Calf Crop Research Articles

Tritrichomonas foetus testing in bulls.

To provide a video tutorial on how to perform preputial scraping for the testing of Tritrichomonas foetus in bulls. Postpubertal bulls. A preputial scraping device is inserted in the prepuce, and back-and-forth scraping movements are made to collect smegma and T foetus organisms. The sample is placed in an appropriate media and prepared for shipment to the diagnostic laboratory. Preputial sampling is an effective method for diagnosing T foetus in infected bulls. Bulls are the primary carriers of T foetus, a protozoan parasite responsible for bovine trichomoniasis. By sampling and testing bulls, veterinarians can identify infected animals and implement control measures to prevent the spread of the disease within herds. Trichomoniasis can lead to significant reproductive problems in cattle, including infertility, embryonic death, and abortions. Sampling bulls allows for the detection of infection, enabling prompt intervention to protect the reproductive health of the entire herd. Trichomoniasis outbreaks can result in substantial economic losses for cattle producers due to reduced conception rates, increased calving intervals, and decreased calf crops. Sampling bulls helps to mitigate these losses by identifying and removing infected animals from the breeding pool, thereby minimizing the spread of the disease and its associated reproductive inefficiencies. In many regions, T foetus testing in bulls is a regulatory requirement for cattle movement and trade. Sampling bulls and obtaining negative test results are often necessary for obtaining health certificates and complying with interstate or international movement regulations.

The “how and why” of assessing micronutrient levels in beef cow-calf systems

Matching the nutritional resources of protein, energy, miner­als, trace minerals and vitamins to requirements of the beef cow at various times of the year is likely the most challenging aspect of meeting the production goals in a cow-calf production system. While each system will have different goals, commonly accepted goals are 95% of females pregnant in 60 days, 65% of the cows calving in the first 21 days, and a 90 % weaned calf crop based on number of cows exposed.18 If goals are not being met, the obvious question is “why?” and a careful evaluation of the entire system should be undertaken as many times these problems are multifactorial. It is not uncommon to find nutri­tion playing a significant role in these problems whether they be reproductive, neonatal health or weaning health (Figure 1).

Population and Production Dynamic of Peranakan Ongole Cattle in The Breeding Source Area

The purpose of this research was to figure out the population structure and productivity of Peranakan Ongole cattle in the breeding source area. The research was conducted from September 2022 to August 2023 in the breeding source area for Peranakan Ongole cattle, Napis village, Tambakrejo sub-district, Bojonegoro district, East Java province. Data was obtained by recording for 1 year on 1,015 heads Peranakan Ongole cattle. Research variables include population structure and cattle productivity. The results of population structure research showed that the number of male calves was 10.34%, female calves 8.13%, bulls 17.61%, and cows 63.93%. Peranakan Ongole cattle calf crop was 55.01%, calf births to the population were 37.04% with the number of male calves born at 53.46% and the number of female calves born at 46.54%. The percentage of cows to the population was 63.94%. The percentage of mortality to the population was 2.27%. Total livestock income to the population was 12.12% and total livestock output to the population was 31.13%. The natural increase in Peranakan Ongole cattle was 34.78%. The research results showed that the Calf crop value is quite good. To increase the percentage of calf crops, it is necessary to limit and select the production of prospective and productive heifers and cows. Prospective heifers and cows who are productive and have good potential must be preserved to increase the number of births and produce good-quality calves.

Population Structure and Production of Madura Cattle n Lenteng Subdistrict, Sumenep District, East Java Province

The objective of this research was to examine the population structure and production of Madura cows. Indonesian local Madura cows are originally from Madura island. Its development is constantly improved to sustain the existence and production of Madura cows as the main contributor to beef. The research was conducted in Lenteng sub-district, Sumenep district, East Java province from August to September 2023. The research method used was the survey method and sampling was done by accidental sampling. Madura cows data used were 263 heads. Data analysis using descriptive. The results showed that the population structure of Madura cows was 9.89% male calves and 13.69% females, 7.22% young males and 28.52% females, 0% bull and 41% cows. The number of cows to the population was 40.68%, the number of births to the population was 13.69%, the number of mortalities to the population was 2.28%, the Natural Increase was 11.41% with Calf Crop was 29.51%. The results indicated that the production of Madura cows is still low. It is suggested to procure selected males for artificial insemination or natural mating. Based on the population structure there is a rarity of males.

