Profitability Of Dairy Herds Research Articles

Incidence of puerperal metritis and associated risk factors in dairy cows in Hawassa, Southern Ethiopia

Metritis has considerable economic impact on dairy herd profitability due largely to reduced reproductive performance. Studies in Ethiopia only report prevalence, with no available data on the incidence of metritis. The present prospective cohort study aimed to estimate the incidence of puerperal metritis, identify risk factors, and isolate the causative bacteria in dairy cows in Hawassa. Daily follow-up of 120 dairy cows from parturition to 21 days postpartum was carried out from November 2019 to February 2021. Of these, 21 developed puerperal metritis with an incidence rate of 0.94 cases per 100 cow days at risk (95 % CI: 0.6–1.4). The cumulative incidence was found to be 17.5 % (95 % CI: 11.8–25.6). Over 90 % of the puerperal metritis occurred within the first 10 days of parturition. The mean day of occurrence of puerperal metritis was 7.7 days postpartum and the mean rectal temperature in metritic cows was 40.5 °C. Retained fetal membranes (RFM) (p < 0.001) emerged as the only predisposing factor for metritis in the final Cox regression model. Cows with RFM faced a 14.9 times higher risk of metritis compared to cows without RFM. A total of 52 bacterial isolates, belonging to 4 genera, were recovered from the aerobic culture of 21 uterine swab samples. E. coli and Staphylococcus spp. were the most frequently isolated bacteria, with recovery from 21 (100 %) and 20 (95.2 %) of the metritic uteri, respectively. Results of this study suggested the importance of reducing incidence of RFM to reduce incidence of metritis in dairy cows.

Effect of bovine subclinical mastitis on milk production and economic performance of Brazilian dairy farms

This review summarized the significant results from Brazilian studies published in peer-reviewed scientific papers about the effect of bovine subclinical mastitis (SM) on economic performance and milk production. Different approaches were considered for (i) disease detection (indirect measurement of somatic cell count (SCC) and directly using microbiological culture) and (ii) milk sampling strategy (mammary quarters, composite cow samples, and bulk milk tank). Globally, bovine mastitis is the most common disease of dairy herds, and the subclinical presentation is the most frequent. Dairy farmers usually underestimate the economic losses associated with SM because no visual changes in milk and quarters, udder, and systemic symptoms are observed. SM reduces milk yield and quality, reducing dairy herds’ profitability. The estimation of losses depends on the causative pathogen, the lactation stage, and the parity of affected cows. Thus, estimating the economic caused by SM in milk production and economic performance in dairy herds can be used to decide which mastitis control strategies to adopt. Mastitis control involves adopting specific measures associated with the characteristics of each herd, the period of the highest frequency of cases, the transmission form, and the profile of the pathogens involved in cases of intramammary infection. Thus, using individual SCC, the microbiological identification of pathogens causing SM, adopting efficient drying-off protocols, and other management practices are essential for mastitis control, improved milk quality, and greater profitability of dairy herds.

Genomic Selection for Dairy Cattle Behaviour Considering Novel Traits in a Changing Technical Production Environment.

Cow behaviour is a major factor influencing dairy herd profitability and is an indicator of animal welfare and disease. Behaviour is a complex network of behavioural patterns in response to environmental and social stimuli and human handling. Advances in agricultural technology have led to changes in dairy cow husbandry systems worldwide. Increasing herd sizes, less time availability to take care of the animals and modern technology such as automatic milking systems (AMSs) imply limited human-cow interactions. On the other hand, cow behaviour responses to the technical environment (cow-AMS interactions) simultaneously improve production efficiency and welfare and contribute to simplified "cow handling" and reduced labour time. Automatic milking systems generate objective behaviour traits linked to workability, milkability and health, which can be implemented into genomic selection tools. However, there is insufficient understanding of the genetic mechanisms influencing cow learning and social behaviour, in turn affecting herd management, productivity and welfare. Moreover, physiological and molecular biomarkers such as heart rate, neurotransmitters and hormones might be useful indicators and predictors of cow behaviour. This review gives an overview of published behaviour studies in dairy cows in the context of genetics and genomics and discusses possibilities for breeding approaches to achieve desired behaviour in a technical production environment.

