Day Of Parturition Research Articles

Influence of a marine algae supplementation on the oxidative status of plasma in dairy cows during the periparturient period

This study was part of a larger study that addressed the effects of marine algae (ALG) supplementation in the ration of high yielding periparturient dairy cows. The objectives were to induce milk fat depression (MFD) in early lactation by feeding docosahexaenoic acid (DHA) from ALG and to determine the effects on milk production, milk components and metabolic status early post partum. This study focuses on the oxidative status in the plasma during the ALG supplementation. Plasma samples were collected from 16 Holstein Friesian cows at the day of parturition and at −1, 2, 4 and 6 weeks relative to calving with half of the cows receiving the ALG supplement (44gDHA/d) from 3 weeks pre partum on. The following parameters were measured in plasma: ferric reducing ability of plasma (FRAP), α-tocopherol level, glutathione peroxidase activity (GSH-Px) and thiobarbituric acid reactive substances (TBARS) concentration. There was a significant effect of time for FRAP and α-tocopherol indicating changes in the plasma oxidative status around parturition. The ALG supplementation was successful in creating a milk fat depression (MFD) but could not improve the energy balance. Feeding of ALG significantly increased lipid peroxidation as measured by TBARS, probably through their high content of n-3 polyunsaturated fatty acids.

Effectiveness of a redesigned vaginal implant transmitter in mule deer

AbstractOur understanding of factors that limit mule deer (Odocoileus hemionus) populations may be improved by evaluating neonatal survival as a function of dam characteristics under free‐ranging conditions, which generally requires that both neonates and dams are radiocollared. The most viable technique facilitating capture of neonates from radiocollared adult females is use of vaginal implant transmitters (VITs). To date, VITs have allowed research opportunities that were not previously possible; however, VITs are often expelled from adult females prepartum, which limits their effectiveness. We redesigned an existing VIT manufactured by Advanced Telemetry Systems (ATS; Isanti, MN) by lengthening and widening wings used to retain the VIT in an adult female. Our objective was to increase VIT retention rates and thereby increase the likelihood of locating birth sites and newborn fawns. We placed the newly designed VITs in 59 adult female mule deer and evaluated the probability of retention to parturition and the probability of detecting newborn fawns. We also developed an equation for determining VIT sample size necessary to achieve a specified sample size of neonates. The probability of a VIT being retained until parturition was 0.766 (SE = 0.0605) and the probability of a VIT being retained to within 3 days of parturition was 0.894 (SE = 0.0441). In a similar study using the original VIT wings (Bishop et al.2007), the probability of a VIT being retained until parturition was 0.447 (SE = 0.0468) and the probability of retention to within 3 days of parturition was 0.623 (SE = 0.0456). Thus, our design modification increased VIT retention to parturition by 0.319 (SE = 0.0765) and VIT retention to within 3 days of parturition by 0.271 (SE = 0.0634). Considering dams that retained VITs to within 3 days of parturition, the probability of detecting at least 1 neonate was 0.952 (SE = 0.0334) and the probability of detecting both fawns from twin litters was 0.588 (SE = 0.0827). We expended approximately 12 person‐hours per detected neonate. As a guide for researchers planning future studies, we found that VIT sample size should approximately equal the targeted neonate sample size. Our study expands opportunities for conducting research that links adult female attributes to productivity and offspring survival in mule deer. © 2011 The Wildlife Society.

Influence of feeding Tinospora cordifolia peripartum on lactation parameters in crossbred cows

For studying the effect of dietary supplementation of guduchi (Tinospora cordifolia) peripartum on lactation an investigation was conducted on 15 pregnant Karan Fries crossbred cows which were divided into two groups: treatment group of eight cows which were supplemented with guduchi at 60 g/day for 45 days prepartum and 120 g/day for 45 days postpartum; control group of seven pregnant cows which were not supplemented with guduchi. Jugular blood samples were collected from all cows during the periparturient period for analysis of various blood cell and plasma parameters. A significantly higher total leukocyte count, lymphocyte count, neutrophil count and neutrophil/lymphocyte ratio was recorded in the guduchi supplemented treatment group in comparison to untreated control cows throughout the experimental period. The increase of milk production over 305 days of lactation due to guduchi supplementation was significant (p < 0.05). A significant (p < 0.05) reduction in somatic cell count was also observed during the experimental period. Milk composition (fat, protein, lactose and SNF) was similar (p > 0.05) for both the groups. Plasma non esterified fatty acid (NEFA) concentrations were significantly higher (p < 0.01) in cows supplemented with guduchi throughout the course of study. Plasma concentration of growth hormone in the treated cows was also significantly higher beginning on the day of parturition up to 3 weeks postpartum (p < 0.05) in comparison to unsupplemented group.