Sustainability Indicators of Kalang Buffalo Production Systems in Swamp Ecosystems in South Kalimantan

This study aims to identify problems, identify and analyze stakeholders and determine indicators (qualitative and quantitative) for the sustainability of kalang buffalo production systems in swamp ecosystems in South Kalimantan. The kalang buffalo is a type of mud buffalo that is reared using the kalang system. In the local language, kalang is an enclosure built in the middle of swamp waters. This study is expected to be a source of information for academics, farmers, communities and policymakers in South Kalimantan Province regarding the strategic function of Kalang buffalo for the people of South Kalimantan. Data collection was done by describing the problem and determining relevant stakeholders. The literature study was conducted with expert discussion. FGDs were also conducted to explore important issues, followed by SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis and to determine relevant issues. Situation analysis and secondary data showed that the Kalang buffalo population is declining. Stakeholder identification identified the central and local governments as primary stakeholders; secondary stakeholders were scientists/academics, butchers, sellers, and consumers. The primary stakeholders selected were buffalo farmers, central and local governments, while secondary stakeholders consisted of scientists/academics, butchers, farmer sellers, and consumers. The selected indicators on the EES issue are economic indicators such as gross margin (GM), body weight, weaning weight, and reproduction (calf crop (%)); environmental indicators such as total grazing land use and waste disposal; and social indicators such total of buffalo, feeding procedures, mating system, cages, record keeping, time allocation for maintenance, social status and land use conflicts.

284 Supranutritional Mineral Supplementation During Pregnancy Alters Placental Blood Flow and Calf Mineral Concentrations

Abstract Fetal development is dependent on maternal nutrient status, and the maternal-fetal connection is mediated by the placenta. There are well-established nutrient requirements for gestating cattle aimed at promoting the health of dam and fetus; however, there is limited information on the impact of supranutritional nutrient availability on placental function and calf development. This study evaluated the effect of supranutritional mineral administration during gestation on uterine artery blood flow and calf mineral status. Angus and SimAngus cows (n = 52) were bred via artificial insemination. At d 60 of gestation, cows were assigned to treatment groups; an injectable group (INJ, n = 26) receiving a single subcutaneous mineral injection and access to free-choice trace minerals and a control group (CON; n = 26) having access to free-choice trace minerals. Liver mineral content was analyzed in a subset of cows (CON n = 10; INJ n = 6) at d 60 and 209 ± 1 of gestation. At d 139.5 ± 0.5 and 209 ±1 of gestation, uterine artery measurements were collected using Color Doppler ultrasonography. Placental cotyledons, liver tissue, and blood samples were collected from a subset of animals at calving (n = 11; CON, n = 5; INJ, n = 6). Analysis revealed a TRT*day interaction at d 139.5 ± 0.5 for circulating Co concentrations which were greater (P = 0.05) and Se tended to be greater in INJ cows (P = 0.09) compared with CON cows. Circulating Zn concentrations tended to be decreased at d 209 ± 1 (P = 0.06) in INJ cows compared with the CON cows. Circulating Cu tended to be increased (P = 0.09) and Mn was decreased (P = 0.04) in INJ cows throughout the study. Hepatic Fe concentrations were decreased in INJ cows (P = 0.01) at d 209 ± 1. At d 139.5 ± 0.5, non-gravid uterine artery area, diameter, and circumference were increased in the INJ cows (P < 0.006 ). Additionally, pulsatility index of the gravid uterine artery tended to be increased (P = 0.09) in the INJ cows. Blood and liver samples were collected from calves (CON n = 24; INJ n = 26) at 4 to 8 d post-calving to assess mineral concentrations. INJ calves had greater liver Se (P = 0.001), decreased Fe (P = 0.04), and tended to have increased Zn (P = 0.09) and Mn (P = 0.08) concentrations compared with CON calves. Finally, INJ calves tended to have greater serum Se concentrations (P = 0.09) compared with CON calves. Trace minerals have roles in immune function and impact overall calf health. These results indicate that supranutritional trace mineral administration during early gestation alters placental blood flow and improves calf mineral availability. This supplementation protocol may provide the opportunity to improve the health of future calf crops.

