Large Animal Review

Presence of Antibiotic Resistance Genes in Staphylococci Isolated From Bovine Subclinical Mastitis

Sun, 16 Jun 2024 00:00:00 +0200

The prevalence of antibiotic resistance increases rapidly worldwide, and the primary culprit is represented by their widespread use. Subclinical mastitis is the leading cause of most antibiotic treatment, representing also one of the significant problems of bovine herd management. One of the main causes of subclinical mastitis is Staphylococcus aureus. Therefore, the determination of antibiotic resistance against Staphylococcus aureus is an essential step in the treatment of subclinical mastitis. The aim of this study was to identify antibiotic resistance genes in staphylococci obtained from cases of bovine subclinical mastitis in three provinces and the relationship between antibiotic resistance and ease of antibiotic availability (Burdur, Hatay and Van) in Turkey. In total, 283 isolates (Burdur, n = 36; Hatay, n = 47; Van, n = 200 isolates) were studied. The isolates were first identified as Staphylococcus aureus and/or non-aureus staphylococci (NAS) by conventional phenotypic methods, and the species was then confirmed by a multiplex polymerase chain reaction (PCR). A simplex PCR assay was performed to detect antibiotic resistance genes (mecA, mecC, aacA-aphD, ermA, ermB, ermC, tetK, tetM and blaZ). Among the isolates from all three provinces, the blaZ gene was the most prevalent antibiotic resistance gene, present in 43 out of 156 (28%) NAS isolates, 27 out of 127 (21%) S. aureus isolates and 25% of all the isolates. In contrast, tetM was the most prevalent gene in the Hatay isolates, detected in 64% of all isolates. The mecA-gene was present in 10% of the NAS, and in 3% of the S. aureus isolates. The mecC and ermA genes were not detected in any of the isolates. This shows that antimicrobial resistance, as determined by PCR, is common in Staphylococcus isolates from mastitis in Turkey, and warrants systematic treatment protocols as well as the implementation of preventative strategies to reduce antimicrobial usage.

Comparison of immunoglobulin G concentrations in colostrum and newborn calf serum from animals of different breeds, parity and gender

Sun, 16 Jun 2024 13:28:03 +0200

Bovine neonatal enteritis is a major cause of losses in cattle production, involving microbial and extra-microbial causative factors. Failure of passive transfer (FPT) plays a critical role in the development of this disease, and colostrum management and quality have a direct impact on FPT. The aim of this study was to investigate the effects of breed, parity and calf gender on colostrum IgG content and newborn calf immunity. Understanding the influence of these factors could be useful in implementing effective strategies to improve calf health. Breed emerged as a major factor affecting colostrum quality and calf immunity. IgG levels were compared in colostrum and newborn calf serum across dairy (Italian Friesian, Reggiana and Bianca Modenese) and cow-calf type (Piemontese and Limousine) breeds. Italian Friesian cattle showed significantly lower IgG levels in both their colostrum and newborn calf serum compared to the other breeds. Parity did not significantly affect overall colostrum quality or FPT prevalence. However, first-calf heifers had a lower prevalence of inadequate colostrum compared to multiparous cows, suggesting their colostrum is suitable for colostrum banks. With regard to gender, the analysis of IgG levels and FPT prevalence in Italian Friesian newborn calves revealed a significant sex disparity. Females exhibited higher IgG levels and lower FPT prevalence compared to males, suggesting potential management practices influencing these outcomes. In conclusion, results revealed significant differences in IgG concentration between colostrum and newborn calf serum samples across breed, parity, and calf gender. Newborn calves are particularly vulnerable and prone to enteritis. Poor colostrum management and breeding practices that prioritize high milk production can lead to lower IgG levels, further compromising calf immunity. While colostrum banks and cow vaccination offer potential solutions, limitations exist. Moreover, effective control requires close cooperation between farmers and veterinarians, which is often lacking.

Relationship of some hormone levels and some biochemical parameters with parity in repeat breeder dairy cows

Kudret Yenilmez, Halef Doğan, Sezai Arslan, Elif Gökçe — Sun, 16 Jun 2024 13:29:56 +0200

