Pregnant Lactating Research Articles

The Blood Biochemical Profiles in Algerian Rabbits of the Semi-arid Region of Aures (Algeria) At Different Physiological Stages

Background: In recent years, several works have examined the reproductive traits of Algerian local population rabbit does but no standardization study has been done on the plasmatic parameters of this population of rabbits reared in the Aures region during their different physiological stages. Therefore, the present study evaluated the effect of these on certain blood parameters in local rabbit does.Methods: The rabbit does (n=120) were randomly divided into 4 treatment groups; Empty (E), Pregnant (P), Pregnant lactating (P-L) and Lactating (L). Does were first mated at the age of 16.5 weeks with an average body weight of 3107.1 ± 53.5g and with body condition scoring (BCS) of loin and rump ranging from 2 to 3 on a scale of 1- 5 following a 42-day rhythm. Four blood samples were collected from females of five rabbits in each group viz. E, P, P-L and L respectively.Result: Milk yield differs significantly (p less than 0.05) between the two experimental groups (P-L and L). Litter size and litter weight of does at birthing was higher (p less than 0.01) in L group than in P and P-L groups. That the mean levels glucose in non-pregnant group recorded as 0.22±0.04g/l which was increased 3rd week of pregnancy (0.65± 0.1 g/l followed by low mean value 0.35+0.2g/l and 0.4+0.1g/l at pregnant lactating and lactating stages of experimental rabbits. The lowest level of protein was recorded in the second week of pregnancy (p less than 0.05). The increase in total protein, albumin and globulin concentrations in lactating group might be physiological. Concerning total lipids, there was a strong mobilization of body fat in pregnant females (97 mg/dl ± 0.10; p less than 0.05). However, a marked decrease (p less than 0.05) was recorded in cholesterolemia in lactating females. Regarding triglyceridemia, we have recorded a significant raise (37.7 ± 35.6; p less than 0.001) in pregnant females. The creatinine value recorded was close to the physiological norms 1.3-2.7 mg/dl vs 1.08 -0. 92 mg/dl. T3 plasma levels were lower (p less than 0.05) in lactating females’ group. Pregnant and lactating does showed an increase (p less than 0.05) of leptin level. The higher (p less than 0.05) progesterone levels in pregnant and pregnant-lactating does than its concentrations in empty and lactating does might be attributed to maintaining pregnancy. Therefore, the current study confirms that the analysis of metabolites represents a good tool to understand the physiological mechanisms.

Heat Stress and Body Temperature in Brown Swiss Cows Raised in Semi-Arid Climate of Ceará State, Brazil

Background: In tropical countries like Brazil, air temperature and relative humidity have a significant effect on animal physiology; there is a great impact of solar radiation on physiological parameters, especially on body temperature. This study evaluated the occurrence of heat stress in Brown Swiss cows in a tropical semi-arid climate, and checked for the correlation between internal body temperatures [rectal temperature (RT) and vaginal temperature (VT)] with surface temperature (ST) to determine if these variables are associated.Materials, Methods & Results: Twenty-eight Brown Swiss cows at three stages of the lactation cycle were used in this study: 10 nonpregant lactating (NPL) cows, 8 dry pregnant (DP) cows, and 10 pregnant lactating (PL) cows. These animals were between the second and third calving, weighed between 346 and 720 kg, and had ages between 2 and 13 years. During the experimental period, air temperature and relative humidity (RH) at the experimental site were measured using a digital thermohygrometer. The temperature and humidity index (THI) was calculated according to methodology described by Thom (1958), and was used as an environmental comfort parameter. For the evaluation of RT and VT, two digital clinical thermometers, one inserted in the vagina and the other in the rectum, were used simultaneously to minimize stress. Surface temperature (ST) was assessed using a digital infrared laser thermometer at a distance of 50 cm from the animal. Surface temperature was measured in the forehead (FST), thorax (TST), flank (FLST), and legs (LST). During the study period, the ambient temperature (AT) was significantly higher outside (in the sun) than inside of the facilities (in the shade) (P < 0.05). RH was inversely proportional to AT, and was significantly higher inside than outside the facilities (P < 0.05). Like AT, THI was significantly higher outside (in the sun) than inside the facilities (in the shade), with significant differences between these locations (P < 0.05). The amplitudes of the differences between the locations were as follows: 3.8°C for AT, 6.2% for RH, and 2.6 for THI. Mean values of rectal and vaginal temperatures were not significantly different from each other independent of lactation cycle stage, and were almost always significantly higher than the measured surface temperatures (P < 0.05). The maximum values obtained for each lactation cycle stage in this study were higher when compared to the mean values, showing that they are more representative of the occurrence of heat stress. Correlations between internal temperatures (RT and VT) and surface temperatures (TSF, TST, TSFL, and TSP) were weak and non-significant. ST values exhibited mostly weak, non-significant correlations, with the exception of FST with FLST and LST, which had moderate, significant correlations, as shown by the following coefficient factors: FST x FLST, 0.34; LST x FST, 0.415; and LST x FLST, 0.37.Discussion: A temperature of 34°C with RH ranging from 46% to 80% (i.e., a THI between 83 and 89) has been reported to have a significant thermal impact on dairy Brown Swiss cows; the THI values found in the present experiment were close to those. Body temperatures exhibited significant variations depending on the lactation cycle stage of the cows. Lactation concomitant with pregnancy significantly increases internal temperatures (RT and VT) in DP and NPL cows. This finding may be explained by the fact that pregnancy concomitant with lactation accelerates the metabolism, which results in higher food intake and increased production of body heat with consequent increase in internal body temperature. The maximum values of internal body temperatures (RT and TV) at all stages of the lactation cycle were higher than their corresponding average values, which indicates that some cows exhibited, at given moments, hyperthermia.