한우 수정란이식에 의한 쌍자 생산

This study investigated two blastocyst fertilized eggs of Korean native cattle (Hanwoo) developed in vitro for 3 years in 18 farm houses. The fertilized eggs were transferred into 208 cattle recipients in 7~8 days of estrous cycle. Then, their pregnancy rate, delivery rate, calf crop rate, twin crop rate and miscarriage / stillbirth rate were investigated. As a result of transferring Hanwoo blastocyst fertilized eggs developed in vitro to 208 cattle recipients, the pregnancy rate was found 53.8% (112/208); and delivery rate, 92.9% (104/112), showing no significant yearly variation. Twin delivery rate in 1st and 2nd years was 45.2% (14/31) and 47.9% (23/48), respectively, significantly higher than the 3rd-year rate of 8.0% (2/25) (P< .05). The average twin delivery rate was 37.5% (39/104). Calves produced based on pregnancy accounted for 108.1% (121/112). In the 1st year and 2nd year, the rate was 115.2% (38/33) and 114.0% (57/50), respectively, significantly higher than the 3rd year rate of 96.3% (27/26) (P< .05). The average twin calf production after Hanwoo embryo transfer was 32.2% (39/121), recording 36.8% (14/38) in the 1st year and 40.4% (23/57) in the 2nd year. In the 3rd year, 26 calves were produced including 2 twins, accounting for 7.7%. This number in 3rd year is significantly lower than the 1st and 2nd-year results (P< .05). Among the 31 calves delivered in the 1st year, 4 were stillbirths; and 4, miscarriage. The male-female cattle ratio was 10:28. Female calves accounted for 26.3%. Among the 48 calves produced in the 2nd year, 10 were miscarriage; and 4, stillbirth. A cow produced triplets. Male-female cattle ratio was 21:36. Female cattle accounted for as high as 36.8%. Among the 25 calves produced in the 3rd year, 2 were stillbirth. Male-female cattle ratio was 12:14. Female cattle accounted for 46.2%, representing good improvement result. In all of the years, the male-female ratio was 43:78. Female cattle accounted for as high as 35.5%. Miscarriage/stillbirth ratio was as high as 21.4% (24/112).
 The results above showed no remarkable difference in pregnancy rate and delivery rate after embryo transfer to 208 cattle recipients for 3 years. This study also found higher miscarriage/stillbirth rate than those of other studies. With respect to twin production, the 1st and 2nd-year Hanwoo embryo transfer showed significantly higher results of twin production than that in the 3rd year (P< .05). Regarding male-female ratio, female caves were found to account for larger part with time. Based on the findings, it is deemed necessary to establish improvement foundation earlier as a way to homogenize Hanwoo genetic traits and secure fattening cattle for quality meat production. Moreover, for higher income of farm houses, embryo transfer-based twin production technology will need to be developed through continued research.

Evaluation of breeding objectives, breeding practices and reproductive performance of indigenous dairy cows in selected districts of Kaffa Zone, South West Ethiopia.

