due to the small size of the cervix, the catheter could only be passed up to the first cervical ring, the site at which the semen was deposited. Over two breeding seasons, nine does were inseminated with frozen-thawed spermatozoa; each doe was inseminated once each estrous cycle at one of the following times: 0, 6, 12, 18, 24 or 30 h. after detection of estrus. Of the nine does inseminated with frozen-thawed spermatozoa, six conceived and carried to term 11 healthy normal fawns, yielding an overall conception rate of 67%.

Journal Article↗

PubMed2001

Adverse impact of heat stress on embryo production: causes and strategies for mitigation.

The production of embryos by superovulation is often reduced in periods of heat stress. The associated reduction in the number of transferable embryos is due to reduced superovulatory response, lower fertilization rate, and reduced embryo quality. There are also reports that success of in vitro fertilization procedures is reduced during warm periods of the year. Heat stress can compromise the reproductive events required for embryo production by decreasing expression of estrus behavior, altering follicular development, compromising oocyte competence, and inhibiting embryonic development. While preventing effects of heat stress can be difficult, several strategies exist to improve embryo production during heat stress. Among these strategies are changing animal housing to reduce the magnitude of heat stress, utilization of cows with increased resistance to heat stress (i.e., cows with lower milk yield or from thermally-adapted breeds), and manipulation of physiological and cellular function to overcome deleterious consequences of heat stress. Effects of heat stress on estrus behavior can be mitigated by use of estrus detection aids or utilization of ovulation synchronization treatments to allow timed embryo transfer. There is some evidence that embryonic survival can be improved by antioxidant administration and that pharmacological treatments can be developed that reduce the degree of hyperthermia experienced by cows exposed to heat stress.

Animals↗

PubMed2000

Beta-carotene uptake and changes in ovarian steroids and uterine proteins during the estrous cycle in the canine.

The uptake of beta-carotene by reproductive tissues and the effects of beta-carotene on reproductive function in the dog are unknown. We studied the uptake of beta-carotene by blood, corpus luteum, and uterine endometrium and the role of dietary beta-carotene in influencing ovarian steroid and uterine protein production during the estrous cycle in the dog. Mature female Beagle dogs (n = 56) were fed diets containing 0, 2, 20, or 50 mg of beta-carotene daily for approximately 6 wk before estrus detection. Blood was sampled at regular intervals from estrus through d 45 after ovulation (d 0 = ovulation), when laparotomy was performed. The ovaries were obtained for the isolation of corpus luteum. The uterus was flushed with phosphate-buffered saline and the endometrium obtained by scraping. Beta-carotene was not detectable in plasma, corpus luteum, or endometrium of unsupplemented dogs. However, beta-carotene and alpha-carotene in plasma, corpus luteum, and uterine endometrium increased in a dose-dependent manner. Alpha-carotene made up a high percentage of total carotenoids even though the alpha-carotene content in the dietary source was very low. Dogs fed 50 mg of beta-carotene had significantly higher concentrations of plasma progesterone between d 12 and 26 compared with unsupplemented dogs. Dietary beta-carotene did not influence plasma estradiol-17beta and total uterine proteins. Therefore, beta-carotene is absorbed into plasma, corpus luteum, and uterine endometrium of dogs. Furthermore, dietary beta-carotene increased plasma progesterone concentrations during the estrous cycle. It is possible that dietary beta-carotene may improve reproductive function in the canine.

Animals↗

PubMed1995

Factors associated with use of prostaglandins in reproductive herd health programs for dairy cows.

Use of prostaglandin F2 alpha products (PG) in dairy cows was studied by use of computerized reproductive herd health data compiled from 29 dairy herds in Minnesota and Wisconsin during 1983 through 1988. Treatment with PG was recorded in 1,856 of 7,139 (26.0%) complete lactations. More than 1 treatment with PG was administered in 534 of the 1,856 (28.8%) lactations in which PG were used. The proportion of lactations in which treatment was used varied among herds and years, and was associated with the proportion of cows in which natural breeding was attempted and, to a lesser extent, with estrus detection index and conception rates; these associations were potentially modified by time between veterinary herd health visits. Calving-to-treatment intervals (mean +/- SD) were 100.4 +/- 55.1 days for first treatments only, and 116.2 +/- 66.1 days for all treatments. These values varied considerably among herds and years and among reasons for treatment. Much of the variation in proportions of lactations in which treatment was used and in the time of treatment within lactations could not be accounted for with the variables included in this study, and was probably related to individual considerations for each cow.