Impact of COVID-19 on Dairy Herd Profitability: A Review at the Global Level

The occurrence of several pandemics in recent decades has posed a significant threat to human and animal health. The COVID-19 pandemic, which rapidly spread to 187 countries, has caused significant economic disruption in various industries, including the dairy industry. The dairy industry has been affected by supply chain disruptions, consumer behavior changes, and global demand shifts due to the pandemic. The present review aims to evaluate the impact of the COVID-19 pandemic, mainly from the dairy farm level, and propose strategies for mitigating the effects of future global crisis events. The dairy industry, a major source of income for many dairy herds, was significantly impacted by the COVID-19 pandemic. The consumption patterns of milk and dairy products underwent substantial alterations, leading to decreased profitability of dairy farms due to disruptions in the supply chain, increased transportation costs resulting from transportation restrictions, and a shift in consumer purchasing behavior. These factors collectively resulted in reduced revenue from selling milk and dairy products. Heifer replacement considerations also impacted the economic viability of dairy farms. The pandemic caused a shortage of meat (beef, pork, poultry) and a surplus of milk. In addition to the abovementioned factors, the COVID-19 pandemic also impacted other economic indicators, such as gross returns from the sale of culled dairy animals and dairy feed costs. These impacts further amplified the financial challenges faced by the dairy industry and dairy farmers, underscoring the need for robust mitigation strategies and resilient policies to minimize the economic impact of pandemics and other crises. In conclusion, the COVID-19 pandemic has profoundly impacted the dairy industry, affecting supply chains and international commerce. Governments are encouraged to implement measures to mitigate the impact of future pandemics on the dairy sector. The authors of this review propose several recommendations for dairy farmers and veterinarians to increase their resilience in the face of future outbreaks. These recommendations include sourcing feed from reliable local farms, acquiring internet connectivity equipment to facilitate communication during travel restrictions, maintaining a sufficient supply of personal protective equipment, incorporating mechanization in farm operations, stockpiling essential veterinary medications and vaccines, and training technicians to perform veterinary procedures in emergencies when veterinary services are unavailable.

Estrus Detection in a Dairy Herd Using an Electronic Nose by Direct Sampling on the Perineal Region.

Estrus detection is very important for the profitability of dairy herds. Different automatic systems for estrus detection have been developed over the last decades. Our study aimed to assess the ability of the electronic nose (EN) MENT-EGAS prototype to detect estrus, based on odor release from the perineal headspace in dairy cattle by direct sampling. The study was performed in an Italian dairy farm using 35 multiparous Holstein-Friesian cows. The cows were divided into three groups: group I included 10 lactating 5-month pregnant cows, group II included 19 lactating cycling cows, and group III included 6 cows that were artificially inseminated 18 days before the trial. Odors from the perineal headspace were collected using the MENT-EGAS prototype. In group I, odors were collected once a day for 5 consecutive days. In group II, odors were collected twice daily from day 18 until day 1 of the reproductive cycle. In group III, odors were also collected twice daily from the presumable day 18 of gestation until day 22. Principal component analyses (PCA) of the perineal headspace samples were performed. PCA in group I revealed no significant discrimination. PCA in group II revealed clear discrimination between proestrus and estrus, and between estrus and metestrus but no significant discrimination was obtained between proestrus and metestrus. PCA in group III revealed that in four cows the results were similar to group I and in two cows the results were similar to group II. On day 40 of the presumable pregnancy, the ultrasound examination revealed that only the four cows were pregnant and the other two cows were regularly cycling. On the basis of our findings, we conclude that it is possible to accurately detect estrus in dairy cattle from directly collected odor samples using the MENT-EGAS prototype. This represents the first study of estrus detection using an EN detection by direct sampling. EN technologies, such as MENT-EGAS, could be applied in the future in dairy cattle farms as a precise, non-invasive method for estrus detection.

Economic analysis of different pregnancy rates in dairy herds under intensive management

The pregnancy rate (PR) is nowadays the most informative reproductive parameter, as it encompasses the proportion of cows that become pregnant from the total number of cows eligible for insemination in each estrous cycle. In the international scientific literature, there are several analyses concerning PR change effects on the profitability of dairy herds. In this study, the economic consequences of PR changes in a dairy herd under intensive management was calculated. We developed a mathematical model, based on the Monte Carlo simulation model, to estimate herd performance and economic utility using different pregnancy rates (between 15 and 30). The simulation was done using a fixed conception percentage of 30, so the increment in pregnancy rate only depended on the efficiency of estrus detection (EED) increase. In the generated model scenarios, PR increase had a positive effect on the annual cow income per year; however, the extra income had a quadratic trend with a revenue decline, when PR reached 20 %. So for every percentage point, where PR was increased from 15 to 20 %, an additional cow income of USD 40.46 per year was generated. Furthermore, the additional income for every percentage point, when the PR was increased from 20 to 25 % was USD 21; and USD 6.88, when the increase was from 25 to 30 %. We can conclude that any changes in herd management to increase the EED and thereby the PR should have lower costs compared

