Ultrasonic biparietal diameter of second trimester Pygmy goat fetuses

Four does pregnant with seven Pygmy goat fetuses were scanned transabdominally from Day 36 to Day 102 of gestation using a real-time ultrasound 5 MHz linear-array scanhead. Fetal biparietal diameter (BPD) was measured on symmetrical frozen images using internal electronic calipers. The relationship between gestational age (GA) in days and BPD in millimeters in Pygmy goat fetuses is expressed as: [GA = 23.2 + 2.08 BPD]. This equation can assign GA to Pygmy goat fetuses of unknown conception dates and allow confinement of does near kidding for induced or observed parturition. Mean kid birthweight was 2.0 + 0.45 kg SEM. These observations are consistent with relationships which have been determined for Toggenburg, Nubian and Angora goat fetuses.     

Efficiency of utilization of high and low quality forage by three goat breeds

Alpine, Angora and Nubian kids, 6–8 months old and weighing 15–25 kg were grazed on high quality (wheat) or low quality pasture (dormant bermudagrass) for 54 d to evaluate breed differences and metabolic responses. Each kid on the bermudagrass pasture also received daily 200 g of a 24% CP supplement to stimulate intake.

Wheat pasture had an in vitro organic matter digestibility (IVOMD) of 78 vs. 35% for the Bermuda pasture. Goats gained 50 g/d on wheat pasture vs. 10 g/d on Bermuda pasture (P<0.02). Angora kids gained the least weight on Bermuda (−8 g/d; P<0.05) and most on wheat pasture (62 g/d; P<0.05). Mohair production was greater for Angora goats on wheat pasture compared to those on Bermuda pastures (9.9 vs. 6.2 g/100 cm²; P<0.05). Angora goats on Bermuda pastures had elevated levels of NEFA and plasma ammonia, and reduced levels of plasma urea N, consistent with catabolism of body tissue stores. Angora goats tended to have lower concentration of rumen VFA and ammonia. Angora goats appear to be more sensitive to inanition as compared to Alpine and Nubian goats. Presumably, their obligate nutrient requirements for hair production limits their ability to adapt, making them more vulnerable to nutritional stress.     

Real-time ultrasonic biparietal diameter of second trimester Suffolk and Finn sheep fetuses and prediction of gestational age

Six Suffolk fetuses of known gestational age were examined every other day from Day 43 to Day 96 of gestation using transabdominal real-time ultrasound. Biparietal diameter (BPD) was measured on symmetrical fetal head images. The relationship between days gestational age (GA) and mean BPD in millimeters is described by the equation: [GA = 22.5 + 1.81 BPD]. Repeated ultrasound examination of 9 Finn ewes between 35 and 95 d of gestation revealed the relationship: [GA = 21.4 + 1.85 BPD]. Biparietal diameters were determined for 56 Suffolk X Hampshire fetuses which ranged from 41 to 77 d of gestation. The predicted fetal age using the Suffolk equation was within 1 d of the recorded age for 22 56 , +/-2 d for 34 56 , and +/-3 d for 44 56 fetuses.     

Real-time ultrasonic biparietal diameter measurement for the prediction of gestational age in llamas

Llama (Lama glama ) fetuses (n = 25) of known gestational age (Day 66 to Day 235) were examined transabdominally using real-time ultrasound with a 5 MHz linear-array scanhead. Maximum head width, or biparietal diameter (BPD), was measured in symmetrical images using electronic linear distance calipers. The fetus was easily located and the BPD measured as early as Day 66 of gestation. During the last trimester, measurement became increasingly difficult due to the posture of the fetus and the limited penetration of the 5 MHz frequency. The relationship between days of gestational age (GA) and mean BPD in millimeters is described by the equation: [GA = 18.8 + 3.79 BPD]. Assignment of gestational age allows estimation of parturition date in this frequently pasture-bred and newly polular domestic ruminant.     