Effects of supplementation with 2-hydroxy-4-(methylthio)-butanoic acid isopropyl ester on splanchnic amino acid metabolism and essential amino acid mobilization in postpartum transition Holstein cows

The present study aimed to investigate the effects of 2-hydroxy-4-(methylthio)-butanoic acid isopropyl ester (HMBi) supplementation on splanchnic AA metabolism, essential AA (EAA) mobilization, and plasma AA status in postpartum transition dairy cows. The EAA mobilization was calculated by difference: EAA excretion in milk protein − net portal absorption of EAA or net splanchnic release of EAA. Eight Holstein cows fitted with permanent indwelling catheters in the hepatic portal vein, hepatic vein, mesenteric vein, and an artery in the dry period preceding second parturition were used in the study. Cows were randomly allocated to 1 of 4 treatments in a 2×2 factorial arrangement with factor 1: control (calcium carbonate) versus HMBi [1.5g of HMBi/kg of dry matter (DM)] and factor 2: high dietary ethanol (19g/kg of DM) versus high dietary propanol (16g/kg of DM). Only factor 1 data are presented. Treatments were administered in 4 total mixed rations and initiated on the day of parturition. Cows were sampled 14 d before expected parturition and 4, 15, and 29 d after parturition. Supplementation with HMBi tended to increase milk fat content but not fat yield, tended to impose a slower rate of decrease in milk casein content with increasing days in milk (DIM), prevented the decrease in plasma Met associated with parturition for control, reduced plasma concentration of Ser, tended to reduce plasma concentrations of Gly and His, and tended to increase hepatic uptake of Met postpartum. Cows excreted 248±18g more EAA in the milk at 4 DIM than was released from splanchnic tissues. The EAA deficiency decreased as lactation progressed and was not affected by HMBi supplementation. It was estimated that 4,700±600g of EAA from extra-splanchnic tissues were secreted in milk protein during the first 29 DIM. Extra-splanchnic EAA mobilization can be crucial to sustain milk protein yield in the postpartum transition period and HMBi is a fast-working Met source that can improve Met status of postpartum transition cows.

Data logging of body temperatures provides precise information on phenology of reproductive events in a free-living arctic hibernator

Precise measures of phenology are critical to understanding how animals organize their annual cycles and how individuals and populations respond to climate-induced changes in physical and ecological stressors. We show that patterns of core body temperature (T (b)) can be used to precisely determine the timing of key seasonal events including hibernation, mating and parturition, and immergence and emergence from the hibernacula in free-living arctic ground squirrels (Urocitellus parryii). Using temperature loggers that recorded T (b) every 20min for up to 18months, we monitored core T (b) from three females that subsequently gave birth in captivity and from 66 female and 57 male ground squirrels free-living in the northern foothills of the Brooks Range Alaska. In addition, dates of emergence from hibernation were visually confirmed for four free-living male squirrels. Average T (b) in captive females decreased by 0.5-1.0°C during gestation and abruptly increased by 1-1.5°C on the day of parturition. In free-living females, similar shifts in T (b) were observed in 78% (n=9) of yearlings and 94% (n=31) of adults; females without the shift are assumed not to have given birth. Three of four ground squirrels for which dates of emergence from hibernation were visually confirmed did not exhibit obvious diurnal rhythms in T (b) until they first emerged onto the surface when T (b) patterns became diurnal. In free-living males undergoing reproductive maturation, this pre-emergence euthermic interval averaged 20.4days (n=56). T (b)-loggers represent a cost-effective and logistically feasible method to precisely investigate the phenology of reproduction and hibernation in ground squirrels.

