Oxytocin treatment immediately after calving does not reduce the incidence of retained fetal membranes or improve reproductive performance in crossbred Zebu cows

The objective was to determine the effect of oxytocin treatments after calving on the incidence of RFM and reproductive performance in dual purpose cows under tropical conditions. Five hundred thirty six pluriparous, crossbred Zebu cows were randomly assigned to two groups: Oxy (n = 280): cows were given 30 IU of oxytocin im immediately after normal unassisted calving, and again 6 h later; C (n = 256): control. Expulsion of fetal membranes was evaluated 24 h after delivery. After a 30-d voluntary waiting period, AI was done 12 h after cows were detected in estrus. Oxytocin had no effect on the incidence of RFM (4.6 vs. 3.1% for Oxy and C, respectively, P > 0.05). Cows in Oxy and C had similar first service and overall pregnancy rates (54.0 vs. 47.8% and 75.4 vs. 73.4%; respectively, P > 0.05). There were no differences between Oxy and C for calving to first estrus (83.6 ± 3.7 vs. 77.2 ± 3.8 d) and calving to conception intervals (113.6 ± 5.0 vs. 110.5 ± 5.2 d), as well as rates of anestrus (13.6 vs. 13.7%), repeat breeding (21.8 vs. 20.7%), and culling (15.7 vs. 16.4%). In conclusion, oxytocin treatment after normal unassisted calving did not significantly reduce the incidence of RFM or improve reproductive performance in crossbred Zebu cows under tropical conditions.     

Effect of fermentation temperature on hydrogen production from cow waste slurry by using anaerobic microflora within the slurry

We examined hydrogen production from a dairy cow waste slurry (13.4 g of volatile solids per liter) by batch cultures in a temperature range from 37 to 85°C, using microflora naturally present within the slurry. Without the addition of seed bacteria, hydrogen was produced by simply incubating the slurry, using the microflora within the slurry. Interestingly, two peaks of fermentation temperatures for hydrogen production from the slurry were observed at 60 and 75°C (392 and 248 ml H₂ per liter of slurry, respectively). After the termination of the hydrogen evolution, the microflora cultured at 60°C displayed hydrogen-consuming activity, but hydrogen-consuming activity of the microflora cultured at 75°C was not detected, at least for 24 days. At both 60 and 75°C, the main by-product was acetate, and the optimum pH of the slurry for hydrogen production was around neutral. Bacteria related to hydrogen-producing moderate and extreme thermophiles, Clostridium thermocellum and Caldanaerobacter subterraneus, were detected in the slurries cultured at 60 and 75°C, respectively, by denaturing gradient gel electrophoresis analyses, using the V3 region of 16S rDNA.     

A simple mathematical model of the bovine estrous cycle: follicle development and endocrine interactions

Bovine fertility is the subject of extensive research in animal sciences, especially because fertility of dairy cows has declined during the last decades. The regulation of estrus is controlled by the complex interplay of various organs and hormones. Mathematical modeling of the bovine estrous cycle could help in understanding the dynamics of this complex biological system. In this paper we present a mechanistic mathematical model of the bovine estrous cycle that includes the processes of follicle and corpus luteum development and the key hormones that interact to control these processes. The model generates successive estrous cycles of 21 days, with three waves of follicle growth per cycle. The model contains 12 differential equations and 54 parameters. Focus in this paper is on development of the model, but also some simulation results are presented, showing that a set of equations and parameters is obtained that describes the system consistent with empirical knowledge. Even though the majority of the mechanisms that are included in the model are based on relations that in the literature have only been described qualitatively (i.e. stimulation and inhibition), the output of the model is surprisingly well in line with empirical data. This model of the bovine estrous cycle could be used as a basis for more elaborate models with the ability to study effects of external manipulations and genetic differences.     

