[The role of reproductive biology in SDGs] Global warming and cattle reproduction: Will increase in cattle numbers progress to global warming?

The livestock industry produces a large amount of greenhouse gases (GHG) that cause global warming. A high percentage of GHG emissions are derived from cattle and has been suggested to be a factor in global warming. With the global increase in the consumption of livestock products, the number of farm animals has increased. In addition, the reduction in productivity and reproductive capacity of cattle has resulted in accelerated GHG emissions. In a high-temperature environment, the pregnancy rate decreases, leading to an increase in animals that do not contribute to production. Consequently, GHG emission per unit product increases, thereby accelerating global warming. To reduce this environmental impact, it is important to improve the breeding efficiency of cattle by the use of reproductive technology and, thus, reduce the number of non-productive animals. Thus, reproductive biology plays a major role in mitigating global warming related to the livestock industry.     

Reptile adenoviruses in cattle?

This paper describes a hypothesis on the origin of the members of the recently established adenovirus genus, Atadenovirus, invading cattle, sheep, deer, duck and poultry. Comparison of the phylogenetic trees of adenoviruses and their hosts suggests a very ancient but common origin for the atadenoviruses. The surprisingly large difference between these virus types and other adenoviruses infecting the same host can be easily understood by assuming their separate evolution in different hosts (e.g., in reptiles versus a coevolution with mammals and birds, respectively) followed by a later host switch.     

Does Rhipicephalus microplus tick infestation increase the risk for myiasis caused by Cochliomyia hominivorax in cattle?

The larval phase of Cochliomyia hominivorax (screwworm) is an obligate parasite of vertebrate animals, particularly mammals, and widespread in South America, where it remains one of the most important parasitic diseases of domestic animals. The skin of cattle highly infested by ticks, with cutaneous lesions, exudation of tissue fluid and blood scent seems to produce the ideal environment for fly attraction. However, an association between these parasites was never investigated. The aim of this work was to verify if there is an association between Rhipicephalus microplus tick load and the occurrence of C. hominivorax myiasis in cattle, and to quantify the risk. Sixty bovine (Bos taurus taurus, Angus breed) under field conditions were observed for 24 weeks, during which weekly tick counts and examination for the presence of myiasis were performed. There was a significant association between a high tick burden (24-week mean above 50 ticks per animal) and myiasis occurrence (P = 0.0102). The calculated relative risk (RR) for C. hominivorax myiasis occurrence in cattle with high tick burden was 3.85 (CI95% = 1.23–12.13); indicating that cattle highly parasitized by R. microplus have about four times more risk of myiasis than those with a low parasite load. As far as we aware, this is the first statistically based evidence of the relationship between R. microplus parasitic load and occurrence of myiasis by C. hominivorax. This result could be useful for the design of integrated control strategies for these parasites and to provide more information for the understanding of cattle tick parasitism in cattle production.     

Bovine tuberculosis in badgers in four areas in Ireland: does tuberculosis cluster?

We described the distribution of badger populations in four different areas in the Republic of Ireland. The data came from periodic targeted badger-removal and subsequent post-mortem examinations conducted between 1989 and September 1997, and from a formal badger-removal project in the same areas from 1997 through 1999. Records were complete for 2292 badgers regarding the date of capture, tuberculosis status, geographical area and specific sett from where the badgers were snared. Of 3187 setts, 2290 had no badgers recorded against them (i.e. were inactive).The badger-level prevalence of tuberculosis differed among areas (range 13-29%). Badger populations were highly clustered by sett, and this result was similar over the four study areas. The median number of badgers per active sett was 2. Tuberculous badgers also clustered within a sett. The third quartile of tuberculous badgers was 1 per active sett. The prevalence of tuberculous badgers within a sett was not related to the total number of badgers. There was little evidence of spatial clustering with only one local cluster of tuberculous setts in each of three areas, and none in the fourth area. After adjusting for the number of badgers per sett, only one area had spatial clusters identified.     

Does temporomandibular joint pathology affect performance in an equine athlete?

Temporomandibular joint (TMJ) pathology is a rarely reported cause of decreased performance among equine athletes or at least seldom recognised. This case report describes the work‐up of a high level dressage horse with decreased performance. Temporomandibular joint pathology was suspected based on computed tomography (CT) and the horse responded very well to joint treatment.     

Did vaccination with an infectious bovine rhinotracheitis (IBR) marker vaccine on thirteen cattle farms give rise to chronic wasting among dairy cattle?

