Milk Production Losses Research Articles

Genetic relationships between weight loss in early lactation and daily milk production throughout lactation in Holstein cows

After calving, high-yielding dairy cows mobilize body reserves for energy, sometimes to the detriment of health and fertility. This study aimed to estimate the genetic correlation between body weight loss until nadir and daily milk production (MY24) in first- (L1) and second-lactation (L2) Holstein cows. The data set included 859,020 MY24 records and 570,651 daily raw body weight (BWr) phenotypes from 3,989 L1 cows, and 665,361 MY24 records and 449,449 BWr phenotypes from 3,060 L2 cows, recorded on 36 French commercial farms equipped with milking robots that included an automatic weighing platform. To avoid any bias due to change in digestive content, BWr was adjusted for variations in feed intake, estimated from milk production and BWr. Adjusted body weight was denoted BW. The genetic parameters of BW and MY24 in L1 and L2 cows were estimated using a 4-trait random regression model. In this model, the random effects were fitted by second-order Legendre polynomials on a weekly basis from wk 1 to 44. Nadir of BW was found to be earlier than reported in the literature, at 29 d in milk, and BW loss from calving to nadir was also lower than generally assumed, close to 29 kg. To estimate genetic correlations between body weight loss and production, we defined BWL5 as the loss of weight between wk 1 and 5 after calving. Genetic correlations between BWL5 and MY24 ranged from -0.26 to 0.05 in L1 and from -0.11 to 0.10 in L2, according to days in milk. These moderate to low values suggest that it may be possible to select for milk production without increasing early body mobilization.

Biochemical and genotyping analyses of camels (Camelus dromedaries) trypanosomiasis in North Africa

Camels are considered an important food source in North Africa. Trypanosomiasis in camels is a life-threatening disease that causes severe economic losses in milk and meat production. Therefore, the objective of this study was to determine the trypanosome genotypes in the North African region. Trypanosome infection rates were determined by microscopic examination of blood smears and polymerase chain reaction (PCR). In addition, total antioxidant capacity (TAC), lipid peroxides (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were determined in erythrocyte lysate. Furthermore, 18S amplicon sequencing was used to barcode and characterizes the genetic diversity of trypanosome genotypes in camel blood. In addition to Trypanosoma, Babesia and Thelieria were also detected in the blood samples. PCR showed that the trypanosome infection rate was higher in Algerian samples (25.7%) than in Egyptian samples (7.2%). Parameters such as MDA, GSH, SOD and CAT had significantly increased in camels infected with trypanosomes compared to uninfected control animals, while TAC level was not significantly changed. The results of relative amplicon abundance showed that the range of trypanosome infection was higher in Egypt than in Algeria. Moreover, phylogenetic analysis showed that the Trypanosoma sequences of Egyptian and Algerian camels are related to Trypanosoma evansi. Unexpectedly, diversity within T. evansi was higher in Egyptian camels than in Algerian camels. We present here the first molecular report providing a picture of trypanosomiasis in camels, covering wide geographical areas in Egypt and Algeria.

Review: Reproductive consequences of whole-body adaptations of dairy cattle to heat stress.

Heat stress has far-reaching ramifications for agricultural production and the severity of its impact has increased alongside the growing threats of global warming. Climate change is exacerbating the already-severe consequences of seasonal heat stress and is predicted to cause additional losses in reproductive performance, milk production and overall productivity. Estimated and predicted losses are staggering, and without advancement in production practices during heat stress, these projected losses will threaten the human food supply. This is particularly concerning as the worldwide population and, thus, demand for animal products grows. As such, there is an urgent need for the development of technologies and management strategies capable of improving animal production capacity and efficiency during periods of heat stress. Reproduction is a major component of animal productivity, and subfertility during thermal stress is ultimately the result of both reproductive and whole-body physiological responses to heat stress. Improving reproductive performance during seasonal heat stress requires a thorough understanding of its effects on the reproductive system as well as other physiological systems involved in the whole-body response to elevated ambient temperature. To that end, this review will explore the reproductive repercussions of whole-body consequences of heat stress, including elevated body temperature, altered metabolism and circulating lipopolysaccharide. A comprehensive understanding of the physiological responses to heat stress is a prerequisite for improving fertility, and thus, the overall productivity of dairy cattle experiencing heat stress.

