Dual-purpose Cattle Research Articles

Risk factors associated with leptospirosis in dual-purpose cattle based on the One Health approach in the department of Huila, Colombia

Leptospirosis significantly impacts beef and dairy cattle production, particularly in tropical regions, although it remains a disease of global relevance. This zoonotic disease primarily causes abortions during the final third of gestation. The present study aimed to analyze the risk factors associated with leptospirosis in the southern Andean region of Colombia. To this end, 360 cattle were sampled across 24 municipalities within the department of Huila. A seroprevalence of 49.2% was determined using enzyme-linked immunosorbent assays (ELISA). These results were subsequently correlated with various variables obtained through epidemiological surveys. The findings revealed that the primary risk factors for leptospirosis were linked to inadequate livestock management practices. These included improper methods of food storage, failure to implement quarantine protocols for infected animals, the introduction of new fattening cattle into the herd without proper precautions, infrequent weighing of animals, poor storage management of veterinary medications, lack of segregation of sick animals, insufficient estrus detection practices, inadequate hand hygiene when interacting with the herd, and the use of unclean instruments during routine procedures. Conversely, the presence of well-defined internal pathways and the separation of poultry production from cattle operations were identified as protective factors. Understanding these risk factors is critical from a One Health perspective, as it facilitates the implementation of preventive measures aimed at safeguarding both animal and human health.

Transcriptomic and Metabolomics Joint Analyses Reveal the Influence of Gene and Metabolite Expression in Blood on the Lactation Performance of Dual-Purpose Cattle (Bos taurus).

Blood is an important component for maintaining animal lives and synthesizing sugars, lipids, and proteins in organs. Revealing the relationship between genes and metabolite expression and milk somatic cell count (SCC), milk fat percentage, milk protein percentage, and lactose percentage in blood is helpful for understanding the molecular regulation mechanism of milk formation. Therefore, we separated the buffy coat and plasma from the blood of Xinjiang Brown cattle (XJBC) and Chinese Simmental cattle (CSC), which exhibit high and low SCC/milk fat percentage/milk protein percentage/lactose percentages, respectively. The expression of genes in blood and the metabolites in plasma was detected via RNA-Seq and LC-MS/MS, respectively. Based on the weighted gene coexpression network analysis (WGCNA) and functional enrichment analysis of differentially expressed genes (DEGs), we further found that the expression of genes in the blood mainly affected the SCC and milk fat percentage. Immune or inflammatory-response-related pathways were involved in the regulation of SCC, milk fat percentage, milk protein percentage, and lactose percentage. The joint analysis of the metabolome and transcriptome further indicated that, in blood, the metabolism pathways of purine, glutathione, glycerophospholipid, glycine, arginine, and proline are also associated with SCC, while lipid metabolism and amino-acid-related metabolism pathways are associated with milk fat percentage and milk protein percentage, respectively. Finally, related SCC, milk fat percentage, and milk protein percentage DEGs and DEMs were mainly identified in the blood.

Win-win or lose-win? Economic-climatic synergies and trade-offs in dual-purpose cattle systems

CONTEXTResearchers have identified numerous strategies to improve economic performance and reduce greenhouse gas (GHG) emission intensity in combined milk and beef production on dairy farms. However, there remains a need to better understand how the effectiveness of these strategies varies under different operational conditions. OBJECTIVEThis study aims to examine how the economic and GHG emission intensity mitigation effectiveness of increased milk yield, extended longevity of dairy cows, reduced age at first calving, and intensified beef production from bulls depend on operational conditions in dual purpose cattle systems. METHODWe present a quantitative framework to (1) economically optimize production at farm level under various constraints and (2) calculate corresponding GHG emissions. The framework is tailored for Norwegian dual-purpose cattle systems and used to assess the economic and GHG emission intensity mitigation effects of incremental adjustments in relevant decisions. RESULTS AND CONCLUSIONSThe results show that increased milk yield, extended productive life of dairy cows, reduced age at first calving, and lower slaughter age of bulls can lead to economic and climatic win-wins in terms of higher gross margins and reduced emissions per kg of protein produced. However, they may also result in lose-win and win-lose outcomes depending on the operational conditions. All four measures free up roughage production capacity, which, if used to maintain/increase milk and/or beef production, typically results in economic gains. However, if e.g., the available milk quota or space prevent this, economic losses may occur. The climate impact also depends on how the freed-up capacity is used: if it boosts production, the effects vary based on the scale and type of increase and the farm's initial setup, while unused capacity leads to reduced emission intensity. Conflicts typically arise when: 1) the extra capacity increases less climate-friendly production, raising emission intensity despite economic gains, or 2) extra capacity cannot be used, causing economic losses despite climate benefits. Our results also show that what can be labeled a win in climate terms, and to what extent, depends on the selected target metric(s). SIGNIFICANCEGovernments and societies strive to balance food production with environmental goals. In this context, it is essential to identify farm-level economic and climatic win-win and lose-win scenarios, not only for farmers but also for policymakers and the broader society. This study could inform decision-making and policy development, potentially enhancing economic and climatic performance in combined milk and meat production.

