Distocia em éguas ­ Estudo retrospectivo de cinco casos / Dystocia in mares ­ Retrospective study of five cases

O objetivo deste trabalho foi realizar um estudo retrospectivo de cinco casos de cesarianas em éguas, atendidos no Hospital Veterinário da Universidade Estadual de Maringá, campus Umuarama (HVGA-UEM), no período de 2019 a 2021, em quatro éguas da raça Quarto de Milha e uma da Crioula, com queixa principal de parto prolongado e distocias por diferentes motivos. Destes, três casos (60%) tiveram alta médica (3/5), enquanto 40% (2/5) em consequência de complicações pós-operatórias e pela gravidade do quadro clínico evoluíram para o óbito. As distocias são raras em éguas, quando comparados com outras espécies e, essa particularidade, pode ser justificada pela conformação anatômica do sistema reprodutivo e a classificação placentária das éguas, que propiciam contrações rápidas e efetivas facilitando a progressão do parto normal. Dessa forma, nos casos de distocia, em que as manobras obstétricas são incapazes de corrigir o mau posicionamento fetal, a cesariana passa a ser o procedimento de eleição, no presente estudo, nenhuma égua apresentou dilatação suficiente para que fosse conduzida a fetotomia. Como medida complementar, norteada pelos princípios de bem-estar animal, foi sugerido aos proprietários, que não colocassem esses animais na estação reprodutiva seguinte, restringindo-se a sua utilização somente como doadoras de embriões. Portanto, foi possível concluir que a sobrevida das éguas submetidas a cesariana é de 60% nas condições deste estudo, o monitoramento das éguas gestantes é um fator determinante sobre os índices de mortalidade materno-fetal.

The objective of this study was to make a descriptive analysis of 5 cases of caesarean sections in mares. The five reported cases were treated at the Veterinary Hospital of the State University of Maringa, campus Umuarama (HVGA-UEM), from 2019 to 2021. Four Quarter Horse mares and one Crioula, complaining of prolonged delivery and dystocia due to different reasons. Of these, three cases were discharged 60% (3/5), while the other three 40% (2/5), due to postoperative complications and the severity of the clinical condition, progressed to death. Dystocia births are rare in mares, when compared to other species, this particularity, can be justified by the anatomical conformation of the reproductive system and the placental classification of mares, which provide rapid and effective contractions, which facilitate the progression of normal or eutocia birth. Thus, in cases of dystocia in mares, those in which obstetric maneuvers are unable to correct fetal malposition, cesarean section becomes the emergency procedure of choice. As a complementary measure, guided by the principles of animal welfare, owners were suggested not to place these animals in the next reproductive season, restricting their use only as embryo donors. Thus, it was possible to conclude that the survival of mares undergoing cesarean is 60% under the conditions of this study, uses had no vital signs at the time of the procedure and/or evolved to death during the post-surgical period immediate.

[Birth of a vital puppy following prolonged whelping in a Labrador Retriever]. / Geburt eines lebenden Labradorwelpen nach deutlich verlängerter Geburt.

An 8-year-old primiparous Labrador Retriever bitch was presented to the clinic 46 hours following the delivery of 2 vital and one stillborn puppy due to an increase of vaginal discharge. At the veterinary clinic, the dog spontaneously delivered an additional healthy puppy without any obstetric support. The findings of the general and gynaecological examinations as well as results of blood analyses were within normal limits. This case shows that extremely prolonged whelping process may be a rare but possible phenomenon in bitches. However, it is recommended to re-evaluate dam and fetuses regularly in case the inter-whelping interval exceeds the normal time span in order to recognize further signs of dystocia and induce obstetric support when clinically indicated.

Breed- and trait-specific associations define the genetic architecture of calving performance traits in cattle.