Heart rate and heart rate variability in pregnant dairy cows and their fetuses determined by fetomaternal electrocardiography

In this study, fetomaternal electrocardiograms were recorded once weekly in cattle during the last 14 weeks of gestation. From the recorded beat-to-beat (RR) intervals, heart rate and heart rate variability (HRV) variables standard deviation of the RR interval (SDRR) and root mean square of successive RR differences (RMSSD) were calculated. To differentiate between effects of lactation and gestation, pregnant lactating (PL) cows (n = 7) and pregnant nonlactating (PNL) heifers (n = 8) were included. We hypothesized that lactation is associated with stress detectable by HRV analysis. We also followed the hypothesis that heart rate and HRV are influenced by growth and maturation of the fetus toward term. Maternal heart rate changed over time in both groups, and in PL cows, it decreased with drying-off. During the last 5 weeks of gestation, maternal heart rate increased in both groups but was lower in PL cows than in PNL heifers. Maternal HRV did not change over time, but SDRR was significantly higher in PL cows than in PNL heifers, and significant interactions of group × time existed. On the basis of HRV, undisturbed pregnancies are thus no stressor for the dam in cattle. Fetal heart rate decreased from week 14 to week 1 before birth with no difference between groups. Gestational age thus determines heart rate in the bovine fetus. The HRV variables SDRR and RMSSD increased toward the end of gestation in fetuses carried by cows but not in those carried by heifers. The increase in HRV indicates maturation of fetal cardiac regulation which may be overrun by high sympathoadrenal activity in fetuses carried by heifers as suggested by their low HRV.

Sex and physiological state influence the rate of resource acquisition and monopolisation in urban free-ranging dogs, Canis familiaris

In animal populations, the constraints of energy and time can cause intraspecific variation in foraging behaviour. The proximate developmental mediators of such variation are often the mechanisms underlying perception and associative learning. Here, experience-dependent changes in foraging behaviour and their consequences were investigated in an urban population of free-ranging dogs, Canis familiaris by continually challenging them with the task of food extraction from specially crafted packets. Typically, males and pregnant/lactating (PL) females extracted food using the sophisticated ‘gap widening’ technique, whereas non-pregnant/non-lactating (NPNL) females, the relatively underdeveloped ‘rip opening’ technique. In contrast to most males and PL females (and a few NPNL females) that repeatedly used the gap widening technique and improved their performance in food extraction with experience, most NPNL females (and a few males and PL females) non-preferentially used the two extraction techniques and did not improve over successive trials. Furthermore, the ability of dogs to sophisticatedly extract food was positively related to their ability to improve their performance with experience. Collectively, these findings demonstrate that factors such as sex and physiological state can cause differences among individuals in the likelihood of learning new information and hence, in the rate of resource acquisition and monopolization.

