Veterinary and Animal Science最新文献

Postpartum uterine disease in dairy cows can cause important health problems in animals and economic losses to producers. An adequate management of animals around calving is crucial for maintaining animal health status and future lactation. Omega-3 fatty acids, such as docosahexaenoic acid (DHA), have been shown to have beneficial effects on the health of cows. In this pilot study, we analyzed the effect of intrauterine administration of DHA in cows with subclinical endometritis. Cows with subclinical endometritis at 26 ± 3 days in milk (DIM) were randomly assigned to receive an intrauterine infusion of: (i) DHA 0.16 % dissolved in saline solution (DHA group), or (ii) only the vehicle without DHA (control group). Uterine fluid was collected by non-surgical uterine flushing in all cows 24 h after treatment to analyze metabolomics using gas chromatography-mass spectrometry (GC-MS) and cytokine concentration by ELISA assay. Metabolites of the citric acid cycle (TCA cycle), linoleic acid metabolism, pantothenate and CoA biosynthesis, alanine, aspartate, and glutamate metabolism, and glyoxylate and dicarboxylate metabolism were reduced in the uterine fluid of the DHA group. Linoleic acid was reduced in the DHA group, which is relevant because of its role as a regulator of the innate immune function. In addition, a trend toward lower levels of IL-8 in the endometrial fluid was observed in cows in the DHA group. These findings suggest potential benefits of DHA on the uterine immune response in vivo, which could improve the health status of cows with subclinical endometritis.

This study examined the association between energy metabolism-related variables and conception rate at first service (CRFS) in Holstein cows. It focused on identifying confounding relationships among key factors. Data came from a large dairy farm in Coahuila, Mexico. The dataset included 1056 lactations recorded in 2024. Of these, 419 were primiparous and 637 were multiparous cows. Only cows that completed a synchronization protocol and received timed artificial insemination (TAI) were included. A logistic regression model was used to predict CRFS. In the model, body condition score (BCS) at calving and postpartum diseases were not significant when subclinical ketosis (SCK) and BCS loss were included. This suggested confounding effects. Key associations were found: Cows with BCS ≥ 3.75 at calving were 5.55 times more likely to lose ≥ 0.75 BCS units by first breeding than cows with BCS ≤ 3.5. Cows with BCS ≤ 3.5 at calving were 0.45 times as likely to develop SCK compared to cows with BCS ≥ 3.75. Cows with postpartum diseases were 4.42 times more likely to develop SCK than healthy cows. Multicollinearity was observed between postpartum diseases and SCK and between BCS at calving and postpartum BCS loss. The best-fitting model for CRFS included: breeding season, milk yield at week 8 postpartum, parity, SCK, and postpartum BCS loss. SCK and BCS losses, as well as postpartum diseases, were key factors associated with CRFS and were also confounded by BCS at calving.

Crossbreeding between Duroc and Pietrain breeds is widely applied in genetic improvement programs to enhance productivity and carcass quality, aligning with sustainability goals and consumer demands. Additionally, sex is a relevant factor influencing performance and carcass traits. This study evaluate performance, carcass characteristics, and primary cut weights in pigs from different genetic lines and sexes, as well as their interactions. A total of 600 pigs were evaluated across three sire lines: Line d- Duroc, Line H- Hybrid (Duroc and Pietrain), and Line P- Pietrain, including both females and immunocastrated males (ICM). At the end of the growing period, 120 animals with body weights closest to the pen average were selected for slaughter and carcass analysis. No significant interactions were observed between genetic line and sex (P ≤ 0.05). ICM showed superior average daily gain (ADG), final weight, feed conversion (FCR), and backfat thickness, while females had higher carcass yield and lean meat percentage. D and H lines outperformed P in carcass yield and weight, whereas P had greater backfat thickness but lower lean percentage and loin depth. For primary cuts, ICMs had heavier bellies, while females yielded more lean cuts. The results underscore the impact of genetic and sex-based selection on pork quality and sustainability.

Domesticated guinea pigs (cavies) are crucial in mixed crop-livestock farming systems in the Democratic Republic of the Congo (DRC), providing meat, income, and organic fertilizer. This research assessed the genetic diversity and population structure of guinea pig populations from South Kivu, North Kivu, Katanga, and Kinshasa. A total of 343 samples were screened using thirteen (13) polymorphic simple sequence repeat (SSR) markers. The study identified 113 alleles across the four populations, with an average of 5.77 alleles per locus per population. South Kivu had the highest allele count (7.23), while Kinshasa had the lowest (4.69). The mean observed heterozygosity (Ho) and expected heterozygosity (He) were 0.34 and 0.58, respectively. Genetic analysis showed higher levels of inbreeding (FST=0.080, FIS=0.464) with observed heterozygosity (50.7%) lower than expected. Genetic diversity within populations was lower compared to between populations. South Kivu exhibited the lowest inbreeding rate among other African populations. The observed molecular variance suggests potential for selection within populations before crossbreeding, providing avenues for genetic enhancement. Phylogenetic analysis of the 343 individuals grouped them into three distinct clusters, indicating that DRC's cavy populations consist of three gene pools. This study on guinea pigs' molecular diversity offers valuable insights for breeding programs, facilitating the selection of genetically diverse parents to establish breeding populations aimed at improving and conserving guinea pigs.