Farrowing induction induces transient alterations in prolactin concentrations and colostrum composition in primiparous sows1

Hormonal changes involved in the farrowing process partly control the initiation of lactation. Inducing farrowing by injection of PG may alter the normal prepartum hormonal cascade. The aim of the study was to investigate the consequences of farrowing induction on colostrum yield and composition, as well as newborn piglet growth. Gilts were treated with 2 mg of alfaprostol on d 113 of gestation (induced farrowing, IF, n = 9) or were injected with 1 mL of a saline solution (natural farrowing, NF, n = 11). Colostrum production was estimated during 24 h, starting at the onset of parturition, based on piglet BW gains. Colostrum samples were collected during the 36 h after the onset of parturition. Blood samples were collected from sows as of d 112 of pregnancy until d 2 postpartum (d 0 being the day of parturition). Piglet blood samples were obtained at birth, on d 1, and on d 21. Litter size and litter weight at birth did not differ between groups (P > 0.10). Farrowing induction did not influence (P > 0.10) colostrum yield (3.96 ± 0.20 kg) or piglet BW gain during d 1 postpartum (116 ± 8 g). At the onset of farrowing (T0), lactose content in colostrum was greater in IF sows than in NF sows (P < 0.05), whereas colostrum ash and protein contents were less (P < 0.05) in IF sows. Concentrations of IgG in colostrum were similar in both groups of sows, whereas concentrations of IgA at T0 were less in IF than in NF sows (P < 0.01). Overall, endocrine changes in blood from d -2 until d 2 (cortisol, prolactin, progesterone, and estradiol-17β) were not altered by farrowing induction (P > 0.10), but 1 h after the injection of alfaprostol, IF sows had greater circulating concentrations of prolactin (P < 0.01) and cortisol (P < 0.10) than NF sows. The greater concentration of lactose in colostrum from IF sows could be attributed to this transient increase in prolactin and cortisol. At birth, concentrations of white blood cells were less in piglets born from IF sows (P < 0.01). On d 1 and 21, piglets from IF sows had similar IgG concentrations in plasma to piglets from NF sows (P > 0.1). In conclusion, farrowing induction at 113 d of pregnancy induced transient hormonal changes in sows and alterations in colostrum composition, without significantly affecting colostrum yield. It also modified some hematological variables of piglets at birth.

Metabolic effects of feeding ethanol or propanol to postpartum transition Holstein cows

Eight lactating Holstein cows implanted with a ruminal cannula and permanent indwelling catheters in major splanchnic blood vessels were used to investigate metabolism of propanol and ethanol in the postpartum transition period. Cows were randomly allocated to 1 of 4 treatments in a randomized design with a 2 by 2 factorial arrangement of treatments. Factor 1 was 2.6g of calcium carbonate/kg of dry matter (DM) versus 1.5g of 2-hydroxy-4-(methylthio)-butanoic acid isopropyl ester/kg of DM. Factor 2 was supplementation with 14g of propanol/kg of DM (propanol treatment; PT) versus 14g of ethanol/kg of DM (ethanol treatment; ET). Only factor 2 data are presented in the present paper. Treatments were administered in silage-based total mixed rations and cows were fed the experimental total mixed ration from the day of parturition. Daily rations were fed in 3 equally sized portions at 8-h intervals. Eight hourly sets of ruminal fluid, arterial, and hepatic portal and hepatic vein samples were collected at day −15±5, 4, 15, and 29 relative to parturition. Dry matter intake and milk yield increased with days in milk (DIM), but were not affected by treatment. From prepartum to 4 DIM ruminal concentrations of propanol and ethanol increased with PT and ET, respectively. Postpartum, alcohol intake increased 49% in PT and 34% in ET from 4 to 29 d in milk, respectively. Ruminal concentrations of the alcohols remained unaffected by DIM. Treatments did not affect total ruminal volatile fatty acid concentrations, but the molar proportion of acetate increased in ET and the molar proportion of propionate increased in PT compared with the contrasting treatment. Propanol treatment decreased milk fat content at 15 to 29 DIM compared with ET. The net portal release of propanol and ethanol increased with increasing ruminal concentration of the respective alcohol. The portal release of alcohol accounted for 43 to 85% of ingested propanol and 36 to 57% of ingested ethanol. Hepatic uptake of propanol and ethanol equaled the net portal flux and no effect of treatment was detected for net splanchnic release of propanol and ethanol. In conclusion, ruminal metabolism is a major component of alcohol metabolism in dairy cows. The postpartum transition dairy cow has sufficient metabolic capacity to cope with high dietary concentrations of primary alcohols even when alcohol intake is abruptly increased at the day of calving. Alcohol intake affects milk fat content and alcohol composition of silage might be important to improve predictions of milk composition.

