Twin-pregnant Ewes Research Articles

The relationship between OXT gene polymorphisms and reproductive hormones in pregnant and lactating Awassi Ewes.

Numerous genetic loci interact intricately to control reproduction in mammals. The oxytocin gene (OXT) is a promising candidate for reproductive traits in mammals. Previously, sheep and goats have been studied for the presence of the OXT polymorphism. As of yet, no polymorphisms have been identified in the OXT gene of Awassi sheep. Thus, this study was conducted to determine the effects of OXT polymorphism and litter size on reproductive hormones in pregnant and lactating Awassi ewes. This study evaluated 232 ewes aged 3 and 4 years (123 single-progeny ewes and 109 twin-producing ewes). Serum was collected to measure reproductive hormones using ELISA kits manufactured by ELK Biotechnology. DNA was extracted from sheep blood for genotyping and sequencing to identify variations in OXT gene (exon 2, 266bp). Genotyping analysis revealed three genotypes within 266bp: CC, CA, and AA. Sequence analysis revealed a novel mutation in exon 2: 188C > A. Statistical analysis showed significant associations between the 188C > A SNP and phenotypic traits. Twin-pregnant ewes carrying CC genotypes had higher estrogen, progesterone, and follicle-stimulating hormone/luteinizing hormone levels (65.86 ± 3.87) (pg/mL), (6.51 ± 0.39) (ng/mL), and (20.22 ± 1.27) (ng/mL)/( 23.37 ± 2.14) (ng/mL) respectively, compared to CA and AA genotypes in the fourth month of twin-pregnant ewes compared to single-pregnant ewes. This study found that the 188C > A SNP negatively affected reproductive hormone levels in Awassi sheep. These findings provide breeders with a new insight into the sheep OXT gene, useful for future breeding.

Association of birth type and LHX4 gene polymorphism with reproductive hormones, growth hormone, and prolactin in Awassi ewes.

LIM homeobox transcription factor 4 (LHX4) is a promising candidate gene for mammalian reproductive traits. LHX4 polymorphism has previously been associated with phenotypic traits in goats and cattle. However, there have been no LHX4 gene polymorphisms identified in Awassi sheep. Therefore, this study investigated the effects of the LHX4 polymorphism on reproductive hormones, growth hormones, and prolactin in Awassi ewes. A total of 232 ewes between the ages of 3 and 4 years were selected for this study (123 single-progeny ewes and 109 twin-producing ewes). Serum was collected to measure reproductive hormones, growth hormone, and prolactin using ELISA kits made by ELK Biotechnology. Genomic DNA was extracted from sheep blood, genotyped, and sequenced to confirm variations in LHX4 (exon 1, 207bp). Genotyping revealed three genotypes in 207bp: AA, AG, and GG. Sequence analysis detected a novel mutation in exon 1: 160A > G. Statistically, the 160A > G SNP was significantly associated with the phenotypic traits. Ewes carrying AA genotypes had higher estrogen, progesterone, follicle-stimulating hormones/luteinizing hormones, and growth hormone, and lower prolactin levels (65.63 ± 3.84) (pg/mL), (6.67 ± 0.38) (ng/mL), (22.34 ± 1.27) (ng/mL)/(23.89 ± 2.13) (ng/mL), (1.30 ± 0.05) (ng/mL), and (13.16 ± 0.75) (pg/mL), respectively, compared to AG and GG genotypes in the fourth month of twin-pregnant ewes compared to single-pregnant ewes. This study suggests that the 160A > G SNP negatively affects the Awassi sheep's hormone levels. It provides valuable insight into the sheep LHX4 gene, which could be an effective marker in marker-assisted selection.