Relationships between hematological parameters and Cl and Na homeostasis in dairy herds and abortion

Abortion is among reproductive parameters affecting the profitability of dairy herds. Abortion incidence is influenced and/or controlled by different infectious, environmental, and managerial factors and so forth. The effect of environmental and nutritional conditions on minerals, as well as interactions between minerals and physiological conditions, are leading parameters to consider during gestation. This study attempts to assess links between these factors and abortion by determining and measuring homeostasis-electrolyte factors, such as Na and Cl, and hematological parameters, such as complete blood count, in dairy herds with abortion. A total of 40 Holstein dairy herds were chosen and split into two 20-member control and aborted groups. Abortions were reported by ranchers, and blood samples were taken considering the history and current status of herds and clinical examinations. Blood samples were taken twice, once with EDTA to study hematological characteristics and once with no anticoagulant to measure hemostasis-electrolyte factors (Na, Cl) from the serum of herds with abortion. The relationships between these parameters and variations observed in dairy herds with abortion were compared with those in the control group. There was no significant difference in concentrations of sodium and chlorine between the two groups (p&gt; 0.05).

Effect of Calving Difficulties and Calf Mortality on Functional Longevity in Polish Holstein-Friesian Cows.

Simple SummaryLongevity, or the length of a cow’s productive life, is important in terms of profitability, animal welfare and environmental sustainability. In genetic evaluations, interest focuses on functional longevity, defined as a cow’s ability to avoid forced culling, an ability that increases the possibility of voluntary disposal based on economic criteria. Longevity is affected by several non-productive functional traits, among them those related to calving performance: calving ease (dystocia) and perinatal calf mortality (stillbirth). Parturition is a critical event in a cow’s life that has a number of different short- and long-term consequences. In the Polish Holstein-Friesian population, the incidence of dystocia and stillbirth is within the lower range of frequencies found in other dairy cattle populations. Our research showed that both traits affect functional longevity. Difficult calvings occur more frequently in heifers and increase the risk of involuntary culling more than in later parturitions. Additionally, a higher risk of culling is related to birth of a male calf. Moreover, the negative impact of calf mortality on longevity is also more pronounced in primiparous cows and in the case of delivery of male calves. Reducing the incidence of calving problems and perinatal mortality may improve the longevity of dairy cows.Longevity is one of the functional traits that considerably affect dairy herd profitability. A Weibull proportional hazards model was used to evaluate the impact of difficult calvings and calf stillbirths on cow functional longevity, defined as length of productive life corrected for milk production. The data for analysis comprised calving ease and calf mortality scores of 2,163,426 calvings, 34.4% of which came from primiparous cows. The percentage of male calves was 53.4%. Calving ease was scored as “without assistance” (34.44%), “with assistance” (62.03%), “difficult—hard pull” (3.39%), and “very difficult, including caesarean section” (0.14%). Calf mortality scores were “live born” (94.21%) and “stillborn or died within 24 h” (5.79%). The Weibull proportional hazards model included classes of calving ease or calf mortality scores × parity (1, ≥2) × sex of calf as time-dependent fixed effect. The model also included time-dependent fixed effects of year × season, parity × stage of lactation, annual change in herd size, fat yield and protein yield, time-independent fixed effect of age at first calving, and time dependent random herd × year × season. In first-parity cows, very difficult birth of a bull or heifer increased the relative risk of culling, respectively, 2.18 or 1.26 times as compared with calving without assistance. In later parities, the relative risk of culling related to very difficult calving was 2.0 times (for male calves) and 1.33 times (for female calves) higher than the relative risk of culling associated with calving without assistance. Calf mortality showed a negative impact on longevity in both heifers and cows. First-parity stillbirth increased the relative risk of culling depending on sex of calf by 18% in females and by 15% in males; in later parities the increase of the relative risk of culling was lower (by 7% for females, 9% for males). Difficult calvings and their consequences, especially in primiparous cows, may negatively influence dairy herd profitability by reducing the length of cows’ productive life.