Early prepartum shearing increases milk production of wool sheep and the weight of the lambs at birth and weaning

The use of mid prepartum shearing has been described as a possible tool to increase the weight of the lambs at birth and at weaning. The effect of prepartum shearing (53 days of gestation) on production and chemical composition of milk, weight of the lambs at birth and weaning and growth rate were evaluated in this trial. Twenty Polwarth ewes were inseminated with rams of the same breed in May (autumn), 2009. All ewes bore singletons and were maintained together under cultivated grazing conditions, during the experimental period. The ewes were allocated to two treatments groups, based on expected day of parturition, body weight and BCS of the dams. Ten ewes were shorn at 53 days of gestation (S53) and 10 ewes were kept unshorn during gestation (US). Milking of the ewes was recorded 7 days after parturition, and this was repeated weekly for 15 weeks. Milk production of the S53 ewes was 22.2% higher ( P < 0.05), when compared to US control ewes – with no change in the milk composition. At lambing, the lambs born to the S53 ewes were 1.41 kg ( P < 0.05), and at weaning 4.5 kg heavier ( P < 0.05), than lambs born to US ewes. In conclusion, it can be said that the higher weaning weight of the S53 lambs was the result of both a higher birth weight and an increased growth rate up to weaning in part, due to an improved milk production of the ewes.

Perinatal exposure to low-dose DE-71 increases serum thyroid hormones and gonadal osteopontin gene expression

Polybrominated diphenyl ethers (PBDEs) are flame retardants that have been widely used in manufacturing. They are major household and environmental contaminants that bioaccumulate. Humans are exposed primarily through dust inhalation and dietary ingestion of animal products. In animal studies, high doses of penta-brominated diphenyl ethers (penta-BDEs) in the mg/kg body weight (BW) range negatively impact brain development, behavior, memory, circulating thyroid hormone concentrations, the reproductive system and bone development. We investigated the effects of ingestion of a relatively low dose of the penta-BDE mixture DE-71 by pregnant and lactating rats on reproductive and thyroid parameters of the F1 offspring. F0 mothers received 60 μg/kg BW of DE-71 or vehicle daily by gavage from Day 1.5 of pregnancy through lactation (except the day of parturition). F1 pups were sacrificed at 21 d of age or outbred at approximately 80 d of age. Bred F1 females were sacrificed at Day 14.5 of pregnancy or at five months of age. Bred F1 males were sacrificed at five months of age. DE-71 treatment of the mothers affected the F1 females as evidenced by lower body weights at 80 d and five months of age, elevated serum T3 and T4 concentrations at Day 14.5 of pregnancy and increased thyroid gland weight and ovarian osteopontin mRNA at five months of age. Perinatal DE-71 exposure also increased testicular osteopontin mRNA in 21-day-old F1 males. Utilizing a granulosa cell in vitro model, we demonstrated that DE-71 activated the rat osteopontin gene promoter. Our results are the first to demonstrate that PBDEs increase rodent circulating T3 and T4 concentrations and gonadal osteopontin mRNA, and activate the osteopontin gene promoter. These changes may have clinical implications as others have shown associations between human exposure to PBDEs and subclinical hyperthyroidism, and overexpression of ovarian osteopontin has been associated with ovarian cancer.

Levels of protein fractions in blood serum of periparturient goats

The aim of the study was to compare contents of individual protein fractions determined by electrophoresis in blood serum of healthy periparturient goats. Eight clinically healthy white shorthaired goats were examined. Blood samples of these goats were taken from v. jugularis three weeks and two weeks before the anticipated parturition, on the parturition day, 7 days after the parturition, and 28 days after the parturition. Individual protein fractions, albumins, α1-, α2-, β1-, β2- and γ-globulins were identified by electrophoretic analysis of blood serum. Percentage shares of individual protein fractions were converted from total protein values to g·l-1values. The results indicated that individual serum protein fractions in periparturient goats showed significant dynamics of change. There were no significant differences between samples taken before the parturition and on the parturition day (except for the increase of β2 from 2.5 ± 0.3 g·l-1observed 3 weeks before the parturition to 3.2 ± 0.4 g·l-1measured 2 weeks before the parturition, and the decrease of γG levels from 9.5 ± 2.6 g·l-1observed three weeks before the parturition to 8.1 ± 1.7 g·l-1found on the parturition day), yet most indicators measured after the parturition were significantly higher (p&lt; 0.05) than on the parturition day (values in g·l-1observed on the parturition day versus values measured 28 days after the parturition: total protein 60.6 ± 4.3 vs. 71.3 ± 2.4, albumins 37.4 ± 2.9 vs. 42.7 ± 1.0, α2 3.4 ± 0.5 vs. 4.1 ± 0.8, β1 5.6 ± 0.5 vs. 6.3 ± 0.9, γG 8.1 ± 1.7 vs. 12.3 ± 1.9). The results bring new knowledge on the values of individual fractions of serum proteins in healthy goats, which is necessary for diagnostic interpretation of pathological findings in animals and also for experimental studies.

