Calf Production Research Articles

Management considerations of moose life‐history characteristics in Colorado, USA

Wildlife management agencies are obliged to provide evidence‐based management recommendations to stakeholders. However, allocation of resources towards the management of species is rarely uniform. The consideration of life‐history characteristics of moose offers wildlife managers a more robust understanding of population ecology, while also providing insight into potential limiting factors for long‐term management. From 2014–2020 we simultaneously measured survival of adult female moose, as well as calf productivity, in relation to the nutritional condition of adult females, in Colorado. Mean annual adult survival was high (93% and 95% confidence interval: 91–95%). Human hunter harvest was the leading source of mortality and lowered annual adult survival to 88%. Malnutrition was the leading source of natural mortality. Mean annual pregnancy rates were relatively low (77%) and highly variable (95% confidence interval: 65–88%). However, low pregnancy rates were compensated for by high apparent calf survival. The best predictor of moose pregnancy was nutritional condition. Our data suggest that bottom‐up ecological processes were affecting moose population growth, but populations were likely increasing during our study, with a simulated population growth rate of 1.04 (95% confidence interval: 0.94–1.17).

Characterisation of Antimicrobial Resistance in Special-Fed Veal Production Environments.

Antimicrobial resistance (AMR) is one of the leading public health threats globally. AMR genes can be transferred between bacteria through lateral gene transfer, and AMR organisms can spread through environments by contaminated water, agriculture and animals. Thus, widespread environmental dissemination of bacteria and lateral gene transfer facilitate AMR transmission pathways. Farm environments in dairy and calf production are known to harbour AMR bacteria that pose a risk for food contamination and to workers in direct or indirect contact with animals. Escherichia coli is present in farm environments and is known to participate in lateral gene transfer, providing a good marker of resistance genes in each environment. In this study, E. coli from nine cohorts of calves was isolated at different time points from nine barns, nine trailers and one slaughterhouse environment in a single special-fed veal calf production facility. The antimicrobial susceptibility to 15 antimicrobials, classified as highly or critically important by the World Health Organization, was characterised for E. coli isolates using Kirby-Bauer disk diffusion. The highest proportion of isolates showing multidrug resistance was present in barn environments (51.7%), where calves were housed from their arrival at < 2 weeks of age until they were transported to slaughter. Additionally, 15 E. coli isolates were resistant to 11 of the 15 antimicrobials tested. Trailer and slaughterhouse environments had greater prevalence of resistance after accommodating calves, including resistance to third-generation cephalosporins. These data highlight the importance of calf environments in the dissemination of resistant bacteria and gives insight into where interventions could be most effective in combatting antimicrobial-resistant bacteria that could infect humans and livestock.

The intrauterine effects of a maternal winter diet of either kale or fodder beet on measures of calf stature and bone morphology at birth

ABSTRACT Fodder beet and kale are commonly used winter crops in New Zealand dairy and dairy support farm systems. Fodder beet (FB) is known to have lower crude protein, phosphorus and calcium content compared to kale. The intrauterine effects of feeding FB during late pregnancy on bone growth and development in calves requires attention. This study aimed to examine the intrauterine effects of a maternal diet of either kale or FB on measures of calf stature and bone morphology at birth. In winters 2019 and 2020, two herds of pregnant Friesian × Jersey cows were fed either kale (2019, 2020 n = 20) or FB (2019, 2020 n = 20) supplemented with pasture baleage. Calves born from these mobs were euthanised within ten days of birth and a forelimb and section of rib including the costochondral junction were harvested for peripheral quantitative computed tomography and histological analysis. Calves from the FB treatment had reduced bone density and strength compared to calves from the kale treatment (p < .05). The effect of a nutritional deficit on bone morphology at birth emphasises the importance of sufficient nutrition in pre-calving diets. Future research is required to examine the long-term impact of dam undernutrition on calf growth and production.

Repeat Breeder Syndrome Therapies in Dairy Cows: A Review.