Animals↗

PubMed2005

Patterns of expression of steroidogenic enzymes during the first wave of the ovine estrous cycle as compared to the preovulatory follicle.

The expression patterns of steroidogenic enzymes in ovarian antral follicles at various stages of growth in a follicular wave have not been reported for sheep. Ovaries were collected from ewes (n=4-5 per group) when the largest follicle(s) of the first wave of the cycle, as determined by ultrasonography, reached (i) 3 mm, (ii) 4 mm, (iii) > or =5 mm in diameter or when there was a single (iv) preovulatory follicle in the last wave of the cycle, 12h after estrus detection. The expression pattern of steroidogenic enzymes was quantified using immunohistochemistry and grey-scale densitometry. The expression of CYP19 in the granulosa and 3beta-HSD and CYP17 in the theca increased (P<0.01) progressively from 3 to > or =5 mm follicles in the first wave of the cycle and was lower (P<0.01) in the preovulatory follicle compared to > or =5 mm follicles. However, the expression of 3beta-HSD in the granulosa increased (P<0.05) from 3 to > or =5 mm follicles and was maintained (P<0.05) at a high level in the preovulatory follicles. The amount of CYP19 in the granulosa of the growing follicles correlated positively (r=0.5; P<0.03) with the concurrent serum estradiol concentrations. We concluded that the expression pattern of steroidogenic enzymes in theca and granulosa of follicles growing in each wave in the ewe, paralleled with serum estradiol concentrations, with the exception that concentrations of 3beta-HSD in granulosa increased continuously from follicles 3mm in diameter to the preovulatory follicle.

3-Hydroxysteroid Dehydrogenases↗

PubMed2000

Effect of sterile service on estrus duration, fertility and prolificacy in artificially inseminated dairy goats.

The effect of sterile service on estrus duration, fertility and prolificacy in artificially inseminated dairy goats during breeding season was studied. Nubian does (n=126) were divided into 2 equal groups: service and control. Estrus was synchronized with intravaginal sponges containing either fluorgestone acetate (FGA; 40 mg) or medroxiprogesterone acetate (MAP; 60 mg) for 12 or 14 d, respectively. Two vasectomized teaser bucks were used to detect estrus at 6-h intervals for 5 d after sponge removal (0600, 1200, 1800 and 2400 h). The teasers were fitted with aprons and permitted to mount all does in both groups, but to penetrate only the service does within the first 12 h of estrus. Does in both groups were inseminated twice at 12 and 24 h after estrus was first detected, using 1 straw per insemination containing 200 million of cooled spermatozoa from 1 buck. The semen was placed in mid-cervix. Estrus duration for the service and control does was (mean +/- SD) 29.4 +/- 6.5 and 41.8 +/- 9.6 h, respectively. Fertility for the service does was 73.7% (46/63); for control does it was 58.7% (37/63). Prolificacy was 2.1 (96/46) and 2.0 (74/37) for service and control does, respectively. Estrus duration (P<0.001) and fertility (P<0.05) differed between the service and control group, but prolificacy was similar (P>0.05). It is concluded that sterile service reduces the duration of estrus and increases fertility in artificially inseminated dairy goats.

Animals↗

PubMed1997

Non-invasive detection and monitoring of estrus, pregnancy and the postpartum period in pygmy loris (Nycticebus pygmaeus) using fecal estrogen metabolites.

Estrone-conjugates (E1C) were measured in the feces of six female pygmy lorises (Nycticebus pygmaeus) during estrus (n = 12), pregnancy (n = 4) and the postpartum period (n = 3). Noninvasive feces collection permitted frequent sampling throughout estrus and pregnancy, without disturbance of animals. The estrous period was defined as an increase in fecal E1C levels above an average of 70 ng/g feces with peaks above 100 ng/g feces obtained in consecutive fecal samples collected over a 6- to 11-day period between the end of July and the first third of October. Comparison of the periovulatory profile of E1C and the stage of labial opening of the vagina revealed a high agreement (P < 0.001). In all pregnant females, an E1C rise was found approximately 47 days postestrus, the source of which may be the growing fetal placental unit. Estimated gestation lengths ranged between 187 and 198 days (n = 4).