At the end of May 1999 the author was asked by the Dutch Animal Health Service (GD) to evaluate problems with 'chronic wasting' cows on 13 farms. The cows were thought to have become ill after vaccination with an IBR marker vaccine. On nine farms a number of cows aborted shortly after vaccination. On eight farms lameness was a problem, as was mastitis. Diarrhoea occurred on four farms. A number of farms had problems with stillbirth, subfertility, abomasal displacement, and decreasing body condition. It was concluded that the abortions, stillbirth, and weak calves at birth in the first weeks after vaccination might be associated with the vaccination. However, the author found no indication that the other problems were associated with the vaccination. This was because the symptoms on the 13 farms were not uniform, and many of the herds already had problems before the herd was vaccinated. The 'chronic wasting' problem cannot be attributed to vaccination with the IBR marker vaccine. 'Chronic wasting' concerns a multifactorial complex of diseases, and has always been present, but has increased in incidence in the last years as a result of 'Holsteinization', a very high milk production, longer periods of housing indoors (and in many cases insufficient quality of the stable and cubicles), a too high work load, and insufficient management.     

Is a nonsteroidal anti-inflammatory drug required to alleviate pain behavior associated with liver biopsy in cattle?

Liver samples are collected from cattle for a variety of reasons. Samples are taken by percutaneous biopsy, and, as this causes pain in cattle, it is usually performed under local anesthesia (LA). However, postbiopsy inflammation can cause pain and sensitization of the wound site after the effects of LA have worn off. If significant, inflammatory pain has the potential to affect animal welfare and productivity. Eighteen Friesian heifers and cows (mean body weight = 534 kg) were used in this study; all received LA at the incision site. Six animals were biopsied with no further drug administration (LA), 6 were given 15 mL meloxicam intravenously and then biopsied (LAN), and 6 were sham-biopsied (control, C). Paddock behavior was observed for 4 hours after biopsy: totals for the whole observation period as well as hourly totals were analyzed. Overall, LA cows spent less time ruminating than C cows (C vs. LA: t₁₀ = 2.72, P = 0.05), whereas LAN cows did not differ from controls. In contrast, LAN cows looked at the incision site more often than did C cows overall (t₉ = ?2.86, P = 0.04). When hourly totals for this behavior were considered, LAN cows looked at the wound site significantly more often in the fourth hour than did C cows, and LA cows tended to look more often than C cows. The reduced rumination in LA cows, as well as the higher frequency of looking at the wound site in the fourth hour by all biopsied cows, suggests that liver biopsy caused some inflammatory pain when LA had worn off. Administration of meloxicam before biopsy had only a minor effect on pain behavior. There were no significant differences in the behavior of LAN cows compared with those given LA alone. However, rumination in cows given meloxicam did not differ from controls, suggesting a mild effect of the drug on behavior. The current study provides some evidence that cows did experience mild inflammatory pain after liver biopsy, but that meloxicam had negligible effects on this pain.     

Postpartum reproductive failure in cattle: is the examination of gene expression in the endometrium a key to success?

High reproductive performance is required for successful management of dairy farms. After calving, especially endometritis is one of the main reasons for reproductive failure. However, subclinical endometritis remains undetected in many cases and causes a high financial loss. To elucidate the cellular processes in the endometrium, the acquisition of the gene expression will provide helpful information. In the literature, numerous cytokines and enzymes were discussed to play important roles in preparing the endometrium for implantation. This review gives an overview about our present understanding of the functions of cyclooxygenases 1 and 2 (COX-1/COX-2), tumor necrosis factor alpha (TNFalpha), the inducible nitric oxide synthase (iNOS), haptoglobin as well as the interleukins 1 and 6 (IL-1/IL-6). Their role is not only to regulate certain physiological processes in the bovine reproductive tract, but to act also as inflammatory mediators in infectious diseases. A better understanding of cellular processes may help to improve identification and treatment of postpartum reproductive failure.     

Acute lead poisoning in western Canadian cattle — A 16-year retrospective study of diagnostic case records

This study describes the epidemiology of acute lead poisoning in western Canadian cattle over the 16-year period of 1998 to 2013 and reports background bovine tissue lead concentrations. Case records from Prairie Diagnostic Services, Western College of Veterinary Medicine, identified 525 cases of acute lead toxicity over the investigational period. Poisonings were influenced by year (P < 0.0001) and month (P < 0.0001). Submissions were highest in 2009 (15.6%), 2001 (11.2%), and 2006 (9.9%). Most cases were observed during May, June, and July (62.3%). Cattle 6 months of age and younger were frequently poisoned (53.5%; P < 0.0001). Beef breeds were predominantly poisoned. Mean toxic lead concentrations (mg/kg wet weight) in the blood, liver, and kidney were 1.30 ± 1.70 (n = 301), 33.5 ± 80.5 (n = 172), and 56.3 ± 39.7 (n = 61). Mean normal lead concentrations in the blood, liver, and kidney were 0.036 ± 0.003 mg/kg (n= 1081), 0.16 ± 0.63 mg/kg (n = 382), and 0.41 ± 0.62 mg/kg (n = 64).     