Repeat breeder (RB) cows are clinically healthy animals with regular oestrous cycles that do not become pregnant after three or more services. This syndrome has an incidence ranging between 10.1% and 24%. Repeat breeder syndrome (RBS) in dairy cows leads to economic losses to dairy farmers by increasing the calving interval and consequently reducing milk and calf production. RBS has a complex oetiopathogenesis as many factors are involved in its onset. The causes can be grouped into two categories: causes leading to fertilisation failure and factors leading to early embryonic death. Accurate identification of the cause and early diagnosis of RBS is essential to minimise the problems that this issue brings to the farm, but is not always possible. Hypothesising the underlying aetiology of the syndrome is also crucial for targeted therapy, whether pharmacological or managerial. The aim of this review is to report the different therapies, proposed in the literature, for the treatment of RBS in cattle, based on the knowledge of possible aetiological causes.

Climate change stands as the new challenge for whale watching and North Pacific gray whales (Eschrichtius robustus) in Bahia Magdalena, Mexico, after their recovery from overexploitation

IntroductionSocial-ecological systems (SES) recognize the intricate relationship between human activities and the environment and advocate for comprehensive approaches to address complex environmental issues. This study investigates the factors influencing whale watching, particularly the gray whale (Eschrichtius robustus) in northern Mexico, after significant recovery following overexploitation. Despite reaching a peak in 2015, the eastern North Pacific gray whales experienced unusual mortality events (UME), the most recent from 2019 to 2023, leading to a population decline and historically low calf production in 2022. This decline is evident in the reduced presence of whales and calves in winter breeding lagoons. Concurrently, whale watching has become a significant tourist attraction in these areas.MethodsOur objective was to develop a mental model of the SES of gray whale watching, integrating ecological and socioeconomic data to identify key variables and interactions that support system resilience. From an ecological perspective, we analyzed the long-term temporal trends of eight years of gray whale counts in the southernmost breeding and nursing lagoons within the Bahía Magdalena–Bahía Almejas Complex, Mexico. Additionally, we incorporated the current discussion in the literature about the potential impact of global climate change on gray whale populations. In the socioeconomic subsystem, we used participatory methods, including interviews, surveys, and workshops with government officials, tourism operators, and visitors. We also added on-site assessments of compliance with welfare regulations to understand tourism dynamics. ResultsOur findings identified as main external stressors the changes in ice levels in feeding areas and sea warming in breeding areas, and as internal stressors the compliance with official regulations and the number of vessels observing whales at the same time. The key socioeconomic factor of the system was tourist satisfaction, influenced by factors such as the quality of the information provided by operators. DiscussionUltimately, our mental model provides a framework for further exploration of relevant interactions and trajectories, offering insights for developing effective management strategies.

336 Effects of feeding an immunomodulatory feed additive (NutraGen) on metabolite concentrations and cortisol production in calves following exposure to a combination bovine respiratory disease challenge

Abstract Two 89-d experiments (Exp 1 and Exp 2) evaluated the effects of feeding an immunomodulatory feed additive (NutraGen; NG) in calves following exposure to bovine viral diarrhea virus (BVDV) on d -3 and Mannheimia haemolytica (MH) infection on d 0. For each experiment, steers [body weight (BW) = 251 ± 38.2 kg)] were randomly allocated to 1 of 3 treatments. Treatments included a placebo (CON; Exp 1 n = 5; Exp 2 n = 5), a placebo fed from d -18 to d -3 followed by NG fed from d -3 to d 28 (CHLG; Exp 1 n = 5; Exp 2 n = 6), and NG fed from d -18 to d 28 (PREC; Exp 1 n = 6; Exp 2 n = 5). Data were analyzed using the GLIMMIX procedure of SAS Version 9.4 (SAS Institute, Cary, N.C.). Animal served as the experimental unit and time served as a repeated measure. Treatment, time, and the treatment × time interaction served as fixed effects. Block was included as a random effect. Multiple treatment × time interactions and time effects occurred for serum glucose, lactate, blood urea nitrogen, and non-esterified fatty acid concentrations (P ≤ 0.003) in both experiments. There was a general trend for serum glucose to decrease over time post-challenge, suggesting increased cellular utilization of glucose in response to the challenge. In Exp 1, treatment effects occurred for serum glucose (P ≤ 0.001) and serum lactate (P ≤ 0.01), where calves assigned to the CHLG treatment displayed the greatest concentrations of the metabolites. Blood urea nitrogen concentrations peaked at h 48 in Exp 1 and h 6 in Exp 2. There were no treatment effects or treatment × time interactions for serum cortisol, hair cortisol, or fecal corticosterone concentrations in either experiment (P ≥ 0.17). There were, however, multiple time effects for serum cortisol, hair cortisol, and fecal corticosterone concentrations in both experiments (P ≤ 0.02), indicating that the challenge directly impacted cortisol and corticosterone production. Serum cortisol steadily increased from h 96 to h 168 in both experiments. Trends in cortisol and corticosterone production were similar in both experiments; however, peak concentration times for these variables occurred later in Exp 2. These data suggest that feeding NG to calves may alter glucose availability and nutrient utilization in response to infection resulting from a bovine respiratory disease challenge.