Genetic Evaluation of Monthly Test-Day Milk Yields of Jersey Crossbred Cattle Under Farmers' Production System in Tamil Nadu, India.

Tamil Nadu, a state in southern India, is bereft of any native dairy or dual-purpose cattle breeds, and the state depends chiefly on crossbred cattle for milk production. Jersey crossbred cattle account for 90% of the state's milk production. This genetic evaluation study aimed to assess milk production traits, including test-day milk yields (TDMYs), total lactation milk yield (TMY), and 305-day milk yield (305MY), in these cattle reared under farmers' conditions. Data on monthly TDMYs (TDMY1 to TDMY10) of Jersey crossbred cows (n = 75,627) reared by the farmers over 11 years (2012-2022) were collected for evaluation. The influence of non-genetic factors viz., location (agroclimatic zones), period and season of calving, and parity on TDMYs, TMY and 305MY were assessed, and the variance and covariance components for genetic parameters (heritability and genetic correlation) of the traits were estimated by the method of restricted maximum likelihood (REML) under a multivariate animal model and by a random regression model (RRM). The overall means of various TDMYs ranged from 4.98 (TDMY10) to 9.95 kg (TDMY2), and for TMY and 305MY, the means were 2480.33 and 2393.71 kg, respectively. The heritabilities estimated by the multivariate animal model for TDMYs were moderate and ranged from 0.26 ± 0.02 to 0.37 ± 0.02 and the estimates were less variable throughout lactation, while the estimates obtained by RRM were medium to high and ranged between 0.29 ± 0.01 and 0.67 ± 0.02 for milk yield on day 5 to 305 (DIM 5-DIM 305). The heritabilities estimated for TMY and 305MY were 0.43 ± 0.02 and 0.43 ± 0.02, respectively. The estimates of heritability for mid-lactation yields were comparatively less than those at the beginning and the end of lactation. The moderate to high estimates of heritabilities for TDMYs, TMY, and 305MY obtained in the present study offer ample scope for improving milk production through selective breeding. Genetic correlations between TDMYs estimated by the multivariate animal model were positive and high, with a range between 0.75 ± 0.03 and 0.99 ± 0.00. Considerably higher estimates (0.98-0.99) were observed between adjacent TDMYs showing strong genetic associations. By RRM, genetic correlations estimated between DIMs were positive (except for DIM 5 with DIM 125 to DIM 185 and DIM 125 with DIM 305), and the magnitude of genetic correlation decreased with an increase in the interval between the DIMs. The high genetic correlation observed between the TDMYs (in the early stage of lactation) and total lactation milk yield suggested that these test-day yields could be used favorably for the early selection of cows for milk production, which facilitates reduction in the generation interval and consequently increases the annual genetic gain for the milk production traits.

Effect of the addition of IGF-1 during in vitro culture on the embryonic development speed from different crossbreed bovine embryos.

Supplementation with insulin-like growth factor type 1 (IGF-1) during in vitro culture of bovine embryos has yielded mixed results, likely due to genetic variability among embryos. This work aimed to evaluate the effect of IGF-1 at two concentrations on the development speed embryos from primary F1 crossbreeds used in dual-purpose cattle farming in the Colombian low tropics. Specifically, we investigated the influence of IGF-1 and embryo breed on the blastocyst formation rate. Oocytes were sourced from non-pregnant cows: Bos taurus indicus (20 Brahman and 14 Gyr) and Bos taurus taurus (12 Holstein and 28 Romosinuano). Oocytes were fertilized with semen from specific bulls (Recoil for Holstein, Gabinete for Gyr, and UBER POI 1490 for Brahman). The resulting embryos from each crossbreed group were randomly distributed in three different cultured media with 50 ng/mL IGF-1, 100 ng/mL IGF-1, or no IGF-1 (control) for 7 days. Results showed that 50 ng/mL IGF-1 significantly increased embryo production by day 6 (25.9%±14.56%) compared to control (20.5%±11.84%) and 100 ng/mL IGF-1 (23.0%±9.54%) (p < 0.05). By day 7, both 50 ng/mL (42.6%±26.55%) and 100 ng/mL (49.7%±21.98%) IGF-1 groups exhibited significantly higher production rates compared to the control group (p < 0.001). The embryo breed also influenced development, with Gyr-Holstein (GxH) crossbreeds showing the highest production rates (p < 0.001). In conclusion, IGF-1 supplementation enhances in vitro embryo production, with the effect influenced by both breed and IGF-1 concentration. These findings suggest that breed-specific optimization of IGF-1 conditions is necessary to maximize embryonic development outcomes.