Influence of litter size on the hematologic profile of Awassi ewes during gestation and lactation

Physiological status and litter size affect ewes' hematological parameters, which serve as health indicators. These parameters reflect changes in an animal's physiological condition. Therefore, this study examined the hematological profiles of Awassi ewes with single and twin pregnancies during pregnancy and postpartum. A total of 232 sexually mature and healthy ewes (123 with single pregnancies and 109 with twin pregnancies) between the ages of 3 and 4 years were included in the current study. The sheep's blood was collected and hematological tests were conducted immediately on the samples. Results revealed variation in hematological parameters between ewes during pregnancy based on litter size. Twin-pregnant ewes had significantly higher amounts of RBC, PCV %, MCH, and MCHC during pregnancy months as compared to single-pregnant ewes. Compared to single pregnancies, Awassi ewes with twin pregnancies had higher leukocytes, lymphocytes, granulocytes, lymphocytes %, and granulocytes % than those with a singleton. Logistic regression confirmed that litter size contributes to the increase in hematological parameters. In conclusion, Awassi ewes with twin pregnancies exhibited an increase in the counts of leukocytes and erythrocytes constituents. This study provided valuable information about the association of twin-pregnant ewes with hematological parameters that could be used in sheep breeding and reproduction to improve diagnosis, prognosis, and treatment in the field.

Examination of blood cortisol and some parameters at parturition and on 30th day postpartum in single and twin - pregnant ewes

Lambs gain about 70 % of their birth weight in the last 6 weeks of pregnancy. In this period, many physiological events occur in ewe metabolism. The increase in the number of fetuses also affects these events. The aim of this study was to determine the effect of single and twin pregnancy on serum cortisol, glucose, triglyceride, HDL-cholesterol, total protein, total cholesterol, calcium and phosphorus levels at birth and postpartum days. This study was conducted on 2 - 3 aged single (n = 11) and twin (n = 8) pregnant Anatolian Merino ewes which housed the Department of Animal Breeding and Animal Production of Konya Bahri Dağdaş International Agricultural Research Institute in Turkey. Blood samples were collected from the jugular vein immediately after parturition and on 30th day postpartum in single and twin pregnant ewes. According to the data obtained, the differences between single and twin pregnant ewes of serum cortisol and phosphorus values at parturition were found statistically significant. The differences between parturition and 30th day postpartum were found statistically significant for the cortisol and glucose values in single pregnant ewes. The differences between the parturition and 30th day postpartum for glucose, triglyceride and phosphorus values were found statistically significant in twin pregnant ewes. In conclusion, it can be said that cortisol and some blood parameters in ewes are affected by pregnancy and the number of fetuses.

Determination of pregnancy protein levels to distinguish between singleton and twin pregnancies in Awassi sheep

Determining the fetal number to avoid pregnant sheep management, feeding, and delivery issues is of vital importance. This study aimed to determine the levels of pregnancy-associated glycoprotein (PAG) and pregnancy-specific protein B (PSPB), which are pregnancy proteins, to accurately predict singleton and twin pregnancies in Awassi sheep. A total of 40 Awassi sheep were used for the study. According to the number of offspring, pregnant ewes were separated into two groups. The study's first group (Group 1) included singleton pregnant ewe (n=20), while the second group (Group 2) included twin pregnant ewe (n=20). Blood samples were collected from the ewes of both study groups at 30th, 45th, 60th, 75th and 90th day of gestation, which were used for PAG and PSBP evaluation along with ultrasonographic examination. Independent samples t-test and repeated measurements ANOVA were used to analyze the data. The correlations between the measures were calculated using Pearson correlation coefficients. Accordingly, a statistically significant difference was observed between single and twin pregnant sheep for all PAG and PSBP measurements at days 30-45-60-75 and 90 (p<0.05). In singleton and twin pregnant ewes, there was a statistically significant difference in PAG and PSBP measurements (p<0.05). In singleton pregnant ewes, a significant positive correlation was found between PAG30 and PSPB30 values (p<0.05), while a significant negative correlation was found between paired measures of PAG45-PSPB90, PAG60-PSPB90, and PAG75-PSPB90 (p<0.05). In conclusion, significant differences in pregnancy protein levels were found in singleton and twin pregnant ewes. It was deduced that knowledge of this difference might give sheep breeders an idea about management factors.

