Dairy Cattle Production Systems Research Articles

An integral assessment of the impact of diet and manure management on whole-farm greenhouse gas and nitrogen emissions in dairy cattle production systems using process-based models

Feed management decisions are crucial in mitigating greenhouse gas (GHG) and nitrogen (N) emissions from ruminant farming systems. However, assessing the downstream impact of diet on emissions in dairy production systems is complex, due to the multifunctional relationships between a variety of distinct but interconnected sources such as animals, housing, manure storage, and soil. Therefore, there is a need for an integral assessment of the direct and indirect GHG and N emissions that considers the underlying processes of carbon (C), N and their drivers within the system. Here we show the relevance of using a cascade of process-based (PB) models, such as Dutch Tier 3 and (Manure)-DNDC (Denitrification-Decomposition) models, for capturing the downstream influence of diet on whole-farm emissions in two contrasting case study dairy farms: a confinement system in Germany and a pasture-based system in New Zealand. Considerable variation was found in emissions on a per hectare and per head basis, and across different farm components and categories of animals. Moreover, the confinement system had a farm C emission of 1.01 kg CO2-eq kg−1 fat and protein corrected milk (FPCM), and a farm N emission of 0.0300 kg N kg−1 FPCM. In contrast, the pasture-based system had a lower farm C and N emission averaging 0.82 kg CO2-eq kg−1 FPCM and 0.006 kg N kg−1 FPCM, respectively over the 4-year period. The results demonstrate how inputs and outputs could be made compatible and exchangeable across the PB models for quantifying dietary effects on whole-farm GHG and N emissions.

Characterization and Seasonal Dynamics of Tick Populations in Dairy Cattle Production Systems of Northwestern Colombian Amazon.

Cattle ticks are a significant health concern in tropical livestock production due to their hematophagous behavior and potential as vectors for human and animal pathogens. In this study, we investigated the tick population present in dairy cattle production, calves, and grazing areas of livestock systems in the northwestern Colombian Amazon. Identification was based on taxonomic keys and molecular markers. Phylogenetic relationships were established using mitochondrial COX1 and 16S genes. Population structure analysis was performed considering age, racial type (B. indicus vs. B. taurus), and the influence of environmental factors and the geomorphological landscape on tick population dynamics. Our findings revealed the presence of a single tick species, with a unique haplotype identified for each mitochondrial gene assessed. Phylogenetic analysis classified the found species within Clade A of the Rhipicephalus microplus complex. Ticks were more prevalent during periods of low rainfall and high temperature, and B. taurus cows exhibited the highest tick abundance. Thus, these results provide insights into the population characteristics and distribution of the tick species present in dairy cattle production systems in the northwestern part of the Colombian Amazon. This information is fundamental for developing targeted strategies based on seasonal variation and host characteristics to mitigate tick infestation severity in the region.

Modelling the effect of context-specific greenhouse gas and nitrogen emission mitigation options in key European dairy farming systems

Understanding the environmental consequences associated with dairy cattle production systems is crucial for the implementation of targeted strategies for emission reduction. However, few studies have modelled the effect of tailored emission mitigation options across key European dairy production systems. Here, we assess the single and combined effect of six emission mitigation practises on selected case studies across Europe through the Sustainable and Integrated Management System for Dairy Production model. This semi-mechanistic model accounts for the interacting flows from a whole-farm perspective simulating the environmental losses in response to different management strategies and site-specific conditions. The results show how reducing the crude protein content of the purchased fraction of the diet was an adequate strategy to reduce the greenhouse gas and nitrogen emission intensity in all systems. Furthermore, implementing an anaerobic digestion plant reduced the greenhouse gas emissions in all tested case studies while increasing the nitrogen emissions intensity, particularly when slurry was applied using broadcast. Regarding the productivity increase, contrasting effects were observed amongst the case studies modelled. Moreover, shallow slurry injection effectively mitigated the intensity of nitrogen losses from the fields due to strong reductions in ammonia volatilisation. When substituting urea with ammonium nitrate as mineral fertiliser, site-specific conditions affected the mitigation potential observed, discouraging its application on sandy-loam soils. Rigid slurry covers effectively reduced the storage-related nitrogen emissions intensity while showing a minor effect on total greenhouse gas emission intensity. In addition, our results provide novel evidence regarding the advantages of cumulative implementation of adapted mitigation options to offset the negative trade-offs of single-option applications (i.e. slurry covers or anaerobic digestion and slurry injection). Through this study, we contribute to a better understanding of the effect of emission mitigation options across dairy production systems in Europe, thus facilitating the adoption of tailored and context-specific emission reduction strategies.