Identification of lignans and related compounds in Anthriscus sylvestris by LC-ESI-MS/MS and LC-SPE-NMR

The aryltetralin lignan deoxypodophyllotoxin is much more widespread in the plant kingdom than podophyllotoxin. The latter serves as a starting compound for the production of cytostatic drugs like etoposide. A better insight into the occurrence of deoxypodophyllotoxin combined with detailed knowledge of its biosynthestic pathway(s) may help to develop alternative sources for podophyllotoxin. Using HPLC combined with electrospray tandem mass spectrometry and NMR spectroscopy techniques, we found nine lignans and five related structures in roots of Anthriscus sylvestris (L.) Hoffm. (Apiaceae), a common wild plant in temperate regions of the world. Podophyllotoxone, deoxypodophyllotoxin, yatein, anhydropodorhizol, 1-(3′-methoxy-4′,5′-methylenedioxyphenyl)1-ξ-methoxy-2-propene, and 2-butenoic acid, 2-methyl-4-[[(2Z)-2-methyl-1-oxo-2-buten-1-yl]oxy]-, (2E)-3-(7-methoxy-1,3-benzodioxol-5-yl)-2-propen-1-yl ester, (2Z)- were the major compounds. α-Peltatin, podophyllotoxin, β-peltatin, isopicropodophyllone, β-peltatin-a-methylether, (Z)-2-angeloyloxymethyl-2-butenoic acid, anthriscinol methylether, and anthriscrusin were present in lower concentrations. α-Peltatin, β-peltatin, isopicropodophyllone, podophyllotoxone, and β-peltatin-a-methylether have not been previously reported to be present in A. sylvestris. Based on our findings we propose a hypothetical biosynthetic pathway of aryltetralin lignans in A. sylvestris.     

Relationships between cytology, bacteriology and vaginal discharge scores and reproductive performance in dairy cattle

The objective was to compare three diagnostic approaches for intrauterine infection and inflammation: scoring of vaginal contents; quantification of percentage of nucleated cells that were polymorphonuclear leukocytes (PMN) following endometrial cytology; and intra-uterine bacteriology. Dairy cows (n = 303) were examined twice, Days 28 (D28) and 42 (D42), where Day 0 = day of calving. Associations between gross vaginal inflammation scores, uterine cytology, and bacteriology, and subsequent reproductive performance were examined using multivariable models. There was fair agreement at D28 (Kappa = 0.29), but only slight agreement at D42 (Kappa < 0.15), between PMN% and gross vaginal inflammation score. Cows were categorized as having PMN% in the highest quartile (H), or not (L), at both D28 and D42; therefore, cows were categorized as PMNLL, PMNLH, PMNHL, or PMNHH. Cows in the highest PMN% quartile at both time periods were slower to conceive (P < 0.001) than those in all other quartiles (mean ± SEM 32.2 ± 2.3, 37.0 ± 5.3, 40.8 ± 4.1, and 55.3 ± 7.3 d from start of breeding to conception for PMNLL, PMNLH, PMNHL, and PMNHH PMN% cows, respectively). Milk yield was greater (P = 0.001) in cows in the lower quartiles for PMN% at D28 and D42 (i.e., PMNLL) than those in the PMNHH and PMNHL categories, with PMNLH intermediate (P = 0.001). We concluded that PMN% was a better predictor of reproductive performance than either intra-uterine bacteriology or gross vaginal inflammation score. Cows in the highest quartile for PMN% at both D28 and D42 had lower pregnancy rates, took longer to conceive, and had a lower milk yield than those in the lower PMN% categories.     

In vivo and in vitro studies of the role of the adrenergic system and follicular wall contractility in the pathogenesis and resolution of bovine follicular cysts