Reducing the incidence of both the degree of assistance required at calving, as well as the extent of perinatal mortality (PM) has both economic and societal benefits. The existence of heritable genetic variability in both traits signifies the presence of underlying genomic variability. The objective of the present study was to locate regions of the genome, and by extension putative genes and mutations, that are likely to be underpinning the genetic variability in direct calving difficulty (DCD), maternal calving difficulty (MCD), and PM. Imputed whole-genome single-nucleotide polymorphism (SNP) data on up to 8,304 Angus (AA), 17,175 Charolais (CH), 16,794 Limousin (LM), and 18,474 Holstein-Friesian (HF) sires representing 5,866,712 calving events from descendants were used. Several putative quantitative trait loci (QTL) regions associated with calving performance both within and across dairy and beef breeds were identified, although the majority were both breed- and trait-specific. QTL surrounding and encompassing the myostatin (MSTN) gene were associated (P < 5 × 10-8) with DCD and PM in both the CH and LM populations. The well-known Q204X mutation was the fifth strongest association with DCD in the CH population and accounted for 5.09% of the genetic variance in DCD. In contrast, none of the 259 segregating variants in MSTN were associated (P > × 10-6) with DCD in the LM population but a genomic region 617 kb downstream of MSTN was associated (P < 5 × 10-8). The genetic architecture for DCD differed in the HF population relative to the CH and LM, where two QTL encompassing ZNF613 on Bos taurus autosome (BTA)18 and PLAG1 on BTA14 were identified in the former. Pleiotropic SNP associated with all three calving performance traits were also identified in the three beef breeds; 5 SNP were pleiotropic in AA, 116 in LM, and 882 in CH but no SNP was associated with more than one trait within the HF population. The majority of these pleiotropic SNP were on BTA2 surrounding MSTN and were associated with both DCD and PM. Multiple previously reported, but also novel QTL, associated with calving performance were detected in this large study. These also included QTL regions harboring SNP with the same direction of allele substitution effect for both DCD and MCD thus contributing to a more effective simultaneous selection for both traits.

Surgical repair of third-degree perineal lacerations with rectovestibular fistulae in dairy cattle: a series of four cases (2010-2018).

We describe the successful surgical repair of third-degree perineal lacerations with rectovestibular fistulae in four cases using the single-stage modified Aanes method with purse-string suture of the vaginal vestibule and rectum. Fistulae formation and dehiscence of the repair were not observed after surgery. Two cows had five calves and one cow had four calves after surgery. The pregnant cows delivered normally. Additionally, there was no dehiscence of the suture line during the subsequent parturition. The breeding and fertility results obtained after the surgery are presented. According to the results of the present study, the modified Aanes method for the repair of third-degree perineal lacerations with rectovestibular fistulae appears to have a good prognosis for fertility following surgery in cows.

REVIEW OF VETERINARY INTERVENTION IN REPRODUCTION OF CAPTIVE WESTERN LOWLAND GORILLAS (GORILLA GORILLA GORILLA) FROM 1996 TO 2016.

In order to gain an understanding of the frequency of veterinary intervention during the periparturient period of western lowland gorillas (Gorilla gorilla gorilla) in captivity between 1996 and 2016, a survey was sent to institutions associated with the Association of Zoos and Aquariums' Gorilla Species Survival Plan®. A total of 193 births were reported during the survey period, from 51/53 institutions. There were six incidences of prolonged labor (longer than 6 hr; 3%), six cases of cesarean section (3%), and three incidences of veterinary intervention that did not involve a cesarean section (2%). Fifty-one gorilla neonates (26%) were assist-reared (required intervention lasting longer than 24 hr). Out of 51 attempts to reintroduce neonates to dams or surrogates, 42 were accepted (82%), while nine attempts (18%) were deemed failures. The age group with the highest rate of maternal or surrogate acceptance after reintroduction was between 6 and 12 mo of age. Compared to data from a 1981 survey, the percentage of assist-reared gorillas decreased from 64% to 26%. Results show that veterinary intervention in the periparturient period is low, and there is a high rate of acceptance of neonates by either the dam or a surrogate after intervention. Advances in captive husbandry and veterinary knowledge have led to a reduced risk of veterinary intervention during gorilla parturition; however, the long-term effects on behavioral development of the neonate should be considered before removal of the infant from the dam for any period of time.

COMPLICATIONS ASSOCIATED WITH PREGNANCY AND PARTURITION IN AFRICAN WHITE-BELLIED PANGOLINS (PHATAGINUS TRICUSPIS).