Short communication: Do veterinary diagnoses coming from electronic recording system of veterinary treatments have the potential to be used for breeding in small populations? The case of the dual-purpose Alpine Grey cattle breed

In cattle breeding, emphasis has historically been placed on productive traits, so-called primary traits, while health and fitness traits have been overlooked due to their low heritability and partly negative genetic correlations with productivity. In addition, the recording of phenotypes caused problems due to a lack of high-quality information and / or high costs of recording. This oversight has additionally led to increased incidences of fertility issues and health problems in cattle populations, resulting in economic losses and consumer concerns regarding animal welfare and food safety. This study investigates the potential use of veterinary diagnoses, collected via the Italian electronic recording system of veterinary treatments, for breeding decisions in the local dual-purpose Alpine Grey cattle breed for which the consideration of functional traits in breeding has also become imperative over the last years. The dataset comprised 97 821 records spanning from 2021 to 2023, representing 8 273 individuals and 18 110 lactations of the Alpine Grey breed. Each record documented the administration of treatments for mammary, respiratory, and urogenital pathologies. After data editing and model development, heritability estimates were obtained for each pathology using univariate linear animal models and gibbs sampling algorithms. Results indicate that mammary pathologies affected the highest number of cows (11%), followed by respiratory (4%) and urogenital (5%) pathologies. Heritability estimates ranged from 0.01 to 0.04 across all traits, confirming generally low heritability values. Respiratory pathologies exhibited the highest heritability (0.04; sd 0.04), followed by mammary (0.03; sd 0.01) and urogenital (0.01; sd 0.01) pathologies. This study, although preliminary, provides valuable insights into the health status of local dual-purpose Alpine Grey cattle and highlights the potential of considering veterinary diagnoses for improving animal health and welfare in dairy cattle breeding. However, the low heritability of these traits, which is consistent with literature data, clearly shows the current limitations of using them for breeding. Further, the diagnostic key of the Italian electronic recording system of veterinary treatments should be specified for the use of health data for breeding purposes, as it is formulated in too general manner in its current form. Nevertheless, their significance for animal welfare and economic sustainability underlines the need for their consideration in dairy cattle breeding. Therefore, further research with larger sample sizes and consideration of additional indicators, such as somatic cell counts, is recommended to enhance the accuracy of genetic evaluations and improve breeding strategies for sustainable cattle production.

Effect of management system and dietary seasonal variability on environmental efficiency and human net food supply of mountain dairy farming systems

Although mountain dairy cattle farming systems are pivotal for the economy, as well as for social and environmental aspects. They significantly contribute to the rural development which is currently strongly prioritized in the common EU agricultural policy, at the same time they are also increasingly criticized for having relatively high environmental impacts per kg of product, such as greenhouse gas emissions. Consequently, the aim of this study was to assess and compare the environmental efficiency of 2 common alpine dairy farming systems, with focus on the effects of grazing, considering the seasonal variability in feeding at individual cow level and farm management over a 3-year period. This study focuses on alpine farming systems but can be considered to represent well other topographically disadvantaged mountain areas. An intensively managed and globally dominating production system (high-input), aiming at high milk yield through relatively intensive feeding and the use of the high-yielding dual-purpose Simmental cattle, permanently confined in stables, was compared with a forage-based production system (low-input), based on seasonal grazing and the use of the autochthonous dual-purpose breed Tyrolean Grey. For the present analysis, a data set with information on feed intake and diet composition as well as animal productivity at individual cow level, and farm management data based on multiyear data recording was used. Four impact categories were quantified for 3 consecutive years: Global Warming Potential (GWP100), Acidification Potential (AP), Marine Eutrophication Potential (MEP), and Land Use (LU, m2yr and Pt, with the latter additionally considering the Soil Quality Index). Besides being attributed to 1 kg of fat and protein corrected milk (FPCM), these impact categories were also related to 1 m2 of on-farm area. Due to limited agronomic options beyond forage production and pasture use in alpine regions, net provision of protein was calculated for both farming systems to assess food supply and quantify the respective food-feed competition. Overall, the low-input farming system had greater environmental efficiency in terms of MEP per kg FPCM, as well as MEP and AP per m2 than the high-input system. LU was found to be consistently higher for the high-input than for the low-input system, the GWP100 per kg of FPCM was lower for the high-input system. Additionally, pasture access had a significant effect on the reduction of environmental impacts. Lastly, the net protein provision was slightly negative for the high-input system and marginally positive for the low-input system, indicating a lower food-feed competition for the latter. Future studies should also address the social and economic aspects of the farming systems, to offer a comprehensive overview of the 3 key factors necessary for achieving more sustainable farming systems, particularly in disadvantaged marginal regions such as mountain areas.