Hepatic triacylglycerols and serum non-esterified fatty acids (NEFA) variations in indigenous water buffalo (Bubalus bubalis) in the province of Khuzestan, Iran

Fatty liver is a metabolic disorder of dairy cows in early lactation, and approximately half of multi-parous dairy cows experience a moderate to severe fatty liver at calving. Since the occurrence of fatty liver in buffalo is not known, the aim of this study was to evaluate the hepatic content of triacylglycerols (TAG) and total lipids (TL), and the serum content of non-esterified fatty acids (NEFA) in native buffalo at different stages of productivity. The relationship between body condition score (BCS), age, serum NEFA content and hepatic TAG and TL content was also considered. A total of 119 blood and liver samples were randomly collected from indigenous buffalo immediately after slaughter. Buffalo were divided into six groups: male, heifer, non-pregnant lactating, 1-8 months pregnant lactating, late pregnant and immediately post parturient. Serum NEFA concentration in late pregnant and recently calved buffalo was significantly higher than that of males and heifers. Liver TAG content rose significantly in the first months after parturition, but liver TL content was not affected by the physiological status of the animals. Serum NEFA concentration was not associated with liver TAG or TL content. BCS had no significant correlation with either serum NEFA concentration or age of the animals. The results showed that an increase in liver TAG and serum NEFA was seen in late pregnancy and after parturition in buffalo, similar to results in cows. However, TAG and NEFA levels were much lower than in dairy cattle and it can therefore be concluded that there is no indication of fatty liver in buffalo.

Impact of concurrent pregnancy and lactation on maternal nestbuilding, estradiol and progesterone concentrations in rabbits

We evaluated the impact of concurrent pregnancy and lactation on: nest-building (i.e., digging, straw-carrying, hair-pulling), food intake, milk output, body weight, and the concentration of estradiol and progesterone in blood. Digging was lower in pregnant-lactating (PL) rabbits, compared with pregnant-only (PO) does, on 21-23 d (52±64 vs. 104±86 g, respectively; mean±SD; P<0.05). Straw-carrying was also reduced in PL does on 24-26 d (9±27 vs. 79±94 g; P<0.005), 27-29 (27±56 vs. 99±77 g; P<0.005), and in the total amount of material introduced into the nest box (132±167 vs. 286±217 g; P<0.02). Hair-pulling was expressed by practically all animals. Food intake declined in PO does on the three days preceding parturition (P<0.01) and increased markedly during lactation; this increase was much larger in PL than in lactating-only (LO) rabbits (P<0.01). Milk output was similar between PL and LO does during the first 21 d of lactation but a marked decline in this parameter occurred in PL does from then until 30 d. The differences in nest-building between PL and PO rabbits may be related to the concentrations of estradiol and progesterone on specific days of pregnancy. PL does showed significantly higher estradiol levels than PO animals on pregnancy 1 d (33±13 vs. 23±4 pg/mL; P<0.02) and 21 (34±19 vs. 24±6 pg/mL; P<0.05) and also higher levels of progesterone on pregnancy 1 d (4±5 vs. 1±2 ng/mL; P<0.05). However, PL rabbits had lower levels of progesterone on 7 d (6±3 vs. 9±2 ng/mL; P<0.02) and 14 d (8±3 vs. 11±3 ng/mL; P<0.005) than PO does. Our results indicate that the unique endocrine milieu of PL rabbits has a direct bearing on specific behavioral and physiological phenomena that impact productivity on the farm.

Uterine blood flow during the first 3 weeks of pregnancy in dairy cows

Transrectal color Doppler sonography was used to compare changes in uterine blood flow between cyclic and early pregnant lactating dairy cows. Examinations were carried out in 53 multiparous lactating cows on days 3, 6, 9, 11, 13, 15, 18 and 21 (day 0=estrus). Fourteen cows were examined during the estrous cycle and thirty-nine cows after insemination with frozen/thawed sperm. Uterine blood flow was reflected by the time-averaged maximum velocity (TAMV) and the pulsatility index (PI) in the uterine artery ipsilateral to the corpus luteum. Twenty-one cows that were not pregnant on day 25 were excluded from the study. There was high inter-individual variability in PI- (CV: 22-62%) and TAMV-values (CV: 22-42%) at all examinations. In cyclic cows, TAMV values increased between days 13 and 18 and PI values decreased between days 15 and 21 (P<0.05). In pregnant cows (n=18), TAMV values increased from days 9 to 11 and then decreased to minimal values by day 18 (P<0.05). The PI values decreased between days 3 and 11 and then increased to maximum levels on day 18 (P<0.05). On day 21, both variables reached (P<0.05) values that did not differ (P>0.05) from those on day 11. The changes in TAMV were correlated with estrogen and progesterone concentrations (r=0.69 and -0.70, respectively; P<0.05) in cycling cows, but not in pregnant cows (P>0.05). The PI values did not correlate with steroid hormone levels (P>0.05). Differences in uterine blood flow between cycling and early pregnant cows were observed only on day 18 (P<0.05). The results show that in pregnant cows changes in uterine blood supply can be detected already in the second week after insemination; these changes do not occur in the second week of the cycle.