The effect of twinship on selected hematological and biochemical parameters in late pregnant ewes

This study aimed to determine the effect of twinship on the hematological and biochemical parameters in ewes of the Kıvırcık breed commonly raised in the Thrace region of Turkey. The study material consisted of 30 Kıvırcık ewes at days 130-150 of gestation, aged 3-5 years, weighing 55.61 ± 0.76 kg. After ultrasound examination, the ewes included in the study were divided into a single-pregnant group (n = 15) and a twinpregnant group (n = 15), and their blood samples were taken. The levels of red blood cells (RBC), hematocrit (HCT), hemoglobin (HGB) white blood cells (WBC), lymphocytes (LYM), monocytes (MON), non-esterified fatty acid (NEFA), β-hydroxybutyrate (BHBA), glucose, cholesterol, total protein, aspartate aminotransferase (AST), alanine aminotransferase (ALT) were determined in their blood samples. It was found that, although twinship did not affect hemogram values in ewes (p > 0.05), the biochemical parameters, BHBA, ALT, and AST values, were significantly affected by twinship (p <0.05). A high positive correlation was found between BHBA and NEFA. Thus it was concluded that twin pregnancy did not cause any significant changes in hematological parameters in Kıvırcık ewes. However, the significantly higher BHBA in twin-pregnant ewes and the high positive correlation between BHBA and NEFA indicate that the negative energy balance started to affect these animals, and a carbohydrate deficiency emerged. Therefore, twin-pregnant ewes should be monitored closely to reduce the risk of ketosis.

Pregnancy-associated glycoprotein concentrations during early gestation in pregnant Awassi sheep

This study was aimed at determining the serum pregnancy-associated glycoprotein (PAG) profile of pregnant Awassi sheep during early gestation. A total of 122 Awassi ewes were used, which were in days 28-56 (28, 30, 32, 36, 42, 49, and 56) of gestation. Blood samples were taken via jugular venepuncture. Out of these animals, 104 ewes that had delivered (singleton lambs, n = 60; twin lambs, n = 44), according to lambing records, were selected for the assessment of serum PAG levels. The serum PAG level was measured using a commercial enzyme-linked immunosorbent assay (ELISA) kit (IDEXX Bovine Pregnancy Test). Whereas serum PAG levels (mean ± standard error) on days 28, 30, 32, 36 and 42 of gestation were found to be similar (0.237 ± 0.031, 0.402 ± 0.067, 0.329 ± 0.036, 0.397 ± 0.075, and 0.409 ± 0.060, respectively), the levels measured on days 49 and 56 of gestation were significantly higher (0.712 ± 0.088 and 0.798 ± 0.115, respectively) (p < 0.05). The serum PAG levels of the twin-pregnant ewes on days 28, 30 and 42 of gestation were higher than those of the singlepregnant ewes (twin-pregnant ewes: 0.314, 0.648 and 0.594, respectively; single-pregnant ewes: 0.186, 0.258 and 0.308, respectively; p < 0.05). With a cut-off sample minus negative (S–N) value set at > 0.300, the sensitivity of serum PAG level-based pregnancy diagnosis was 51.95% between days 28 and 42 of gestation and 92.69% between days 49 and 56 of gestation. On the other hand, with a cut-off S–N value set at > 0.100, the sensitivity of the PAG ELISA test was 94.81% between days 28 and 42 of gestation and 100% between days 49 and 56 of gestation. In conclusion, the serum PAG levels of the pregnant Awassi sheep remained similar between days 28 and 42 of gestation, but progressively increased thereafter. The serum PAG levels of the twin-pregnant Awassi ewes were significantly higher than those of the single-pregnant sheep on days 28, 30 and 42 of gestation, but they were not different on days 32, 36, 49 and 56 of gestation.

Prenatal over- and undernutrition differentially program small intestinal growth, angiogenesis, absorptive capacity, and endocrine function in sheep.

The aim was to test the hypothesis that prenatal under‐ and overnutrition in late gestation can program small intestinal (SI) growth, angiogenesis, and endocrine function to predispose for a hyperabsorptive state, thereby increasing the susceptibility to the adverse effects of an early postnatal obesogenic diet. Twin‐pregnant ewes were exposed to adequate (NORM), LOW (50% of NORM), or HIGH (150% energy and 110% protein of NORM) diets through the last trimester (term ~147 days). From 3 days to 6 months of age, their lambs were fed either a moderate (CONV) or a high‐carbohydrate high‐fat (HCHF) diet. At 6 months of age, responses in plasma metabolites and insulin to refeeding after fasting were determined and then different segments of the SI were sampled at autopsy. Prenatal overnutrition impacts were most abundant in the duodenum where HIGH had increased villus amplification factor and lowered villi thickness with increased IRS‐1 and reduced GH‐R expressions. In jejunum, HIGH lambs had an increased expression of Lactate gene and amplified when exposed to HCHF postnatally. Specifically, in LOW, sensitivity to HCHF was affected in ileum. Thus, the mismatching LOW‐HCHF nutrition increased expressions of angiogenic genes (VEGF, VEGF‐R1, ANGPT1, RTK) and increased mucosa layer (tunica mucosa) thickness but reduced muscle layer (Tunica muscularis) thickness. The SI is a target of prenatal nutritional programming, where late gestation overnutrition increased and shifted digestive capacity for carbohydrates toward the jejunum, whereas late gestation undernutrition predisposed for ileal angiogenesis and carbohydrate and fat hyperabsorptive capacity upon subsequent exposure to postnatal obesogenic diet.