In Vitro Antibacterial Activity of Selected South African Plants against Drug-Resistant Staphylococci Isolated from Clinical Cases of Bovine Mastitis

Bovine mastitis in dairy livestock production is a serious economic problem causing milk production losses and increased management costs. Staphylococcus aureus and non-aureus staphylococcus (NAS) are important causes of bovine mastitis. Antimicrobial resistance can limit the control of mastitis pathogens. Antibacterial and cytotoxic activities of acetone and ethanol extracts of nine South African plants were determined against reference and drug-resistant staphylococci isolated from clinical cases of bovine mastitis. The nine plants, namely, Antidesma venosum, Elaeodendron croceum, Erythrina caffra, Indigofera frutescens, Pleurostylia capensis, Searsia lancea, Searsia leptodictya, Trichilia emetica, and Ziziphus mucronata, were chosen for research material. The antibacterial activity of extracts was determined using a serial microdilution method, while a tetrazolium-based assay was used to determine their cytotoxicity against Vero cells. The values of antibacterial minimum inhibitory concentration (MIC) obtained were promising, with MIC ranging between 0.01 and 1.41 mg/mL. Generally, acetone extracts of most plants had better activity than their ethanol counterparts. The S. aureus strains were more susceptible to all the extracts than the NAS strains. The plant extracts’ half-maximal toxicity (LC50) was higher than 0.02 mg/mL, which is the recommended cytotoxic cut-off concentration. The ethanol extract of E. caffra, which showed better MIC values than its acetone extract, had the highest mean selectivity index (SI) of 8.30. Among the plants tested, S. lancea exhibited the most potent antibacterial activity, suggesting its potential usefulness as a broad-spectrum antibacterial agent against staphylococci associated with bovine mastitis, at relatively non-cytotoxic concentrations. Therefore, it is recommended for further investigation.

The first study on the impact of lumpy skin disease outbreaks on monthly milk production on dairy farms in Khon Kaen, Thailand.

Outbreaks of lumpy skin disease (LSD) have resulted in substantial economic losses to the dairy industry in Thailand. This study aimed to determine the influence of LSD outbreaks on monthly milk production levels. Milk production for dairy farms located in Khon Kaen Province, Thailand, belonging to the Khon Kaen Dairy Cooperative, was affected by LSD outbreaks from May to August of 2021. The resulting data were analyzed using general linear mixed models. It was estimated that the LSD outbreak caused economic losses totaling 2,413,000 Thai Baht (68,943 USD) over the outbreak period. The monthly farm milk production level in May differed from the levels in June and August. Dairy farmers experienced losses between 8.23 and 9.96 tons of milk each month, which equated to between 4180 and 14,440 Thai Baht (119.43 and 412.57 USD) in monthly income. This study demonstrated that LSD outbreaks on dairy farms resulted in significant farm milk production losses. Our findings will increase awareness among authorities and stakeholders in the dairy industry of Thailand, as well as to assist in the prevention of future LSD outbreaks and minimize the negative impacts of LSD.

Assessment of the Current Status of Milk Production and Farm-level Milk Losses among Smallholder Dairy Farmers in Mogotio Sub-county, Baringo County

Smallholder dairy farmers account for up to 80% of total dairy producers and 56% of total milk production in Kenya. The reduction of farm level milk losses at the farm level is a critical point in the milk supply chain where improvements can contribute to increased income.
 The target population included 840 accessible smallholder dairy farmers and 120 dairy farmers who were purposefully sampled as study respondents during the baseline survey. Thirty farmers were purposefully chosen to participate in focus group discussions. A structured questionnaire, Focus Group Discussion guides, and a Key Informant Interview schedule were used to collect data. Focus Group Discussions and Expert Interviews yielded qualitative data. The data's reliability was then estimated using Cronbach's Alpha Coefficient, a measure of internal consistency. Data analysis required the application of both descriptive and inferential statistics. T-tests and the Pearson chi-square test of independence were used for inferential statistics, while measures of central tendency, dispersion and proportions analysis were used for descriptive statistics. According to the findings of the study, the most common milk losses included spillage (30%), excessive consumption by the calves (22%), spoilage (19%) and non-collection of milk due to free-range grazing (17%). Furthermore, most of the farmers (67%) used plastic milk containers. This is worrying because despite a wide variety of plastics existing it is only a few of them that are food grade approved. Microbial contamination through calf suckling is predominant with (71%) practicing free suckling methods which is known to reduce milk yield through milk rejection. The purpose of the study was to assess the current status of milk production and farm-level milk losses among smallholder dairy farmers in Mogotio Sub-county, Baringo County.