Animals↗

PubMed2000

Effects of FSH commercial preparation and follicular status on follicular growth and superovulatory response in Spanish Merino ewes.

Ovarian follicular development was characterized in 24 Spanish Merino ewes to study effects of the follicular status and the FSH commercial product used on follicular growth and subsequent superovulatory response. Estrus was synchronized using 40 mg fluorogestone acetate sponges. The superovulatory treatment consisted in 2 daily i.m. injections of FSH from 48 h before to 12 h after sponge removal. Sheep were assigned randomly to 2 groups treated with 6 decreasing doses (4, 4, 3, 3, 2, 2 mg) of FSH-P or with 6 doses of 1.25 mL of OVAGEN. Growth and regression of all follicles > or = 2 mm were observed by transrectal ultrasonography, and recorded daily from Day 6 before sponge insertion to the first FSH injection, and then twice daily until estrus was detected with vasectomized rams. Differences were detected in follicular development from the first FSH injection to detection of estrus (-48 to 36 h from sponge removal) between groups. Administration of FSH-P increased the appearance of new follicles with respect to OVAGEN (6.3 +/- 0.7 vs 4.8 +/- 0.4; P < 0.05), and the mean number of medium (4 to 5 mm) follicles (8.9 +/- 1.2 vs 6.6 +/- 0.9; P < 0.05). However, the mean number of follicles that regressed in size after sponge removal (5.9 +/- 0.4 vs 3.3 +/- 0.4) and the number of preovulatory sized follicles that did not ovulate (60 vs 42.4%) were also higher in FSH-P treated ewes (P < 0.05). So, finally, there were no differences in ovulation rate, as determined by laparoscopy on Day 7 after sponge removal, between ewes treated with FSH-P or OVAGEN (6.3 +/- 1.9 vs 7.0 +/- 1.7 CL). In all the ewes, the ovulatory response was related (P < 0.05) both to the number of small follicles (2 to 3 mm in diameter) present in the ovaries at the start of treatment with exogenous FSH and to the number of follicles that reached > or = 4 mm in size at estrus, despite differences in the pattern of follicular development when using different commercial products.

Animals↗

PubMed1999

Effect of prepubertal feeding regimen on reproductive development of gilts.

The effect of prepubertal feed level on growth and reproductive development of gilts was investigated. At 13 wk. of age, white crossbred gilts were penned individually and assigned to the following treatments: Ad lib, ad libitum intake from 13 to 25 wk. of age (n = 64); Control, ad libitum intake from 13 wk. of age until 100 kg BW and then 90% of ad libitum intake until 25 wk. of age (n = 65); and Restricted, 74% of ad libitum intake from 13 wk. to 25 wk. of age (n = 64). Feed was formulated to primarily restrict energy intake. The study was replicated in two seasons. At 25 wk. of age, gilts were moved to group pens, approximately 16 gilts/pen, allowed ad libitum access to feed, and estrus detection was initiated. Gilts were mated at first estrus and those recycling were remated. After mating, gilts were moved to gestation stalls and fed 1.5x maintenance. At 30 d of gestation, reproductive tracts were harvested, and numbers of corpora lutea (CL) and live embryos were recorded. From 13 to 25 wk. of age, feed consumption was 258 for Ad lib, 251 for Control, and 189 kg/gilt for Restricted, and, from 13 wk. of age until 30 d of gestation, total feed consumption was 367 for Ad lib, 356 for Control, and 299 kg/gilt for Restricted gilts. Age at puberty (196 d) and pregnancy (200 d) was not affected (P>.18) by treatment. However, the rate at which gilts attained puberty (e.g., percentage pubertal at 28 d) was greatest in Ad lib (75) and least in Control (61) gilts. Number of CL and live embryos at 30 d of gestation/gilt assigned to the study was unaffected (P>.21) by treatment. Quantity of feed consumed from 13 wk. of age to 30 d of gestation per live embryo in gilts assigned to the study was 40.0 for Ad lib, 39.8 for Control, and 30.6 kg/gilt for Restricted gilts. These results indicate that moderate feed restriction of gilts during prepubertal development may increase efficiency of swine production without negative impact on reproductive performance through 30 d of gestation.