Superovulation and recovery of zygotes from Nubian and Alpine dairy goats

Thirty-five purebred dairy goats (18 Alpines and 17 Nubians) were subjected to a superovulating hormone program consisting of an 11-d 6alpha-methyl-17alpha-acetoxy-progesterone; (MAP; 60 mg) intravaginal sponge treatment; 125 ug i.m. injections of the prostaglandin F(2alpha) analogue cloprostenol on d 1 and 9 of vaginal sponge treatment; and a 3-d, twice-a-day injection of 2.5 mg of pituitary follicle stimulating hormone (FSH-P) i.m. starting at day 9. Vaginal sponges were pulled the morning of day 11 at the time of the fifth FSH-P injection. Of 40 initiated superovulatory cycles, 33 does (10 Alpines and 23 Nubians) responded with an average of 17.7 (range 1 to 29) ovulations. There was no significant difference between the breeds with respect to corpora lutea (CLs) plus follicles ovarian response. A significantly greater (P< 0.05) number of Nubian does were in estrus and mated by 36 h after MAP sponge removal. All does that responded to treatment had done so within 72 h of sponge removal. Of the seven (17.5%) does that showed no estrous response to hormone treatment, six were Alpines (P < 0.01). Six goats (two Alpines and four Nubians) were subjected to a second hormone treatment cycle after a 45-d rest. Five of six does responded to a second hormone treatment cycle with four of five responding with a lower total ovarian response. The interval from sponge removal to mating did not affect the stage or quality of eggs harvested. Rather, the interval from mating to surgical flushing determined the stage of egg development. All animals examined from 24 to 32 h after initial mating had not ovulated. By 50 h, 20 of 22 does had ovulated. A total of 242 ovulated eggs (63%) was harvested, of which 199 (82%) were fertilized. Day 7 flushings yielded 36 eggs (67%), of which 28 (78%) were fertilized. This rate of superovulation, fertilization, and embryo recovery lends credibility to this technique in its ultimate objective of rapidly increasing the number of offspring from superior animals.     

Use of fetal biometry to determine fetal age in late pregnancy in llamas

Sixty-three pregnant llamas of known breeding date were used in this study. Forty-six of them were submitted to surgery between 186 and 320 days of gestation (52-91% of average gestation period, respectively). Under general anesthesia their fetuses were exteriorized and fetal weight (W), biparietal diameter (BPD) and femoral (F), tarsus-hoof (T-H), tibial (T)) and fronto-occipital (F-O) length were determined. Additionally, the same variables were determined on 16 newborn llamas. The weight was measured in kg and the length in cm. All the collected data was entered into a spreadsheet and different regression analyses as a function of gestational age (GA) were assessed. The best fit equations and their correlation for linear regression were the following: GA=169.448+16.66(*)W, r=0.99; GA=-51.713+44.77(*)BPD, r=0.88; GA=-72.139+39.48(*)F-O, r=0.71; GA=39.304+8.35(*)T-H, r=0.97; GA=91.276+8.23(*)T, r=0.86; GA=102.029+9.94(*)F, r=0.91. For multiple regression, the dependent variable GA can be predicted by the following equation: GA=67.462+11.163(*)W+20.297(*)BPD. Results of the present study indicated measured variables to be highly correlated with GA. This could be useful on daily basis in clinical examination of the neonates, in assessment of fetal growth and well being with cesarean sections, in the determination of GA in late gestation abortions, and in perinatal and reproductive research in the llama.     

Ear mites from domestic goats in Florida

Ear canals of 284 domestic goats from Florida were examined via swabbing for the presence of ear mites; 57% were infested withPsoroptes cuniculi. Raillietia caprae was recovered from 2 goats in one herd. Breeds examined were Nubian, Alpine, Saanen, Toggenburg, La Mancha, Spanish/ Woods and Pygmy. Goats with dependent ear types were infested more commonly than those with erect ears; no goats with vestigial ears were found to harbor mites. Goats less than 1 year old had a significantly higher mite prevalence than did goats over 1 year of age. Gross lesions were noted in the ear canals of only three individuals.This paper was previously accepted for publication in the journal Goat and Sheep Research prior to that journal's demise.     