Valuation of the sustainability of the dairy cattle production system in high andean areas of Colombia

The dairy cattle production system (SPGL) in the high areas of Colombia, located in the Ubaté and Chiquinquirá hydrographic basinaround the Fúquene lagoon, is considered one of the best areas to produce dairy products in the country. Many research andinvestment has been carried out in those areas to improve its competitiveness. Under this context, the objective of assessing the level ofsustainability of the SPGL was defined, from the supply and cultural ecosystem services (ES). The mixed approach methodologycollects primary information, validated with groups of experts that characterized the SPGL, and then assesses its sustainability. Thereliability and trustworthiness of the data are based on an Exploratory Factor Analysis (EFA), which refines the variables and thenperforms a Confirmatory Factor Analysis (CFA) that exceeds the adjustment levels for this type of research. The results showsignificant direct causality of the SPGL sustainability level from the supply and cultural ES. Concluding, the dairy cattle production systems of the municipalities surrounding the Fúquene lagoon presents serious environmental, social, and productive problems, and only a holistic or novel approach such as the valuation of the in Supply and Cultural Ecosystem Services helps to resolve these problems.

Fatty Acid, Carotenoid and Fat-Soluble Vitamin Composition of Multispecies Swards Grown in Ireland—Implications for a Sustainable Feed in Dairy Farming

Although traditional ryegrass pastures are still commonly used, they require intense management and input and do not perform well during the summer months. Multispecies systems have been recognised as more sustainable, needing less fertiliser and being tolerant to drought and heat. While data on monoculture system fat composition exist, information for multispecies is scarce. The present study compared the fatty acid (FA), carotenoid and fat-soluble composition of a multispecies system (consisting of perennial ryegrass, timothy, white clover, red clover, chicory and plantain) (MULTI) with two other conventional grazing systems (monoculture perennial ryegrass (PRG) and a binary mixture of perennial ryegrass and white clover (PRG+WC)) over the Irish late-summer grazing season of dairy cattle (July–September). The results showed that the three systems had similar levels of FAs (p > 0.05), with mean α-linolenic acid values of 20.00 mg/g in PRG, 18.51 mg/g in PRG+WC, and 17.90 mg/g in MULTI and mean linoleic acid values of 3.84 mg/g in PRG, 4.16 mg/g in PRG+WC, and 4.39 mg/g in MULTI. Fourfold and twofold increases in the concentrations of α-linolenic acid and linoleic acid, respectively, were observed throughout July–September. Variations in stearic acid concentrations were not significant (p > 0.05), and palmitic acid concentrations increased over time (p < 0.05). The average values of lutein (36.68 mg/kg in PRG, 31.26 mg/kg in PRG+WC, and 35.75 mg/kg in MULTI) and α-tocopherol (2.28 mg/kg in PRG, 1.49 mg/kg in PRG+WC, and 1.83 mg/kg in MULTI) were similar among the grazing systems (p > 0.05), and the average β-carotene value was 25% higher in monoculture ryegrass (140.74 mg/kg) than in the multispecies (102.51 mg/kg) (p < 0.05). Nonetheless, the levels of β-carotene found in the multispecies were still above the recommended intake required for ruminants. In conclusion, multispecies pastures could be included in dairy cattle production systems as a sustainable alternative to traditional pastures while also providing typically adequate sources of fats for animal diets.