There are no studies to date on the normal reproductive physiology of African white-bellied pangolins (Phataginus tricuspis). As a reclusive species, little is known about normal gestation, successful parturition, and potential complications during pregnancy. Ten female P. tricuspis were diagnosed as pregnant and monitored under professional care. Five developed complications during pregnancies or during parturition and are detailed in this case series. Dystocia occurred in two dams each, with malposition of a singleton fetus. Both dams were successfully treated with surgical intervention by caesarian section. Of the two individuals, one fetus was nonviable, but the other neonate survived and was reared by the dam to weaning. A third pregnant female died during pregnancy from septicemia resulting in death of the preterm fetus. The two additional dams of the five gave birth to full-term neonates. One fetus was stillborn with evidence of fetal distress, and the other died immediately after birth (perinatal death) with undetermined etiology. Based on this case series, complications associated with pregnancy occur in P. tricuspis, indicating the need for further study and close monitoring during impending parturition.

Periparturient Diseases in the Dam.

This article provides an overview of some of the most common diseases affecting the dam in the periparturient period, including disorders of lactation, inappropriate maternal behavior, mastitis, metritis, and eclampsia. The dam experiences hormonal, physiologic, and physical changes during pregnancy, parturition, and lactation. Obtaining a detailed history and performing a thorough physical examination are essential for accurately diagnosing and treating the dam during this unique time. A particular challenge exists when identifying problems in the periparturient period, because all medications and aspects of management impact the health of both the dam and her offspring.

Parturition induction in ewes by a progesterone receptor blocker, aglepristone, and subsequent neonatal survival: Preliminary results.

The clinical effects of aglepristone treatment to induce parturition in ewes and their newborns were reported. Three experimental groups were defined: group AG5 (n = 5), group AG10 (n = 5), and group CG (n = 5) in which ewes were injected twice with 5, 10 mg/kg of aglepristone, and saline solution of ewes, respectively. Different parameters associated with parturition in ewes and their newborns were investigated. Serum progesterone, oxytocin, and free and conjugated total estrogens were measured after treatments until parturition. No statistical difference was found from first aglepristone administration to onset of lambing between AG5 and AG10 (23.90 ± 6.20, 40.00 ± 6.71 hours). Parturition induction in two groups shortened the gestational length significantly compared with the control group (P = 0.003). Dystocia was observed in two ewes in group AG10. The placental weight showed statistically significant difference only between the AG10 and CG (P = 0.039), but no difference was observed in the placental expulsion period between the groups. Decrease in food consumption 24 to 36 hours after parturition in all ewes and skin necrosis in an ewe in group AG5 were observed. Progesterone concentration was significantly lower in AG5 than that in ewes in group AG10 and CG (P < 0.05). No difference was observed in concentrations of free total estrogens and oxytocin between groups. The body temperature of lambs was significantly different between AG10 and CG groups both right after (P = 0.011) and 12 hours after parturition (P = 0.014). The lambs in CG had the highest mean birth weight (4.29 ± 0.28 kg), which was significantly different from the induced groups. No significant difference of blood pH and blood gases values between groups was identified both at birth and 12 hours after parturition for lambs. Significant differences could clearly be observed in total protein and blood urea nitrogen and total protein findings 12 hours after parturition (P < 0.05), whereas no difference was found in blood glucose, albumin, inorganic phosphor, triglyceride, or total cholesterol parameters. The results of this study show that the administration of aglepristone to induce parturition can precisely control lambing time without any side effects in either mothers or lambs.

Breed effects and genetic parameter estimates for calving difficulty and birth weight in a multibreed population.

Birth weight (BWT) and calving difficulty (CD) were recorded on 4,579 first-parity females from the Germplasm Evaluation Program at the U.S. Meat Animal Research Center (USMARC). Both traits were analyzed using a bivariate animal model with direct and maternal effects. Calving difficulty was transformed from the USMARC scores to corresponding -scores from the standard normal distribution based on the incidence rate of the USMARC scores. Breed fraction covariates were included to estimate breed differences. Heritability estimates (SE) for BWT direct, CD direct, BWT maternal, and CD maternal were 0.34 (0.10), 0.29 (0.10), 0.15 (0.08), and 0.13 (0.08), respectively. Calving difficulty direct breed effects deviated from Angus ranged from -0.13 to 0.77 and maternal breed effects deviated from Angus ranged from -0.27 to 0.36. Hereford-, Angus-, Gelbvieh-, and Brangus-sired calves would be the least likely to require assistance at birth, whereas Chiangus-, Charolais-, and Limousin-sired calves would be the most likely to require assistance at birth. Maternal breed effects for CD were least for Simmental and Charolais and greatest for Red Angus and Chiangus. Results showed that the diverse biological types of cattle have different effects on both BWT and CD. Furthermore, results provide a mechanism whereby beef cattle producers can compare EBV for CD direct and maternal arising from disjoined and breed-specific genetic evaluations.