Linear Mixed-Effects Model to Quantify the Association between Somatic Cell Count and Milk Production in Italian Dairy Herds.

Milk production loss due to mastitis in dairy herds is economically important. Before estimating the economic impacts of mastitis, it is crucial to quantify the association between mastitis and milk production. The objective of this study was to estimate the association between somatic cell count (SCC, as an indicator of intramammary infection due to mastitis) and milk production for dairy cows in Lombardy, Italy. The test-day (TD) records data of 3816 dairy herds located in three different geographical areas of Lombardy from January 2016 to December 2018 were used. After data editing, the final dataset comprised 10,445,464 TD records from 2970 farms and 826,831 cows. The analysis was carried out by using a mixed-effects model with six fixed effects (geographical Area, Breed, Days in Milk, Parity, Season and Year) and nested random effects for each cow and herd. The results confirmed that the SCC had a negative association with milk production. On average, this study found that any two-fold increase of SCC resulted in a milk production loss of 0.830 (95% CI: -0.832, -0.828) kg/cow/day in the whole of Lombardy. These results can be used for economic calculations on the costs of mastitis.

Effects of air temperature and relative humidity on milk yield of Holstein dairy cattle raised in hot-dry Southeastern Anatolia Region of Türkiye

The aim of this study is to investigate the possibilities of using the meteorological data obtained from the public meteorology station in determining the effect of air temperature and relative humidity on milk yield in Black and White dairy cattle raised in Diyarbakır province of Turkey. Records on daily milk yield obtained from a commercial farm in Diyarbakır province were used in the study. Meteorological records containing daily maximum and minimum temperature and daily maximum and minimum humidity data were obtained from nearest public weather station in Diyarbakır province. Data set related to milk yields includes 46 438 daily records during five different lactations of 185 healthy Black and White dairy cattle and information of some environmental factors of the animals. In the study, five different temperature-humidity index (THI) types consisting of different combinations of daily maximum, minimum and average temperature and humidity values were considered to evaluate the effect of heat stress on milk production.
 
 This study confirmed that weather stations located away from the farms contain useful information for research on heat stress in dairy cows. Using the combination of maximum daily air temperature and minimum daily humidity in THI formula performed better than other THI types in quantifying the heat stress in this study. This combination was less affected by other environmental factors and the results obtained from this combination seems to be more biologically meaningful. According to this, dairy cattle were exposed to heat stress for 160 days between May and October in a year. In this period, the losses of milk production were 1518.85 and 0.73 kg for per cow per year and per unit THI increase, respectively.

Forming the production potential of dairy cattle breeding as a factor of sustainable development of food systems

Sustainable development of food systems is a global challenge for both Russian and world economy. Within each country, the economic, social and environmental aspects of sustainability should be considered in symbiosis when forming conditions for the development of agricultural sectors. Dairy cattle breeding has always been one of the leading sub-sectors of agriculture, the prerogative of which is to provide the population with milk and dairy products in an amount that advises recommended consumption standards. Digital transformation of the sub-sector is considered as an element of the global project in the Ministry of Agriculture of Russia “Digital Agriculture”. The paper presents analytical materials on the level of self-sufficiency and economic availability of milk and dairy products in Russia as a whole, as well as the current state of the production potential of dairy cattle breeding in the Krasnoyarsk region. It was found that the loss of gross milk production due to a decrease in the number of cows compensates for the increase in productivity. It is noted that in Russia the agricultural industries are going through the next stage of serious technological changes, which is associated with the need to modernize production based on the use of information technologies, automation capabilities, digital technologies and platform solutions. This process helps to solve the main task – to ensure the sustainable development of food systems on the basis of increasing the production potential of industries.