The use of skin delayed‐type hypersensitivity as an adjunct test to diagnose brucellosis in cattle: A review

Summary

Brucellosis, caused by bacteria of the genus Brucella, is a contagious disease that causes economic loss to owners of domestic animals due to loss of progeny and milk yield. Because cattle, sheep, goats, and to a lesser extent pigs are considered to be the source of human brucellosis, serological tests have been used to screen domestic animals for antibodies against Brucella. Although the serological tests helped to eradicate brucellosis in many countries, serological tests are not always adequate to detect latent carriers of Brucella. Therefore, the use of the skin delayed‐type hypersensitivity (SDTH) test, which is independent of circulating antibodies, might improve the diagnosis of brucellosis. In the literature, however, there are conflicting reports as to the value of the SDTH test for the diagnosis of brucellosis. Some studies consider the test unreliable, whereas others advocate its use because it detects brucellosis earlier than serological tests. The objectives of this study were therefore to assess the characteristics of the SDTH test, to select a Brucella strain that will yield a suitable brucellin for use in the field, and to determine whether the use of serological tests in combination with the SDTH test improves the detection of brucellosis. The results of this study clearly show that the SDTH test detects latent carriers of Brucella and confirms brucellosis in cattle with ambiguous serological test results. Brucellins prepared from smooth or mucoid strains of Brucella are better suited for use in the field than brucellins prepared from rough strains because they detect brucellosis in cattle with acute as well as chronic infection. The SDTH test is highly specific (99.3% specificity), and repeated testing of naive cattle or cattle infected with microorganisms that serologically cross‐react with Brucella does not sensitize cattle to subsequent SDTH tests. However, it is possible that some naive cattle may serologically react to the injection of brucellin. The effect of these serological reactions on the sero‐diagnosis of brucellosis is limited, because cattle may only now and then react serologically either with the serum agglutination test (SAT) or the complement fixation test (CFT). Nevertheless, cattle infected with microorganisms that serologically cross‐react with Brucella may test seropositive for brucellosis 4 to 7 weeks after injection of brucellin, depending on the cross‐reacting microorganism. The value of the SDTH test for the diagnosis of brucellosis was demonstrated after an outbreak of brucellosis. When the SDTH test was used in combination with SAT and CFT at diagnostic threshold ≥2 mm or ≥1 mm (increase in skinfold thickness), respectively, 39/44 (88%) or 42/44 (95%) of the infected cattle were detected compared with only 27/44 (61%) when SAT and CFT were used. When cattle in areas of low prevalence or in areas free from brucellosis are tested with the SDTH test an increase ≥2 mm in skinfold thickness should be considered indicative of infection. When the control and eradication of brucellosis is based on test‐and‐slaughter, an increase of ≥1 mm in skinfold thickness should be considered indicative of infection. Repeated serological testing complemented with the SDTH test in this programme will shorten the quarantine (movement control) period of a suspect herd, limiting the financial loss incurred during outbreaks of the disease. Consequently, since the SDTH test usually does not interfere with the serological diagnosis and can safely be used to establish the infection status of cattle in a suspect herd, it is opportune to consider adding the SDTH test to the procedure currently used to diagnose brucellosis in individual animals.     

Anthelmintic resistance in cattle nematodes in New Zealand: Is it increasing?

Extract

In contrast to the situation in sheep, anthelmintic resistance in cattle nematodes in New Zealand appears to be relatively uncommon. A brief review in 1991 indicated that only six confirmed cases had been reported(l). All related to resistance to benzimidazole anthelmintics and involved infections of Cooperia and, to a lesser extent, Ostertugia and Trichostrongylus. Since then, however, a further 13 cases of benzimidazole resistance in cattle have been identified by faecal egg count reduction tests conducted on submissions to the Batchelar and Ruakura Animal Health Laboratories (Table I). In addition, another two cases have recently been detected by similar means by ethers ⁽²⁾⁽³⁾. In the latter two instances, these not only involved resistance to benzimidazole drenches but to milbemycin/ avermectin type anthelmintics as well. Like those listed in Table I, the main parasite genus implicated on both of these occasions was Cooperia.