Nitrogen metabolism and blood metabolites in three goat breeds fed increasing amounts of protein

Twelve wethers (27–33 kg and 12–14 months of age) representing meat (Nubian), milk (Alpine) and mohair (Angora) producing goats were used to evaluate breed differences in protein utilization with diets containing 9 (L), 15(M) or 21% CP (H) and 2.4 Mcal ME/kg DM in a digestion trial. Fecal N, urine N and absorbed N as percent of N intake were not affected (P>0.05) by breed. Retained N as percent of absorbed N was not different (P>0.05) between breeds. Ruminal propionate (molar %) was lower (P<0.05) in Angora, but other ruminal VFA and ammonia-N were not affected (P>0.05) by diet or breed. Plasma urea-N increased (P<0.01) with dietary CP level (8.3, 22.0 and 33.3 mg/dl for L, M and H, respectively), and concentrations were lowest for Angoras and highest for Nubians (18.5 vs. 21.2 vs. 23.9 mg/dl) (P<0.01). Plasma total protein (mean 69.7 g/l), glucose (mean 83.1 mg/dl), non-esterfied fatty acids (mean 101.4 μEq/l) and cortisol (mean 10.8 ng/ml) were not affected (P>0.05) by breed or diet. Plasma glucagon concentrations increased (P<0.05) with increasing CP intake (72.4, 167.6 and 239.1 pg/ml for L, M and H, respectively). The study indicated that there was no apparent breed difference between Nubian, Alpine and Angora goats in nitrogen utilization when goats were fed pelleted diets containing 9 to 21% CP.     

Real-time ultrasonic fetal head measurement and gestational age in dairy goats

Dairy breed goat fetuses (n = 219) of known gestational age (Day 39 to Day 100) were examined transabdominally using a real-time ultrasound scanner with a 5 MHz linear-array transducer. Maximum head width was measured in symmetrical images using electronic linear distance calipers. This biparietal diameter (BPD) can be accurately measured as early as Day 40, but measurement becomes difficult after Day 105 of gestation due to the variability of fetal location and posture. The uniform, linear increase in BPD in the second trimester should allow for the accurate assignment of gestational age for doe confinement or induction of kidding.     

Umbilical artery doppler sonography in Saanen goat fetuses during singleton and multiple pregnancies

The objective of this study was to evaluate the blood flow from the umbilical artery (UA) in healthy pregnant goats. Doppler sonography examinations were performed every two weeks in Saanen goats with a singleton (n = 5) or multiple (n = 4) pregnancy from 40 to 145 days of gestation. Fetal heart rates (FHR), pulsatility index (PI), and resistance index (RI) were recorded from the mid-cord site of the free-floating umbilical cord. FHR decreased gradually as the pregnancy progressed and significantly decreased during the last two examinations of all fetuses (P < 0.05). The mean PI level was dramatically different (P < 0.05) until 85 days of gestation, after which it reached a plateau level until parturition. Similar to PI, RI decreased by 85 days of gestation (P < 0.05), and decreased again by 130s gestation. No reverse or absent end-diastolic flow were observed in fetuses during any examinations. When comparing singleton and multiple pregnancies, there were no significant differences in UA pulsatility or resistance in fetuses seen. The middle of the second trimester was observed to be a threshold stage for indices in the pattern of caprine pregnancy.In conclusion, this work provides additional values that might be useful when evaluating singleton and multiple pregnancies, and may be evaluated in further studies regarding fetal monitoring.     