Relationship between mammary blood flow, infrared thermography and ovine placental lactogen during the periparturient period in ewes

The aim of the study to verify the hypothesis whether a drop in the oPL levels in the blood in the periparturient period is associated with changes in the right mammary vein blood flow (RMVBF) and udder skin temperature (UST). We were also interested in comparing variations in the above-mentioned parameters in single- and twin-pregnant ewes. Beginning six days before parturition (-6th day) until four days postpartum (4th day), every second day each of 15 experimental pregnant ewes was subjected to color Doppler ultrasound performed with continuous wave-equipment (My Lab One/Touch) and infrared thermography (IRT), which allowed for noninvasive collection of data. Plasma oPL levels were determined using quantitative sandwich ELISA Kit specified for sheep placental lactogen 1 (oPL). The measured values of UST were affected by the periparturient period but not by the number of lambs delivered. The highest udder temperatures were recorded at four days before parturition, which was followed by their gradual decrease. As a result, UST achieved the lowest values in single- and also in twin-pregnant ewes on the day of parturition (35.70 ± 0.65°C and 35.42 ± 0.45°C, respectively). Among all the time points of measuring IRT and oPL, a significant positive correlation (P≤0.01) was estimated at -4 and 0 days before parturition for single- (r= 0.99) and twin- (r= 0.59) pregnant ewes. In comparison to control ewes, right mammary vein blood flow (RMVBF) significantly (P≤0.05) increased in all pregnant ewes under study. Especially in twin-pregnant ewes, a positive correlation between the plasma concentration of oPL and blood flow occurred between the -4th and 0 day (r = 0.76). Maximal velocity of blood flow in the mammary vein in single- (25.90 ± 5.95 cm/s) and twin-pregnant ewes (24.62 ± 4.86 cm/s) was recorded at the 2nd and 4th day postpartum, respectively. The highest values of plasma oPL (0.56 ± 0.05 µg/ml) recorded at the beginning of the experimental period (-6 days before parturition) dropped significantly (P≤0.05) during the subsequent days, until parturition. The curve of the temporal changes in the concentrations of plasma oPL remains unchanged regardless of the number of fetuses. Three-phasic thermal changes in the periparturient period and an increase in blood flow parameters are related to the disappearance of oPL from the circulation, which should be taken into account when assessing a pathological state of this gland.

Impacts of pre- and postnatal nutrition on glucagon regulation and hepatic signalling in sheep.

To evaluate the long-term impacts of early-life nutritional manipulations on glucagon secretion and hepatic signalling, thirty-six twin-pregnant ewes during their last trimester were exposed to NORM (fulfilling 100% of daily energy/protein requirements), HIGH (fulfilling 150/110% of daily energy/protein requirements) or LOW (50% of NORM) diets. Twin lambs were assigned after birth to a moderate (CONV) or high-carbohydrate high-fat (HCHF) diet until 6 months. Then, responses in plasma glucagon concentrations and glucagon ratios relative to previously reported values for insulin, glucose and lactate were determined after intravenous bolus injections of glucose or propionate (fed and 2-day fasting state). Hepatic mRNA expressions of glucagon receptor (GCGR), glucose-6-phosphatase (G6PC), phosphoenolpyruvate carboxykinase (PEPCK) and fructose 1,6-biphosphatase (FBP) were also determined in a sub group of autopsied lambs. Expression of GCGR and all three enzymes were supressed by prenatal LOW compared to NORM (except PEPCK) and HIGH (except FBP) nutrition. The postnatal HCHF diet reduced plasma glucagon responses to propionate and hepatic mRNA expression of all genes. In response to propionate, insulin/glucagon ratio was decreased (fasted state), but lactate/glucagon and glucose/glucagon increased in HCHF compared to CONV lambs. In conclusion, prenatal undernutrition and postnatal overnutrition had similar long-term implications and reduced hepatic glucagon signalling. Glucagon secretory responses to propionate were, however, not related to the prenatal nutrition history, but negatively affected by the postnatal obesogenic diet. The pancreatic α-cell compared to β-cells may thus be less sensitive towards late gestation malnutrition, whereas hepatic glucagon signalling appears to be a target of prenatal programming.

