Seropositivity and risk factors for Brucella in dairy cows in urban and peri-urban small-scale farming in Tajikistan

In this cross-sectional study, we assessed and mapped the seroprevalence of brucellosis in small-scale dairy farming in an urban and peri-urban area of Tajikistan and investigated factors associated with seropositivity. As urban and peri-urban farming is both an opportunity to improve the livelihood for small-scale farmers and a potential public health hazard, studies are warranted to reveal possible peculiarities in the epidemiology of brucellosis in this type of dairy farming. In total, 904 cows of breeding age belonging to 443 herds in 32 villages were serologically tested with indirect enzyme-linked immunosorbent assay (ELISA) and positive samples confirmed with competitive ELISA. Two logistic regression models were used to investigate an association between seropositivity and risk factors at herd and individual level. The herd and individual seroprevalences were 4.1 and 2.0 %, respectively. Herds with a history of abortions were found to be associated with seropositivity [odds ratio (OR)?=?5.3; 95 % confidence interval (CI), 1.3–21.3]. Large herds with more than eight cattle were more likely to be seropositive compared to smaller herds with one to two cattle (OR?=?13.9; 95 % CI, 1.6–119). The number of calves produced per cow (indicating age) was found to be associated with seropositivity. Younger cows with one to two produced calves were less likely to be seropositive compared to older cows with more than six produced calves (OR?=?0.24; 95 % CI, 0.06–1.0). Neither introduction of new cattle to the herd nor communal grazing was associated with seropositivity. This study shows that infection with Brucella (1) is present in small-scale urban and peri-urban dairy farming in Tajikistan and (2) has significant negative effects on reproductive performance in this farming system and (3) that some previously known risk factors for seropositivity in rural farming system were absent here.     

Regulation by growth hormone of number of chondrocytes containing IGF-I in rat growth plate

Whether growth hormone stimulates longitudinal bone growth by a direct effect at the site of the growth plate or indirectly by increasing the concentration of circulating somatomedins (insulin-like growth factors) has been the subject of controversy. Immunohistochemical methods were used to explore the localization and distribution of insulin-like growth factor I (IGF-I) immunoreactivity in the epiphyseal growth plate of the proximal tibia of male rats. Cells in the proliferative zone of the growth plate of normal rats exhibited a bright immunofluorescence, whereas cells in the germinal and hypertrophic zones stained only weakly. In rats subjected to hypophysectomy, the number of fluorescent cells was markedly reduced. When the hypophysectomized rats were treated with growth hormone, either systemically or at the site of the growth plate, the number of IGF-I-immunoreactive cells in the proliferative zone was increased. The results show that IGF-I is produced in proliferative chondrocytes in the growth plate and that the number of IGF-I-containing cells is directly regulated by growth hormone. These findings suggest that IGF-I has a specific role in the clonal expansion of differentiated chondrocytes and exerts its function locally through autocrine or paracrine mechanisms.     

Native and renatured transfer ribonucleic acid

Transfer ribonucleic acid, isolated under conditions in which the original macromolecular structure is never denatured, is indistinguishable from transfer ribonucleic acid prepared by conventional methods involving denaturing steps. This finding is consistent with the absence of direct genetic control of the formation of macromolecular structure of transfer ribonucleic acid.     

Stallion spermatozoa selected by single layer centrifugation are capable of fertilization after storage for up to 96?h at 6°C prior to artificial insemination

Background

One of the challenges faced by equine breeders is ensuring delivery of good quality semen doses for artificial insemination when the mare is due to ovulate. Single Layer Centrifugation (SLC) has been shown to select morphologically normal spermatozoa with intact chromatin and good progressive motility from the rest of the ejaculate, and to prolong the life of these selected spermatozoa in vitro. The objective of the present study was a proof of concept, to determine whether fertilizing ability was retained in SLC-selected spermatozoa during prolonged storage.

Findings

Sixteen mares were inseminated with SLC-selected sperm doses that had been cooled and stored at 6°C for 48 h, 72 h or 96 h. Embryos were identified in 11 mares by ultrasound examination 16–18 days after presumed ovulation.

Conclusion

SLC-selected stallion spermatozoa stored for up to 96 h are capable of fertilization.     

Dairy science and health in the tropics: challenges and opportunities for the next decades

In the next two decades, the world population will increase significantly; the majority in the developing countries located in the tropics of Africa, Asia, Latin America, and the Caribbean. To feed such a population, it is necessary to increase the availability of food, particularly high-value animal protein foods produced locally, namely meat and dairy products. Dairy production in tropical regions has a lot of growth potential, but also poses a series of problems, particularly as dairy production systems were developed in temperate countries and in most cases are difficult to implement in the tropics. Drawbacks include hot weather and heat stress, the lack of availability of adequate feeds, poor infrastructure, and cold chain and the competition with cheap imports from temperate countries. This position paper reviews the major drawbacks in dairy production for the five major dairy species: cattle, water buffalo, sheep, goat, and camel, as well as the future trends in research and development. It also concerns the major trends in reproduction and production systems and health issues as well as environmental concerns, particularly those related to greenhouse gas emissions. Tropical Animal Health and Production now launches a topical collection on Tropical Dairy Science. We aim to publish interesting and significant papers in tropical dairy science. On behalf of the editorial board of the Tropical Animal Health and Production, we would like to invite all authors working in this field to submit their works on this topic to this topical collection in our journal.

     

Safety of a topically applied spot-on formulation of metaflumizone plus amitraz for flea and tick control in dogs

Four laboratory studies were conducted in Beagle dogs to evaluate the safety of a novel ectoparasiticide combination of metaflumizone plus amitraz (ProMeris/ProMeris Duo for Dogs, Fort Dodge Animal Health, Overland Park, KS) when applied according to the recommended dosage of >/=20mgmetaflumizonekg(-1) plus >/=20mgamitrazkg(-1), at exaggerated and repeated dosages, and if accidentally orally ingested. Parameters evaluated included body weight, food consumption, clinical, physical and neurological examinations, clinical pathology and gross and microscopic pathology. Exaggerated and repeated topical treatment with metaflumizone plus amitraz administered at 1x, 3x and 5x the recommended dose had no effect on clinical findings, heart rates, body weight, food consumption, physical/neurological examinations, macroscopic and microscopic pathology. Very slight, transient, clinically insignificant increases in serum urea nitrogen were noted in some dogs treated at all dose rates tested. This effect was not persistent, was not dose-responsive, nor aggravated by repeated applications and was not associated with a corresponding increase in creatinine or renal pathology. Therefore, these increases in urea nitrogen were suspected to be of non-renal origin and were not considered toxicologically significant. Exaggerated doses (3x and 5x) caused very mild, transient hyperglycemia, most notably in some adult females. Transient and inconsistently noted mild increases in leukocytes, neutrophils and monocytes were observed in some 3x and 5x treated dogs at some intervals. None of the effects noted were aggravated by repeated administration. When 10% of the recommended topical dose was orally administered to mimic exposure due to licking the application, avoidance behaviors including spitting, head shaking, and salivation were noted immediately in all animals. Consequently, voluntary oral ingestion is considered unlikely. Transient decreased activity, slightly reduced body temperature and pale oral mucous membranes were noted in some animals beginning 1-2h posttreatment. Ataxia, resolving within 4h posttreatment, was noted in one female. Oral administration had no effect on clinical pathology. Results from these four studies indicate repeated use of metaflumizone plus amitraz causes no adverse health effects when used as recommended in dogs as young as 8 weeks of age.