Evaluation of galactagogue activity of lactovedic: A polyherbal formulation

Lactovedic is a lactogenic polyherbal formulation containing Jivanti, Shatavari, Vidarikanda, Yashtimadhu and Shatapushpa, and is processed with swarasas of Brahmi, Mandukaparni, Matsyakshi, Shatavari and Kokilaksha. The aim of this study was to evaluate the galactagogue activity of lactovedic. Rats (175–200 g) suckling eight to nine pups were divided into four groups (n=6). Control group rats were treated with vehicle (2 ml of 1% carboxymethyl cellulose sodium in normal saline) orally, Group II and Group III rats were orally administered 270 and 540 mg/kg body weight, respectively, of lactovedic suspended in vehicle, and Group IV animals were treated orally with 2.7 mg/kg body weight of domperidone suspended in vehicle from 3rd day of parturition to 15th day of parturition. Milk yield at 18 hours, the weight of pups at 18 and 23 hours and the daily weight of the mother rat were estimated. On 16th day, blood samples were collected and mother rats were sacrificed. Glycogen and total protein content in mammary gland and serum prolactin and cortisol were estimated. Results were statistically analysed using analysis of variance (ANOVA), followed by Tukey-Kramer post hoc test. Histopathology of mammary gland was performed. Lactovedic increases the milk yield, pups’ body weight, weight of the mother rat, glycogen and protein content of mammary gland tissue, and serum prolactin and cortisol, compared to the control animals. Transverse section of mammary gland of lactovedic treated rats showed proliferation of acini and marked increase in milk secretion in the ducts. It can be concluded that lactovedic possesses significant galactagogue activity. Key words: Cortisol, galactagogue, histopathology of mammary gland, lactovedic, milk yield, prolactin, pups weight

Effects of different starch sources on metabolic profile, production and fertility parameters in dairy cows

The objective of the study was to determine the effect of replacing triticale (high rumen degradable starch) with maize grain (low rumen degradable starch) during the transition period and the first 120 days of lactation on metabolic and hormonal profile indices, milk production and fertility performance in cows. Forty-eight Holstein-Friesian dairy cows were divided into 4 groups: TT (2.5 kg triticale grain/cow per day supplemented from 14 days prepartum to day 120 postpartum), TM (2.5 kg triticale grain/cow per day supplemented from day 14 before parturition to calving, and then 2.5 kg maize grain to 120 days of lactation), MT (2.5 kg maize grain/cow per day supplemented from day 14 before parturition to calving, and then 2.5 kg triticale grain to 120 days of lactation), MM (2.5 kg maize grain/cow per day supplemented from 14 days prepartum to day 120 postpartum). Blood samples were collected 3 weeks and 1 week before calving and on days 14, 56 and 70 of lactation, and they were analyzed in terms of concentrations of glucose, insulin, leptin, insulin-like growth factor I, nonesterified fatty acids, triglycerides, cholesterol, blood urea nitrogen and activities of aspartate aminotransferase and gamma glutamyl transpeptidase. Milk samples were collected twice a day at weekly intervals and analyzed for fat, protein and lactose. Milk yield and individual dry mater intake were recorded at weekly intervals. Body condition was estimated 3 weeks before calving, on parturition day and on days 14, 56 and 120 of lactation. Replacing triticale grain with maize grain in the transition period and during lactation positively affected fertility of lactating cows. An increased first service conception rate and shortening of the days open period was observed in MM and TM groups in comparison to those found in group MT (P < or = 0.05). The lowest number of services per conception was recorded in groups MM and TM (P < or = 0.05). Although the impact of milk production and the most of the blood indices were not significantly affected by this treatment, the results of the study suggest that maize grain in the transition period and lactation might be a more effective energy source for dairy cows than triticale grain.