Animal Feed↗

PubMed2001

Effect of prepubertal feeding regimen on reproductive development and performance of gilts through the first pregnancy.

Development of gilts that conceive early and continue to produce offspring is an objective of swine production. We investigated different patterns of growth on reproductive development and performance of gilts through the first farrowing. At 13 wk of age and 43 kg BW, 286 white crossbred gilts were penned individually and assigned to treatments: Ad lib, ad libitum intake from 13 to 25 wk of age; Control, ad libitum intake from 13 wk of age until 100 kg BW and then 90% of ad libitum intake until 25 wk of age; and Restricted, 74% of ad libitum intake from 13 wk to 25 wk of age. Feed was formulated to restrict energy intake. The study was replicated in three seasons. At 25 wk of age, gilts were moved by treatment to group pens, fed for ad libitum consumption, and estrus detection was initiated. Gilts were inseminated at first estrus, and those recycling were remated. Postmating gilts were fed 1.5x maintenance until 105 to 110 d of pregnancy. Gilts were moved either to the farrowing facility or the abattoir at 105 to 110 d of pregnancy. Those taken to the abattoir were slaughtered and number, weight, and condition of the fetuses were recorded. Gilts moved to the farrowing facility were allowed to farrow, and number, weight, and condition of the piglets were recorded. Daily feed intake during breeding was 3.4 kg/d by Restricted gilts, 2.9 by Control gilts, and 2.7 kg/d by Ad lib gilts. Increased feed intake by Restricted gilts during breeding resulted in compensatory gains that overcame the reduced reproductive performance that resulted from the reduced BW and backfat these gilts carried at the start of breeding. Days to first estrus and pregnancy were not influenced by development period treatment (P < 0.13). Percentage of Ad lib, Control, and Restricted gilts that successfully completed their pregnancies were 61, 74, and 66, respectively (P > 0.19). Total feed fed from 13 wk of age to end of the first pregnancy per gilt assigned did not differ among Ad lib (506 kg) and Control (498 kg) gilts but was less (P < 0.01) in Restricted gilts (451 kg). Number of piglets born per gilt assigned (P > 0.09) and piglets produced per kilogram of feed fed from 13 wk of age to term (P > 0.29) were 6.47 and 0.0134 in Ad lib gilts, 7.26 and 0.0150 in Control gilts, and 6.38 and 0.0149 in Restricted gilts, respectively. Moderate feed restriction, 74% of ad libitum intake, reduced feed consumed from 13 wk of age to end of the first pregnancy with no significant impact on efficiency of piglet production.

Animal Feed↗

PubMed2026

Saliva-based RT-LAMP assays support heat shock protein 70 as a promising transcript marker for estrus identification in buffaloes.

Buffaloes do not exhibit overt estrus signs particularly during summer, leading to a significant economic loss to farmers. Previous studies have identified several candidate transcripts (HSP70, TIMP1, TLR4 and HSD17B1), abundant in buffalo saliva during estrus stage. However, there is no widely applicable technology for estrus detection targeting these transcripts. Therefore, the present study aimed to develop reverse transcription loop mediated isothermal amplification (RT-LAMP) assays for these candidate transcripts using buffalo saliva. Saliva samples were collected from 10 cyclic buffaloes and RT-LAMP assays were optimized for salivary RNA as well as direct saliva. Among the four candidate transcripts, HSP70 showed a statistically significant colour change (p-value = 0.0191) at the estrus stage compared to the diestrus stage. This abundance of HSP70 was also supported in large simulated population datasets (10,000 animals) generated using R. Further, the RT-LAMP assays were tested using direct saliva without RNA isolation, and the colour change in the samples during estrus suggested the feasibility of estrus identification using direct saliva, overcoming the tedious step of RNA isolation. The detection of HSP70 using either direct saliva or salivary RNA indicated its potential as a marker for estrus identification. Similarly, TLR4 appeared to be another potential biomarker for RT-LAMP reaction using direct saliva, but it needs further validation in both RNA and direct saliva samples. Overall, the proof-of-concept on RT-LAMP assays optimized for salivary transcripts in the present study would be useful for estrus identification in tropical production systems following further validation on a larger sample size.

Animals↗

PubMed1996

Evaluation of timed insemination using a gonadotropin-releasing hormone agonist in lactating dairy cows.