Histopathological study of sheep lung roaming in dump zones

Respiratory system disease is common in sheep, which is frequently difficult to detectable in live animals until it becomes serious and complicated. This study was aimed to describe sheep lung lesions in Mosul city, which roam in dump zones and have been slaughtered at butchers’ shops, fifty male and female sheep 1-5 years were used at the current work from March to December 2021; affected Samples were collected and prepared for standard histopathological analysis. The special stain was also used for carbohydrates demonstrated inside and around lung lesions. The results of the current study showed the presence of gross and histological finding changes, the gross lesion presented by inflammation of the upper right lope, congestion, and bleeding on all parts of the lope in addition to different sizes of the nodular lesion. In contrast, the pneumonic histological finding was 12.1%, circulatory disturbance 3.5%, parasitic infections 10.0%, disturbance of growth 7.1%, Necrotic area surround by swirling macrophage 2.0% in addition to the deposition of calcium salt and hemosiderin pigmentation. Organizing Pneumonia (OP) and Masson’s bodies were one of the most detected lesions in the roaming sheep, it was scored by Masson Trichrome from mild, moderate, and severe fibrosis. All lesions were categorized according to the type of lesion, grade, and kind of it. From the current work, we demonstrated that pneumonic disorder represented a considerable and serious problem in the animal livestock industry and leads to economic loss in milk, wool, and sheep meat production. Additional studies are recommended to determine the etiological agent of sheep lung lesions whether it is a fungal, bacterial, or viral agent.

High Prevalence of Prototheca bovis Infection in Dairy Cattle with Chronic Mastitis in Ecuador.

The genus Prototheca, a unicellular, non-photosynthetic, yeast-like microalgae, is a pathogen of concern for the dairy industry. It causes bovine mastitis that currently cannot be cured, and hence generates significant economic losses in milk production. In this study, for the first time in Ecuador, we identify Prototheca bovis as the etiologic agent of chronic mastitis in dairy cattle. Milk samples (n = 458) of cows with chronic mastitis were cultured on Sabouraud Dextrose Agar (SDA). Microscopy and cytB gene sequencing were used to identify Prototheca, whereby Prototheca bovis was isolated from 15.1% (n = 69) of the milk samples, one of the highest infection rates that can be found in the literature in a "non-outbreak" situation. No other Prototheca species were found. We were unable to isolate the alga from environmental samples. We showed that P. bovis was relatively resistant to disinfectants used to sterilize milking equipment on the cattle farms where it was isolated. We discuss how to avoid future infection and also hypothesize that the real prevalence of Prototheca infection in bovine mastitis is probably much higher than what was detected. We recommend a protocol to increase the diagnostic yield in the bacteriology laboratory.

The costs of chronic mastitis: A simulation study of an automatic milking system farm

Mastitis is a production disease in dairy farming that causes economic losses. Especially chronic mastitis (i.e., mastitis cases continuing longer than 28 days) can substantially affect the risk of transmission of intramammary infections (IMI) and total milk production losses. Insights into the impact of chronic mastitis on production and farm economics are needed to guide chronic mastitis decision-making. We aimed to estimate the costs of chronic mastitis with a Monte Carlo simulation model in which the costs of chronic mastitis were estimated as part of the total mastitis costs. The model simulated milk yields, IMI dynamics, somatic cell count (SCC), and pregnancy status on an average Dutch dairy farm with 100 cow places over 9 years. The model was parameterized using information from the literature and actual sensor data from automatic milking system (AMS) farms. The daily subclinical milk production losses were modeled using a generalized additive model and sensor data. Transmission of IMI was modeled as well. The model results indicated median total costs of mastitis of € 230 per generic IMI case (i.e., a weighted average of all pathogens). The most substantial cost factors were the extra mastitis cases due to transmission, culling, and milk production losses. Other significant costs originated from dry cow treatments and diverted milk. The model also indicated median total costs due to chronic mastitis of € 118 (51 % of the total mastitis costs). The share of chronic mastitis relative to the total mastitis costs was substantial. Transmission of contagious bacteria had the largest share among the chronic mastitis costs (51 % of the costs of chronic cases). The large share of chronic mastitis costs in the total mastitis costs indicates the economic importance of these mastitis cases. The results of the study point to the need for future research to focus on chronic mastitis and reducing its presence on the AMS dairy farm.