Bovine viral diarrhea virus (BVDV) infection: Effect on reproductive performance and milk yield in dairy herds

The impact of an outbreak of bovine viral diarrhea (BVD) on reproductive performance and milk production was investigated in 28 Spanish dairy herds using an observational study design. Mean calving to conception interval (CCI), mean number of inseminations per conception (AI/P) and mean daily milk yield were recorded from herds affected by outbreaks. Infection was confirmed by evidence of viral transmission to young stock (heifers 9–24 months) and persistently infected animals, after previous BVD-free status. Fifteen herds did not use vaccines (G1) whereas the remaining 13 received modified live BVD virus (BVDV) vaccines (G2). In G1 herds, a significant increase in CCI (13.8 days; 95% CI, 0.4–27.3 days; P = 0.050) was observed during the BVD outbreak compared to the year before the outbreak. In G2 herds, there was a not a significant increase in CCI (3.0 days; 95% CI, −1.2–7.2 days; P = 0.558). Changes in AI/P between periods were not significant in any of the herds. In G1 herds, there was an increase of 0.09 units (P > 0.05) during the outbreak, whereas in G2 herds, AI/P decreased 0.08 units (P > 0.05). Compared to milk production in the year before the BVD outbreak, there was no significant change in G1 herds throughout the study period (P > 0.05), but there were significant increases in G2 herds over the study period (P1–P2, 1.4 kg/day increase, P = 0.019; P1–P3, 2.0 kg/day increase, P = 0.007). These results indicate that BVDV infection affected reproductive performance, which is critical in maintaining dairy herd profitability.

Feasibility and accuracy of using different methods to detect pregnancy by conceptus-stimulated genes in dairy cattle

Development of new methods for early diagnosis of pregnancy can be important to increase the reproductive efficiency and profitability of dairy herds. The bovine conceptus secretes IFN-τ that stimulates the transcription of several genes in circulating immune cells and extrauterine tissues. The aims of this study were to evaluate the mRNA abundance for pregnancy predictability of a classic gene stimulated by IFN-τ (ISG15) and a novel potential pregnancy marker (LGALS3BP) in peripheral blood mononuclear cells (PBMC), total blood leukocytes (TBL) or milk leukocytes (TML), and cervical cells (CC) on d 20 after timed artificial insemination (TAI) in dairy cattle. Eighteen Holstein females (12 cows and 6 heifers) were submitted to an estrous synchronization protocol for TAI (d 0). On d 20 post-TAI, blood samples were collected from coccygeal vessels for isolation of PBMC and in Tempus Blood RNA tubes (Applied Biosystems) for TBL. Samples of CC were collected using a cytological brush, and the TML were isolated from milk samples collected before routine milking. Pregnancy diagnosis was performed on d 30 post-TAI using transrectal ultrasonography, and females were classified as pregnant (n = 8) or nonpregnant (n = 10). Total RNA was extracted and mRNA abundance of target genes (ISG15 and LGALS3BP) was quantified by reverse-transcription quantitative PCR and normalized in relation to reference genes. Data were analyzed by ANOVA using the MIXED procedure of SAS (SAS Institute Inc.). The mRNA abundance of ISG15 was greater in pregnant than in nonpregnant animals for PBMC, TBL, and CC. No difference was detected for TML based on pregnancy status. For LGALS3BP mRNA abundance, no difference was detected between pregnant and nonpregnant animals for PBMC, TBL, and TML, but a tendency for greater abundance in pregnant animals was observed for CC. The fold change for ISG15 in each pregnant cow related to the mean of nonpregnant animals was 2.73 ± 0.31, 3.40 ± 2.17, 1.64 ± 0.29, and 0.005 ± 0.002 for PBMC, CC, TBL, and TML, respectively. The fold change for LGALS3BP in each pregnant cow related to the mean of nonpregnant animals was 0.97 ± 0.38, 1.77 ± 0.39, 0.20 ± 0.08, and 0.70 ± 0.11 for PBMC, CC, TBL, and TML, respectively. The receiver operating characteristic curve analysis indicated that ISG15 abundance predicted pregnancy in PBMC (area under curve, AUC = 0.92) and CC (AUC = 0.77) but not in TBL (AUC = 0.72) or TML (AUC = 0.52). In conclusion, mRNA abundance for ISG15 in PBMC was the best predictor for pregnancy at d 20 post-TAI, whereas TBL and TML were not good predictors of pregnancy on d 20 post-TAI. The mRNA abundance of LGALS3BP was not associated with pregnancy status in any type of cell evaluated.