The aim of this study was to determine the role of anti-müllerian hormone (AMH), progesterone, insulin, thyroid stimulating hormone (TSH), triiyodotironin(T3), tiroksin(T4), non-esterified fatty acids (NEFA), beta hydroxy butyrate (BHBA) and glucose concentrations in the etiology of Repeat Breeder (RB) cows. In the study, 60 RB Holstein cows, all housed on the same farm and receiving identical care, feeding, and reproductive management, were inseminated at least three times but did not achieve pregnancy and were confirmed to have no gynecological problems through ultrasonographic examination. Were categorized into three groups based on parity: Group I (1-2 lactation), Group II (3-4 lactation), and Group III (5-6 lactation). During estrus, 10 ml blood samples were collected from all the animals in the study. Blood samples collected on the day of estrus were used to assess serum levels of AMH, insulin, BHBA, NEFA, glucose, T3, T4, and TSH. Additional blood samples were taken on days 9 and 17 post-mating for serum progesterone (P4) analysis. The serum samples were separated and stored at -80°C until analysis. T3, T4, TSH, AMH and insulin levels were measured using an ELISA device, and serum progesterone, NEFA, BHBA and glucose determination were measured using an autoanalyzer. When comparing the results of hormone measurements across lactation groups, it was observed that T3 levels were highest in Group II and lowest in Group III. As for AMH, T4, TSH, insulin, and progesterone hormones, no statistically significant differences were found among the groups. Group I exhibited significantly lower NEFA levels compared to the other two groups, while Group I also had significantly higher glucose levels than the other two groups. In Group II, a statistically significant negative correlation of 69.7% was observed between T4 and AMH. In conclusion, this study determined that T3 hormone, NEFA and glucose levels may play a role in the etiology of RB cows, while AMH and other parameters do not seem to be effective.

Locomotor activity measured by actigraphy as a means of estimating social mixing and animal density-induced stress in lambs

Jose Alfonso Abecia — Sun, 16 Jun 2024 13:31:52 +0200

This study aimed to determine whether social mixing and density-induced stress affect locomotor activity in lambs. Eighteen 50-70 d lambs on a commercial farm were fitted with accelerometers for nine days. Lambs were housed with another 25 lambs in a 64- m² pen (density: 0.40 lambs/m²; farm phase, FP). After nine days, lambs were transported to a feedlot and had the sensors affixed for another nine days. The 43 lambs were pooled with another 25 lambs that came from other farms, and were housed in a 10 x 10-m pen (density: 0.67; low-density phase, L-DP). After 5 d, another 49 lambs were added to the pen (density: 1.21; high-density phase, H-DP). Activity rates did not differ between FP and L-DP; however, lambs were less active in the H-DP than in the L-DP. Activity did not differ between males and females. The proportion of the lambs that exhibited a 24-hour circadian rhythm was higher in the FP than in the L-DP and the H-DP, which differed from each other. In conclusion, social stress, caused by social mixing and high densities can affect the locomotor activity and disrupt the circadian rhythms of lambs. This study demonstrated the usefulness and feasibility of using sentinel animals (fitted with sensors) in commercial feedlots to monitor changes in activity so that measures can be taken to improve animal welfare if necessary. Future studies should investigate the effects of disruptions in circadian rhythms on the immune response and weight gain of lambs under commercial conditions.

Protein level and β2-adrenergic agonist supplementation on growth performance and dietary energy of hairy lambs

Sun, 16 Jun 2024 13:35:26 +0200

Zilpaterol hydrochloride (ZH) is a β2-adrenergic agonist used as a feed additive during fattening phase that increases growth performance and carcass in lambs by increasing tissue protein accretion. However, information about the effects of high protein level in diet on the responses to ZH in feedlot diets for lambs is unknown. For this reason, a study was conducted to evaluate the interaction of two dietary protein levels (15 and 18% CP, dry matter basis) and two dietary ZH levels (0 and 6 mg/kg of diet dry matter) on growth performance, dietary energy, and carcass dressing percentage of finishing lambs. For the above, 40 Pelibuey × Katahdin (37.8±2.2 kg) crossbred intact male lambs were used in a feeding trial which lasted 33 days. Lambs were grouping to 5-pen blocks (two lambs per pen, 5 replicas per treatment). Both diets contained similar energy concentration (~2.05 Mcal NE_m/kg). At the final of feeding trial, all lambs were slaughtered and dressing percentage was determined. No interactions were detected between protein level and ZH supplementation. Increasing crude protein level from 15 to 18% did not affect (P≥0.18) dry matter intake (DMI), average daily gain (ADG), gain to feed ratio (GF), and dietary net energy (NE). Inclusion of ZH in diets did not affect (P=0.17) DMI, but increased (P<0.01) ADG (16.2%), increasing GF and dietary NE (16 and 10.5%, respectively). Protein level did not affect (P≥0.78) carcass weight or carcass dressing percentage, while ZH supplementation increased both carcass weight (4.2%, P<0.01) and dressing percentage (2.59%, P=0.04) independent of protein level. The β2-adrenergic agonist zilpaterol hydrochloride is a tool to enhance growth performance and carcass in finishing lambs. The increase in protein level from 15 to 18% during the late phase of finishing (i.e., 30 d) did not improve growth performance or carcass weight in response to ZH supplementation.