Identification of representative dairy cattle and fodder crop production typologies at regional scale in Europe

European dairy production faces significant economic, environmental, and social sustainability challenges. Given the great diversity of dairy cattle production systems in Europe, region-specific concepts to improve environmental and socioeconomic sustainability are needed. Regionally integrated dairy cattle-crop systems emerge as a more resilient and sustainable alternative to highly specialized farming systems. Identifying different dairy cattle production typologies and their potential interactions with fodder crop production is presented as a step in transitioning to optimized agricultural systems. Currently existing typologies of integrated systems are often insufficient when characterizing structural, socioeconomic, and environmental components of farms. We fill this gap in the literature by identifying, describing, and comparing representative dairy cattle production system typologies and their interrelation with regional fodder crop production at the European regional scale. This is a necessary step to assess the scope for adapted mitigation and sustainability measures in the future. For this purpose, a multivariate statistical approach is applied. We show how different land-use practices, farm structure characteristics, socio-economic attributes, and emission intensities condition dairy production. Furthermore, the diversity of regional fodder crop production systems is demonstrated by analyzing their distribution in Europe. Together with identified typologies, varying degrees of regional specialization in milk production allow for identifying future strategies associated with the application of integrated systems in key European dairy regions. This study contributes to a better understanding of the existing milk production diversity in Europe and their relationship with regional fodder crop production. In addition, we discuss the benefits of integrated systems as a clear, viable, and resilient alternative to ongoing livestock intensification in the European context. Identifying interactions between components of integrated systems will facilitate decision-making, the design and implementation of measures to mitigate climate change, and the promotion of positive socio-economic and environmental interactions.

Water productivity of milk produced in three different dairy production systems in Southern Brazil

Water is a crucial resource to produce dairy milk and studies are required to identify opportunities for improvements in water management. This study evaluates the water productivity of milk (WPMilk) produced on 67 farms located in southern Brazil and the influence of dairy cattle production systems (pasture-based, 57 farms; semi-confined, 7 farms; confinement, 3 farms) on water productivity. Indirect and direct water flows were taken into account and the dairy milk was the output. Pasture yield was estimated based on a weighted average. Indirect water represented >98 % of water consumption for milk production on farms assessed. In the pasture-based system, the WPMilk ranged from 0.27 to 1.46 kg FPCM (Fat Protein Corrected Milk) m−3 of water; in the semi-confined system it ranged from 0.59 to 1.1 kg FPCM m−3; in the confined system, it ranged from 0.89 to 1.09 kg FPCM m−3. Results show that 20 farms in the pasture-based system presented higher WPMilk than the maximum WPMilk of farms in the semi-confined system. Comparing outcomes of farms in the confined system with pasture-based system, similar results were observed with higher WPMilk on 22 farms in the pasture-based system. Results indicate that, regardless of the type of production system, water productivity is influenced by the dairy productivity indicators of the farm, such as milk yield and feed components. The large variability in the WPMilk was expected and reflects the inherent attributes and conditions affecting this indicator, which underlines the importance of assessing it on a farm scale. Consequently, achieving high dairy productivity indicators should be encouraged in the pasture-based system due to the environmental, economic and social advantages for the farmer. Results advance the knowledge about water flows and WPMilk in different dairy cattle production systems besides defining the first benchmarks for WPMilk produced on farms in Brazil.

Harnessing the value of reproductive hormones in cattle production with considerations to animal welfare and human health.

The human population is ever increasing while the quality and quantity of natural resources used for livestock production decline. This calls for improved product efficiency and the development of improved and sustainable cattle production methods to produce higher quality products to satisfy the demands of both the modern and transient world. The goal of this review was to summarize the interactions, challenges, and opportunities in cattle production relating to their endocrine system, and how reproductive hormones and others impact economically important traits, animal welfare, and human health. A comprehensive literature search was conducted with a focus on analysis of natural hormones and the use of exogenous hormone administration for reproduction, growth, and development of beef and dairy cattle. Hormones regulate homeostasis and enhance important traits in cattle, including fertility, growth and development, health, and the production of both meat and milk products. Reproductive hormones such as testosterone, estradiol, progesterone, and related synthetics like trenbolone acetate and zeranol can be strategically utilized in both beef and dairy cattle production systems to enhance their most valuable traits, but the impact of these substances must account for the welfare of the animal as well as the health of the consumer. This scientific review provides a comprehensive analysis of the bovine endocrine system's impact on food animals and product quality which is vital for students, researchers, livestock producers, and consumers. Although important advances have been made in animal science and related technological fields, major gaps still exist in the knowledge base regarding the influence of hormones on the production and welfare of food animals as well as in the public perception of hormone use in food-producing animals. Filling these gaps through transformative and translational research will enhance both fundamental and applied animal science to feed a growing population.