Factors That Optimize Reproductive Efficiency in Dairy Herds with an Emphasis on Timed Artificial Insemination Programs.

Simple SummaryReproductive efficiency is critical for profitability of dairy operations. The first part of this manuscript discusses the key physiology of dairy cows and how to practically manipulate this reproductive physiology to produce timed artificial insemination (TAI) programs with enhanced fertility. In addition, there are other critical factors that also influence reproductive efficiency of dairy herds such as genetics, management of the transition period, and body condition score changes and improve management and facilities to increase cow comfort and reduce health problems. Using optimized TAI protocols combined with enhancing cow/management factors that impact reproductive efficiency generates dairy herd programs with high reproductive efficiency, while improving health and productivity of the herds.Reproductive efficiency is closely tied to the profitability of dairy herds, and therefore successful dairy operations seek to achieve high 21-day pregnancy rates in order to reduce the calving interval and days in milk of the herd. There are various factors that impact reproductive performance, including the specific reproductive management program, body condition score loss and nutritional management, genetics of the cows, and the cow comfort provided by the facilities and management programs. To achieve high 21-day pregnancy rates, the service rate and pregnancy per artificial insemination (P/AI) should be increased. Currently, there are adjustments in timed artificial insemination (TAI) protocols and use of presynchronization programs that can increase P/AI, even to the point that fertility is higher with some TAI programs as compared with AI after standing estrus. Implementation of a systematic reproductive management program that utilizes efficient TAI programs with optimized management strategies can produce high reproductive indexes combined with healthy cows having high milk production termed “the high fertility cycle”. The scientific results that underlie these concepts are presented in this manuscript along with how these ideas can be practically implemented to improve reproductive efficiency on commercial dairy operations.

Autoregressive model for genetic evaluation of longitudinal reproductive traits in Brazilian Holstein cattle.

Reproductive efficiency is major determinant of the dairy herd profitability. Thus, reproductive traits have been widely used as selection objectives in the current dairy cattle breeding programs. We aimed to evaluate strategies to model days open (DO), calving interval (CI) and daughter pregnancy rate (DPR) in Brazilian Holstein cattle. These reproductive traits were analysed by the autoregressive (AR) model and compared with classical repeatability (REP) model using 127,280, 173,092 and 127,280 phenotypic records, respectively. The first three calving orders of cows from 1,469 Holstein herds were used here. The AR model reported lower values for Akaike Information Criteria and Mean Square Errors, as well as larger model probabilities, for all evaluated traits. Similarly, larger additive genetic and lower residual variances were estimated from AR model. Heritability and repeatability estimates were similar for both models. Heritabilities for DO, CI and DPR were 0.04, 0.07 and 0.04; and 0.05, 0.06 and 0.04 for AR and REP models, respectively. Individual EBV reliabilities estimated from AR for DO, CI and DPR were, in average, 0.29, 0.30 and 0.29 units higher than those obtained from REP model. Rank correlation between EBVs obtained from AR and REP models considering the top 10 bulls ranged from 0.72 to 0.76; and increased from 0.98 to 0.99 for the top 100 bulls. The percentage of coincidence between selected bulls from both methods increased over the number of bulls included in the top groups. Overall, the results of model-fitting criteria, genetic parameters estimates and EBV predictions were favourable to the AR model, indicating that it may be applied for genetic evaluation of longitudinal reproductive traits in Brazilian Holstein cattle.

Ketosis an Old Story Under a New Approach

Ketosis, characterized by high concentrations of ketone bodies in the blood, urine, and milk, affects a considerable number of cows immediately after calving. Although much is known about ketosis, dairy cows continue to be affected in every herd world-wide. Cows affected by ketosis are treated with palliative treatments after the disease is diagnosed. This is a very expensive approach and costs the dairy industry extra expenses, contributing to lower profitability of dairy herds. In this review article, we summarize the mainstream view on ketosis, classification of ketosis into three types, current diagnostic approaches to ketosis, and the economic impact of ketosis on dairy farms. Additionally, we discuss the most recent applications of the new ‘omics’ science of metabolomics in studying the etiopathology of ketosis as well as its contribution in identification of novel screening or diagnostic biomarkers of ketosis.

