Ruminants, Volume 4, Issue 2 (June 2024) – 5 articles

Two experiments were conducted to assess the effects of water medication technology on beef cattle behaviour and performance in tropical conditions. Experiment 1 involved 30 Droughtmaster yearling steers monitored over seven days in a controlled environment. Feed and water consumptions were monitored with Smart Feed Pro^® systems, with three water treatments administered via uDOSE^® technology. The results indicated an average water intake of 13.6 L/head/d. Experiment 2 had 120 yearling steers from four genetic groups grazing on an extensive pasture system. Throughout four 24-day periods, forage availability and chemical composition were measured once monthly. Experiment 2 revealed a variation in water intake, ranging from 16.2 L/head/d down to 4.75 L/head/d. Notably, the lower intake coincided with a rainfall event documented during the fourth experimental period. Overall, results from both experiments indicated that water medication did not alter cattle water preference. There was no preference for treated water sources in Experiment 1, while differences in Experiment 2 appeared to be influenced by external factors like weather and prior habits. These experiments demonstrate the feasibility of water medication for beef cattle without disruption of their natural behaviour. Full article

As the beef industry moves towards efficient animal production to improve sustainability in agriculture, new production and management approaches are emerging. Among the many facets of the beef industry, cow–calf operations have the most opportunity for efficiency improvement, including improvements in fertility. This project accounts for measures and methods of (1) twinning reproductive technologies and (2) twin calf perinatal care and pre-weaning rearing. The overall objective was to produce twin calves using two reproductive technologies—embryo transfer and artificial insemination. The subobjectives were to determine accuracy of twin pregnancies embryo/fetal losses using ultrasonography, evaluate parturition and dystocia, and determine the effects of different twin-raising methods on neonatal behavior and growth. A fixed-time artificial insemination (FTAI) protocol was applied to 77 multiparous Angus-cross cows from a commercial beef herd in northcentral South Dakota during the summer of 2019. Cows were assigned to two different treatments groups: only artificially inseminated (AI) or received an embryo transfer following artificial insemination (ET + AI). They were estrous-synchronized, artificially inseminated (AI) with black Angus semen at day 0, and received and embryo transfer (ET) at day 7. Ultrasound examination detected 56% pregnancy risk for both groups, with sensitivity, specificity, and accuracy of 75%, 100%, and 90.5%, respectively, for bilateral twin detection. Calves were born during spring 2020. Twin calves (n = 34) and singleton calves (n = 11) were assigned to one of three raising methods: (1) twin born and twin raised (TT; n = 16), (2) twin born and single raised (TS; n = 18), and (3) single born and single raised (S; n = 11). Neonatal nursing behavior and birth weights were recorded, and adjusted day 200 and day 280 were calculated measures of vitality and growth. Blood samples were collected at age 24 h for colostrum intake measures (total serum protein, IgG1, and IgM). Twin calves were born 20% (p < 0.05) lighter in body weight than singletons; however, weights did not differ at day 280 between TT and S calves. TS calves had the shortest average latency to stand, but immunoglobulin concentrations did not differ among treatments. At weaning, cows that had birthed and raised twins produced more kilograms of live weight per pregnancy than cows birthing and raising singletons. Using ET + AI proved to increase twinning rate, and growth was maintained when raising both twins with their dam. Full article

This study aimed to characterize the hot iron branding (HIB) procedure by assessing its implications for animal welfare and its efficiency for cattle identification. The study was carried out in two stages: First, with 37 Nellore calves, by measuring the skin temperatures in the place of HIB application (ONB) and 10 cm above it (OFFB) immediately after its application and during four consecutive days, the time required for application of each HIB digit and the occurrences of rebranding; second, with two batches of cows (N = 97 and N = 94, respectively, by measuring the time spent to read cattle ID and comparing the efficiency of HIB vs. EET (electronic ear tag) and visual ear tags (VET) vs. EET. Skin temperature was significantly affected by the interaction between the place where the skin temperatures were taken (on and 10 cm above the HIB) and assessment day, with temperatures in ONB on days d0 and d2 being higher than in OFFB (p < 0.05), and 86% of the calves required at least one rebranding. EET reading was faster than HIB and VET (p < 0.001), and fewer errors were made when reading EET than HIB (1/97 vs. 17/97) and VET (2/94 vs. 12/94). We concluded that HIB potentially compromises cattle welfare and has a lower efficiency for cattle identification than EET and VET. Full article

This study focused on exploring the metabolomic profiles of crossbred beef cattle with varying levels of residual feed intake (RFI), a measure of feed efficiency in beef cattle. Sixty-seven crossbred growing beef steers (BW = 277 ± 29.7 kg) were subjected to a high-forage total mixed ration for 64 days to determine their RFI phenotypes. At the end of the 64d feeding trial, beef steers were divided into two groups based on their RFI values: low (or negative)-RFI beef steers (n = 28; RFI = −1.08 ± 0.88 kg/d) and high (or positive)-RFI beef steers (n = 39; RFI = 1.21 ± 0.92 kg/d). Blood samples were collected, and plasma samples were analyzed using Nuclear Magnetic Resonance spectroscopy, resulting in the identification of 50 metabolites. The study found a distinct metabolomic signature associated with RFI status. Eight metabolites, including amino acids (tyrosine, glycine, valine, leucine, and methionine) and other compounds (dimethyl sulfone, 3-hydroxy isovaleric acid, citric acid, creatine, and L-carnitine), showed differential abundance between low- and high-RFI groups. Specifically, tyrosine, glycine, and dimethyl sulfone exhibited significant specificity and sensitivity, which produced a discriminatory model with an area under the receiver operating characteristic (ROC) curve of 0.7, making them potential markers for RFI. A logistic regression model incorporating these biomarkers effectively distinguished between high- and low-RFI steers, with a threshold cutoff point of 0.48, highlighting a distinctive metabolite profile associated with efficient nutrient utilization in low-RFI cattle. The logistic regression model, incorporating these biomarkers, holds promise for accurately categorizing RFI values, providing insights into the metabolic basis of feed efficiency in beef cattle. Full article

This manuscript summarizes information on the diverse range of RNA molecules and their role as competing endogenous RNAs (ceRNAs). Moreover, it provides an overview of ceRNA regulatory networks and their applications in ruminant biology. Knowledge of co-expression networks has increased with microarrays, RNA-seq, and scRNA-seq characterizing molecular mediators across various biological scales, using sequences from numerous blood and tissue samples. By synthesizing existing knowledge, this study summarizes interactions between coding and non-coding RNAs through microRNA response elements (MREs), elucidating large-scale regulatory networks throughout the transcriptome that influence the expression and activities of various ceRNAs. Identification of non-coding RNAs with important regulatory functions will revolutionize understanding of RNA biology, shifting from an mRNA-centric model to a complex network of RNA crosstalk. The ceRNA networks offer a more comprehensive and arguably more realistic perspective compared to protein–protein interaction (PPI) networks and weighted gene co-expression networks (WGCN). These ceRNA regulatory networks can describe potential molecular regulatory mechanisms related to functional and economically important traits in ruminants, plus contribute to disease and pathology research, by elucidating pathogenesis and potential drug effects in disease and cancer models. Furthermore, they can provide insights into farm animal biology, e.g., reproductive traits in goats and sheep, regulation of fat metabolism in beef cattle, heat stress responses, and lactation regulation in dairy cattle, fertility and muscle characteristics in buffalo, and resistance to high-salt and water-deprivation conditions in camels. In conclusion, ceRNA and associated regulatory networks should promote a new understanding of molecular mechanisms and identify candidate genes and metabolic-signaling pathways in ruminants. Full article