Breeding objectives are designed to achieve targeted dairy cow production goals, which can be affected by production type, farmer preferences, environmental factors and genetic factors individually or in combination. Breeding practices, such as both controlled and uncontrolled, and artificial insemination (AI) are the tools used to obtain the desired breeding objectives. The lower reproductive performance of indigenous dairy cows affects the total milk production and calf crops that are produced during their lifetime. Designing appropriate breeding objectives and breeding practices can improve the reproductive performance of dairy cows and their overall production performance. The current study was conducted with the objective of evaluating the breeding, practices and performance of indigenous dairy cattle in the south western part of Ethiopia. The districts of Gesha and Chena were purposefully chosen. The study design for the 384 household surveys was a cross-sectional survey with a simple random sample approach. Data analysis was carried out by MS-Excel (2010) and the general linear model procedure of SAS of 2008. The current study revealed that methods of breeding were predominantly natural-controlled mating, followed by natural-uncontrolled mating and AI in descending order. Breeding objectives were input function, output function, sociocultural and economic functions and assets and security functions in decreasing order of rank. Reproduction performance indexes of indigenous dairy cows age at first service (3.72±0.05 years), age at first calving (AFC) (4.71±0.07 years), calving interval (CI) (1.58±0.03 years), days open (DO) (4.26±0.11 months), services per conception in natural mating (1.4±0.08) and AI (2.73±0.14), age of bull at maturity (4.17±0.74 years), interoestrus interval (23.18±0.61 days), calves crop (7.53±0.22) and the life span of indigenous dairy cow (11.94±0.26 years) were significant (p<0.01) between two districts, whereas the values of age of bull at maturity and number of services per conception in natural mating were significant (p<0.05) between districts. Using AI and major reproduction performances, such as AFC, CI and DO of indigenous dairy cows in the study area, were very low. Therefore, concerned bodies should intervene to improve reproduction performance through the utilization of AI techniques, with the integration of forage development activities and improvements in livestock health care.

Practical applications of genomics

Genomic testing serves multiple functions for beef cattle popu­lations. Since their inception in the late 2000s, genomic tests have been critical tools for detecting mutations that cause genetic defects, parentage testing, and improving the quality of genetic predictions. Sire selection is one of the most conse­quential decisions that commercial operations make. This chal­lenge is compounded by the relatively low levels of information available on the unproven herd sires that commercial herds purchase. Selection tools in the form of Expected Progeny Dif­ferences (EPDs) allow commercial operations to reduce the risk involved in sire selection. EPDs isolate the genetic component of economically-relevant traits and increase selection accuracy. While parent average EPDs are more reliable than phenotypic selection, unproven sires can still experience significant EPD shifts as more information becomes available. Genomic testing enhances the EPDs for unproven and low-accuracy sires. These increases in accuracy are equivalent to approximately a calf crop’s worth of records in a genomic evaluation (from 10 to 30 phenotypes depending on the trait). Nearly all breed associa­tions calculate genomically-enhanced EPDs, making their use imperative for commercial operations. Beyond bull selection, opportunities exist for commercial producers to utilize genom­ics for heifer selection and marketing terminal animals.

Comparative Study Of Livestock Appearance And Beef Cattle Breeder Income In Aek Kuo District Of North Labuhanbatu Regency

Beef cattle farming in Aek Kuo District, North Labuhanbatu Regency, North Sumatra Province is traditionally managed in an intensive and semi-intensive system. This study aimed to determine differences in the appearance of cattle and the income of beef cattle breeders using intensive and semi-intensive maintenance systems. The number of respondents used in this study were 30 breederss with livestock ownership of at least two heads of beef cattle and had been running a livestock business for at least two years. The methods used are site surveys and interviews based on questionnaires. The analysis used in this study was followed by a significant partial test (T-test) assisted by the SPSS version 25 program. The results showed an increase in the intensive population rate of 42.37% and semi-intensive 24.60%, intensive calf crop of 73% and semi-intensive 40%, calving interval intensive 17.52 months and semi-intensive 20.03 months, intensive mortality 0.4 % and semi-intensive 4%. In contrast, the income of beef cattle is IDR 11,816,617.00/year/breeder, and semi-intensive IDR 4,891,733.00/year/breeder with a comparison of the R/C Ratio of an intensive system of 1.8 and a semi-intensive system of 1.5. The partial significance test (T-test) results showed that the performance and income of farmers who used intensive rearing systems had higher values ​​and were significantly different compared to farmers who used semi-intensive rearing systems