PSII-5 Effect of short-term feeding of hemp (Cannabis sativa) on stress biomarkers in weaned beef calves

Abstract Hemp research is growing rapidly due to its health benefits for animals; however, there is little information on its effects on stress. The objective of this study was to determine the effects of hemp supplementation on stress biomarkers in beef calves during weaning. Calves (n = 12) were completely randomized into Control (CC: received commercial concentrates before and after weaning), Treatment 1 (CH: received commercial concentrates before weaning and 25 g of hemp diet after weaning), Treatment 2 (HC: received 25 g hemp diet before weaning and commercial concentrates after weaning) and Treatment 3 (HH: received 25 g hemp diet before and after weaning). The study lasted for 28 d; blood samples were collected at 7-d intervals for enzyme-linked immunosorbent assay. Plasma was analyzed for heat shock protein 90, cortisol, haptoglobin, total antioxidant capacity, and glutathione peroxidase. There was treatment x time interaction in cortisol concentrations, with the (CH) group showing the greatest concentration of cortisol (124.23 ng/mL) in wk 3. There was no significant (P = 0.0675) difference in total antioxidant capacity. There was a treatment x time interaction (P = 0.0009) in glutathione peroxidase concentrations, with the (HH) group showing the greatest concentration of glutathione peroxidase of 46.83 ng/mL in wk 2 and 47.57ng/mL in wk 3. There was no significant (P &amp;lt; 0.05) difference in heat shock protein and haptoglobin. We concluded that hemp supplementation could reduce weaning stress in beef cattle, thereby improving the productivity and performance of beef calves

317 Microbial interventions to improve gut health in neonatal ruminants

Abstract Colonization and establishment of a balanced and healthy gut microbiome during the neonatal period can directly and indirectly influence animals by affecting the development and metabolism, nutrition absorption, barrier and immune functions, and endocrine and neuron transmitter secretions. Therefore, neonatal period represents a crucial window of time in animal’s life that induces long-term developmental and immune memory. Therefore, alterations in the early gut microbial composition and colonization trajectories lead to long-term negative effects on animals’ production and health. While the rapidly developing gut microbial community is affected by various external factors due to its instability, it provides a great opportunity for microbial intervention to alter microbial colonization trajectories and their subsequent impact on gut health. Recent advance research has been successful in restoring altered gut microbial communities by using microbial interventions such as vaginal seeding, fecal microbial transplantation, probiotics, and prebiotics. However, there is a lack of understanding on the long-term effects of these interventions on gut health in neonatal ruminants. Direct fed microbes (live naturally existing microbes that can improve health and production performance) with psychobiotic function (a type of probiotic that affect cognitive and behavioral functions of the host via the gut-brain axis) can be one of the novel microbiome solutions to target and alter the microbiome dysbiosis. The use of direct fed microbes, postbiotics and psychobiotics and their potential implications in improving calf health and productivity leads to a novel solution to the manipulation of the gut microbiome in calves.