Effect of Nigella Sativa seeds, Royal jelly and Pregnant Mare Serum Gonadotrophine on Some Reproductive Traits of Ossimi Ewes

ABSTARCTForty-eight Ossimi ewes aged 2-4 years and averaged 41±2.5 kg body weights were randomlyassigned into four equal groups (12/ each). All ewe groups were synchronized for estrous by intra -vaginal progesterone-releasing sponges.Sponges were inserted and remained in situ for 12 days before removal (as estroussynchronization protocol). Control group not drenched anything. First group (T1) daily drenched orally100 mg Nigella Sativa seeds (NSS) powder/kg/head for 12 days starting at the time of sponge insertionuntil the time of sponge withdrawal. The second group (T2) drenched orally fresh Royal jelly (RJ) 500mg per day/for 12 days, starting at time of sponge insertion until sponge withdrawal. Royal jelly (RJ)was kept into natural drug capsules. The third group (T3) was intramuscularly injected at time of spongewithdrawal, with 750 IU of Pregnant Mare Serum gonadotropin (PMSG).A fertile, Ossimi ram ran with the ewes immediately following sponge removal at (day 0). Ewesobserved three times daily to identify and detect estrus for 3 days. Ultrasound scanner apparatus wasused to count number of corpus luteum and diagnose of pregnancy. Detection of pregnancy dependedon presence of embryos and/or embryonic fluid that filled the uterus.The results indicated that the response of ewes to estrus synchronization did not differ amongthe four groups. The response of the four groups was 100%. At the same time treatments led to increasepercentage of occurred estrus in the first 24 hr and also the estrus duration increased in the control group.Ovulation rate at 8±1 days post mating as indicated by number of corpus luteum (CLs) recorded (p<0.01 ) the higher values in T3 followed by T2, T1 and then control group for single or twin pregnantewes. The percentages of improvement in ovulation rate were 150%, 130% and 105% for T3, T2 andT1, respectively compared to the control group (100%). Regardless of treatments, progesterone levelsat 8±1 or at 34±1 days were higher in twining pregnant ewes compared to single pregnant ones. Also,percentages of conception rate were higher in T2 and T3 (91%), while the lowest value was recorded incontrol group. Litter size per ewe at birth increased as a result of treatment effect. The highest valuesrecorded in T3 (1.63) flowed by T2 (1.54) and T1 (1.50), while the lowest values were recorded incontrol group (1.22).According to the net profit percentages, it could conclude that the best and more beneficial effects are occurred with PMSG. However, from the practical point of view, treatment with Nigella Sativa seeds could be preferred and effectively applied as it showed the lowest cost.

Long-Term Impacts of Foetal Malnutrition Followed by Early Postnatal Obesity on Fat Distribution Pattern and Metabolic Adaptability in Adult Sheep.

We aimed to investigate whether over- versus undernutrition in late foetal life combined with obesity development in early postnatal life have differential implications for fat distribution and metabolic adaptability in adulthood. Twin-pregnant ewes were fed NORM (100% of daily energy and protein requirements), LOW (50% of NORM) or HIGH (150%/110% of energy/protein requirements) diets during the last trimester. Postnatally, twin-lambs received obesogenic (HCHF) or moderate (CONV) diets until 6 months of age, and a moderate (obesity correcting) diet thereafter. At 2½ years of age (adulthood), plasma metabolite profiles during fasting, glucose, insulin and propionate (in fed and fasted states) tolerance tests were examined. Organ weights were determined at autopsy. Early obesity development was associated with lack of expansion of perirenal, but not other adipose tissues from adolescence to adulthood, resulting in 10% unit increased proportion of mesenteric of intra-abdominal fat. Prenatal undernutrition had a similar but much less pronounced effect. Across tolerance tests, LOW-HCHF sheep had highest plasma levels of cholesterol, urea-nitrogen, creatinine, and lactate. Sex specific differences were observed, particularly with respect to fat deposition, but direction of responses to early nutrition impacts were similar. However, prenatal undernutrition induced greater metabolic alterations in adult females than males. Foetal undernutrition, but not overnutrition, predisposed for adult hypercholesterolaemia, hyperureaemia, hypercreatinaemia and hyperlactataemia, which became manifested only in combination with early obesity development. Perirenal expandability may play a special role in this context. Differential nutrition recommendations may be advisable for individuals with low versus high birth weights.