An experiment compared the effectiveness of a timed AI and an AI at observed estrus. Lactating dairy cows were injected with PGF2 alpha at 30 +/- a range of 3 d postpartum, with a GnRH agonist at 65 +/- a range of 3 d, and with PGF2 alpha 7 d later; control cows (n = 128) were inseminated at detected estrus, but cows in the timed AI group (n = 171) received a second injection of GnRH agonist 48 h after the injection of PGF2 alpha and were inseminated 16 h later. Control cows that were not inseminated within 7 d were resynchronized with GnRH agonist, followed 7 d later with an injection of PGF2 alpha. Pregnancy rate was 30.5% for control cows and 29.0% for cows in the timed AI group, and conception rate was 41.5% for control cows and 26.5% for cows in the timed AI group. Days open for cows that conceived by 120 d postpartum was 83.6 d for control cows and 79.2 d for cows in the timed AI group. Treatment by month interactions indicated that pregnancy and conception rates and days open for cows that conceived were more consistent across months for cows in the timed AI group. Differences (control vs. timed AI) were not detected for overall pregnancy rate by 120 d postpartum (58.8 +/- 4.7% vs. 56.2 +/- 4.4%). Conception and pregnancy rates at first synchronization were influenced positively by body condition and plasma concentrations of progesterone at 65 d postpartum. Timed AI was an effective alternative for reproductive management.

Animals↗

PubMed2000

Effect of intrauterine treatment with prostaglandin E2 prior to insemination of mares in the uterine horn or body.

Two trials were conducted to investigate the effects of intrauterine infusion of PGE2 and uterine horn insemination on pregnancy rates in mares achieved by breeding with a suboptimal number of normal spermatozoa. Estrus was synchronized and mares were teased daily with a stallion to detect estrus. Mares in estrus were examined by transrectal palpation and ultrasonography to monitor follicular status. On the first day a 35-mm diameter follicle was present, hCG (1500 IU, iv) was administered and the mares were bred the next day. Mares (Trial 1, n = 34; Trial 2, n = 28) were inseminated with 25 million total spermatozoa from either a stallion with good semen quality (Trial 1) or poor semen quality (Trial 2). In each trial, mares were assigned to 1 of 4 treatment groups as follows: Group PGE-HI - infusion of 0.25 mg PGE2 into the proximal end of the uterine horn ipsilateral to the dominant follicle 2 h prior to insemination in the proximal end of the same uterine horn; Group PGE-BI - infusion of 0.25 mg PGE2 into the proximal end of the uterine horn ipsilateral to the dominant follicle 2 h prior to insemination in the uterine body; Group SAL-HI - infusion of 1 mL sterile saline into the proximal end of the uterine horn ipsilateral to the dominant follicle 2 h prior to insemination in the proximal end of the same uterine horn; or Group SAL-BI - infusion of 1 mL sterile saline into the proximal end of the uterine horn ipsilateral to the dominant follicle 2 h prior to insemination in the uterine body. After breeding, mares were examined daily by transrectal ultrasonography to confirm ovulation, and were re-examined 14 to 16 d after ovulation for pregnancy status. Data were analyzed by Chi-square. Overall pregnancy rates were 59% for stallion 1 and 29% for stallion 2. Group pregnancy rates did not differ for mares bred by either stallion (P > 0.10). Pregnancy rates were not altered by horn insemination for either stallion (P > 0.10). Intrauterine infusion of PGE2 improved pregnancy rate in mares bred by the stallion with good quality semen (P < 0.05), but did not alter pregnancy rate in mares bred by the stallion with poor quality semen (P > 0.10). Further research is warranted to determine if intrauterine infusion of PGE2 will enhance spermatozoal colonization of the oviduct and pregnancy rates in mares, and if PGE-treatment will improve pregnancy rates achieved by subfertile stallions.

Animals↗

PubMed2003

Effect of boar exposure at time of insemination on factors influencing fertility in gilts.