Potential Contribution of Cytomegalovirus Infection to Prenatal and Early Neonatal Mortality of Monkeys in the Adler Breeding Center.

Scrapings from the cervical canals and uterine cavities of females with a history of miscarriages, pathological deliveries, and stillbirths were tested for the cytomegalovirus DNA. The incidence of the agent in the females with a history of gestosis and abnormal deliveries was significantly higher than in females without anamnesis of this kind. Parenchymatous organs of stillborn neonates and animals dead during the first month of life were studied. This analysis and studies of the umbilical cords and placentas showed generalized cytomegalovirus infection in 22% dead animals, which objectively proved intrauterine infection.

Evaluation of the effects of treating dairy cows with meloxicam at calving on retained fetal membranes risk.

Some non-steroidal anti-inflammatory drugs increase the risk of retained fetal membranes. This is the first study to investigate the effects of meloxicam on the risk of retained fetal membranes. Administration of meloxicam to dairy cattle immediately following calving revealed no differences in the incidence of retained fetal membranes between meloxicam-treated and untreated animals. There was no difference between the 2 groups in the incidence of periparturient diseases following calving. Meloxicam can be used on the day of calving in lactating cows without increasing the risk of retained fetal membranes.

L'évaluation des effets d'une injection de méloxicam immédiatement après le vêlage chez la vache laitière sur le risque de rétention des membranes foetales. Certains médicaments inflammatoires non-stéroïdiens augmentent le risque de rétention de membranes fœtales. Cette étude est la première à examiner les effets du méloxicam quant au risque de rétention de membranes fœtales. Aucune différence n'a été notée dans le cas de rétention de membranes fœtales lors du vêlage chez la vache laitière entre les vaches qui ont reçu une injection de méloxicam immédiatement après le vêlage et celles qui n'ont rien reçu. De plus, il n'y avait aucune différence d'incidence de maladies périnatales observées suite au vêlage entre les deux groupes. On peut donc administrer du méloxicam aux vaches laitières le jour du vêlage sans augmenter le risque de rétention de membranes fœtales.(Traduit par les auteurs).

Hand-assisted laparoscopic repair of a grade IV rectal tear in a postparturient mare.

CASE DESCRIPTION: An 8-year-old multiparous Thoroughbred broodmare was admitted for evaluation of a rectal tear sustained during parturition. CLINICAL FINDINGS: On initial evaluation, the mare had mild signs of abdominal discomfort. A full-thickness rectal tear located 30 cm cranial to the anus and extending approximately 15 cm longitudinally along the surface of the small colon between the 4 and 6 o'clock positions, when viewed from behind, was diagnosed on examination per rectum. TREATMENT AND OUTCOME: Laparoscopic evaluation of the abdomen was performed to assess the tear and extent of peritoneal contamination. A hand-assisted repair via a flank incision was performed. The tear was closed in a single-layer, simple continuous pattern with size-0 polydioxanone with a handheld needle holder. Subsequently, a ventral midline celiotomy was performed, and intestinal contents were evacuated via a pelvic flexure enterotomy and a typhlotomy. Following surgery, the mare was managed with IV fluid therapy, partial parenteral nutrition, antimicrobials, and NSAIDs for 5 to 7 days before being gradually reintroduced to a complete pelleted feed and alfalfa hay. Prior to discharge, examination per rectum revealed no stricture formation associated with repair. The mare was discharged from the hospital and performed successfully as a broodmare, with the delivery of a live foal 1 year after surgery. CLINICAL RELEVANCE: Successful repair with an excellent outcome was achieved in this mare. Hand-assisted laparoscopic repair should be considered as a possible treatment option in horses with grade IV rectal tears.