Application of sexed semen of sires in breeding farms of Kaluga region

Relevance. The main direction in the improvement of dairy cattle breeds is the search for ways and methods of creating highly productive herds. However, the successful solution of these issues is impossible without the use of modern methods and technologies. Among them, sexed sperm is a sperm divided into Xand Y-containing spermatozoa. When using sexed sperm in dairy cattle breeding, it is possible to regulate the receipt of the desired sex (heifers). The effective use of sexed semen will provide farms with a complete set of their own breeding stock and will allow the sale of heifers.Methods. The object of research was cows inseminated with sexed sperm of stud bulls of different breeds in a breeding unit. The fertilization of the breeding stock, the duration of pregnancy, the effect of the season on fertilization, analytic investigation of calf crop percent were investigated. For analysis the data were used from the database for zootechnical and pedigree data registration «SELEKS».Results It was found that the fertilization of heifers from the first insemination with sexed sperm was 38,8%, subsequently it decreased and amounted to 27,7% at the second insemination, 5,5% at the third. 28% remained infertile, 72% of heifers from the total remained pregnant. 85% of live heifers and 15% of bulls were obtained. During the initial insemination of cows of the first calving with sexed sperm, 27,7% of cows became pregnant, with repeated insemination — 27,7%. Fertilization decreased, 39,1% of the animals remained infertile. The best results of fertilization of breeding stock using sexed semen were obtained during the primary insemination of heifers

Interactions between animal temperament and exposure to endophytic tall fescue: Effects on cell-mediated and humoral immunity in beef heifers

Two experiments (n=12 Angus heifers/experiment) investigated influences of animal temperament, as indicated by exit velocity (EV; determined at weaning) and consumption of toxic endophyte-infected tall fescue seed on peripheral lymphocyte production of interferon-γ. Heifers were selected from calves born on the University of Kentucky’s C. Oran Little Research Center. In experiment 1, calves were randomly selected from 50 heifers within a single calf crop. In experiment 2, calves with the 6 fastest and 6 slowest EV in the subsequent year’s calf crop were selected. In both experiments, heifers were assigned to either high or low EV treatments based on relative ranking, and endophyte treatments (toxic endophyte-infected, E+, or endophyte-free, E-, fescue seed) were balanced by body weight. Rations were restricted to 1.8 x NEm and common diet was top-dressed with fescue seed each morning. Experiment 1 had four phases (pre-endophyte treatment/thermoneutral, increased room temperature, increased room temperature/endophyte treatment, and post-endophyte/thermoneutral) and experiment 2 had two phases (increased room temperature/endophyte treatment and thermoneutral). During endophyte treatment phases, heifers were fed their respective treatment seed. During all other phases, all heifers received E- seed. In experiment 1, proportions of lymphocytes producing interferon-γ were decreased in E+ heifers during the heat/endophyte phase (P=0.03) whereas during the subsequent thermoneutral period this response was greater in high, compared with low, EV heifers on E- treatment, with no difference observed among E+ heifers (interaction P=0.08). Also during the recovery phase, average lymphocyte production of interferon-γ was higher in E+ heifers (P=0.01). Consistent with experiment 1 findings, during the recovery period of experiment 2, endophyte exposure increased the per cell production of interferon-γ (P&amp;lt;0.01). In this experiment, the difference was of sufficient magnitude to result in a concomitant increase (P=0.03) in total interferon-γ production during that period. These results indicate peripheral lymphocyte production of interferon-γ can be influenced by both EV and endophyte exposure following periods of increased ambient temperature humidity indices, though there was minimal indication of interactions between temperament and alkaloid exposure. This may imply that cattle with high exit velocities and those previously exposed to toxic endophyte-infected tall fescue are better poised against cell-mediated challenges.