Polymorphism of bone morphogenetic protein 4 gene and its relationship with litter size of Jining Grey goats

Two pairs of primers (P1 and P2) were designed to detect single nucleotide polymorphisms of exon 2 and intron 2 of bone morphogenetic protein 4 (BMP4) gene in both high fecundity breed (Jining Grey goat) and low fecundity breeds (Boer, Angora and Inner Mongolia Cashmere goats) by single strand conformation polymorphism. Results showed that no polymorphism was detected for exon 2 (primer P1) of BMP4 gene in four goat breeds. For intron 2 (primer P2), three genotypes (AA, AB and BB) were detected in Jining Grey and Inner Mongolia Cashmere goats, two genotypes (AB and BB) in Angora goats, and only one genotype (AA) in Boer goats. Sequencing revealed one mutation (2203G>A) of BMP4 gene in the genotype BB in comparison to the genotype AA. The differences of litter size between AA, AB and BB genotypes were not significant (P > 0.05) in Jining Grey goats. A pair of primer (P3) was designed to detect polymorphism in the 3' flanking region of BMP4 gene that contained dinucleotide repeated sequence (CA) in the four goat breeds by microsatellite analysis. For primer P3, three genotypes (CC, CD and DD) were detected in four goat breeds. Sequencing revealed one more CA dinucleotide in genotype DD than in genotype CC. The Jining Grey does with genotype CC had 0.55 (P < 0.05) or 0.72 (P < 0.05) kids more than those with genotype CD or DD. These results preliminarily indicated that allele C of BMP4 gene is a potential DNA marker for improving litter size in goats.     

NMR studies of triple-strand formation from the homopurine-homopyrimidine deoxyribonucleotides d(GA)4 and d(TC)4

The complexes formed by the homopurine and homopyrimidine deoxyribonucleotides d(GA)4 and d(TC)4 have been investigated by one- and two-dimensional 1H NMR. Under appropriate conditions [low pH, excess d(TC)4 strand] the oligonucleotides form a triplex containing one d(GA)4 and two d(TC)4 strands. The homopurine and one of the homopyrimidine strands are Watson-Crick base paired, and the second homopyrimidine strand is Hoogsteen base paired in the major groove to the d(GA)4 strand. Hoogsteen base pairing in GC base pairs requires hemiprotonation of C; we report direct observation of the C+ imino proton in these base pairs. Both homopyrimidine strands have C3'-endo sugar conformations, but the purine strand does not. The major triplex formed appears to have four TAT and three CGC+ triplets formed by binding of the second d(TC)4 strand parallel to the d(GA)4 strand with a 3' dangling end. In addition to the triplexes formed, at least one other heterocomplex is observed under some conditions.     

Power of 22 microsatellite markers in fluorescent multiplexes for parentage testing in goats (Capra hircus)

Two multiplex systems, each containing 11 microsatellite loci, were developed for semiautomated parentage testing in goats. Eight of the loci originate from goats, nine from cattle and five from sheep. Eighteen of the loci have been mapped to 16 different autosomes (in goats and cattle). Parentage exclusion probabilities were computed from allele frequencies in approximately 30 unrelated individuals from each of four economically important breeds: Mongolian Native Cashmere, Turkish Angora, Swiss Saanen, and Spanish Murciana-Grenadina. In cases where genotypes are known for one parent and an offspring, the 22 markers will exclude an (erroneously) alleged parent with a probability of > 0.999999 in the cashmere breed, > 0.99999 in Angora and Murciana-Grenadina, and > 0.9999 in Saanen. The multiplexes provide very high power for individual identification as the probability of finding two identical genotypes for the 22 loci is < 1 in 1.10(15) in each of the four breeds. The multiplexes will also be useful for studies of population structure, history, and diversity in goats and also in wild Capra species that represent important resources for genetic improvement of domestic breeds.     