Dairy calving management: description and assessment of a training program for dairy personnel.

The objective of this study was to assess the effectiveness of a comprehensive calving management program designed to enhance the flow of applied, research-based, calving information to dairy personnel. Calving personnel (n=70), serving an estimated 18,100 cows from 18 Ohio dairies, attended the calving management program (∼1h of training and ∼2h of demonstration). Description of the birth canal, behavioral signs of normal parturition (stages I to III), dystocia (presentations, positions, and postures), hygiene practices during the assistance procedure, strategies for intervention (when and how to intervene), record-keeping, communication (when to call for help), and newborn care were discussed. Posttraining follow-ups (2/yr) were available for participating personnel. Educational materials were delivered through lectures followed by group discussions and hands-on demonstrations. Attendees were assessed using pre- and posttests of knowledge to determine the level of knowledge gained during the training program. Participants evaluated the program and provided feedback at the conclusion of the program. Dairy personnel reported that the overall program, presentations, and discussions were useful. The presented materials and demonstrations substantially increased the knowledge level of the attendees by 20.9 percentage points from pre- to posttest scores. Importance of open communication within the farm team, recognizing the landmarks for parturition, signs of calving progress, reference times for intervention, hygiene practices at calving, and strategies to correct abnormal presentation, position, or posture were listed as learned concepts with immediate field application. The follow-up assessment with participant personnel revealed that they were able to implement and apply their learned skills, communicate calving records with the farm team, and follow written calving protocols. Results indicated that the workshop was relevant and effective, offering information with immediate field application.

Perioperative risk factors for mortality and length of hospitalization in mares with dystocia undergoing general anesthesia: a retrospective study.

This study investigated associations between perioperative factors and probability of death and length of hospitalization of mares with dystocia that survived following general anesthesia. Demographics and perioperative characteristics from 65 mares were reviewed retrospectively and used in a risk factor analysis. Mortality rate was 21.5% during the first 24 h post-anesthesia. The mean ± standard deviation number of days of hospitalization of surviving mares was 6.3 ± 5.4 d. Several factors were found in the univariable analysis to be significantly associated (P < 0.1) with increased probability of perianesthetic death, including: low preoperative total protein, high temperature and severe dehydration on presentation, prolonged dystocia, intraoperative hypotension, and drugs used during recovery. Type of delivery and day of the week the surgery was performed were significantly associated with length of hospitalization in the multivariable mixed effects model. The study identified some risk factors that may allow clinicians to better estimate the probability of mortality and morbidity in these mares.

TRPV6 and Calbindin-D9k-expression and localization in the bovine uterus and placenta during pregnancy.

BACKGROUND: Transient receptor potential channel type 6 (TRPV6) and Calbindin-D9k (CaBP-9k) are involved in the active calcium (Ca2+) transport mechanism in many tissues including placenta and uterus, suggesting a role in the establishment and maintenance of pregnancy. Moreover, TRPV6 and CaBP-9k seem to support the materno-fetal Ca2+ transport that is crucial for fetal Ca2+ homeostasis, bone growth and development. However, it is unknown if these proteins are also involved in the aetiology of pathologies associated with parturition in cows, such as retained fetal membranes (RFM). The aim of the current study was to create an expression profile of uterine and placentomal TRPV6 and CaBP-9k mRNAs and proteins during pregnancy and postpartum in cows with and without fetal membrane release. METHODS: Uteri and placentomes of 27 cows in different stages of pregnancy and placentomes of cows with and without RFM were collected. Protein and mRNA expression of TRPV6 and CaBP-9k was investigated by real-time PCR, immunohistochemistry and Western blot. RESULTS: In the uterine endometrium, highest TRPV6 and CaBP-9k expression was found in the last trimester of pregnancy, with a particular increase of protein in the glandular epithelium. In the placentomes, a gradual increase in TRPV6 mRNA was detectable towards parturition, while protein expression did not change significantly. Placentomal CaBP-9k expression did not change significantly throughout pregnancy but immunohistochemistry revealed an increase in staining intensity in the maternal crypt epithelium. Immunohistochemical, stronger placental CaBP-9k signals were seen in animals with RFM compared to animals with an undisturbed fetal membrane release, while protein levels, measured by Western blot analyses did not change significantly. CONCLUSIONS: The results of the present study demonstrate a dynamic expression of TRPV6 and CaBP-9k during pregnancy in the bovine uterine endometrium and placentomes, suggesting a functional role for these proteins in Ca2+ metabolism during pregnancy. The temporal and spatial expression patterns indicate that TRPV6 and CaBP-9k may be involved in materno-fetal Ca2+ transport, mainly through an interplacentomal transport, and that both proteins may participate in physiological processes that are crucial for fetal and placental development. However, neither TRPV6 nor CaBP-9k seem to be causative in the retention of fetal membranes.