Determinating the relationship between starch level and acidosis in high starch containing diets in lambs

Şevket EVCİ, Mehmet Akif KARSLI — Sun, 16 Jun 2024 13:37:02 +0200

The aim of this study was to determine the effects of high starch levels in the diet on the formation of subacute acidosis in lambs and to determine the ideal starch level in lamb fattening diet. Three different diets with starch content of 25% (1st Ration-R1), 30% (2nd Ration-R2) and 32% (3rd Ration-R3) were prepared to induce subacute rumen acidosis to achive this purpose. These diets were fed to 6 Akkaraman lambs, aged 11-12 months, with a body weight of 30-35 kg, in a repelicated 3x3 Latin Square design to determine daily nutrient consumptions and digetibilities of nutrients. Rumen fermentation parameters (pH, organic acid and ammonia nitrogen) were determined in the rumen fluid sampled at 0, 2, 4, 6, 8 hours post-feeding in each period. Blood samples were also taken at 0- and 6-hours post-feeding in order to determine blood gases and blood biochemistry parameters. Blood glucose, total protein, triglyceride, urea, creatinine and albumin, pH, pCO₂, HCO₃ and base clearance were measured in these blood samples. It was observed that the daily nutrient consumptions of animals decreased in parallel with the increases in starch in the diets (P<0.05). Similarly, in parallel with the increase in the starch level of the diet, there was a general tendency to decrease in digestion of nutrients other than starch (P=0.08). There was no statistical difference in general between rumen pH, total organic acid, organic acid ratios, only rumen ammonia levels were found to differ between the groups before and immediately after feeding (2nd hour) (P<0.05). While blood pH values and HCO₃ values decreased after feeding, no significant change was observed in other parameters. Among the blood biochemistry parameters, only creatinine decreased statistically (P<0.01) in the R1 group after feeding, and no difference was observed between other parameters. There was no signiicant difference among the groups in any of the blood parameters. It can be concluded that increasing the starch level above 25% in the diets of lambs adversely affects the nutrient consumption and nutrient digestion of the animals in general, and also reduces the blood pH and HCO₃ levels, thus creating a risk of subacute acidosis.

Formulazione topica di eprinomectina somministrata per via orale: quali potenzialità nei piccoli ruminanti?

Sun, 16 Jun 2024 00:00:00 +0200

L'eprinomectina è un endectocida appartenente al gruppo dei lattoni macrociclici. Questa molecola, ben tollerata da animali di diversa età, razza, sesso e condizione fisiologica, è ampiamente utilizzata in bovini, ovini e caprini da latte poiché il suo utilizzo è approvato durante il periodo di lattazione per i bassissimi residui nel latte. L’eprinomectina ha un ampio spettro di attività antielmintica ed è altamente efficace contro i nematodi gastrointestinali (NGI) e broncopolmonari. Diversi studi condotti su piccoli ruminanti infestati sperimentalmente o naturalmente da NGI hanno mostrato un’elevata efficacia antielmintica dell’eprinomectina (al dosaggio di 1 mg/kg di peso corporeo) sia se somministrata per via topica che per via orale.

Summary

Eprinomectin is an endectocide belonging to the group of macrocyclic lactones. This molecule is widely used in dairy cattle, sheep and goats as it is well tolerated by animals of different ages, breeds, sex and physiological condition. Its use is approved during the lactation period due to the very low residues in milk. Eprinomectin has a broad spectrum of anthelmintic activity and is highly effective against both gastrointestinal and pulmonary nematodes. Several studies conducted in small ruminants experimentally or naturally infected with gastrointestinal nematodes showed high anthelmintic efficacy of eprinomectin (1 mg/kg body weight) against gastrointestinal nematodes after either topical or oral administration.

A case of renal amyloidosis associated with udder cleft dermatitis in an adult dairy cow

Giovanni Capuzzello, Isabella Nicola, Alexander Gray — Sun, 16 Jun 2024 00:00:00 +0200

Amyloidosis is a group of disorders characterised by the injurious deposition of abnormal proteins in tissues. Most common in cattle and other animals is secondary or reactive systemic amyloidosis associated with chronic inflammation, resulting in deposition of acute-phase serum amyloid A (SAA) in organs like the kidneys, liver, and spleen. While chronic diseases like mastitis, metritis and pododermatitis are usually the most common diseases identified as inflammatory sources, any persistent inflammation can trigger this disorder. Cattle affected by amyloidosis often exhibit symptoms like weight loss and kidney dysfunction. Here we present the case of a five-year-old Holstein Friesian referred to the University of Glasgow for weight loss and chronic diarrhoea. Clinical examination revealed low body condition score, watery diarrhoea, mild dehydration (5%), mild submandibular oedema, left renomegaly, and udder cleft dermatitis. Biochemistry and urine analysis indicated hypoalbuminemia with normal globulin levels and marked proteinuria. Gross post-mortem findings suggested a diagnosis of secondary amyloidosis, and histopathology confirmed SAA deposition in the glomeruli and renal medullary interstitium. In the absence of another grossly appreciable chronic inflammatory focus/ foci the udder cleft dermatitis was considered the likely contributing comorbidity.