This paper examines the effect of age at first calving and milking system on the overall lactation performance and incidence of lactation failure of 442 F1 Bos indicus/Bos taurus dairy crossbreds in Sabah. The two types of crossbred used in the study were imported F1 Sahiwal x Friesian and locally bred Friesian x Local Indian Dairy. Heifers which did not lactate for at least 120 days or produced less than 20 kg of milk during the fourteenth week of lactation were considered to have failed to establish a lactation. The imported and locally bred heifers recorded failure rates of 23.4 and 21.4% respectively. Three milking systems were examined namely machine milking without calf, machine milking with calf and hand milking. They produced failure rates of 30, 12 and 5.6% respectively. The cows that passed recorded 120 day milk production figures of 878, 1,134 and 1,054 kg respectively. The three age groups of less than 30 months, 30 to 34 months and greater than 34 months recorded failure rates of 37, 22 and 10% respectively. The heifers machine milked without their calf which calved at less than 30 months of age recorded a failure rate of 44% while those which calved at greater than 34 months recorded a failure rate of only 17%.
Study site: Tawau and Sebrang Livestock Breeding Centres, Sabah, Malaysia
We examined the gross and microscopic anatomy of placental tissues and umbilical cords from six species representing the three living families of the Suina. These species included, of the Suidae, the wart hog (Phacochoerus aethiopicus), the giant forest hog (Hylochoerus meinertzhageni), the domestic pig (Sus scrofa), and the banded pig of Malaysia (Sus scrofa vittatus); of the Tayassuidae, the white-lipped peccary (Tayassu pecari); of the Hippopotamidae, the hippopotamus (Hippopotamus amphibius) and the pigmy hippopotamus (Choeropsis liberiensis). All these species have a diffuse epitheliochorial placenta. The chorion is folded, and has on its surface rows of shallow ripples or villi, interrupted by round, oval or irregularly shaped areolae. Placental capillaries indent the epithelial layer covering the tops and sides of the interareolar villi, but not the columnar cell layer lying in the troughs between these villi or covering the areolae. Cuboidal cells cover the crests of the villi in the Suidae and Hippopotamidae, whereas in the Tayassuidae the epithelium is syncytial in appearance. The similarities in placental structure between the six species are more apparent than the differences. Suidae and Tayassuidae have smooth umbilical cords containing two arteries and one vein; those of the Hippopotamidae are pustule-encrusted and contain two arteries and two veins.
Although melatonin supplementation is known to influence numerous physiological functions, little is however known of its effects on pregnancy outcome. This study investigated the effects of melatonin supplementation on pregnancy outcome in Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats aged 12-13 weeks. Upon confirmation of proestrus, each female rat was housed overnight with a male of the same strain. On the next morning, following confirmation of mating (vaginal smear), WKY female rats were isolated into individual metabolic cages and given 0, 25, 50 or 100 mg/kg per day of melatonin in drinking water from day 1 of pregnancy to day 21 postpartum. SD females were given 0 or 100 mg/kg per day of melatonin. Maternal weight, duration of pregnancy, litter size, birth weight and body weight of pups up to day 42, and pup mortality were recorded. Data were analyzed using ANOVA for repeated measures. Compared to controls, maternal weight gain during pregnancy was significantly lower in melatonin-supplemented dams (P < 0.01). Litter size was significantly smaller in melatonin-supplemented dams (P < 0.01). Mean birth weight of pups was significantly lower only in pups of dams given 100 mg/kg per day of melatonin (P < 0.001). Mean body weight of pups of dams given melatonin was significantly lower than controls (P < 0.01). Pup mortalities were 9.5% and 21.6% in WKY dams given 25 and 100 mg/kg per day of melatonin respectively, and all pup deaths occurred after day 21 of weaning. The results suggest that melatonin supplementation during antenatal and postpartum period appears to adversely affect litter size, pup growth and mortality in WKY and SD rats. The precise mechanism causing the death is not clear.
Our aim was to determine the disposition of creatine in ovine pregnancy and whether creatine is transferred across the placenta from mother to fetus. Pregnant ewes received either1) a continuous intravenous infusion of creatine monohydrate or saline from 122 to 131 days gestation, with maternal and fetal arterial blood and amniotic fluid samples collected daily for creatine analysis and fetal tissues collected at necropsy at 133 days for analysis of creatine content, or2) a single systemic bolus injection of [13C]creatine monohydrate at 130 days of gestation, with maternal and fetal arterial blood, uterine vein blood, and amniotic fluid samples collected before and for 4 h after injection and analyzed for creatine, creatine isotopic enrichment, and guanidinoacetic acid (GAA; precursor of creatine) concentrations. Presence of the creatine transporter-1 (SLC6A8) and l-arginine:glycine amidinotransferase (AGAT; the enzyme synthesizing GAA) proteins were determined by Western blots of placental cotyledons. The 10-day creatine infusion increased maternal plasma creatine concentration three- to fourfold (P< 0.05) without significantly changing fetal arterial, amniotic fluid, fetal tissues, or placental creatine content. Maternal arterial13C enrichment was increased (P< 0.05) after bolus [13C]creatine injection without change of fetal arterial13C enrichment. SLC6A8 and AGAT proteins were identified in placental cotyledons, and GAA concentration was significantly higher in uterine vein than maternal artery plasma. Despite the presence of SLC6A8 protein in cotyledons, these results suggest that creatine is not transferred from mother to fetus in near-term sheep and that the ovine utero-placental unit releases GAA into the maternal circulation.
We conducted cross-sectional and longitudinal studies to determine the distribution of and risk factors for seropositivity to Nipah virus (NiV) among Pteropus vampyrus and P. hypomelanus bats in Peninsular Malaysia. Neutralizing antibodies against NiV were detected at most locations surveyed. We observed a consistently higher NiV risk (odds ratio 3.9) and seroprevalence (32.8%) for P. vampyrus than P. hypomelanus (11.1%) bats. A 3-year longitudinal study of P. hypomelanus bats indicated nonseasonal temporal variation in seroprevalence, evidence for viral circulation within the study period, and an overall NiV seroprevalence of 9.8%. The seroprevalence fluctuated over the study duration between 1% and 20% and generally decreased during 2004-2006. Adult bats, particularly pregnant, with dependent pup and lactating bats, had a higher prevalence of NiV antibodies than juveniles. Antibodies in juveniles 6 months-2 years of age suggested viral circulation within the study period.