Reproductive traits of cows of Holstein breed and dynamics of their changes during productive life

In order to obtain maximum milk productivity of cows, it is necessary to constantly maintain a high level of reproduction traits of cows in the herd to ensure timely eff ective insemination of them for the annual production of calves. The economy of dairy farming, the level of breeding work, the longevity of animals depends on the state of reproduction of the herd. The purpose of the research was to study the reproductive traits of cows of Holstein breed and the dynamics of their changes during productive life. The research was carried out on the basis of the Agricultural Production Cooperative “Plamya”, a milk production enterprise where Holstein cattle are bred. In order to conduct the study, the indicators of the reproductive traits of cows of the entire productive herd were evaluated in dynamics over 5 years of production use. The material for the analysis of the dynamics of change was taken from the database of the information and analytical system “SELEX-Dairy cattle”. Thus, it was found that during the study period the annual calf crop increased by 102,4 % or by 2 calves. The average number of inseminations per effective one was 2,1 doses over the period. In the period from 2017 to 2021, in the herd the duration of the open days period ranged from 128 to 140 days. The best indicator was noted in 2019. On average, for the herd over a fi ve-year period, there was an increase in the duration of the open days period by 12 days compared to 2017 data. As a result of a comprehensive analysis of the state of reproduction traits of cows in the herd, it was found that the indicators of reproductive trais of cows had a slight deviation from the threshold (normative) values, which indicates a fairly high level of breeding work carried out by specialists of the farm.

Productive Traits and Reproductive Capacity of First-Calf Cows at Different Selection Options

The research work is aimed at determining and establishing the degree of influence of various selection options on the productive and reproductive qualities of the first-calf cows of the black-and-white breed. The research results showed that according to the Parental Index of Cows (PIC), animals of the 5th experimental group surpass their mates in the 2 and 3 groups in milk yield by 746 kg, with p≤0.05 and 1746 kg, with p≤0.001 and the difference in fat content is 0.07 and 0.01%, respectively. The same advantage in milk yield over the 3 experimental groups is possessed by the 1st control and the 4th experimental groups 1827 and 1885 kg, with p≤0.001. In terms of protein, group 3 cows are inferior to first-calf heifers of groups 1, 2, and 5 by 0.03, 0.08, and 0.09%, with a significant difference p≥0.99. Groups 1, 2, and 5 have superiority over animals of the 4th -0.03%, with p≤0.05, as well as 0.05 and 0.06%, with p≤0.01. The Realization of the Genetic Potential (RGP) in milk yield for 305 days of lactation was higher in the 5th experimental group and amounted to 88.3%, which is 7.1% more than in the control, with p≤0.05. For milk fat, animals of groups 1 and 3 have a high potential of 99.5 and 99.9%. In terms of the mass fraction of protein, first-calf heifers of the 1st control and the 4th experimental groups surpass their mates from group 3 by 2.1 and 1.8%, with p≤0.05. The control group has the most optimal indicator of the calving period (406.5), while the tested ones exceed it by more than 40 days. The service period in all groups has been increased by almost 2 times. The highest calf crop (92.3%) and reproduction rate (0.92%) are observed in the control group.

Phosphorus supplementation improves the growth and reproductive performance of female Brahman cattle grazing phosphorus-deficient pastures in the Victoria River District, Northern Territory, Australia