Effect of dairy cattle production systems on sustaining soil organic carbon storage in grasslands of northern Spain

Effect of dairy cattle production systems on sustaining soil organic carbon storage in grasslands of northern Spain

Using rumination and activity data for early detection of anaplasmosis disease in dairy heifer calves

Bovine anaplasmosis causes considerable economic losses in dairy cattle production systems worldwide, ranging from $300 million to $900 million annually. It is commonly detected through rectal temperature, blood smear microscopy, and packed cell volume (PCV). Such methodologies are laborious, costly, and difficult to systematically implement in large-scale operations. The objectives of this study were to evaluate (1) rumination and activity data collected by Hr-Tag sensors (SCR Engineers Ltd.) in heifer calves exposed to anaplasmosis; and (2) the predictive ability of recurrent neural networks in early identification of anaplasmosis. Additionally, we aimed to investigate the effect of time series length before disease diagnosis (5, 7, 10, or 12 consecutive days) on the predictive performance of recurrent neural networks, and how early anaplasmosis disease can be detected in dairy calves (5, 3, and 1 d in advance). Twenty-three heifer calves aged 119 ± 15 (mean ± SD) d and weighing 148 ± 20 kg of body weight were challenged with 2 × 107 erythrocytes infected with UFMG1 strain (GenBank no. EU676176) isolated from Anaplasma marginale. After inoculation, animals were monitored daily by assessing PCV. The lowest PCV value (14 ± 1.8%) and the finding of rickettsia on blood smears were used as a criterion to classify an animal as sick (d 0). Rumination and activity data were collected continuously and automatically at 2-h intervals, using SCR Heatime Hr-Tag collars. Two time series were built including last sequence of -5, -7, -10, or -12 d preceding d 0 or a sequence of 5, 7, 10, or 12 d randomly selected in a window from -50 to -15 d before d 0 to ensure a sequence of days in which PCV was considered normal (32 ± 2.4%). Long short-term memory was used as a predictive approach, and a leave-one-animal-out cross-validation (LOAOCV) was used to assess prediction quality. Anaplasmosis disease reduced 34 and 11% of rumination and activity, respectively. The accuracy, sensitivity, and specificity of long short-term memory in detecting anaplasmosis ranged from 87 to 98%, 83 to 100%, and 83 to 100%, respectively, using rumination data. For activity data, the accuracy, sensitivity, and specificity varied from 70 to 98%, 61 to 100%, and 74 to 100%, respectively. Predictive performance did not improve when combining rumination and activity. The use of longer time-series did not improve the performance of models to predict anaplasmosis. The accuracy and sensitivity in predicting anaplasmosis up to 3 d before clinical diagnosis (d 0) were greater than 80%, confirming the possibility for early identification of anaplasmosis disease. These findings indicate the great potential of wearable sensors in early identification of anaplasmosis diseases. This could positively affect the profitability of dairy farmers and animal welfare.

Gastrointestinal nematodes and Fasciola hepatica in Norwegian cattle herds: a questionnaire to investigate farmers\u2019 perceptions and control strategies