Late gestation under- and overnutrition have differential impacts when combined with a post-natal obesogenic diet on glucose-lactate-insulin adaptations during metabolic challenges in adolescent sheep.

To determine whether late gestation under- and overnutrition programme metabolic plasticity in a similar way, and whether metabolic responses to an obesogenic diet in early post-natal life depend on the foetal nutrition history. In a 3 × 2 factorial design, twin-pregnant ewes were for the last 6 weeks of gestation (term = 147 days) assigned to HIGH (N = 13; 150 and 110% of energy and protein requirements, respectively), NORM (N = 9; 100% of requirements) or LOW (N = 14; 50% of requirements) diets. The twin offspring were raised on high-carbohydrate-high-fat (HCHF; N = 35) or conventional (CONV; N = 35) diets from 3 days to 6 months of age (around puberty). Then intravenous glucose (GTT; overnight fasted), insulin (ITT; fed) and propionate (gluconeogenetic precursor; PTT; both fed and fasted) tolerance tests were conducted to evaluate (hepatic) metabolic plasticity. Prenatal malnutrition differentially impacted adaptations of particularly plasma lactate followed by glucose, cholesterol and insulin. This was most clearly expressed during PTT in fasted lambs and much less during ITT and GTT. In fasted lambs, propionate induced more dramatic increases in lactate than glucose, and HIGH lambs became more hyperglycaemic, hyperlactataemic and secreted less insulin compared to the hypercholesterolaemic LOW lambs. Propionate-induced insulin secretion was virtually abolished in fasted HCHF lambs, but upregulated in fasted compared to fed CONV lambs. HCHF lambs had the greatest glucose-induced insulin secretory responses. Prenatal malnutrition differentially programmed glucose-lactate metabolic pathways and cholesterol homeostasis. Prenatal overnutrition predisposed for hyperglycaemia and hyperlactataemia, whereas undernutrition predisposed for hypercholesterolaemia upon exposure to an obesogenic diet. Prenatal overnutrition (not undernutrition) interfered with pancreatic insulin secretion by non-glucose-dependent mechanisms.

Late gestation over‐ and undernutrition predispose for visceral adiposity in response to a post‐natal obesogenic diet, but with differential impacts on glucose–insulin adaptations during fasting in lambs

To investigate if late gestation under- or overnutrition has similar adverse impacts on visceral adiposity, metabolic and endocrine function in sheep, and if subsequent exposure to a high-fat diet in early post-natal life exaggerates the prenatal programming outcomes later in life. Thirty-six twin-pregnant ewes were fed a NORM (fulfilling 100% of daily requirements for energy and protein), LOW (50% of NORM) or HIGH diet (150% of energy and 110% of protein requirements) during the last 6 weeks of gestation (term = 147 days). Post-natally, the twin lambs were subjected to a high-fat or a moderate diet until 6 months of age (around puberty), where metabolic and endocrine adaptability to fasting was examined, and subgroups of animals were killed. Animals exposed to either prenatal under- or overnutrition had reduced subcutaneous fat deposition when fed a high-fat diet, resulting in higher ratios of mesenteric and peri-renal fat relative to subcutaneous fat compared to controls. This was not related to prenatal influences on plasma glucose or insulin. Irrespective of the prenatal diet, high-fat-fed lambs underwent changes resembling the metabolic syndrome with higher plasma glucose, cholesterol, non-esterified fatty acids, triglyceride and lactate combined with abdominal obesity. Peri-renal fat appeared to be a particular target of a high-fat diet post-natally. Both prenatal under- and overnutrition predisposed for abdominal adiposity, apparently by reducing the expandability of subcutaneous adipose tissue and induced differential physiological adaptations to fasting. This study does not suggest that exposure to gestational overnutrition will provide a protective effect against development of hyperglycaemia later in life.