The effect of boar exposure during artificial insemination (AI) on semen backflow, fertilization, and embryo quality was evaluated. Gilts (approximately 170 d) were induced into estrus with PG600, and ovulation was synchronized using hCG 72 h later. Estrus detection was initiated after PG600 and continued at 12-h intervals. At estrus, gilts were allotted to receive boar exposure (BE, n = 20) or no boar exposure (NBE, n = 20) during AI. Gilts receiving NBE were identified to be in estrus prior to AI and the boar was then removed for 1 h, whereas gilts in the BE group received 15 min of exposure during AI. Insemination occurred in crates at 12 and 24 h after onset of estrus with 3 x 10(9) sperm/80 mL. Backflow was collected continuously with samples taken at time 0, (during AI), and at 0.25, 0.5, 0.75, 1, 2, 4, and 8 h after first and second AI. The effect of treatment was evaluated for time of insemination (min), backflow (mL), and sperm in backflow samples. Oviducts were flushed 2 d after first AI to evaluate the effect oftreatment on fertilization rate, accessory sperm numbers on embryos (scored 1 to 5), and embryo quality. There was no effect of first or second AI; therefore, data were pooled. Average duration of AI was 3.7 +/- 0.2 min and was not influenced by BE (P < 0.10). However, during the initial stage of AI, BE reduced the volume of semen (18.6 vs 32.4 +/- 3 mL) and the number of sperm lost (0.8 vs 1.3 +/- 0.15 x 10(9) sperm) compared to NBE (P < 0.05). There was a treatment x time effect (P < 0.05) for volume of backflow. By 45 min, the BE gilts lost more volume (9.0 vs 3.6 mL) compared to the NBE group, but sperm loss did not differ. Between 1 and 8 h after AI, neither volume nor sperm loss was influenced by treatment. By 8 h, total leakage (65 vs 63 mL) and total sperm loss (1.6 x 10(9) vs 1.8 x 10(9) sperm) were not influenced by BE (P > 0.10). However, more accessory sperm (P < 0.01) were found on embryos for the NBE (> or = 11 sperm/embryo) compared to BE embryos (< or = 10 sperm/embryo). Despite this observation, percentages of fertilized embryos (99.5 +/- 0.5 %) and number of embryos (11.5 +/- 0.1) were not different (P > 0.10). In conclusion, AI in the presence of a mature boar did not affect total semen leakage, sperm loss, fertilized embryos, or embryo quality. The importance of boar exposure during insemination was evident from less leakage during insemination, but had no effect on fertility; this suggests that the elimination of boar exposure during AI may not be deleterious to reproductive performance.

Animals↗

PubMed2003

Effect of supplemental nutrient source on heifer growth and reproductive performance, and on utilization of corn silage-based diets by beef steers.

Two experiments were conducted to determine effects of oilseeds or soybean hulls on growth and reproductive performance of heifers and utilization of corn silage diets by growing beef cattle. In Exp. 1, 96 beef heifers (249 kg of BW) were used in a randomized complete block design. Treatments were as follows: 1) corn and soybean meal (CON) at 56% of the DMI; 2) whole linted cottonseed at 15% of the DMI (COT); 3) whole raw soybeans at 15% of the DMI (SB); or 4) pelleted soyhulls at 30% of the DMI (SH). Diets were formulated to be isonitrogenous (13.8% CP) and fed to achieve target weights equal to 65% of expected mature BW at the time of AI. Estrus was synchronized and heifers were inseminated by AI in response to detected estrus. Because the energy value for SH was underestimated, cumulative ADG for SH (1.03 kg/d) was greater (P < or = 0.03) than for CON (0.89 kg/d), COT (0.87 kg/d), or SB (0.86 kg/d). Treatment did not affect (P > 0.10) the proportion of pubertal heifers at the beginning of the breeding season: CON (60%), COT (53%), SB (69%), SH (71%), or first-service conception rates: CON (37%); COT (38%); SB (57%); SH (42%). In Exp. 2, crossbred steers (387 kg) were used in a 6 x 6 Latin square design to evaluate the effects of supplemental nutrient source on utilization of corn silage diets. Treatments included diets used in Exp. 1, plus a negative control (soybean meal at 10% of the DMI; SIL) and whole raw soybeans at 25% of the DMI (SB25). Diets were formulated to be isonitrogenous (13.8% CP) except SB25 (17% CP), and were fed twice daily at 1.8 x NEm. Oilseed inclusion decreased (P < 0.10) acetate:propionate ratios and (P < 0.10) apparent ruminal OM and ruminal and total tract NDF digestibilities. The CON and SH diets had the greatest (P < 0.10) total-tract OM digestibilities. Microbial efficiencies were greatest (P < 0.10), and long chain fatty acid flow to the duodenum increased (P < 0.10) with oilseeds. Biohydrogenation averaged 90.4% and increased slightly (P < 0.10) when oilseeds were added to the diet. Adding oilseeds or soybean hulls to corn silage-based diets did not affect reproductive performance of heifers. Although oilseed additions increased total fatty acid flow to the duodenum, a high degree of biohydrogenation occurred, greatly increasing C18:0, with only marginal increases in unsaturated fatty acid flow. Depending on diet and feeding conditions, inclusion of whole oilseeds may not be an effective means of increasing linoleic acid supply for ruminant animals.