Influence of oxidative stress and metabolic adaptation on PON1 activity and MDA level in transition dairy cows

Serum PON1 is a HDL-associated enzyme that protects lipoproteins, both LDL and HDL, against oxidation and it is considered as an antioxidative/anti-inflammatory component of HDL. Dairy cows are highly susceptible to oxidative stress which commonly occurs in late pregnancy and early lactation. During the transition period, increased production of reactive oxygen species is associated to processes of metabolic adaptation to a low-energy balance. We investigated serum paraoxonase-1 (PON1) activity and malondialdehyde (MDA) concentration to assess the antioxidative/prooxidative status during pregnancy and the postpartum period. In order to evaluate metabolic homeostasis, common metabolic parameters (glucose, triglyceride, total cholesterol, HDL-C and albumin concentrations) were determined as well. A significantly lower PON1 activity was found in late pregnancy and early postpartum ( P < 0.05) compared to the first and the second trimester of pregnancy and the mid-lactation. MDA level was significantly higher ( P < 0.05) in the dry period compared to pregnant lactating and postpartum cows. Serum glucose concentration ( P < 0.001) was lower in the early and late puerperium indicating low-energy balance in the early lactation. Serum triglyceride and albumin concentrations were lower in late puerperium ( P < 0.001), while total cholesterol and HDL-C were lower during the dry period ( P < 0.05) as well as in early postpartum ( P < 0.001). Significant correlations of PON1 activity with glucose ( P < 0.05), albumin ( P < 0.05), total cholesterol ( P < 0.001) and HDL-C ( P < 0.001) were also found. The observed lower serum PON1 activity and higher MDA level in late pregnancy and early postpartum could indicate a prooxidants/antioxidants imbalance influenced by reproductive stress and metabolic adaptation in the transition period of dairy cows.

Nutrient digestibility of rabbit does in different stages of reproductive cycle under tropical conditions

Effect of stages of reproductive cycle on body weight, feed intake and apparent nutrient digestibility of rabbits was investigated. Pregnant/lactating (PL) does increased their feed intake above pregnant lactating does. Dry matter (DM) digestibility was higher in pregnant does than in lactating, PL or open does. Digestibility of crude fibre, crude protein (CP) and nitrogen-free extractives (NFE) were significantly higher for open and pregnant does than lactating and PL does. Ether extract (EE) digestibility was similar for pregnant, lactating and PL does. Digestible CP requirement of does increased with physiological state from open to PL states. Open and pregnant does were meeting their protein requirement while lactating and PL does were not meeting their requirement. Feed intake was higher for first week pregnant, fourth week pregnant, first week lactating, first week pregnant/fourth week lactating and second week pregnant/fourth week lactating does than open does. DM digestibility was higher for first and fourth week pregnant does than the other physiological stages. EE digestibility was similar for all physiological stages. CP digestibility was higher in fourth week pregnant does than the other physiological stages. Fourth week pregnant does had higher NFE digestibility than first and fourth week lactating and the various stages of concurrent pregnant and lactating does. Open does, first and fourth week pregnant does were meeting their protein requirement while does in the first and fourth week of lactating and stages of concurrent PL were not meeting their requirement.

Serum paraoxonase activity in dairy cows during pregnancy

Preparturient dairy cows are at high risk of metabolic and reproductive disorders and oxidative stress is considered to be involved in these events. We investigated the serum paraoxonase activity in dairy cows during pregnancy and alterations in lipid and lipoprotein patterns in this period. The relation between paraoxonase activity and HDL-cholesterol concentration was also compared. The study was carried out on 76 pregnant lactating and 26 pregnant dry Holstein dairy cows. The serum paraoxonase activity was determined by the method of hydrolysing of paraoxon, while triglyceride, cholesterol and HDL-cholesterol concentrations were measured by the enzymatic kit methods. A significantly higher serum triglyceride concentration ( P < 0.001) was observed in dry cows compared to lactating cows. The total cholesterol and HDL-cholesterol concentrations were significantly lower ( P < 0.001) in dry cows than in lactating ones. In dry cows, paraoxonase activity was significantly lower than in those lactating ( P < 0.001). There was no significant difference in paraoxonase/HDL-cholesterol ratio between the investigated groups. It seems that the lower HDL concentration could be one of the causes of reduced paraoxonase activity considering the role of HDL as a carrier of most paraoxonase molecules in the blood. A decreased serum paraoxonase activity could diminish the effectiveness and total capacity of the whole antioxidative system during prepartum period in dairy cattle.