Economic impact of the use of anthelmintics in beef cattle in the rearing phase

The objective of the present study was to evaluate the effectiveness of anthelmintics and their influence on the performance of beef cattle supplemented during the rearing period, carrying out a cost analysis of the different treatments. 120 Nelore animals were used, with an average of 9 months of age, 60 males and 60 females. The animals were distributed into 6 groups of males and 6 of females, five treated with anthelmintics and a control group, G1: Moxidectin 1%, G2: Levamisole Phosphate 18.8%, G3: Ivermectin 0.8% + Albendazole Sulfoxide 10%, G4: Albendazole 10%, G5: Fenbendazole 10%, G6: Control (saline solution). Individual weighing was carried out using an electronic scale, at the beginning of the experiment (D0), fourteen days later (D14) and at the end of the experiment (D90), with performance assessed through weight gain (GP). Fecal collections were carried out on the same days as weighing, with individual egg counts per grams of feces (OPG) and stool culture to identify helminth genders. Economic viability was calculated based on the price of the calf and total production cost. The data obtained was subjected to the 5% Tukey test and the effectiveness of the anthelmintics was evaluated using the RESO program. It is concluded that the anthelmintics evaluated were effective, with the exception of Ivermectin 0.8% + Albendazole Sulfoxide 10%, which showed anthelmintic resistance. The anthelmintic treatment provided the animals with better performance, with the greatest weight gain observed in animals treated with Moxidectin 1%, demonstrating better economic indices.

Beef calf production: Consumption and cost-effectiveness – A Mini-Review

Beef calf production: Consumption and cost-effectiveness – A Mini-Review

Evaluation of bovine coronavirus in Korean native calves challenged through different inoculation routes

Bovine coronavirus (BCoV) is a pneumoenteric virus that can infect the digestive and respiratory tracts of cattle, resulting in economic losses. Despite its significance, information regarding BCoV pathogenesis is limited. Hence, we investigated clinical signs, patterns of viral shedding, changes in antibody abundance, and cytokine/chemokine production in calves inoculated with BCoV via intranasal and oral. Six clinically healthy Korean native calves (< 30 days old), initially negative for BCoV, were divided into intranasal and oral groups and monitored for 15 days post-infection (dpi). BCoV-infected calves exhibited clinical signs such as nasal discharge and diarrhea, starting at 3 dpi and recovering by 12 dpi, with nasal discharge being the most common symptoms. Viral RNA was detected in nasal and fecal samples from all infected calves. Nasal shedding occurred before fecal shedding regardless of the inoculation route; however, fecal shedding persisted longer. Although the number of partitions was very few, viral RNA was identified in the blood of two calves in the oral group at 7 dpi and 9 dpi using digital RT-PCR analysis. The effectiveness of maternal antibodies in preventing viral replication and shedding appeared limited. Our results showed interleukin (IL)-8 as the most common and highly induced chemokine. During BCoV infection, the levels of IL-8, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1β were significantly affected, suggesting that these emerge as potential and reliable biomarkers for predicting BCoV infection. This study underscores the importance of BCoV as a major pathogen causing diarrhea and respiratory disease.

Incremental supply of fat, lactose, or protein influences the diurnal pattern of heat production and substrate oxidation in preweaning calves