Age Factors↗

PubMed2005

Effects of prepartum lipid supplementation on FSH superstimulation and transferable embryo recovery in multiparous beef cows.

The objective of this experiment was to determine the effect of prepartum lipid supplementation on the number and quality of embryos recovered following ovarian super-ovulation in postpartum suckled beef cows. Mature cows (n = 40) were assigned to one of two treatments (lipid versus. no lipid) and supplemented for approximately 40 days prior to calving. Supplements provided to cows were isocaloric and isonitrogenous. The treatment group was fed 1.6 kg hd(-1) per day of whole soybeans (WSB; 19.8% ether extract, and 41.8% crude protein) and the control group received a supplement consisting of 1.8 kg hd(-1) day of a soybean meal and soy-hull combination (SBS; 2.15% EE and 36.81% CP). Cows were synchronized using a GnRH [Cystorelin((R)) 100 microg im]-GnRH-PGF(2alpha) [Lutalyse 25 mg im] protocol. Cows were administered two injections of GnRH seven days apart and PG seven days after the second GnRH injection. Twenty-eight cows (WSB, n = 15; SBS, n = 13) responded to estrus synchronization and were superstimulated. Super-ovulation was initiated on day 8-10 of the synchronized cycle by twice-daily injections of pFSH (Pluset) over four days in decreasing doses using a total of 608.4 IU per cow. Prostaglandin F(2alpha) was administered 96 and 108 h after super-stimulation was initiated with FSH. Days postpartum (WSB = 59 days; SBS = 57 days) at initiation of FSH treatments were similar (P > 0.10) for both treatments. Cows were monitored for estrus activity by the HeatWatch Estrus Detection System. Twenty-seven cows (WSB, n = 15; SBS, n = 12) exhibited estrus after FSH and inseminated at 0, 12, and 24 h after the onset of estrus with 1, 2, and 1 units of semen, respectively. Embryos were recovered and evaluated 7-8 days later. Only cows that responded to FSH and that were inseminated were used for statistical analysis. Data were analyzed using the General Linear Models Procedure of SAS. Body condition scores did not differ (P > 0.10) between treatments when cows were evaluated at the initiation of the experiment, two weeks prior to calving, and at initiation of superovulation with FSH. Estrous cyclicity prior to the initiation of estrus synchronization did not differ (P > 0.10) between treatments. There was no difference (P > 0.10) between treatments in recovery of total embryos (WSB, 14.7 +/- 3.5; SBS, 17.5 +/- 3.0), transferable embryos (WSB, 10.3 +/- 2.5; SBS, 13.6 +/- 2.6), degenerate embryos (WSB, 3.3 +/- 1.1; SBS, 1.6 +/- 1.7) or unfertilized ova (WSB, 1.1 +/- 0.5; SBS, 2.3 +/- 1.2). Cows that were supplemented with whole soybeans prior to parturition failed to produce an increased total number of ova or transferable embryos following super-ovulation.

Animals↗

PubMed1989

Equine body temperature and progesterone fluctuations during estrus and near parturition.

Body temperature and serum progesterone concentrations were measured in mares to determine if a change in either could be useful in predicting estrus, ovulation or parturition. There was no significant correlation (P > 0.1) between rectal temperature and the environmental temperature or progesterone concentration. Progesterone concentration did correlate with stage of estrous cycle and the stage of pregnancy. Significant differences (P < 0.05) in temperature were noted at different times throughout the day. No change in temperature occurred that could be utilized to predict estrus, ovulation or parturition. The changes in serum progesterone concentration were only useful in detecting estrus.

Journal Article↗