BackgroundPasture management influences the prevalence and impact of the pasture parasites (PP) in cattle herds, which cause production-limiting disease worldwide. Evaluating farmer management strategies is vital when considering sustainable PP control practices. The aim of this questionnaire-based study was to describe the pasture management and control strategies regarding PP in Norwegian beef cattle (BC) and dairy cattle (DC) production systems with a focus on gastrointestinal nematodes (GIN) and Fasciola hepatica.ResultsA total of 745 responses from BC (return rate 20.5%) and 1347 responses from DC farmers (30.7%) were included. The mean total pasture time for DC was 4.2 months for first-season grazers and 4.3 months for second-season grazers and cows, while the corresponding finding in BC was 5.4 months. Home pasture was used for most of the pasture period, particularly for first-season grazer dairy heifers (81%), which were also commonly grazed on the same pasture every year (79%). For most farmers it was necessary for grazing areas to be used for cattle for more than one season (77% of BC farmers and 89% of DC farmers). However, changing the pasture during the season was common in both DC (67%) and BC (70%) herds. The majority of DC farmers (60%) stated that they did not consider that they had a problem with PP. Of the remaining 40%, few respondents could specify whether their herds had a problem due to infection by GIN (11%) or liver flukes (12%). Treatment for GIN was performed by 52% of DC and 34% of BC farmers. Diagnostic faecal samples were collected upon suspicion of parasitic disease by 5% of DC and 16% of BC farmers. Veterinarians were stated as a central source of information about parasite management and treatment.ConclusionsPotential risks for exposure to PP were identified, such as use of the same pasture every year for first-season grazers and frequent use of home pasture. The perception of problems related to PP appeared low. Regular anthelmintic treatment without concurrent use of diagnostic faecal samples seems to be common practice.

Assessment of Dairy Cattle Production, Handling and Marketing Systems of Milk and Milk Products in Bako Tibe District of West Showa Zone, Ethiopia

Assessment of Dairy Cattle Production, Handling and Marketing Systems of Milk and Milk Products in Bako Tibe District of West Showa Zone, Ethiopia

A descriptive retrospective study on mortality and involuntary culling in beef and dairy cattle production systems of Western Australia (1981-2018).

Identifying and quantifying the relative frequency of involuntary losses is an essential first step in developing fit-for-purpose herd health programmes. The objective of this study was to provide an estimate of the relative frequency of reasons for mortality among south-west Western Australian beef and dairy cattle, based on necropsy findings from a university-based veterinary pathology referral centre over 38 years. A total of 904 cattle were submitted for postmortem examination throughout the study period. Gastrointestinal, cardiopulmonary and reproductive conditions were the most common causes of mortality in cattle submitted for necropsy at Murdoch University for the period 1981-2018. In dairy cattle, the common problems were gastrointestinal (bloat, abomasal displacements) 18% (59/320), cardiovascular (traumatic reticulo-pericarditis) 9% (30/320) and respiratory conditions (pneumonia) 8% (27/320). In beef cattle, the most common conditions were gastrointestinal (bloat, rumen acidosis) 11% (39/358), reproductive (metritis) 11% (38/358), cardiovascular (traumatic reticulo-pericarditis) 7% (25/358), respiratory (pneumonia) 7% (24/358), lameness (fractures) 6%, (21/358) and hepatobiliary conditions (blue-green algae poisoning, hepatotoxicity) 6% (21/358). Selection bias and missing data were potential confounders in this study. Although necropsy investigations provide useful information on animal mortalities and avenues for future herd health programmes, there is a need to standardise data capture methods and disease definition criteria, and conduct more detailed recording of data both at the farm level and at necropsy diagnostic centres.

Evaluating Three-Pillar Sustainability Modelling Approaches for Dairy Cattle Production Systems

Milk production in Europe is facing major challenges to ensure its economic, environmental, and social sustainability. It is essential that holistic concepts are developed to ensure the future sustainability of the sector and to assist farmers and stakeholders in making knowledge-based decisions. In this study, integrated sustainability assessment by means of whole-farm modelling is presented as a valuable approach for identifying factors and mechanisms that could be used to improve the three pillars (3Ps) of sustainability in the context of an increasing awareness of economic profitability, social well-being, and environmental impacts of dairy production systems (DPS). This work aims (i) to create an evaluation framework that enables quantitative analysis of the level of integration of 3P sustainability indicators in whole-farm models and (ii) to test this method. Therefore, an evaluation framework consisting of 35 indicators distributed across the 3Ps of sustainability was used to evaluate three whole-farm models. Overall, the models integrated at least 40% of the proposed indicators. Different results were obtained for each sustainability pillar by each evaluated model. Higher scores were obtained for the environmental pillar, followed by the economic and the social pillars. In conclusion, this evaluation framework was found to be an effective tool that allows potential users to choose among whole-farm models depending on their needs. Pathways for further model development that may be used to integrate the 3P sustainability assessment of DPS in a more complete and detailed way were identified.