Increasing nutrient supply to dairy calves has well known benefits; however, the effects of milk replacer (MR) composition when supplied in higher amounts are not fully understood, particularly in the first weeks of life. To better understand the metabolism of macronutrient supply in young calves (21 d old), we investigated diurnal patterns of heat production and substrate oxidation in young calves fed MR with an incremental supply of fat, lactose, or protein. Thirty-two groups of 3 mixed-sex Holstein-Friesian newborn calves (3.4 ± 1.6 d of age), were randomly assigned to one of 4 dietary treatments and studied for 21 d. Diets consisted of a basal MR (23.3% CP, 21.2% EE, and 48.8% lactose of DM) fed at 550 kJ/kg BW0.85 per day (CON; n = 24), or the basal MR incrementally supplied with 126 kJ of digestible energy/BW0.85 per day as milk fat (+FAT; n = 23), lactose (+LAC; n = 24), or milk protein (+PRO; n = 23). Calves were fed MR in 2 daily meals and had ad libitum access to water, but were not supplied with any calf starter nor forage. After 2 weeks of adaptation to the diets, groups of 3 calves were placed for 1 wk in an open-circuit respiration chamber for nitrogen and energy balance measurements (lasting 7 d). On d 3, glucose oxidation kinetics was estimated by using [U-13C]glucose. Measurements included total heat production (total energy [HP], activity [Hact] expenditure, resting metabolic rate [RMR]), respiration quotient (RQ), carbohydrate (COX) and fat oxidation (FOX) in 10 min. intervals and averaging these values per hour over days. Incremental supply of lactose and fat increased body fat deposition, with observed patterns in RMR indicating that this increase occurred primarily after the meals. Specifically, the average daily RMR was highest in the +PRO group and lowest in the CON treatment. The HP was higher in the +PRO group and throughout the day, hourly means of HP were higher in this treatment mainly caused by an increase in Hact. The recovery of 13CO2 from oral pulse-dosed [U-13C]glucose was high (77%), and not significantly different between treatments, indicating that ingested lactose was oxidized to a similar extent across treatments. Increasing lactose supply in young calves increased fat retention by reduction in fatty oxidation. Calves fed a MR with additional protein or fat raised RMR persistently throughout the day, whereas the extra lactose supply only affects RMR after the meal. Dietary glucose was almost completely oxidized (77% based on (13C) glucose measurement) regardless of nutrient supplementation. Extra protein supply increased HP and FOX compared with similar intakes of fat and lactose. Fasting heat production (FHP) of young, group-housed calves is comparable to literature values and unaffected by energy intake. Overall, these findings deepen our understanding of how different nutrients affect metabolic processes, fat retention, and energy expenditure in young dairy calves.

Acoustic behavior of humpback whale calves on the feeding ground: Comparisons across age and implications for vocal development.

Studying sound production at different developmental stages can provide insight into the processes involved in vocal ontogeny. Humpback whales (Megaptera novaeangliae) are a known vocal learning species, but their vocal development is poorly understood. While studies of humpback whale calves in the early stages of their lives on the breeding grounds and migration routes exist, little is known about the behavior of these immature, dependent animals by the time they reach the feeding grounds. In this study, we used data from groups of North Atlantic humpback whales in the Gulf of Maine in which all members were simultaneously carrying acoustic recording tags attached with suction cups. This allowed for assignment of likely caller identity using the relative received levels of calls across tags. We analyzed data from 3 calves and 13 adults. There were high levels of call rate variation among these individuals and the results represent preliminary descriptions of calf behavior. Our analysis suggests that, in contrast to the breeding grounds or on migration, calves are no longer acoustically cryptic by the time they reach their feeding ground. Calves and adults both produce calls in bouts, but there may be some differences in bout parameters like inter-call intervals and bout durations. Calves were able to produce most of the adult vocal repertoire but used different call types in different proportions. Finally, we found evidence of immature call types in calves, akin to protosyllables used in babbling in other mammals, including humans. Overall, the sound production of humpback whale calves on the feeding grounds appears to be already similar to that of adults, but with differences in line with ontogenetic changes observed in other vocal learning species.

Micro Policy Interventions to Increase Income in Beef Cattle Business in Kupang District

A study has been conducted with the aim to determine the actual behavior of beef cattle farmers' income and formulate micro-policies for beef cattle farmers' income in Kupang district. Sampling in this study was conducted in stages. The first stage was purposive sampling of four sub-districts, the second stage was snow ball sampling of 40 farmers and traders and six government officials using an interview approach. The number of key informants depends on the saturation of information obtained. The software used in this research is Ventana Simulation (Vensim) PLE. The results showed that the actual behavior of calf production and income from beef cattle farmers tended to decrease, each by 20.61% and 3.73% per year, respectively. Therefore, policy interventions are needed: 1) increasing calving rate can increase the population of young beef cattle by 3.35% per year and profits by 3.49% per head per year; 2) adding feed supplementation can increase the population of young beef cattle by an average of 4% per year, fattening males by 2.81% per year, and profits by 4.03% per head per year; 3) increasing stakeholder service intensity can increase the population of young beef cattle by 3.12% per year, fattening male production by 5.04% per year, and average profits by 3.37%.