The effects of low level of feeding on response to synchronization of estrus, ovulation rate and embryo loss in goats

Mature nonlactating British Saanen and Toggenburg does with a body score 2 were fed 25% (n=24) and 100% (n=16) maintenance rations from about 19 days before mating until slaughter at approximately 60 days after mating. Estrus was synchronized using PGF(2alpha), and the ovulation rate was determined by laparoscopic examination of the ovaries once between Days 6 and 10 after mating. Pregnancy rate, potential kidding rate and embryo loss were determined by counts of viable fetuses at slaughter. The proportion of does in estrus within 96 hours of PGF(2alpha) administration was not different (P<0.5) between the feed-restricted and the maintenance groups (71.0% and 87.5%, respectively); however, the time of onset of estrus after PGF(2alpha) tended to be longer (P=0.12) in the feed-restricted group. Ovulation rate, incidence of multiple ovulations and proportion of does pregnant at 60 days were significantly lower (P=0.0004, P=0.025, P=0.05, respectively) in the restricted group. More embryos from single than multiple ovulations were lost in the restricted group (P=0.01). There was no difference in the overall ovulatory activity between right and left ovaries in the 2 groups. Transuterine migrations were observed in all does that had unilateral multiple ovulations. No migration was observed in does which had single ovulations. These data indicate that restricted feed intake in goats tended to delay the onset of estrus and lowered the ovulation rate, incidence of multiple ovulations, and pregnancy rate.     

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.     

Prediction of gestational age by ultrasonic fetometry in llamas (Lama glama) and alpacas (Lama pacos)

Fetal biparietal diameter (BPD) and thorax height (TH) were measured by ultrasound during intrauterine growth in pregnant llamas (Lama glama) and alpacas (Lama pacos). The goal was to establish representative curves that allows estimation of gestational age (GA) from real-time ultrasonic measurements of these fetal structures at any stage of gestation. Llamas and alpacas were mated under controlled conditions. Ultrasound exams were conducted to determine pregnancy status 1 month later. Measurements of fetal BPD and TH were conducted from the second month of pregnancy until term. Observation and assessment of fetal TH was difficult during the last 3 months of pregnancy, specially in llamas. Regression curves were calculated from the data as a function of GA, with the best fit represented by the following equations: llama GA=(BPD-0.002399)43.02293,r=0.98,P<0.001; llama GA=(TH-0.07137)46.94485, r=0.95,P<0.001; alpaca GA=(BPD-0.11376)47.23287, r=0.98,P<0.001; alpaca GA=(TH-0.36436)52.87663, r=0.96,P<0.001, where GA was measured in days and BPD and TH in centimeters. Results indicate that ultrasonic measurement of these fetal biometric variables constitute a valuable tool to estimate GA at any stage of pregnancy in these domestic South American camelids.     

Shearing at the end of summer affects body temperature of free-living Angora goats ( Capra aegagrus) more than does shearing at the end of winter

Angora goats are known to be vulnerable to cold stress, especially after shearing, but their thermoregulatory responses to shearing have not been measured. We recorded activity, and abdominal and subcutaneous temperatures, for 10 days pre-shearing and post-shearing, in 10 Angora goats inhabiting the succulent thicket of the Eastern Cape, South Africa, in both March (late summer) and September (late winter). Within each season, environmental conditions were similar pre-shearing and post-shearing, but September was an average 5°C colder than March. Shearing resulted in a decreased mean (P < 0.0001), minimum (P < 0.0001) and maximum daily abdominal temperature (P < 0.0001). Paradoxically, the decrease in daily mean (P = 0.03) and maximum (P = 0.01) abdominal temperatures, from pre-shearing to post-shearing, was greater in March than in September. Daily amplitude of body temperature rhythm (P < 0.0001) and the maximum rate of abdominal temperature rise (P < 0.0001) increased from pre-shearing to post-shearing, resulting in an earlier diurnal peak in abdominal temperature (P = 0.001) post-shearing. These changes in amplitude, rate of abdominal temperature rise and time of diurnal peak in abdominal temperature suggest that the goats' thermoregulatory system was more labile after shearing. Mean daily subcutaneous temperatures also decreased post-shearing (P < 0.0001), despite our index goat selecting more stable microclimates after shearing in March (P = 0.03). Following shearing, there was an increased difference between abdominal and subcutaneous temperatures (P < 0.0001) at night, suggesting that the goats used peripheral vasoconstriction to limit heat loss. In addition to these temperature changes, mean daily activity increased nearly two-fold after March shearing, but not September shearing. This increased activity after March shearing was likely the result of an increased foraging time, food intake and metabolic rate, as suggested by the increased water influx (P = 0.0008). Thus, Angora goats entered a heat conservation mode after shearing in both March and September. That the transition from the fleeced to the shorn state had greater thermoregulatory consequences in March than in September may provide a mechanistic explanation for Angora goats' vulnerability to cold in summer.     