Dairy Production System, Constraints and Opportunities in Ethiopia

The literature review was conducted with the aim of compiling dairy cattle production system, main constraints and opportunities in Ethiopia. Based on their locations, there are three milk production systems; namely rural, peri-urban and urban milk production systems. Ethiopia has potential for dairy cattle production. Though Ethiopia has large dairy cattle population and favorable climatic conditions, self-sufficiency in milk production is low. The main constraints that affect milk production capacity of dairy cattle in Ethiopia includes feed shortage in terms of quality and quantity, land shortage for farming of improved forage, insufficient veterinary services, diseases, absence of improved breed, poor artificial insemination service, poor management of animals and lack of market-oriented production. So that, it is very important to introduce improved forage, increase AI utilization efficiency, and improve management practices and veterinary services. The finding of different authors conducted in different parts of the country indicated that the existence of large population of milk cows and diverse dairy animal’s genetic resources, fast growing population, change in living standard and income growth of people, rabid urbanization, growing demand and indigenous knowledge in the preservation of milk and milk products, availability of trained manpower, existence of research institutions and technologies, existence of service providers such as veterinary health and artificial insemination centers, development of infrastructural sector like road access, water supply, communication activities were the key opportunities to dairy production. Generally, even though dairy sector constrained by many factors there are still ample opportunities for dairying. Therefore; coordinated activities must be done by respective bodies to minimize the identified constraints which hamper dairy development. Keywords: Constraints, Dairy cattle, Ethiopia, Production system. DOI: 10.7176/JBAH/11-10-03 Publication date: May 31 st 2021

Dairy Production System in Lowland Areas of Gambella, Ethiopia

The objective of this study was to identify and assessing the different types of dairy cattle production systems, management practices, marketing and its constraints that exist in the Itang district. A total of 120 households were selected from four kebeles using simple random selection method after identifying the dairy owner from the community using purposive sampling method. Descriptive statistics, one way ANOVA, chi-square and ranking were analysed using SPSS statistical package. The majority of producers (63.3%) in the pastoral system produced milk for home consumption, while the majority of mixed crop–livestock producers (40.0%) produced milk for selling purpose. In the mixed crop–livestock system, mostly cereal crop based grazing is the major feed resource but these feed resources were managed in a traditional ways. Almost all respondents in the mixed crop-livestock system (96.5%) and pastoral system (100%) did not supplement their lactating cow with additional feeds. More than 400 cattle herds from 2-3 villages graze together between 10 am to 4 pm daily. The majority of households (68.3%) in the mixed crop–livestock system kept their cattle separately in barn, while other 8.3% of the households did the same in pastoral areas. Constraints for dairy development in the area are diseased condition, thieves, lack of veterinary services, lack of credit, feed and feeding and poor extension services. It can be concluded dairy cattle production in the mixed crop-livestock system was economical and based on mixed agriculture (crops plus livestock) with some fishing activity, mining and wild food collection.

Genome-wide association study of economically important traits in Charolais and Limousin beef cows

Genomic selection has proven effective for advancing genetic gain for key profit traits in dairy cattle production systems. However, its impact to-date on genetic improvement programs for beef cattle has been less effective. Despite this, the technology is thought to be particularly useful for low heritability traits such as those associated with reproductive efficiency. The objective of this study was to identify genetic variants associated with key determinants of reproductive and overall productive efficiency in beef cows. The analysis employed a large dataset derived from the national genetic evaluation program in Ireland for two of the most predominant beef breeds, viz. Charolais (n = 5 244 cows) and Limousin (n = 7 304 cows). Single nucleotide polymorphisms (SNPs) were identified as being statistically significantly associated (adj. P < 0.05) with both reproductive and productive traits for both breed types. However, there was little across breed commonality, with only two SNPs (rs110240246 and rs110344317; adj. P < 0.05) located within the genomic regions of the LCORL and MSTN genes respectively, identified in both Charolais and Limousin populations, associated with traits including carcass weight, cull-cow weight and live-weight. Significant SNPs within the MSTN gene were also associated with both reproduction and production related traits within each breed. Finally, traits including calving difficulty, calf mortality and calving interval were associated with SNPs within genomic regions comprising genes involved in cellular growth and lipid metabolism. Genetic variants identified as associated with both important reproductive efficiency and production related traits from this study warrant further analyses for their potential incorporation into breeding programmes to support the sustainability of beef cattle production.