Gray whale (Eschrichtius robustus) post-mortem findings from December 2018 through 2021 during the Unusual Mortality Event in the Eastern North Pacific.

Beginning in December 2018, increased numbers of gray whale (Eschrichtius robustus) strandings were reported along the west coast of Mexico, the United States, and Canada, prompting declaration of a gray whale Unusual Mortality Event (UME) by the United States National Marine Fisheries Service. Although strandings declined in 2020 and 2021 from a peak in 2019, the UME is still ongoing as of fall 2023. Between 17 December 2018 and 31 December 2021, 503 animals stranded along the west coast of North America, with 226 strandings in Mexico, 71 in California, 12 in Oregon, 56 in Washington, 21 in British Columbia, and 117 in Alaska. These included 187 males, 167 females, and 149 whales of undetermined sex; and 193 adults, 194 subadults, 40 calves, 1 fetus, and 75 whales of undetermined age class. We report on 61 of the 503 carcasses (12%) that had external and internal gross necropsy and/or histopathology data: of these 61 whales, findings that contributed to death were identified in 33 (54%) whales. Sixteen of the 61 (26%) were severely emaciated. Gross lesions of blunt force trauma consistent with vessel strike were identified in 11 of the 61 animals (18%), only two of which were emaciated. Two whales (3%) were entangled at time of death, and one died from entrapment. Signs of killer whale (Orcinus orca) interaction were documented in 19 of the 61 animals; five were deemed from recent interactions and three (5%) likely contributed to mortality. A specific cause of death could not be identified in 28 of 61 whales (46%). Additionally, logistical challenges and the advanced state of decomposition of most examined carcasses precluded detection of potential infectious or toxic causes of morbidity or mortality. Up to 2016, the eastern North Pacific population of gray whale population had generally been increasing since the cessation of historic whaling and a prior UME in 1999-2000. However, recent abundance and calf production estimates have declined, a trend that overlaps the current UME. The relative contributions of carrying capacity, environmental change, prey shifts, and infectious, toxic, and other processes to the increased gray whale mortalities have not yet been resolved. Nevertheless, the marked temporal increase in strandings, including findings of malnutrition in some of the whales, along with low calf production, likely represent consequences of complex and dynamic ecological interactions in the ocean impacting the population.

Update on the status of gray whales since the 2020 Implementation Review

The International Whaling Commission’s Scientific Committee conducts regular Implementation Reviews (IRs) of the biology, threats and status of whale species subject to aboriginal subsistence whaling. The last IR of plans for hunting eastern North Pacific (ENP) gray whales by the Chukotka Natives of the Russian Federation and the Makah Tribe of the United States of America occurred in 2020. This paper presents a review of new scientific findings on gray whales to assess whether the current status of the stock(s) is within the parameter space tested in the 2020 IR. Updated information on gray whale stock structure hypotheses, abundance and calf productivity, health and strandings, human removals by hunting and non‐hunting sources, population growth rates, immigration into the Pacific Coast Feeding Group, parameterisation of the Makah hunt, and future episodic mortality events (EMEs) were reviewed for this assessment. For almost all factors, it appears that the current dynamics of the ENP gray whale population are within the parameter space evaluated in 2020 IR. The exception is that EMEs affecting whales in the ENP are occurring more frequently and at a greater magnitude than previously evaluated. However, preliminary evaluations suggest that the performances of the Gray Whale Strike Limit Algorithm (SLA) and Makah Management Plan are robust to recent and future EMEs of Northern Feeding Group gray whales and reductions of productivity of the Pacific Coast Feeding Group, at least under the initial parameterisations. We therefore conclude that there is no compelling need for a Special IR prior to the next scheduled IR in 2026, while noting that additional abundance data for 2022/23 and 2023/24 analysed after drafting this paper could strengthen or weaken the evidence for this conclusion.