Effects of periparturient events on subsequent culling and fertility in eight UK dairy herds.

The occurrence of five periparturient events and their effects on subsequent culling and fertility was recorded in eight herds in the UK. Combining data from all 2105 calvings, the proportion affected by assisted calving, dead calf, retained fetal membranes (RFM), milk fever or twins was 5.9, 8.2, 5.3, 5.0 or 3.3 per cent, respectively. Compared with unaffected herdmates, cows with an assisted calving or a dead calf had higher early (but not late) culling rates, (assisted calving: 8.8 per cent being culled before 100 days after calving compared with 5.7 per cent; P=0.05; dead calf: 12.2 per cent culled compared with 5.3 per cent; P=0.001). Compared with unaffected animals, cows with milk fever were four times more likely to be culled before 100 days after calving (16.2 per cent compared with 5.3 per cent; P=0.001), whereas those with RFM were twice as likely to be culled between 100 and 200 days (14.3 per cent compared with 7.6 per cent; P=0.003), and both groups were twice as likely to not be pregnant by 200 days. Cows with RFM or milk fever also had markedly reduced subsequent fertility: both conditions extended calving to pregnancy intervals (by 20 days; P=0.001, or by 13 days; P=0.03, respectively), lowered 100-day in-calf rates (by 24.5 per cent; P=0.001, or by 17.8 per cent; P=0.008, respectively) and lowered 200-day in-calf rates (by 20 per cent; P=0.001, or by 15 per cent; P=0.002, respectively). The birth of twins had no effect on subsequent culling or fertility.

The reproductive performance of female Forest musk deer (Moschus berezovskii) in captivity.

Reproductive performance of 750 adult female Forest musk deer (FMD, Moschus berezovskii) was monitored (from 2005 to 2009) on two Forest musk deer farms in Sichuan province, China. The mean (± SEM) lengths of the estrous cycle, pregnancy, and consecutive fawning intervals were 17.5 ± 0.8 d (n = 64), 182.9 ± 0.8 d (n =190), and 363.2 ± 2.4 d (n = 120), respectively. Copulation occurred from the end of October to early March, with the majority (84.1 ± 1.9%) during November and December (P < 0.05). The fawning rate was 68.7 ± 2.2% in yearling hinds and 73.3 ± 1.3% in adult hinds. Fawning occurred from the end of April to early September, with the majority (88. 9 ± 2.2%) during May and June (P < 0.005), including a peak in May (52.0 ± 1.0%). Yearling hinds fawned later (7.3 ± 1.8 d) than adult hinds. Rates of premature delivery and dystocia were 2.7 ± 0.4 and 2.0 ± 0.3%, respectively. There was a 1.07:1 female-to-male ratio at birth (P > 0.05), with 67.7% twins, but only two cases of triplets and one set of quadruplets among 537 fawns. Birth weight averaged 518.7 ± 10.3 g, ranging from 304 to 775 g (n = 240), with male fawns slightly heavier than females (521.1 ± 14.8 vs 516.9 ± 14.3 g). Postnatal and pre-weaning mortality rates were 25.0 ± 1.2 and 17.9 ± 3.1%, respectively. Postnatal mortality and urinary calculus were much more common in male fawns (P < 0.01). The mortality rate due to suppuration and dyspepsia were different (P < 0.001) between postnatal and pre-weaning periods. Due to higher mortality of male fawns, the adult sex ratio was significantly female-biased. In conclusion, captive FMD had similar seasonal patterns of copulation and fawning as wild FMD and other musk deer species.

Polwarth and Texel ewe parturition duration and its association with lamb birth asphyxia.