Use of a commercially available relaxin test for detection of pregnancy in cats

To determine the earliest day of gestation at which relaxin could be detected in pregnant queens by use of a commercially available point-of-care test designed for use in dogs, and to calculate sensitivity and specificity of the test for pregnancy detection on any specified day of gestation. Evaluation study. 162 female cats (24 queens from a breeding colony, 128 stray and feral queens undergoing ovariohysterectomy, and 10 ovariohysterectomized cats). 24 queens were monitored for pregnancy. Blood samples were collected daily and tested for relaxin until 2 consecutive positive test results were obtained. The earliest day of pregnancy detection was estimated by counting backward from the day of parturition to the day of the first positive test. The uteri, ovaries, and any fetuses of 128 stray and feral queens undergoing ovariohysterectomy were examined grossly, and gestational day in pregnant queens was determined on the basis of fetal crown-rump length. Blood samples from these queens and from 10 cats ovariohysterectomized prior to the study were collected for relaxin testing. Pregnancy was detected by use of the relaxin test kit as early as gestational day 20; sensitivity of the test was 100% on and after gestational day 29. False-positive results were detected in 3 queens, 2 of which had large (approx 2×3-cm) ovarian cysts, resulting in a specificity of 95.9%. A commercially available relaxin test kit designed for use in dogs can be used to reliably detect pregnancy in cats.

Temporal changes in circulating levels of plasma interleukin-8 during peripartum period in Murrah buffaloes (Bubalus bubalis) under subtropical climate

The objective of this study was to elucidate the changes in circulating levels of plasma interleukin-8 (IL-8) during peripartum period in Murrah buffaloes (Bubalus bubalis). IL-8 was estimated in blood plasma of healthy peripartum Murrah buffaloes (n=6) on days ± 30, ± 15, ± 5, ± 3, ± 1 and 0 pre- and postpartum with respect to the day of parturition (day 0) in each of the two different seasons (hot-humid and spring). The mean microclimate Temperature-Humidity Index (THI) during spring season was significantly lower (p<0.01) than the corresponding THI in hot-humid season. In both the seasons, plasma IL-8 remained lower in prepartum period (≤ 46.56 ± 14.08 pg/ml during spring and ≤ 73.18 ± 18.56 pg/ml during hot-humid season) than in the postpartum period (≥ 51.41 ± 13.82 pg/ml during spring and ≥ 84.13 ± 16.97 pg/ml in hot humid season). During spring, the IL-8 levels were significantly higher (P<0.05) on days+5 and +15 postpartum in comparison to the IL-8 levels on days -30, -5, and -3 prepartum. During hot-humid season, IL-8 level was significantly higher (P<0.05) on day +30 as compared to the IL-8 levels on days -30 and -5 prepartum. The correlation between IL-8 and mean microclimate THI was significant (r=0.25, P<0.01). From the results, it is concluded that peripartum period in buffaloes is associated with an inflammatory response leading to significantly higher plasma IL-8 during parturition and postpartum period than in the pre-partum period.

Effect of abomasal glucose infusion on plasma concentrations of gut peptides in periparturient dairy cows

Six Holstein cows fitted with ruminal cannulas and permanent indwelling catheters in the portal vein, hepatic vein, mesenteric vein, and an artery were used to study the effects of abomasal glucose infusion on splanchnic plasma concentrations of gut peptides. The experimental design was a randomized block design with repeated measurements. Cows were assigned to one of 2 treatments: control or infusion of 1,500g of glucose/d into the abomasum from the day of parturition to 29 d in milk. Cows were sampled 12±6 d prepartum and at 4, 15, and 29 d in milk. Concentrations of glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1(7–36) amide, and oxyntomodulin were measured in pooled samples within cow and sampling day, whereas active ghrelin was measured in samples obtained 30min before and after feeding at 0800h. Postpartum, dry matter intake increased at a lower rate with infusion compared with the control. Arterial, portal venous, and hepatic venous plasma concentrations of the measured gut peptides were unaffected by abomasal glucose infusion. The arterial, portal venous, and hepatic venous plasma concentrations of glucose-dependent insulinotropic polypeptide and glucagon-like peptide 1(7–36) amide increased linearly from 12 d prepartum to 29 d postpartum. Plasma concentrations of oxyntomodulin were unaffected by day relative to parturition. Arterial and portal venous plasma concentrations of ghrelin were lower postfeeding compared with prefeeding concentrations. Arterial plasma concentrations of ghrelin were greatest prepartum and lowest at 4 d postpartum, giving a quadratic pattern of change over the transition period. Positive portal venous-arterial and hepatic venous–arterial concentration differences were observed for glucagon-like peptide 1(7–36) amide. A negative portal venous–arterial concentration difference was observed for ghrelin pre-feeding. The remaining portal venous–arterial and hepatic venous–arterial concentration differences of gut peptides did not differ from zero. In conclusion, increased postruminal glucose supply to postpartum transition dairy cows reduced feed intake relative to control cows, but did not affect arterial, portal venous, or hepatic venous plasma concentrations of gut peptide hormones. Instead, gut peptide plasma concentrations increased as lactation progressed. Thus, the lower feed intake of postpartum dairy cows receiving abomasal glucose infusion was not attributable to changes in gut peptide concentrations.