Opportunities for territorial development in the transisthmic corridor; baseline diagnosis in the region of the Isthmus of Tehuantepec, Oaxaca

Objective: The main objective was to know the current situation of livestock production, problems and potentialities, in the municipalities of Matías Romero, Santa María Petapa and San Juan Guichicovi, Oaxaca, located in the transoceanic corridor of the Isthmus of Tehuantepec. Design/methodology/approach: The diagnosis was made in eight communities in the municipalities of Matías Romero, Santa María Petapa and San Juan Guichicovi, located north of the Isthmus of Tehuantepec region, Oaxaca. To determine the sample size, the formula suggested by (Snedecor and Cochran, 1967 and Rojas, 1979) was used. It indicates that the elements must be selected through a random draw with replacement, to define the population, the list of production units registered in the Ministry of Agriculture and Rural Development, whose universe is 215, from which, a sample of 41 units was taken. Results: 36% of the interviewees indicated that the ownership of their land is ejidal, 34% is communal and 30% is small property. The interviewed livestock producers develop their livestock activities on an average of 37 hectares. The production units with the smallest area are 8.5 hectares and those with the largest area are 140 hectares. Of the total number of interviewees, 78% provide themselves with water for cattle in the pasture or corrals, coming from rivers and streams, other sources are springs with 12% and dams with 10%. It is considered that the characteristics described provide adequate conditions for livestock. A problem that afflicts livestock in the tropics in the presence of Ixodoida spp, in addition to other types of Mites, the options and alternatives to combat the tick in the PRODETER territory are through the bathroom, regularly it is done by using spray backpack, also the use of Pour on (loin) and tick-killing baths. The misuse of tick control products has generated resistance and problems for farmers (Piña et al., 2017). More than half of the farmers do not participate in animal health campaigns, only 36% do participate. The animal health campaigns in which farmers participate in PRODETER are bovine tuberculosis and paralytic rabies, 24% respectively, tick control 20% and finally brucellosis with 16%. Leos-Rodríguez, (2008) in the work of economic and productive characterization of bovine cattle producers that make up the list of PROGAN beneficiaries in Mexico, observed that the percentage of producers that participated in campaigns against ticks, tuberculosis and brucellosis is above 91%. What is superior to what was found in this diagnosis. Limitations on study/implications: One of the main limitations was that the PRODETER Program was financed by the State for one year only and with that, in the first instance, it limited the intervention to see the effects and levels of adoption of the technological model in the Family Production Units Findings/conclusions: There is ignorance in the use of food supplements, so the development of calves, and the milk production and fertility of the cows, do not express the potential due to the lack of the necessary nutrients in the different productive stages. There is little use of the rangelands because the farmers ignore the practices to give maintenance, make divisions in the paddocks, so they do not rotate. Among the problems detected, the following stand out, among others: the lack of training, the lack of availability of technicians or experts to attend them, the cost of artificial insemination technology and the long periods between births, which causes calf production to decrease. Therefore, the lack of training in artificial insemination, stallion evaluation and crossbreeding systems for genetic improvement, limit the development of livestock with better quality standards in the region of the Isthmus of Tehuantepec, Oaxaca. The diagnosis as such provides elements for the territorial development of livestock in the transoceanic corridor, since it offers areas of opportunity throughout the production process and can satisfactorily help livestock in that region

Early microbial intervention reshapes phenotypes of newborn Bos taurus through metabolic regulations.

The rumen of neonatal calves has limited functionality, and establishing intestinal microbiota may play a crucial role in their health and performance. Thus, we aim to explore the temporal colonization of the gut microbiome and the benefits of early microbial transplantation (MT) in newborn calves. We followed 36 newborn calves for 2 months and found that the composition and ecological interactions of their gut microbiomes likely reached maturity 1 month after birth. Temporal changes in the gut microbiome of newborn calves are widely associated with changes in their physiological statuses, such as growth and fiber digestion. Importantly, we observed that MT reshapes the gut microbiome of newborns by altering the abundance and interaction of Bacteroides species, as well as amino acid pathways, such as arginine biosynthesis. Two-year follow-up of those calves further showed that MT improves their later milk production. Notably, MT improves fiber digestion and antioxidant capacity of newborns while reducing diarrhea. MT also contributes to significant changes in the metabolomic landscape, and with putative causal mediation analysis, we suggest that altered gut microbial composition in newborns may influence physiological status through microbial-derived metabolites. Our study provides a metagenomic and metabolomic atlas of the temporal development of the gut microbiome in newborn calves. MT can alter the gut microbiome of newborns, leading to improved physiological status and later milk production. The data may help develop strategies to manipulate the gut microbiota during early life, which may be relevant to the health and production of newborn calves.