In vitro Assessment of the Acaricidal Activity of Laurus nobilis and Croton tiglium Seeds Extract against Hyalomma dromedarii Ticks

Background: Ticks are destructive ectoparasites that feed on the blood of domestic animals and the spread of ticks causes significant losses in meat, milk and leather production. About 800 species of ticks are known around the world, Hyalomma dromedarii is one of the ticks that attack camels as their main host. The objective of this study was to identify the acaricidal activity of Laurus nobilis and Croton tiglium seeds extract against H. dromedarii ticks and comparison with some drugs used against external parasites. Methods: A study was performed to evaluate the acaricidal activities of methanolic extracts of two medicinal plants, namely the seeds of C. tiglium and L. nobilis, against H. dromedarii using an adult immersion test and larval bundle test. Five graduated concentrations of extracts, 6.25, 12.5, 25, 50 and 100 mg/ml, were tested at different periods and changes over time in the viability of ticks were registered for 24 hr. Distilled water and cypermethrin (0.1%) were used as a negative and positive control, respectively. Result: From 30 min after exposure, a concentration of 100 mg/ml of C. tiglium seed extract resulted in higher mortality (p less than 0.05) compared with cypermethrin. A significant rise in tick mortality began 2 hr after exposure to a concentration of 100 mg/ml of C. tiglium seed extract and cypermethrin. At 24 hr after exposure, cypermethrin and concentrations of 50 and 100 mg/ml of C. tiglium extract induced significantly higher tick mortality compared to the rest of the concentrations. A significant increase in tick mortality began 3 hr after exposure to cypermethrin and concentrations of 50 and 100 mg/ml of Laurus nobilis extract and 12 hr after exposure to concentrations of 6.25, 12.5 and 25 mg/ml L. nobilis extract. At 24 hr after the exposure time, concentrations of 50 and 100 mg/ml of the extract and cypermethrin had a comparable higher tick mortality effect compared to the remaining concentrations below 25 mg/ml (p less than 0.05). The lower concentration (6.25 mg/ml) resulted in notably higher mortality of adult ticks and larvae compared to the negative control (distilled water) at 24 hr exposure to both extracts. At 24 hr after the exposure period, the tick mortality of all estimated plant extracts also increased with raised exposure time and concentration. Therefore, studied plants can be used against H. dromedarii as a potential alternative to commercially available medicines. Further studies should include more research on separating each component and validating the materials.

Association of High Somatic Cell Counts Prior to Dry off to the Incidence of Periparturient Diseases in Holstein Dairy Cows.

Intramammary infections (mastitis) of dairy cows, along with other periparturient diseases, have become problematic within the dairy industry as they lead to loss of milk production. The main objective of this study was to determine whether elevated somatic cell counts (SCC) in cows prior to drying off are related to the incidence of other periparturient diseases. Additionally, we determined whether milk composition and milk yield are affected by a high SCC prior to drying off. Somatic cell counts of milk samples were determined prior to dry off (n = 140) and were used to classify cows in the study as high (>200,000 cells/mL) or low (<200,000 cells/mL) SCC. The composition of milk was analyzed before drying off and at 1 and 2 weeks after calving. The results showed that an elevated SCC before drying off was related to the incidence of ketosis. Cows with a high SCC at drying off also showed an increased likelihood of retained placenta, metritis, and lameness postpartum; however, it was not statistically significant. Milk lactose was lower in cows with high SCC, whereas protein content was lower after parturition. Milk production was lower for cows with pre-drying elevated SCC, particularly for cows with retained placenta, ketosis, and mastitis. In conclusion, cows with pre-drying elevated SCC were more likely to develop disease after parturition and produce less milk and with lower lactose and protein content.