Serum LH,FSH, estradiol-17β and progesterone profiles of native and crossbred goats in a tropical semiarid zone of Venezuela during the estrous cycle

The patterns of serum luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone and estradiol-17β during the estrous cycle of six crossbred (Alpine × Nubian × Native) and six native goats showing a 21 day estrous cycle in a semiarid zone of Venezuela are presented. In the crossbred goats, FSH had two significant peaks on Days 19 and 0 (33 ± 8.6 ng ml⁻¹ and 25 ± 6 ng ml⁻¹, respectively); in contrast, native goats only had one significant peak on the day of estrus (22 ± 2 ng ml⁻¹), with the increase beginning on Day 17. During the follicular phase of crossbred goats, estradiol-17β and LH increased to 28 ± 6 pg ml⁻¹ and 23 ± 6.9 ng ml⁻¹, respectively, on Day 0. Prior to Day 0, LH increased to 10.0 ± 4.9 ng ml⁻¹ on Day 18, decreasing to 1.5 ng ml⁻¹ on Day 19, while estradiol-17β was increasing. This relationship between estradiol-17β and LH was not found to exist in native does, which presented a LH peak on Day 0 (30 ± 8 ng ml⁻¹ and 35 ± 10 ng ml⁻¹ in first and second estrus, respectively). LH basal levels were notably higher in native does. The highest concentrations of progesterone (10 and 12 ng ml⁻¹) were detected on Days 12 and 15 in crossbred and native females, respectively. In conclusion, the relationship between estradiol-17β and gonadotropins during the follicular phase in crossbred goats suggests negative and positive feedback effects on both LH and FSH. Serum concentrations of LH were higher in native than in crossbred goats, whereas concentrations of FSH were higher in crossbred does. Thus, genetic factors need to be taken into account when comparing blood levels of gonadotropins in goats raised in tropical semiarid zones.     

Dating of Pregnancy in First versus Second Trimester in Relation to Post-Term Birth Rate: A Cohort Study

Objectives

To evaluate in a national standardised setting whether the performance of ultrasound dating during the first rather than the second trimester of pregnancy had consequences regarding the definition of pre- and post-term birth rates.

Methods

A cohort study of 8,551 singleton pregnancies with spontaneous delivery was performed from 2006 to 2012 at Copenhagen University Hospital, Holbæk, Denmark. We determined the duration of pregnancy calculated by last menstrual period, crown rump length (CRL), biparietal diameter (1^st trimester), BPD (2^nd trimester), and head circumference and compared mean and median durations, the mean differences, the systematic discrepancies, and the percentages of pre-term and post-term pregnancies in relation to each method. The primary outcomes were post-term and pre-term birth rates defined by different dating methods.

Results

The change from use of second to first trimester measurements for dating was associated with a significant increase in the rate of post-term deliveries from 2.1–2.9% and a significant decrease in the rate of pre-term deliveries from 5.4–4.6% caused by systematic discrepancies. Thereby 25.1% would pass 41 weeks when GA is defined by CRL and 17.3% when BPD (2^nd trimester) is used. Calibration for these discrepancies resulted in a lower post-term birth rate, from 3.1–1.4%, when first compared to second trimester dating was used.

Conclusions

Systematic discrepancies were identified when biometric formulas were used to determine duration of pregnancy. This should be corrected in clinical practice to avoid an overestimation of post-term birth and unnecessary inductions when first trimester formulas are used.