Recent advancements to increase success in assisted reproductive technologies in cattle.

Assisted reproductive technologies (ART) are fundamental for cattle breeding and sustainable food production. Together with genomic selection, these technologies contribute to reducing the generation interval and accelerating genetic progress. In this paper, we discuss advancements in technologies used in the fertility evaluation of breeding animals, and the collection, processing, and preservation of the gametes. It is of utmost importance for the breeding industry to select dams and sires of the next generation as young as possible, as is the efficient and timely collection of gametes. There is a need for reliable and easily applicable methods to evaluate sexual maturity and fertility. Although gametes processing and preservation have been improved in recent decades, challenges are still encountered. The targeted use of sexed semen and beef semen has obliterated the production of surplus replacement heifers and bull calves from dairy breeds, markedly improving animal welfare and ethical considerations in production practices. Parallel with new technologies, many well-established technologies remain relevant, although with evolving applications. In vitro production (IVP) has become the predominant method of embryo production. Although fundamental improvements in IVP procedures have been established, the quality of IVP embryos remains inferior to their in vivo counterparts. Improvements to facilitate oocyte maturation and development of new culture systems, e.g. microfluidics, are presented in this paper. New non-invasive and objective tools are needed to select embryos for transfer. Cryopreservation of semen and embryos plays a pivotal role in the distribution of genetics, and we discuss the challenges and opportunities in this field. Finally, machine learning (ML) is gaining ground in agriculture and ART. This paper delves into the utilization of emerging technologies in ART, along with the current status, key challenges, and future prospects of ML in both research and practical applications within ART.

Phyto and mineral complex and Glucolux F enzyme in feeding of calves during preweaning period

One of the main tasks of animal husbandry is the proper rearing of replacement young animals on diets that meet feeding standards for all elements of a detailed nutrition system. However, the nutritional value of animal feeding does not always correspond to the required norms. Having a high antibacterial, immunostimulating, immunomodulating eff ect, extracts of various vegetative organs of plants are used to treat many diseases of contagious and non-contagious etiology, for the prevention of parasitic diseases, and the healing of wound surfaces. Containing biofl avonoids and other biologically active components, they increase feed intake by animals, its digestibility, and nutrient conversion, improve product quality, and reduce feed costs for its production. The purpose of the research was to establish the infl uence of the phyto and mineral complex and the enzyme Glucolux F in the diets of calves during the preweaning period on metabolic processes in their bodies and productivity when used separately and together. When rearing calves on the basic diet were consumed per unit of live weight gain 4,15 energy feed units and 506 g of digestible protein, with the addition of the phyto and mineral complex feed consumption decreased by 1,2–1,8 %, with the Glucolux F enzyme by 1,9–3,1 %, and when they were used together by 0,5–4,6 %. At the same time, in the 4th experimental group there was the highest total live weight gain by 25,29 kg, which exceeded the 1st control group by 4,8 %, the 2nd experimental group by 3,0 and the 3rd experimental group by 1,6 %. The level of profi tability of live weight production of calves was higher in the 2nd experimental group by 2,3 abs.%, in the 3rd experimental group by 3,8 abs.% and in the 4th experimental group by 5,3 abs.% than in the 1st control group. The use of a phyto and mineral complex of biogenic microelements 100 ml/animal/day and the enzyme Glucolux F at a dose of 0,50 kg/t of compound feed in the diet of calves during the preweaning period, both separately and together, made it possible to increase the productivity of animals and the level of profi tability of production. The best results were obtained when using them together.