Economic impact of predominant ticks and tick-borne diseases on Indian dairy production systems

As per 20th livestock census, India possessing 193.46 million cattle and 109.85 million buffaloes in organized and unorganized sectors. These animals are suffering from tick infestation almost throughout the year causing both direct and indirect losses. Repeated use of chemical acaricides for tick management resulted in the establishment of acaricide resistant tick populations, insecticide residues in livestock products and environmental pollution. In the present study, analysis of the data generated during 1990–2021 revealed pooled prevalence of infestations in cattle and buffaloes was 53% [95% CI = 47–60%] and 38% [95% CI = 28–49%], respectively. Based on peripheral blood smear examination the prevalence of theileriosis, babesiosis and anaplasmosis in cattle is estimated as 17% [95% CI = 12–24%], 4% [95% CI = 3–6%] and 5% [95% CI = 3–7%], respectively, while in buffalo the prevalence of infection is estimated as 7% [95% CI = 2–21%], 2% [95% CI = 0–5%] and 8% [95% CI = 2–36%],respectively.To estimate economic impact, both direct (reduction in milk production, cost of treatment, leather depreciation) and indirect (milk loss and treatment cost) losses were taken into consideration. Loss of milk production was predicted as 13.91, 56.91 and 85.34L/cross-bred cow/lactation in low, moderate and high tick infestation conditions, respectively. Whereas, 20.10, 7.01L milk/buffalo/lactation in Hyalomma spp. and Rhipicephalus spp. infestation was estimated. Similarly,the estimated loss of milk production due to clinical theileriosis, babesiosis and anaplasmosis was 57.96, 30.96 and 59.22L, respectively. The cumulative (milk loss, treatment cost and leather loss) loss due to tick infestation was calculated as 46199.31 million INR (USD595.07 million) while due to TBDs 14877.15 million INR (USD191.15 million) = 61076.46 million INR (USD787.63 million). The data provided base line information for the policy maker to develop strategies at government level so that the significantly high cumulative loss of 787.63 million USD due to ticks and tick borne diseases (TTBDs) can be minimized.

Applications to Control the Estrus Cycle in Bovines via Estrus Synchronization: A Review

Estrus Synchronization is the main application of Assisted Reproductive Technologies (ART), it helps in the control of the estrus cycle with the basic help of Hormones and adds controlled Artificial Insemination, reduction in Calving interval which saves time, labor cost and effective dairy farm management. Moreover, old reproductive management is too expensive and it becomes the root of the loss of milk and meat production, it is also costly in case of labor, feed, estrus detection, long inter calving interval, postpartum estrus detection and other disease problems. To get rid of these expensive traditional practices ART has developed many methods to control estrus cycle physiology and endocrinology. Estrus synchronization tools developed in recent breeding management of dairy herds in dairy industries have become an essential part of reproduction. Many of them rely on protocols that allow timed artificial insemination (TAI) to overcome the practical anomalies during estrus detection. Currently developed programs consist of protocols that are used for re-synchronization following first or consequent inseminations. Many programs include scheduled injections of Prostaglandin (PgF2α) and Gonadotropin-releasing hormone (GnRH). Meanwhile, progesterone and estradiol based supplements are also required in many techniques. The main program used for synchronization is "Ovsynch" protocol. Moreover, this review is based on the introduction, history, principles, factors and methods of estrus synchronization that are mostly used for profitable dairy farming, it will assist in the understanding of the basic mechanism that is involved in the control of estrus cycle.

Genome-Wide Association Study for Udder Conformation Traits in Chinese Holstein Cattle.