Bovine follicular cysts (FCs) are a common cause of economic loss in modern dairy herds. Their aetiopathogenesis is not completely understood, even though an inadequate hypothalamic release of GnRH at the time of ovulation is considered to be their main cause. Much evidence, however, suggests a role for adrenergic innervation in ovarian functions, such as follicular development, steroid hormone secretion, and follicular contractility, the latter being an event important for ovulation. Moreover, in humans, polycystic ovary syndrome, a disease very similar to bovine follicular cysts, is characterised by increased density of adrenergic nerves. Given these premises, the aim of our study was to evaluate the effectiveness and mode of action of a novel strategy for the treatment of bovine follicular cysts. In the in vivo experiment, 170 Friesian cows diagnosed with follicular cysts were assigned to four groups (groups A, B, C, and D) to assess the effects of epidural administration of a β-adrenergic antagonist (carazolol) alone or in combination with a GnRH analogue (lecirelin). The four groups underwent the following treatments: Group A was administered lecirelin in combination with carazolol; Group B was administered carazolol; Group C was administered lecirelin; and Group D was administered only normal saline solution. In the in vitro experiment, strips of the walls of cystic follicles recovered post-mortem were suspended in an organ bath, connected to an isometric force transducer and exposed to increasing doses of epinephrine or to the same treatment after exposure to carazolol for 15 min (n = 10). The amplitude and frequency of the contractile activity were recorded. None of the control cows was observed in oestrus or was submitted to AI. The combination of lecirelin and carazolol induced a significant increase in the number of cows in oestrus (88%) compared to lecirelin alone or to carazolol alone (P < 0.05 and P < 0.01, respectively). The combination of lecirelin and carazolol and lecirelin alone were significantly more efficacious than carazolol alone (P < 0.01 and P < 0.05, respectively). In the in vitro experiment, epinephrine increased the amplitude of the contractions of the strips in a dose-dependent manner. This response was significantly enhanced in strips pre-treated with carazolol. The treatments had no effect on the frequency of contractions. In conclusion, our work demonstrates that the epidural administration of a GnRH analogue and a β-adrenergic blocker is an effective means of treating cows with cystic ovarian disease. Moreover, it confirms, from a clinical point of view, that alterations of the adrenergic system and of the contractility of the follicular wall can be considered aetiopathogenic factors involved in the development of FCs. The results of this study lay the basis for a new therapeutic approach to FCs.     

Vermicomposting of mixed solid textile mill sludge and cow dung with the epigeic earthworm Eisenia foetida

This paper reports the results of a study of vermicomposting with Eisenia foetida of solid textile mill sludge mixed with cow dung in different ratios in a 90 days composting experiment. Vermicomposting resulted in significant reduction in C:N ratio and increase in TKN. Total K and Ca were lower in the final cast than the initial feed mixture. Microbial activity measured as dehydrogenase activity increased up to 75 days and decreased on further incubation. Total P was higher in the final product than the initial feed mixture. Total heavy metal contents were lower in the final product than initial feed mixture. Solid textile mill sludge can be potentially useful as raw substrate in vermicomposting if mixed with up to 30% cow dung (on dry weight basis). The growth and cocoon production of the worm species in different feed mixtures were also investigated.     

Effects of impoundment on populations of bullhead Cottus gobio L. and minnow, Phoxinus phoxinus (L.), in the basin of Cow Green Reservoir

The distribution, growth and reproduction of bullhead, Cottus gobio , L., and minnow, Phoxinus phoxinus (L.), were studied at Cow Green Reservoir, Upper Teesdale, for 10 years following impoundment in 1970. Comparisons were made with pre-impoundment results. The length-for-age of bullheads increased after impoundment. The length-for-age of minnows decreased. In winter both species were confined mainly to deep water or to the stone facing of the earth dam. In summer they were found throughout the reservoir though bullheads were scarce in the littoral zone. Female bullheads became sexually mature at an earlier age (84% at age-group I) than before impoundment (33% at age-group I) but no change was apparent amongst males (67–62% in age-group I). The post-impoundment sex ratio did not differ from 1:1 and individual fecundity did not change after impoundment. There was a significant reduction in individual fecundity of the minnow. The mean instantaneous rate of mortality ( Z ) for bullhead of age-groups II to IV was 0.96 ± 0.34 year⁻¹, compared with 0.85 ± 0.29 year in the Tees before impoundment.     

Centriolar dynamics in the bovine embryo: inheritance and perpetuation of the sperm centrosome during fertilization and development

Summary Inheritance of the centrosome (centriole) and its behaviour during fertilization and embryogenesis of cattle is presented. The bovine embryo follows the human pattern of centriole behaviour, which is common to most animals including large mammals. Thus, most mammals obey Boveri's rule of paternal centrosomal inheritance and perpetuation, whereas the mouse is an exception to the rule, showing maternal inheritance. The sperm centrosome was traced from fertilization to the hatching blastocyst stage in the cow and its presence was confirmed at every stage of cleavage, as reported in the human. It is concluded that the bovine embryo is a more appropriate model than the mouse for research in fertilization and assisted-reproduction technology.