INDICADORES DE SALUD EN BOVINOS DE UNIDADES DE PRODUCCIÓN DOBLE PROPÓSITO EN TRÓPICO SECO

&lt;p&gt;&lt;strong&gt;Background:&lt;/strong&gt; Beef ranks third in consumption in the Mexican market, where the diversity in supply sources and management systems used in production units is notable. This diversity is reflected in the health and welfare conditions of cattle. &lt;strong&gt;Objective:&lt;/strong&gt; To evaluate health indicators of dual-purpose cattle in Michoacán, Mexico, aiming to promote quality in the meat industry. &lt;strong&gt;Methodology:&lt;/strong&gt; Data were collected using the protocol adapted from UC Davis Cow-Calf Health and Handling. Bivariate and multivariate statistical techniques (principal component analysis and cluster analysis) were applied to analyze the data. &lt;strong&gt;Results:&lt;/strong&gt; Six factors explain the cattle's current and past health conditions. From these, three groups of cattle were obtained with statistically significant differences in eight key indicators. Group 1 (G1) was characterized by good body condition and favorable past health status. Group 2 (G2) showed recent health problems, skin lesions, wildlife attacks, and parasitosis. Group 3 (G3) presented moderate conditions regarding past and recent health. &lt;strong&gt;Implications:&lt;/strong&gt; This study provides a foundation for designing tools to enhance livestock living conditions by identifying and addressing individuals with poor health and welfare. These actions benefit livestock and directly improve the quality of meat derived from them. &lt;strong&gt;Conclusions:&lt;/strong&gt; Group 2 (G2) was identified as having the greatest health problems, while G3 showed intermediate conditions and G1 grouped cattle with better health indicators. These findings underscore the importance of implementing improved animal health and welfare practices in production units to enhance the quality of meat produced.&lt;/p&gt;

PSXII-10 Post-weaning energy balance in dual-purpose replacement heifers (Giroland-Brown Swiss cross) confined-raised and grazing-raised before and after rainy season in tropical systems livestock

Abstract Common management of dual-purpose (Giroland-Brown Swiss cross) cattle in the Mexican Tropical region is to rear heifer replacement post-weaning in group pens. It is assumed that placing post-weaning heifers in group pens has more access to higher energy reserves due to the reduced foraging behavior. This study compared β-hydroxy-butyrate (BHB), body condition score (BCS), and average daily gain (ADG) in the post-weaning barn-raised and grazing-raised calves. Giroland-Brown Swiss cross (n = 8) were divided into 2 groups: confined-group (CG; n = 4) and grazing-group (GG; n = 4) for 4 mo (June to September). Both groups had ad libitum access to the same pasture (star grass; Cynodon plectostachyus) containing 6.5 % and 12.4 % crude protein (CP) during 2 regional seasons (drought and rainy season). Commercial concentrate was offered daily (0.5 kg; 17.5 % CP and 1 881 Mcal/kg net energy) at 1000 h. CG bunk feeders were refilled with pasture when empty during the day and mineral salts and water were provided at libitum to both groups. BHB was estimated monthly using a test strip (Freestyle Optium Neo, Witney UK). Additionally, BCS and ADG were estimated twice per month. An analysis of variance (ANOVA) model with a factorial design was implemented to assess BHB, BCS, and ADG as dependent variables and group treatment (GG and CG), month (4 levels), and season (drought and rainy) as independent variables. BHB values were not significant in the 2 treatment groups (GG: 300 ± 40 and CG: 230 ± 20 µmol/L; P &amp;gt; 0.05). The ADG (LS Means ± SEM) did not differ between treatment groups during drought season (GG: 419 ± 115 g compared with CG 310 ± 15 g; P &amp;gt; 0.05). Nevertheless, the ADG was significantly different between treatment groups during the rainy season (GG 790 ± 131 g compared with CG - 110 ± 63 g; P &amp;lt; 0.05). In addition, BCS was significantly different at the end of the experiment among treatment groups (GG: 3.13 ± 0.22 compared with CG: 2.6 ± 0.19). Our conclusion is that both management (grazing and confined) were equal to rear calves after weaning during the drought season. However, grazing the calves performed better (&amp;gt; ADG, and BCS) than confined management during the rainy season.