The objective of the present study was to test the hypothesis that parturition duration is related to birth asphyxia in lambs and that asphyxia affects newborn lamb viability and vigor. Two sire and dam genotypes (Texel: TX; Polwarth: PW) and their crosses were represented in the study. Eighty lambs (25 PW sire × PW dam, 13 TX × TX, 25 TX × PW, and 17 PW × TX) born to 69 grazing ewes were used. At birth, the log10 length of the second stage of parturition, birth weight, placental weight, and several body measurements were recorded on all lambs, and jugular blood samples were analyzed with the i-Stat Portable Clinical Analyzer (Abbott, Montevideo, Uruguay). A modified Apgar viability score at birth and lamb behavior during their first hour of life were recorded. Brain weight, muscle:bone ratio, and bone density were recorded in 20 male lambs (5 from each breed group) that were euthanized and dissected 24 h after birth. Data were analyzed by linear regression, least squares ANOVA, and ordinal and binary logistic regressions. Mean blood gas and acid-base variables were 7.21 ± 0.09 for pH, 18.4 ± 9.8 mmHg for partial pressure of oxygen, 53 ± 12.5 mmHg for partial pressure of carbon dioxide, and -4 ± 5.1 mmol/L for extracellular fluid base excess. Parturition duration increased with birth weight (P < 0.001) and was shorter in TX ewes (P < 0.001), female lambs (P < 0.05), twins (P < 0.09), and twin females (sex × litter size interaction, P < 0.02). Twenty-six (32.9%) lambs were born asphyxiated (pO2 < 10 mmHg or pH <7.1). Parturition duration increased the risk of asphyxia (P < 0.001), decreased the viability score (P < 0.001), and increased the latency to suckle the udder (P < 0.05). Twin-born lambs presented at birth a 16-fold greater risk of asphyxia (P < 0.01) and reduced placental efficiency (P < 0.05). Texel-sired lambs appeared immature at birth, with less bone density (P < 0.05), smaller brain (P < 0.05), shorter forelimbs (P < 0.05), greater anterior (P < 0.001) and posterior (P < 0.05) neck circumference, and greater muscle:bone ratio (P < 0.05). Immaturity may explain greater TX biotype survival. Together these results demonstrate that a relationship exists between parturition duration, neonatal viability and behavior, and acid-base balance values in single- and twin-born lambs, suggesting that birth asphyxia is an important risk factor in perinatal lamb mortality.

Calving difficulty in dairy cows has a longer effect on saleable milk yield than on estimated milk production.

A difficult calving affects the welfare of the cow and has economic implications for the farm. The degree of calving difficulty can vary from no assistance needed through a slight pull required to surgery being needed. With respect to milk production, it is not clear at which degree of calving difficulty adverse effects occur or for how long they last. Studies usually only consider the milk produced by animals who completed full lactations but the saleable milk production of the whole herd, regardless of each cow having achieved a full lactation, might be a better indicator of the productivity of the cows and the underlying stresses they experience, as well as being more representative of the real losses that producers incur. The objective of this study was to investigate how various degrees of calving difficulty would alter both the cow's milk production and their production of saleable milk over different stages of their subsequent lactation. The calving difficulty scores and the subsequent milk production were retrieved from an experimental dairy farm (in the United Kingdom) for 2 herds that contained 2,430 and 1,413 lactations. To account for milk saleable by the farmer, individual cumulative saleable milk yields, referred to as saleable milk yields (SMY), were calculated at 30, 60, 90, and 300 d in milk unconditional on the animal having achieved the lactation stage of interest. Lactation SMY were obtained based on the real lactation length achieved by the animal. Mean daily milk yields were also calculated for the same lactation stages as an estimate of the cow's milk production (CMP). Calving difficulty impaired milk production of dairy cows in terms of CMP and SMY in both herds, highlighting impaired income for dairy producers as well as detrimental effects to the productivity of the cows and potentially impaired health and survival. The management of the herd affected the presence of an effect of each degree of difficulty on SMY and CMP as well as its magnitude and duration. The analysis of SMY, independently of each animal having achieved a full lactation, could be a more sensitive indicator of the subsequent long-lasting biological stresses than CMP alone.