Veterinaria México OA

Evaluation of salinomycin for an extended period in laying replacement hens

2026-01-22T19:52:32+00:00

The clinical efficacy of salinomycin premix (Pisacox®) administered in feed to replacement pullets to control coccidiosis was evaluated by dosing during 4 or 14 weeks. The productive performance, signs, and lesions associated with coccidiosis and direct oocyst counts were analyzed in 3 000 Bovans White pullets distributed in 3 groups of 1 000 birds having the same diet: control group (Ctrl) without coccidiostat; Sal₄group with the administration of salinomycin for 4 weeks; and Sal₁₄group that received salinomycin for 14 weeks. Predictably, in both Sal₄ and Sal₁₄treatments, lower oocyst counts than in the control were observed. However, it was more evident with Sal₁₄towards the end of the trial, whose oocyst count was < 5 000 g of feces. This response can be associated with better productivity variables. The coccidial-type intestinal lesions detected in control were classified as severe (2.55), while Sal₄ and Sal₁₄presented values of 1.0 and 0 (mild lesions and normal appearance, respectively). The accumulated mortality associated with coccidiosis was statistically higher in the Ctontrol group (9.8 %) (P < 0.001), 1.33 % for Sal₄, and 0.2 % for Sal₁₄(P < 0.05, between these two groups). In conclusion, using salinomycin for 4 weeks successfully controls clinical coccidiosis. However, the lower rate of coccidiosis, the improvement in productive variables, and the lower accumulated mortality in Sal₁₄allow for the proposal of including the treatment with salinomycin for 14 weeks in replacement pullets.

Physicochemical and microbiological quality according to the production systems of bovine milk and fresh cheese (cuajada) in the Isthmus of Tehuantepec, Mexico

2026-01-22T19:52:57+00:00

The objective of this research was to characterize the physicochemical and microbiological quality of bovine milk and fresh cheese (“cuajada”) produced in the Isthmus of Tehuantepec, Oaxaca, Mexico, as well as to analyze the livestock production systems associated with their manufacture. For each production system, 10 L of raw bovine milk and 10 samples of fresh cheese (500 g each) were evaluated, determining both microbiological and physicochemical parameters. Producers in these systems ranged from 43 to 72 years old and had completed higher education. The cattle herds consisted of 64–187 head, with predominant breeds including Zebu (Bos indicus), Swiss, and Indubrasil (Bos taurus × Bos indicus), yielding 100–168 liters of milk per day. The results showed that both milk and “cuajada” failed to meet the microbiological standards established by Mexican regulations. Regarding physicochemical properties, cheese moisture content was high (50–61 %), while protein ranged from 17–35 % and fat from 8–22 %. Color analysis revealed high lightness (L* 87–93) and yellow hue (b* 15–20), whereas texture profiling indicated significant differences in hardness (5–50 N) and cohesiveness. The findings highlight the importance of providing technical training to improve the quality and safety of these products while preserving their cultural and traditional value.

Codon usage bias and evolutionary dynamics of porcine Sapelovirus: insights into host adaptation

2026-01-22T19:52:45+00:00

Porcine sapelovirus (PSV), a member of the Sapelovirus genus within the Picornaviridae family, is a swine pathogen causing respiratory diseases, polioencephalomyelitis, and gastroenteritis. The infection results in economic loss in the swine industry and often co-occurs with bacterial, viral, or fungal infections. Despite its impact, the evolutionary dynamics and adaptation mechanisms of PSV remain poorly understood. This study investigates the evolutionary forces shaping adaptation of the PSV polyprotein gene through codon usage bias and nucleotide composition analysis. A total of 34 polyprotein coding sequences of PSV were retrieved from the NCBI database and analyzed using bioinformatics tools. The nucleotide composition analysis revealed adenine as the most abundant nucleotide, with thymine predominating at the third codon positions. The Guanine-Cytocine (GC) content was balanced overall, with variations in GC content at the third codon position values suggesting mutational pressure. Relative synonymous codon usage analysis identified overrepresented and underrepresented codons, highlighting host-specific selection pressures. The Effective number of codons and neutrality plots indicated that natural selection predominantly influences codon usage bias in PSV, while mutational pressure contributes less. Chargaff's second parity rule analysis confirmed deviations influenced by these forces, while dinucleotide abundance analysis provided insights into codon usage trends. The codon adaptation index (CAI = 0.584) suggested moderate adaptation of PSV to its natural host, Sus scrofa domesticus, reflecting evolutionary constraints on translational efficiency. Correspondence analysis highlighted factors driving viral evolution. These findings contribute to our understanding of PSV molecular evolution, supporting the development of antiviral strategies, vaccines, and diagnostic for disease control.

Serum lipopolysaccharide as a diagnostic and prognostic biomarker in Canis familiaris pyometra

2026-01-22T19:53:10+00:00

Specific sensitive diagnostic markers for early diagnosis of canine pyometra have been widely attempted, but none have proven to be a perfect diagnostic marker for clinical practice. Lipopolysaccharide (LPS) or endotoxin is a cell wall component of gram-negative bacteria, released during bacterial death. The early release, inherent stability, and serotype-specificity of endotoxin suggest its potential as a good candidate for early diagnosis of pyometra. The present study focused on understanding the potential of LPS as a diagnostic and prognostic marker in canine pyometra. The study also tried to establish the correlation between bacterial isolates cultured from the vaginal discharge and endotoxin levels. A total of 12 animals presented to University Veterinary Hospitals with open and closed-cervix pyometra were selected and divided into two groups of six dogs each. Serum LPS concentration (ng/mL) was estimated on various days of observation using ELISA. Mean serum LPS concentration was higher in both groups on the day of presentation, and significantly higher levels were observed in animals with closed-cervix pyometra. Bacteriological examination revealed a predominance of gram-negative organisms in both groups. Hence, it establishes LPS as a better diagnostic marker of canine pyometra. Conversely, a reduction in the levels of LPS on subsequent days of observation confirms its efficacy as a prognostic marker.