Prenatal l-DOPA exposure produces lasting changes in brain dopamine content, cocaine-induced dopamine release and cocaine conditioned place preference

Dopamine, its receptors and transporter are present in the brain beginning from early in the embryonic period. Dopamine receptor activation can influence developmental events including neurogenesis, neuronal migration and differentiation raising the possibility that dopamine imbalance in the fetal brain can alter development of the brain and behavior. We examined whether elevated dopamine levels during gestation can produce persisting changes in brain dopamine content and dopamine-mediated behaviors. We administered L-3,4-dihydroxyphenylalanine (l-DOPA) in drinking water to timed-pregnant CD1 mice from the 11th day of gestation until the day of parturition. The prenatal l-DOPA exposure led to significantly lower cocaine conditioned place preference, a behavioral test of reward, at postnatal day 60 (P60). However, in vivo microdialysis measurements showed significant increases in cocaine-induced dopamine release in the caudate putamen of P26 and P60 mice exposed to l-DOPA prenatally, ruling out attenuated dopamine release in the caudate putamen as a contributor to decreased conditioned place preference. Although dopamine release was induced in the nucleus accumbens of prenatally l-DOPA exposed mice at P60 by cocaine, the dopamine release in the nucleus accumbens was not significantly different between the l-DOPA and control groups. However, basal dopamine release was significantly higher in the prenatally l-DOPA exposed mice at P60 suggesting that the l-DOPA exposed mice may require a higher dose of cocaine for induction of cocaine place preference than the controls. The prenatal l-DOPA exposure did not alter cocaine-induced locomotor response, suggesting dissociation between the effects of prenatal l-DOPA exposure on conditioned place preference and locomotor activity. Tissue concentration of dopamine and its metabolites in the striatum and ventral midbrain were significantly affected by the l-DOPA exposure as well as by developmental changes over the P14–P60 period. Thus, elevation of dopamine levels during gestation can produce persisting changes in brain dopamine content, cocaine-induced dopamine release and cocaine conditioned place preference.

The behaviour of farm rabbit does around parturition and during lactation.

The effects of parturition and lactation were assessed on eleven multiparous rabbit does caged under farm conditions. Frequency and time for different activities (drinking, eating, caecotrophy, nesting, grooming, chewing, attention to neighbour and resting) were studied for the day of parturition, and days 1, 10 and 28 of lactation. Parturition: Does spent most time during the dark period in drinking (85%) and eating (63%). Conversely, 79% of the time spent in caecotrophy and 55% in resting were recorded during the light period. Eating time was 104 minutes per day, being higher during the dark period and after delivery. Females rested 33 minutes per hour and started one of the observed activities 39 times per hour. A general tendency to reduce main activities was observed around parturition with the exception of time spent nesting. Lactation: Does spent most time during the dark period in drinking (59%), eating (59%), grooming (55%) and neighbour (72%) while they spent less time resting (46%). The level of activity in parturition seems to be maintained or increased on the following day and reduced afterwards. Does were resting 31, 35 and 41 minutes per hour, and started one activity 67, 27 and 24 times per hour during 1st, 10th and 28th lactation days, respectively.

The effect of pregnancy on echocardiographic variables in healthy bitches

Objectives Little is known of the effect of pregnancy on canine cardiovascular function. This study was undertaken to evaluate the effect of pregnancy on canine echocardiographic variables. Animals, materials and methods Serial echocardiographic examinations of 7 healthy, sexually intact female canine mongrels dogs that weighed between 9.7 and 13.4 kg were performed. The subjects were examined prior to ovulation, during early pregnancy, during late pregnancy within 6 days of parturition and again, after puppies were weaned. Results Repeated measures ANOVA disclosed a statistically significant effect of time on end-systolic left ventricular dimension (LVIDs, p = 0.005), left ventricular fractional shortening (%FS, p = 0.001), Doppler-derived inflow and ejection velocities (all p < 0.05), as well as on heart rate (HR, p = 0.03). %FS, HR, aortic ejection velocity, pulmonic ejection velocity and early diastolic mitral inflow velocity were maximal during late pregnancy. The increase in %FS resulted from a decrease in LVIDs. For Doppler-derived flow velocities, the range of differences of least square means (m/s) between early and late pregnancy was 0.21–0.32. Conclusions While the magnitude of effect generally was small, this study provides evidence that pregnancy in healthy bitches is associated with changes in echocardiographic variables.