Simple SummaryUdder conformation traits are economically important for dairy animals in the dairy industry. Milk production loss can be reduced via a better udder structure in dairy cattle. Udder traits are related to milk production and the somatic cell count, which is a sign of mammary infections (mastitis); as such, it is vital to understand the genetic architecture underlying udder traits in Holstein Friesian cattle for genetic development and long-term selection. Through a GWAS on udder structure traits in Chinese Holstein cattle, we identified several significant single-nucleotide polymorphisms (SNPs) and candidate genes associated with udder traits. The results could provide useful information regarding the genetics architecture of udder structure traits, thus improving the genetic information, health, longevity, and production of dairy cattle.Udder conformation traits are one of the most economic traits in dairy cows, greatly affecting animal health, milk production, and producer profitability in the dairy industry. Genetic analysis of udder structure and scores have been developed in Holstein cattle. In our research, we conducted a genome-wide association study for five udder traits, including anterior udder attachment (AUA), central suspensory ligament (CSL), posterior udder attachment height (PUAH), posterior udder attachment width (PUAW), and udder depth (UD), in which the fixed and random model circulating probability unification (FarmCPU) model was applied for the association analysis. The heritability and the standard errors of these five udder traits ranged from 0.04 ± 0.00 to 0.49 ± 0.03. Phenotype data were measured from 1000 Holstein cows, and the GeneSeek Genomic Profiler (GGP) Bovine 100 K SNP chip was used to analyze genotypic data in Holstein cattle. For GWAS analysis, 984 individual cows and 84,407 single-nucleotide polymorphisms (SNPs) remained after quality control; a total of 18 SNPs were found at the GW significant threshold (p < 5.90 × 10−7). Many candidate genes were identified within 200kb upstream or downstream of the significant SNPs, which include MGST1, MGST2, MTUS1, PRKN, STXBP6, GRID2, E2F8, CDH11, FOXP1, SLF1, TMEM117, SBF2, GC, ADGRB3, and GCLC. Pathway analysis revealed that 58 Gene Ontology (GO) terms and 18 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were enriched with adjusted p values, and these GO terms and the KEGG pathway analysis were associated with biological information, metabolism, hormonal growth, and development processes. These results could give valuable biological information for the genetic architecture of udder conformation traits in dairy Holstein cattle.

Seroprevalence of Bovine Leptospirosis using Indirect ELISA

Background: Leptospirosis is a zoonotic bacterial disease causing abortion, stillbirths and loss of milk production in livestock resulting in huge economic losses. Leptospirosis in cattle has been under-reported and under-diagnosed in India due to non-specific symptoms, complex laboratory tests, fastidious nature of bacterium and lack of proper diagnostic facilities. Scanty data pertaining to epidemiological status of leptospirosis is available in land locked states of India including Madhya Pradesh, thus to fulfil the gap, the current work was conducted to investigate seroprevalence of leptospirosis in cattle. Methods: In the present study, cattle with a history of repeat breeding, abortion, haemogalactia and mastitis, were screened from various organized and unorganized farms of Jabalpur. A total of 300 blood samples were collected from suspected cattle and serum was separated. Enzyme linked Immune-sorbent assay was done as per the guidelines. Result: The seroprevalence of leptospirosis among suspected cases was 48.67 per cent, it was significantly higher in organized sector in cattle with the history of abortion followed by repeat breeding. High seropositivity was reported in older cattle.

Propagation of Babesia bigemina in Rabbit Model and Evaluation of Its Attenuation in Cross-Bred Calves.