Context There is a paucity of information on the responses to phosphorus (P) supplementation of breeder herds grazing P-deficient rangelands in northern Australia. Aims A study examined the production and economic benefits of P supplementation of Brahman females grazing P-deficient pastures in the Northern Territory (NT) of Australia. Methods Two treatment groups (initially n ~ 90) grazed two similar P-deficient paddocks for 5 years after weaning (at approximately 6 months of age). Management was the same except that the loose lick mineral supplement either contained P (+P) or did not contain P (−P). Performance attributes were measured from commencement until after the cows had the opportunity to calve during three successive annual cycles. Key results The cows in the +P treatment were overall heavier (P &lt; 0.001), taller (P &lt; 0.001) and had higher plasma inorganic P (PiP) concentrations (P &lt; 0.001) than did those in the −P treatment at every measurement date after the first wet season. Pregnancy rates in lactating cows were 25%, 39% and 63% units higher (P &lt; 0.01) in +P in 2017, 2018 and 2019 respectively and overall average weaner weight was 33 kg heavier (P &lt; 0.001) in +P. Due to higher weaning rates and heavier weaning weights, +P produced about AU$39 365 more value of weaners per 100 heifers allocated to each treatment than did −P over the first three calf crops. The cumulative mortality rate was 12% higher in the −P over the 5 years (14.8% vs 2.2%, P &lt; 0.01), and would have been even higher if at-risk −P cows had not been fed additional supplements. Return on investment calculations indicated that each AU$1 spent on P supplement returned AU$4.98 in value of extra calves weaned and AU$7.88 in extra total liveweight increase over the 5 years of the study. Conclusions The large production and financial benefits from P supplementation observed in this study are relevant to most northern Australian properties where soils are P deficient, although the magnitude of response is likely to vary depending on the level of P deficiency. Implications The large production and economic benefits from P supplementation in this study demonstrated the importance of P supplementation for breeder herds grazing P-deficient pastures.

Anaplasmosis: Practical principles for the diagnosis, treatment and control of field cases and outbreaks

Anaplasmosis, caused by the rickettsial hemoparasite Ana­plasma marginale (Am), is the most prevalent tick-transmitted disease of cattle worldwide and a major obstacle to profitable beef production in the continental United States. Anaplasmosis is readily transmitted through biological and mechanical vec­tors such as ticks and biting flies and iatrogenically through needles and equipment contaminated with infected blood. Clinical anaplasmosis, characterized by anemia, icterus and fever, is associated with significant production losses, abor­tions and mortalities in cattle. It is estimated that the introduc­tion of anaplasmosis into a previously naïve herd can result in a 3.6% reduction in calf crop, a 30% increase in cull rate and a 30% mortality rate in clinically infected adult cattle. Further­more, a study has shown that 16% of pregnant carrier cows will transmit anaplasmosis in utero producing persistently infected offspring. The existence of both horizontal and vertical ana­plasmosis transmission has important implications for disease control in endemic areas. In this presentation, we will use case studies to examine strategies to treat and control anaplasmosis in beef and dairy herds.

Investigating effective testing strategies for the control of Johne's disease in western Canadian cow-calf herds using an agent-based simulation model.

Johne's disease is an insidious infectious disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). Johne's disease can have important implications for animal welfare and risks causing economic losses in affected herds due to reduced productivity, premature culling and replacement, and veterinary costs. Despite the limited accuracy of diagnostic tools, testing and culling is the primary option for controlling Johne's disease in beef herds. However, evidence to inform specific test and cull strategies is lacking. In this study, a stochastic, continuous-time agent-based model was developed to investigate Johne's disease and potential control options in a typical western Canadian cow-calf herd. The objective of this study was to compare different testing and culling scenarios that included varying the testing method and frequency as well as the number and risk profile of animals targeted for testing using the model. The relative effectiveness of each testing scenario was determined by the simulated prevalence of cattle shedding MAP after a 10-year testing period. A second objective was to compare the direct testing costs of each scenario to identify least-cost options that are the most effective at reducing within-herd disease prevalence. Whole herd testing with individual PCR at frequencies of 6 or 12 months were the most effective options for reducing disease prevalence. Scenarios that were also effective at reducing prevalence but with the lowest total testing costs included testing the whole herd with individual PCR every 24 months and testing the whole herd with pooled PCR every 12 months. The most effective method with the lowest annual testing cost per unit of prevalence reduction was individual PCR on the whole herd every 24 months. Individual PCR testing only cows that had not already been tested 4 times also ranked well when considering both final estimated prevalence at 10 years and cost per unit of gain. A more in-depth economic analysis is needed to compare the cost of testing to the cost of disease, taking into account costs of culling, replacements and impacts on calf crops, and to determine if testing is an economically attractive option for commercial cow-calf operations.