Prevalence and potential risk factors of hypocalcaemia in dairy cows during transition period at Northern Egypt

Objective: To identify the most prevalent diseases of transition period in dairy cows and to highlight on risk factors supposed to play a crucial role in the prevalence of hypocalcaemia. Design: Case-control study Animals: 179 transition dairy cows belonged to five farms. Procedures: Clinical examination and serum analyses were the key to diagnose the transition disorders in the investigated cows. Cutoff points for serum analytes (Ca, Ph, Mg, PTH, glucose, K, Na and Cl) were set. A questionnaire was constructed to identify the possible risk factors associated with hypocalcaemia on both farm level and cow level. Results: Frequency test revealed the prevalence of hypocalcaemia to be (48.04%), hypophosphatemia (40.22%), hypomagnesaemia (33.52%) hypoglycemia (29.05%), hypokalemia (58.1%), clinical ketosis (5.59%) and abomasal displacement (1.12%). Moreover, prevalence of post parturient septic metritis was (26.81%), retained placenta (23.46%) and clinical mastitis was (18.99%). Generally, hypocalcaemia was significantly associated with other concurrent diseases (P ≤ 0.05). Levels of serum PTH, glucose, K and Na were significantly related to occurrence of hypocalcaemia with p values: 0.006, 0.001, 0.019 and 0.001, respectively. Impact of diet, housing criteria and periodical health monitoring by metabolic profile test were found to affect significantly on incidence of hypocalcaemia on farm level with p value ≤ 0.008 for all. On cow level, age of cows, parity, body condition score, stage of transition period, daily milk yield and previous transition period disorders were found to have a significant effect on occurrence of hypocalcaemia at p value ≤ 0.001 for each item. Conclusion and clinical relevance: Results of the current study point toward the importance of usual monitoring of transition period disorders in dairy cows, besides identifying potential risks and consequences of hypocalcaemia in an attempt to construct control measures for them, that in-turn would increase dairy herd profitability.

The potential interaction between body condition score at calving and dietary starch content on productive and reproductive performance of early-lactating dairy cows

Improving reproductive performance is one of the most important factors affecting the profitability of dairy herds. This study investigated the effect of feeding a high starch (HS) diet and body condition score (BCS) at calving on blood metabolites, fertility and ovarian function and milk production in Holstein dairy cows. One hundred seventy-four multiparous cows were fed common close-up and early lactation diets during the first 15 days in milk (DIM). Cows were randomly assigned to 1 of 2 experimental diets from 16 until 50 DIM (n = 87 per group); normal starch (228 g/kg diet DM; NS) or HS (270 g/kg diet DM; HS) diets. Each treatment group was further subdivided based on BCS at calving as normal BCS (BCS ⩽ 3.5; normal BCS (NBCS); n = 45) or high BCS (HBCS) (BCS ⩾ 3.75; HBCS; n = 42). A significant difference was detected for increased milk production (47.24 v. 44.55 kg/day) and decreased milk fat (33.93 v. 36.33 g/kg) in cows fed HS or NS, respectively. Plasma glucose and insulin concentrations were significantly higher in cows fed the HS compared to the NS diet. Diets significantly affected DIM at first artificial insemination (AI, 79.51 ± 3.83 v. 90.40 ± 3.83 days for cows fed HS and NS diets, respectively). High BCS groups had greater milk fat content and elevated plasma nonesterified fatty acids (NEFA), β hydroxybutyrate (BHB) and bilirubin concentrations. In general, feeding higher starch diets to normal BCS cows during the first 50 DIM improved productive and reproductive performance of early-lactating dairy cows.

Prospects for predictive modeling of transition cow diseases.

Transition cow diseases can negatively impact animal welfare and reduce dairy herd profitability. Transition cow disease incidence has remained relatively stable over time despite monitoring and management efforts aimed to reduce the risk of developing diseases. Dairy cattle disease risk is monitored by assessing multiple factors, including certain biomarker test results, health records, feed intake, body condition score, and milk production. However, these factors, which are used to make herd management decisions, are often reviewed separately without considering the correlation between them. In addition, the biomarkers that are currently used for monitoring may not be representative of the complex physiological changes that occur during the transition period. Predictive modeling, which uses data to predict future or current outcomes, is a method that can be used to combine the most predictive variables and their interactions efficiently. The use of an effective predictive model with relevant predictors for transition cow diseases will result in better targeted interventions, and therefore lower disease incidence. This review will discuss predictive modeling methods and candidate variables in the context of transition cow diseases. The next step is to investigate novel biomarkers and statistical methods that are best suited for the prediction of transition cow diseases.