Simple SummaryVector-borne diseases (VBDs) cause heavy economic losses in the livestock sector. Among these VBDs, babesiosis is the second most common disease, causing high morbidity, mortality, and reproductive and productive losses in cattle. The causative agents of this disease are globally distributed across tropical and subtropical countries. In the current study, B. bigemina was propagated in vivo in rabbit for attenuation and evaluated for its virulence periodically. This attenuated B. bigemina was then inoculated to naive calves for the evaluation of clinical parameters. Increased parasitaemia and temperature were observed in rabbits following the inoculation of B. bigemina-infected red blood cells. The naive calves did not show symptoms of parasitaemia or temperature elevation when inoculated with rabbit-propagated B. bigemina-infected RBCs. Furthermore, this study also demonstrated that infected cattle periodically had a decreased PCV profile, along with increased temperature and parasitaemia. Moreover, this study also revealed correlations between the temperature, parasitaemia, and packed cell volume of inoculated, infected, and control group calves.Bovine babesiosis (BB) is a vector-borne disease (VBD) that affects cattle in tropical and subtropical areas, caused by the haemoprotozoa Babesia bovis and Babesia bigemina. It is transmitted by tick bites belonging to the genus Rhipicephalus and is clinically characterized by high fever, depression, anorexia, decreased milk and meat production, haemoglobinemia, haemoglobinuria, jaundice, and pregnancy loss. In this study, the propagation of B. bigemina was evaluated by intraperitoneally inoculating 3 × 106 red blood cells infected with B. bigemina into rabbits. The study showed that variations in rabbit body temperatures are related to induced bovine babesiosis. A significant increase in temperature (39.20 ± 0.23 °C) was observed from day 4 onwards, with the maximum temperature (40.80 ± 1.01 °C) on day 9 post-inoculation. This study included susceptible cross-bred calves for in vivo attenuation, and they were compared with an infected group. The calves in the infected group showed a significant increase in temperature (38.79 ± 0.03 °C) from day 3 onwards and a maximum temperature (41.3 ± 0.17 °C) on day 11. Inoculated calves showed a gradual rise in temperature post-inoculation, but the difference was not significant. Inoculated calves did not show parasitaemia, whereas 32% of infected calves displayed parasitaemia. As compared to inoculated calves post-inoculation, packed cell volume (PCV) decreased (16.36 ± 1.30) for infected calves. However, there were statistically significant differences (p ≤ 0.05) in temperatures, parasitaemia, and PCV in both inoculated and infected calves. The current study aimed to attenuate B. bigemina in rabbit models and evaluate the pathogenic potential of this organism in naive calves. In conclusion, B. bigemina proliferation was attenuated in rabbits. The rabbit model can be used to study B. bigemina in vivo in order to reduce its pathogenicity.

Heat stress develops with increased total-tract gut permeability, and dietary organic acid and pure botanical supplementation partly restores lactation performance in Holstein dairy cows.

To evaluate the effects of heat stress (HS) conditions and dietary organic acid and pure botanical (OA/PB) supplementation on gut permeability and milk production, we enrolled 46 multiparous Holstein cows [208 ± 4.65 dry matter intake (DMI; mean ± SD), 3.0 ± 0.42 lactation, 122 ± 4.92 d pregnant, and 39.2 ± 0.26 kg of milk yield] in a study with a completely randomized design. Cows were assigned to 1 of 4 groups: thermoneutral conditions (TN-Con, n = 12), HS conditions (HS-Con, n = 12), thermoneutral conditions pair-fed to HS-Con (TN-PF, n = 12), or HS supplemented with OA/PB [75 mg/kg of body weight (BW); 25% citric acid, 16.7% sorbic acid, 1.7% thymol, 1.0% vanillin, and 55.6% triglyceride; HS-OAPB, n = 10]. Supplements were delivered twice daily by top-dress; all cows not supplemented with OA/PB received an equivalent amount of the triglyceride used for microencapsulation of the OA/PB supplement as a top-dress. Cows were maintained in thermoneutrality [temperature-humidity index (THI) = 68] during a 7-d acclimation and covariate period. Thereafter, cows remained in thermoneutral conditions or were moved to HS conditions (THI: diurnal change 74 to 82) for 14 d. Cows were milked twice daily. Clinical assessments and BW were recorded, blood was sampled, and gastrointestinal permeability measurements were repeatedly evaluated. The mixed model included fixed effects of treatment, time, and their interaction. Rectal and skin temperatures and respiration rates were greater in HS-Con and HS-OAPB relative to TN-Con. Dry matter intake, water intake, and yields of energy-corrected milk (ECM), protein, and lactose were lower in HS-Con relative to HS-OAPB. Nitrogen efficiency was improved in HS-OAPB relative to HS-Con. Compared with TN-Con and TN-PF, milk yield and ECM were lower in HS-Con cows. Total-tract gastrointestinal permeability measured at d 3 of treatment was greater in HS-Con relative to TN-Con or TN-PF. Plasma total fatty acid concentrations were reduced, whereas insulin concentrations were increased in HS-Con relative to TN-PF. We conclude that exposure to a heat-stress environment increases total-tract gastrointestinal permeability. This study highlights important mechanisms that might account for milk production losses caused by heat stress, independent of changes in DMI. Our observations also suggest that dietary supplementation of OA/PB is a means to partly restore ECM production and improve nitrogen efficiency in dairy cattle experiencing heat stress.