The Population structure analysis in Sumbawa buffaloes (Bubalus bubalis) of Indonesia

Buffalo is the important livestock in Indonesia as meat-milk productions and drought animals. This research was carried out to estimate the output of Sumbawa buffalo (Bubalus bubalis) in West Nusa Tenggara (WNT) province of Indonesia. The records data of animals population was collected from Department of Livestock and Animal Health (DLAH) of WNT Province year 2019. This study showed that calf crop, calving rate and natural increase (NI) of animals were 58.15%, 22.76% and 20.18% respectively. Hence, the NI value in Sumbawa buffaloes included of moderate category (15%&lt;NI&lt;30%). In addition, the total animals output at year 2018 was 24.70% (29,671 heads). The net replacement rate (NRR) in total animals was 414.42% and indicated that this population had surplus number of young animal for requirements animal replacement. Unfortunately, the average of growth rate in Sumbawa buffalo was -2.30% per year. Buffalo population in WNT province capable to produce 5,045 heads (male) and 10,703 heads (female) for seedstok. The findings in this study can be used by government and stakeholders as the basic information for monitoring Sumbawa buffaloes in the future.

13 Influence of Prenatal Exposure to Endophyte-infected Tall Fescue on Glucose Metabolism in Weaned Steer Calves

Abstract The objective was to evaluate the influence of prenatal exposure to endophyte-infected tall fescue (toxic fescue) on postweaning glucose metabolism in crossbred steers. Pregnant multiparous cows (n = 36) were maintained on replicated novel or toxic fescue pastures throughout gestation and bermudagrass pastures following calving. From the subsequent calf crop, weaned steers (257±28 d of age) of similar body weight (234±32 kg Toxic; 236±44 kg Novel) were randomly selected (n = 8 Toxic; n = 7 Novel) for a glucose tolerance test. Steers were fitted with jugular vein catheters and fasted for a minimum of 12 h before intravenous administration of a 50% dextrose solution (0.5 mL/kg of body weight). Blood was collected at -10, 0, 10, 20, 30, 45, 60, 90, 120, and 150 min (0 min=glucose administration). Plasma glucose and serum insulin were determined by hexokinase colorimetric assay and radioimmunoassay, respectively. Glucose, insulin, and the insulin to glucose (I:G) ratio were analyzed using MIXED procedures of SAS specific for repeated measures with treatment as a fixed effect and sire as random. All other variables were analyzed using MIXED procedures of SAS with treatment as a fixed effect and sire as random. As expected, glucose, insulin, and the I:G ratio increased in response to glucose administration (time P &amp;lt; 0.01). There was no effect of treatment (P &amp;gt; 0.39) or the treatment by time interaction (P &amp;gt; 0.19) for glucose, insulin, or the I:G ratio. However, Toxic steers exhibited numerically increased glucose, decreased insulin, and decreased I:G ratios relative to Novel steers following glucose administration. There was no difference (P &amp;gt; 0.13) in baseline, peak, time at peak, or time at return to baseline concentrations for insulin or glucose. While prenatal exposure to toxic fescue did not influence glucose or insulin homeostasis in response to exogenous glucose administration in this preliminary study, numerical differences warrant future evaluation with increased animal numbers.

Analysis of the USDA’s 2017 Cow-Calf Management Practices Results: Part 2—Breeding Practices/Reproductive Technologies

This paper discusses the use of breeding practices and reproductive technologies in cow-calf operations, and the ways they affect calf crop. Written by Mario Binelli, João Bittar, and Angela Gonella, and published by the UF/IFAS Department of Animal Sciences, December 2021.