Plasma Concentrations of 13, 14‐Dihydro‐15‐keto‐Prostaglandin F2α, Progesterone and Cortisol During Periparturient Period in Yaks (Poephagus grunniens L.)

An attempt was made to determine plasma concentrations of, 13, 14-dihydro-15-keto-prostaglandin F(2alpha) (PGFM), cortisol and progesterone during periparturient period in yak. Plasma PGFM level showed an increasing trend beginning day 5 prior to parturition (0.48 +/- 0.14 ng/ml) and increased steeply thereafter to reach a peak level (17.16 +/- 1.31 ng/ml) on the day of parturition. The levels, then, declined sharply on day 1 postpartum to reach 1.20 +/- 0.40 ng/ml and thereafter declined gradually over the days to reach 0.28 +/- 0.09 ng/ml on day 20 postpartum and this level was maintained with fluctuation within narrow limits thereafter till conclusion of the blood sampling on day 90 post-calving. The plasma progesterone concentration on days 7 and 6 before parturition was high (2.10 +/- 0.10 and 2.12 +/- 0.10 ng/ml, respectively). The level then decreased gradually and abrupt fall was observed 1-2 days before parturition and became basal on day of parturition (0.24 +/- 0.04 ng/ml). This basal level was maintained till the end of the blood sampling on day 90 postpartum. Plasma cortisol level showed an increasing trend beginning day 2 prior to parturition (2.36 +/- 0.65 ng/ml) and increased steeply thereafter to reach a peak level (26.65 +/- 5.28 ng/ml) on the day of parturition. The levels, then, declined gradually over the days and touched 2.36 +/- 0.25 ng/ml on day 3 postpartum and this level was maintained with fluctuation within narrow limits thereafter till day 7 post-calving.

Feed transition between gestation and lactation is exhibited earlier in sows fed a high-fiber diet during gestation1

The underconsumption of feed frequently observed in young sows during lactation can result from an adaptation problem of the sow to the new feeding management in terms of diet composition and feeding amount. Our study aimed to investigate how the sow manages her own feed transition when given the choice between the gestation diet and the lactation diet from moving into the farrowing crate (12 d before farrowing) until the second week postpartum. The effect of adding dietary fiber to the gestation diet on this transition was also evaluated. During gestation, 16 primiparous sows (Large White x Landrace) were fed 2.4 kg/d of a control (CON) diet (3.5% of crude fiber), or 2.9 kg/d of a high-fiber (HF) diet (12.8% of crude fiber). The daily allowance of NE was 24 MJ in both treatments. Twelve days before the expected parturition day (d -12), sows were moved into farrowing crates that were equipped with a computerized feeding device allowing the gestation and lactation diets to be supplied via 2 rewarded push buttons placed above the trough, until d 14 postpartum. The feeding transition was evaluated through the daily ratio of ingestion of the lactation diet. Feeding behavior was measured through daily feed and energy intakes, number of daily meals, meal size, and the nycthemeral distribution of feeding activity. Sows were weighed and backfat thickness was measured at the beginning and end of gestation and lactation. Piglets were weighed every week from birth until weaning. The transition to the lactation diet occurred earlier in HF sows (P < 0.05); the 50% threshold of lactation diet ingestion was reached on d -8 and 12 in HF and CON sows, respectively. Dietary treatment did not affect the feeding pattern, and all sows presented a diurnal feeding activity. During lactation, there was an interaction (P < 0.05) between the hour of the day and the dietary treatment for the distribution of pushes on the rewarded buttons, with pushes being more spread out throughout the day in CON sows compared with HF sows. Variations in sow backfat thickness were not affected by dietary treatment, but HF sows lost more BW during lactation (P < 0.05). Growth of piglets was not affected by dietary treatment. In conclusion, sows chose the lactation diet spontaneously on the week preceding parturition when they were fed a fibrous diet during gestation. This highlights the possible impact of such a gestation diet to promote early intake of the lactation diet.