Plasma concentrations of essential trace microminerals and thyroid hormones during single or twin pregnancies in fat-tailed ewes

The aim of this study was to monitor changes in plasma concentrations of essential trace microminerals including: Copper (Cu), Zinc (Zn), Iron (Fe), Manganese (Mn), Selenium (Se), Iodine (I) and thyroid hormones in single and twin fat-tailed pregnant ewes. Estrus of 150 fat-tailed Afshari ewes was synchronized using CIDR, inserted for 14 days and ewes given 400IU eCG im on the day of CIDR removal. A total number of 40 apparently healthy pregnant sheep (20 single and 20 twin pregnancies), 4–5 years old, weighing 60.19±1.65kg, were randomly selected using sonography. The ewes were assigned in 2 groups: group 1 (ewes carrying single fetus) and group 2 (ewes carrying twin fetuses). The blood samples were collected at days 30, 60, 90, 120 and 150 of gestation and analyzed for plasma Cu, Zn, Fe, Mn, Se, I, T3 and T4 concentrations. Data were analyzed using a restricted maximum likelihood-based, mixed-effects model, and repeat measures analysis. A t-test was used to evaluate the differences between single and twin pregnancy of plasma micromineral levels, T3 and T4 hormones. Results indicated that the concentrations of Mn, Se, I, T3 and T4 were decreased (P<0.05) in plasma from day 90 in single and twin pregnant ewes. However, the level of Cu, Zn and Fe were decreased (P<0.05) during late gestation period. The Plasma Cu, Se and T3 concentrations in single were higher (P<0.05) than twin pregnant ewes on day 150 of pregnancy. Plasma Zn, Mn, I and T4 measured in twin were lower (P<0.05) than single pregnant ewes on all period of gestation. In conclusion, the twin had lower essential trace microminerals and thyroid hormones than single pregnant ewes during pregnancy (Zn, Mn, I, and T4) or late period of gestation (Cu, Se and T3).

CONSUMO, DIGESTIBILIDADE E TAXA DE PASSAGEM RUMINAL EM OVELHAS GESTANTES

This research was carried out to evaluate the effects of pregnancy, number of fetuses and feed restriction on nutrients intake and digestibility and on ruminal rate passage. Twenty-four ewes were used at 90, 110 and 130 pregnancy days distributed among treatments according to the number of fetuses. They received balanced diet or restricted diet at 15% of energy and protein requirement. Ewes with two fetuses on feed restriction had more dry matter intake than those with one fetus. At 130 day there was the highest dry matter and neutral detergent fiber intake. Twin-pregnant ewes showed the highest nutrient digestibility, except for fiber fraction. Feed restriction caused the smallest dry matter intake. Ruminal rate passage increased in late pregnancy.KEYWORDS: feed management; number of fetuses; prepartum; sheep.

Comparison of placentome diameters in single and twin-pregnant sheep by ultrasonographic method

The aim of this study was to determine the correlation between fetal number and placentome diameters in pregnant sheep. In the present study 25 Kivircik mixed breed pregnant ewes were used. Pregnancy of the ewes was diagnosed by transrectal ultrasonography by the 25th day after insemination. A transabdominal probe (6.5 MHz) was used on the pregnant ewes at the 30th day. At this time the placentomes appeared as hypoechogenic areas with a C-like shape. Throughout the pregnancies 5 placentomes were measured from each ewe every week. The results showed no significant difference between placentome diameter size in single and twin-pregnant ewes except during the 5th and 12th weeks. The average of placentome diameter size in the single and twin-pregnant ewes was, respectively, 6.60 ± 0.56 mm and 8.20 ± 0.45 mm at the 5th week and 34.02 ± 1.62 mm and 29.47 ± 0.63 mm at the 12th week. The minimum significance degree was P < 0.05 in statistical analysis. This study found that measurement of placentome diameter size at the 5th and 12th week of pregnancy is not helpful in determining fetal number in a pregnant ewe. However, further investigations are needed to explain the difference in placentome diameter at the 5th and 12th weeks of pregnancy.