16 Opportunities and challenges from deep-phenotyping of dairy cattle

Abstract Genetic selection has been a very successful tool for the long-term improvement of livestock populations, and the rapid adoption of genomic selection over the last decade has doubled the rate of gain in some populations. However, the full expression of genetic potential requires that animals are placed in environments that support such performance. Increasingly complex dairy cattle production systems require that all aspects of animal performance are measured across individuals’ lifetimes. Selection emphasis is shifting away from traits related to animal productivity towards those related to efficient resource utilization and increased animal welfare. However, phenotypes for many of these new traits are difficult or expensive to measure, or both. This is driving interest in sensor-based systems that provide continuous measurements of the farm environment, individual animal performance, and detailed milk composition. The goal of phenomics is to provide information for making decisions related to on-farm management, as well as genetic improvement. However, many challenges accompany these new technologies, including a lack of standardization, the need for high-speed Internet connections, increased computational requirements, and training to integrate these tools with more traditional management tools. There also is a lack of translational research on the use of these data for real-time precision management. We will identify opportunities and challenges associated with phenomics and discuss on-farm applications of these new tools.

Will dairy cattle production in West Africa be challenged by heat stress in the future?

This study focuses on heat stress conditions for dairy cattle production in West Africa under current and future climatic conditions. After testing the accuracy of the dynamically downscaled climate datasets for simulating the historical daily maximum temperature (Tmax) and relative humidity (RH) in West Africa for 50 meteorological stations, we used the dataset for calculating the temperature-humidity index (THI), i.e., an index indicating heat stress for dairy cattle on a daily scale. Calculations were made for the historical period (1981–2010) using the ERA-Interim reanalysis dataset, and for two future periods (2021–2050 and 2071–2100) using climate predictions of the GFDL-ESM2M, HadGEM2-ES, and MPI-ESM-MR Global Circulation Models (GCMs) under the RCP4.5 emission scenario. Here, we show that during the period from 1981 to 2010 for > 1/5 of the region of West Africa, the frequency of severe/danger heat events per year, i.e., events that result in significant decreases in productive and reproductive performances, increased from 11 to 29–38 days (significant at 95% confidence level). Most obvious changes were observed for the eastern and southeastern parts. Under future climate conditions periods with severe/danger heat stress events will increase further as compared with the historical period by 5–22% depending on the GCM used. Moreover, the average length of periods with severe/danger heat stress is expected to increase from ~ 3 days in the historical period to ~ 4–7 days by 2021–2050 and even to up to 10 days by 2071–2100. Based on the average results of three GCMs, by 2071–2100, around 22% of dairy cattle population currently living in this area is expected to experience around 70 days more of severe/danger heat stress (compare with the historical period), especially in the southern half of West Africa. The result is alarming, as it shows that dairy production systems in West Africa are jeopardized at large scale by climate change and that depending on the GCM used, milk production might decrease by 200–400 kg/year by 2071–2100 in around 1, 7, or 11%. Our study calls for the development of improved dairy cattle production systems with higher adaptive capacity in order to deal with expected future heat stress conditions.

The future of phenomics in dairy cattle breeding.

Increasingly complex dairy cattle production systems require that all aspects of animal performance are measured across individuals' lifetimes. Selection emphasis is shifting away from traits related to animal productivity toward those related to effcient resource utilization and improved health and welfare/ resilience. The goal of phenomics is to provide information for making decisions related to on-farm management, as well as genetic improvement.