Influence of prolactin on foetal survival in rabbit does

Experiments were conducted to assess the influence of prolactin levels on foetal survival in pregnant does. All the females were mated within 12 h following parturition (Day 0), and slaughtered on Day 28 to study reproductive performance. In Experiment 1, lactation was terminated at birth and females in the treated group (Group P, n = 34) were injected with 1 mg of ovine prolactin daily from Day 7 to Day 21. Females in the control group (Group CP, n=31) received no prolactin. On Day 16, the ovine prolactin concentration in Group P was 32.5 ng ml −1. The concentration of rabbit prolactin was higher and the serum level of progesterone was lower in Group P than in Group CP on Day 16 ( P < 0.01). The ovulation rate was similar in both groups but late foetal mortality (> Day 15) was significantly higher in Group P (24.5% vs. 10.6%; P < 0.01). In Experiment 2, females were allowed to suckle seven young and received 1 mg of bromocriptine daily from Day 14 to Day 18 (Group B, n = 34). Females in the control group (Group CB, n=31) received no bromocriptine. The concentration of prolactin was lower in Group B than in Group CB on Days 14 and 18 ( P < 0.01), and the concentration of progesterone was higher in Group B on Day 18 ( P < 0.01). The ovulation rate and early and late foetal mortality were similar in both groups but the number of resorbed foetuses was higher in Group B than in Group CB (1 vs. 0.5; P < 0.05). These results suggest that hyperprolactinaemia during lactation is responsible for the reduced progesterone concentration and the increased late foetal mortality observed in pregnant lactating does. However, short-term suppression of prolactin release after suckling does not improve foetal survival.

The Establishment and Spread of Spilopsyllus Cuniculi (Dale) and Its Location on the Host, Oryctolagus Cuniculus (L.), In the Mallee Region of Victoria.

European rabbit fleas (Spilopsyllus cuniculi) (Dale)) were released into a population of wild rabbits at 7 sites on Pine Plains in the Mallee district of Victoria, Australia, and their establishment and distribution observed monthly for 4 years. After 12 months, including one breeding season, the fleas were found on some rabbits up to 0.8 km from some release sites. By the end of the second breeding season, the distance of spread had doubled, and 4 years after the initial release, including 5 breeding seasons, about 95% of rabbits caught carried S. cuniculi. The furthest spread was about 13 km. When the initial release was made during the summer months, the non-breeding season, spread was slow; in one area, it took 2 years for S. cuniculi to become firmly established. When examples of S. cuniculi infected with myxoma virus were released, no establishment of the disease was observed. The numbers of S. cuniculi per rabbit were low during the first breeding season, but they were high, up to 500/rabbit, after 4 years. In most cases, the fleas were seen on the ears, pinnae and head of the rabbit and occasionally in the body fur. The highest numbers were usually found on pregnant lactating does about to litter, but some bucks also carried a large number.

A Conspectus of Research on Zinc Requirements of Man

Investigations which have figured in the present understanding of hu man requirements for iron are reviewed. Those studies reviewed include those on iron balance and turnover intestinal urinary integumental and menstrual losses of iron iron reserves physiological factors affecting iron absorption factors affecting iron availability from plant animal and other sources iron supplementation practices the assessment of iron deficiency and hemoglobin levels factors affecting iron nutritional status such as environmental stress and exercise the iron requirements of infants premature infants full-term infants children aged 2-5 years 6-12 years and 13-18 years and the iron requirements of pregnant lactating and elderly women.

Diurnal Variation in Plasma Corticosteroid Concentration in Dairy Cattle

Adrenal corticosteroid concentrations were determined by a competitve protein-binding technique in blood samples taken at various times of the day via indwelling jugular cannulae from six cows in each of three groups, pregnant nonlactating, nonpregnant lactating, and pregnant lactating. The results showed a pattern of plasma corticosteroid concentration suggestive of a daily rhythm with higher concentrations between 2:30 and 6:30 AM and lower concentrations at 8:30 PM in the three groups. Pregnancy and lactation status had no significant effect on the daily pattern, but the daily corticosteroid mean was higher in the pregnant, lactating group (.64±.05μg/l00 ml; mean±SE) than in the pregnant, nonlactating group (.50±.03 /μg/100ml).

A Conspectus of Research on Protein Requirements of Man

Investigations which have figured in the present understanding of hu man requirements for iron are reviewed. Those studies reviewed include those on iron balance and turnover intestinal urinary integumental and menstrual losses of iron iron reserves physiological factors affecting iron absorption factors affecting iron availability from plant animal and other sources iron supplementation practices the assessment of iron deficiency and hemoglobin levels factors affecting iron nutritional status such as environmental stress and exercise the iron requirements of infants premature infants full-term infants children aged 2-5 years 6-12 years and 13-18 years and the iron requirements of pregnant lactating and elderly women.