Metabolic and endocrine characteristics of pregnancy toxemia in the ferret

Metabolic and endocrine characteristics of pregnancy toxemia are well documented in small ruminants, but less known in other species. The objective of this study was to measure plasma levels of certain metabolites and metabolic hormones related to the energetic status in blood from sick and healthy, non-pregnant (control) ferrets. Blood was collected from moribund, hypothermic, late pregnant females suffering from pregnancy toxemia (&lt;i&gt;n&lt;/i&gt; = 4) and from healthy female ferrets (&lt;i&gt;n&lt;/i&gt; = 14) to measure glucose, ketone (βOH-butyrate, BHB), insulin, thyroxine (T&lt;sub&gt;4&lt;/sub&gt;) and 3,3’,5-triiodothyronine (T&lt;sub&gt;3&lt;/sub&gt;) concentrations. In contrast to healthy animals, hypoglycemia, hyperketonemia, hypoinsulinemia and decreased T&lt;sub&gt;4&lt;/sub&gt; and T&lt;sub&gt;3&lt;/sub&gt; levels were detected in females with pregnancy toxemia and necropsy showed excessive hepatic lipidosis. In summary, it can be concluded that pregnancy toxemia caused by a negative energy balance in ferrets resembles the late-gestational hyperketonemia of twin-pregnant ewes, and moreover that similar endocrine changes may occur.

Late gestational nutrient restriction: Effects on ewes' metabolic and homeorhetic adaptation, consequences for lamb birth weight and lactation performance

We investigated the effect of 50% nutrient restriction during the last 6 weeks ofgestation on twin-pregnant ewes' plasma glucose, non-esterified fatty acid, β-hydroxybutyrate, insulin, IGF-1 and leptin concentrations and the effects on lamb birth weight and ewes' lactation performance. Plasma metabolite and hormone concentrations in restricted ewes suggest that maternal tissues were being mobilised. Despite the ewes' adaptations their lambs weighed significantly less at birth. Furthermore, colostrum and milk yields were markedly reduced up until the latest measurement at 3 weeks post partum despite ad libitum access to feed. Reduced milk yields coincided with reduced plasma IGF-1 concentration pre partum in nutrient restricted ewes indicating, that mammary gland development may have been compromised. The present data suggest that leptin is not involved in the regulation of early lactation changes in feed intake and energy balance. It is concluded that severely reduced nutrient availability in late gestation affects fetal growth in utero and has a prolonged negative effect on lactation performance.

Twin-pregnancy increases susceptibility of ewes to hypoglycaemic stress and pregnancy toxaemia

Pregnancy toxaemia is a metabolic disorder with a high mortality rate and occurs in twin-bearing ewes in late gestation. Maternal hypoglycaemia is a characteristic symptom of the disease and has been attributed to an increase in glucose uptake by the twin-bearing uterus. The possibility that a reduced maternal glucose production rate might cause hypoglycaemia, has received little attention in the past. It was the aim of this study to investigate this explanation as a possible alternative. Six ewes were sequentially subjected to two types of hypoglycaemic stress, firstly by fasting for 14 h and secondly through induction of moderate hyperketonaemia. Glucose kinetics were assessed in each animal during the dry non-gestational period, during late gestation, and during early lactation. Application of these stress factors was associated with variation of plasma glucose concentration from 4.9 to 0.87 mmol L −1. The plasma glucose concentration was always significantly related to the glucose production rate. The greatest stress-induced reductions in glucose concentration and glucose production rate were seen during late gestation in twin-bearing ewes. The decline in the glucose production rate after an overnight fast and during induced hyperketonaemia was greater in twin-bearing ewes than in single-bearing ewes (59% and 43%, respectively, p < 0.05). The stress conditions resulted in the lowest levels of glucose concentration and glucose turnover rates in the stressed, hyperketonaemic, late gestation twin-bearing ewes. This illustrates that the glucose homoeostatic system of ewes bearing twins is significantly more susceptible to hypoglycaemic stress than that of ewes bearing single lambs. These findings also show that the primary cause of hypoglycaemia in late gestation twin-pregnant ewes is an increased susceptibility to a stress related reduction in glucose production rate. This metabolic condition leaves the twin-pregnant ewe predisposed for the development of pregnancy toxaemia.