English

Suboptimum reproductive performance affects the overall profitability of dairy herds. In order to manage this condition, there is need to clearly understand the different forms in which it presents, as well as its possible risk factors under the Ugandan context. This review study was conducted to highlight the different forms of suboptimum reproductive performances among Ugandan dairy herds through literatures from previous studies. At the same time, underscores the coexistence of risk factors of suboptimum reproductive performance among the same dairy herds in Uganda. In Uganda, dairy cattle experienced pathological postpartum cycling patterns, delayed calving to first service intervals, long calving intervals, low pregnancy rates and high abortion rates. Inadequate nutrition, management errors and infectious genital diseases such brucellosis and bovine viral diarrhea were common in these herds. There is need to undertake studies that link the different forms of suboptimum reproductive performance and their possible risk factors. Key words: Suboptimum reproductive performance, postpartum pathological anestrous, infectious genital diseases. &nbsp

Assessment of on-farm welfare for dairy cattle in southern Spain and its effects on reproductive parameters.

In this Research Communication we analyse the animal welfare status of dairy farms located in southern Spain and test the hypothesis that monitoring of wellbeing could increase the profitability of dairy herds by improving indices of reproduction. Twenty dairy farms were visited and a total of 1650 cows were assessed using the Welfare Quality® (WQ) protocol to determine their welfare status. These farms were selected as representatives of the main types of dairy farms found in the south of Spain. No farms attained a welfare status of 'excellent', but all obtained an adequate score for most parameters. Feeding assessment showed relatively low variability among farms, whereas housing and health assessments exhibited high variability. Significant correlations were found between a number of welfare parameter pairings: between percentage of collisions and time needed to lie down; between cleanliness of water points and cleanliness of various animal parts; between farms with access to an outdoor loafing area and an inadequate body condition score and with animal cleanliness; between the frequency of animals lying partly or completely outside of the lying area and the percentage of integument alterations and finally between the presence of respiratory problems and farm hygiene parameters. Furthermore, significant correlations between welfare parameters, reproductive indices and milk production were found. The percentage of cows exhibiting an inadequate body condition score and farms where cows took longer to lie down were correlated with the calving-first insemination interval. Animals showing a higher incidence of coughing and hampered respiration presented lower heat detection rates and milk production and finally farms with dirtier animals had lower milk production. This study is the first step towards including welfare in the recording of routine data in dairy cattle farms in southern Spain.

0382 Estimation of genetic progress and profitability of dairy herds using varying proportions of in-vitro produced sexed embryos

0382 Estimation of genetic progress and profitability of dairy herds using varying proportions of in-vitro produced sexed embryos

Mutations in genes involved in oestrous cycle associated expression of oestrus

Detection of oestrus is a key determinant of profitability of dairy herds, but oestrus is increasingly difficult to observe in the modern dairy cow, with shorter duration and less intense oestrus. Concurrent with the unfavourable correlation between milk yield and fertility, oestrous detection rates have decreased to less than 50%. A number of mutations have been identified in genes associated with fertility and production traits, but, to date, no single nucleotide polymorphism (SNP) has been associated with oestrous expression. Therefore, the objective of this study was to investigate SNPs, linked to fertility, for the association with oestrous expression. Blood was collected from 205 Holstein Friesian dairy cows and genotyped at 41 loci of 18 genes chosen for their roles in the oestrous cycle and milk production. SNPs were then examined for correlations with increase in activity at oestrus, recorded via activity monitors, using generalised linear models. Physical activity increased at oestrus between two and four fold. Larger increases were associated with mutant alleles in oestrogen receptor-α and gonadotrophin releasing hormone receptor genes (P<0.05) and in the STAT5A gene (P<0.05). Smaller increases were associated with mutant alleles of the activin receptor type IIB and prolactin receptor genes (P<0.10). In conclusion, alleles in these five genes provide the opportunity for selection of animals displaying greater oestrous activity which could aid reversal of the decrease in oestrous detection and thereby contribute to sustainability of the dairy industry worldwide.