Genome-wide association studies for milk production traits in two autochthonous Aosta cattle breeds

Genome-wide association studies (GWASs) are used to identify quantitative trait loci for phenotypic traits of interest. The use of multilocus mixed models allows to correct for population stratification and account for long-range linkage disequilibrium. In this study, GWASs were conducted to identify the genetic bases of milk production (milk yield, protein and fat composition, and yield) in two autochthonous dual-purpose cattle breeds from the Aosta Valley. Using either the breeding values or the deregressed proofs, common significative single nucleotide polymorphisms have been identified for milk yield, protein percentage, and fat percentage. Two major quantitative trait loci regions have been identified on the chromosomes 5 and 14 for the fat percentage, harbouring the MGST1, CYHR1, VPS28, and CPSF1 genes. For the protein percentage, a candidate region has been identified on BTA 6; in this region, the CSN1S1, CSN2, HSTN, CSN3, and RUFY3 genes are annotated. Most of the identified genes have already been associated with milk composition in other studies on cosmopolitan and local cattle. These results show that the genes involved in milk composition quantitative traits in the Aosta cattle are common also in other cattle breeds and they can be further investigated with the use of whole genome sequencing data.

Genomic responses to climatic challenges in beef cattle: A review.

Climate change is a major concern for the near future and for livestock breeding. Cattle breeding, due to its greenhouse gas emissions, is one of the most implicated industries. Consequently, the main future goals are to breed animals resilient to climate change, with the aim of lowering the livestock impact on the environment and selecting animals that will be able to resist different, unsuitable, and changing climates. The aim of this literature review is to compare the most recent studies on the response and adaptation of beef cattle breeds to extreme environments, in terms of genes and pathways involved. Beef breeding is just starting to implement genomics in its selection plans, and shedding light on the genomic responses to extreme climates could speed up and simplify the adaptation of these breeds to climate change. This review discusses the genes involved in climatic stress responses, including those related to extremely cold climates, in beef and dual-purpose cattle breeds. Genes were associated with productive traits, coat and skin structure and development, thermotolerance, cellular physiology and DNA repair mechanisms, immune system, and fertility traits. The knowledge of genes and pathways involved in climate resilience should be taken into consideration for further selection in beef cattle breeding and could promote the valorization of local breeds adapted to extreme environmental conditions. The use of local or resilient breeds could enhance the environmental and social sustainability, animal welfare, and production, compared with the introduction of cosmopolitan breeds with uncertain adaptation in uncontrolled environmental areas.

An Assessment of Sustainability of Dual-Purpose, Dairy and Beef Cattle Production Systems in the Cundinamarca Department (Colombia) Using the MESMIS Framework

An Assessment of Sustainability of Dual-Purpose, Dairy and Beef Cattle Production Systems in the Cundinamarca Department (Colombia) Using the MESMIS Framework

Analyzing Runs of Homozygosity Reveals Patterns of Selection in German Brown Cattle.

An increasing trend in ancestral and classical inbreeding coefficients as well as inbreeding depression for longevity were found in the German Brown population. In addition, the proportion of US Brown Swiss genes is steadily increasing in German Browns. Therefore, the aim of the present study was to analyze the presence and genomic localization of runs of homozygosity (ROH) in order to evaluate their associations with the proportion of US Brown Swiss genes and survival rates of cows to higher lactations. Genotype data were sampled in 2364 German Browns from 258 herds. The final data set included 49,693 autosomal SNPs. We identified on average 35.996 ± 7.498 ROH per individual with a mean length of 8.323 ± 1.181 Mb. The genomic inbreeding coefficient FROH was 0.122 ± 0.032 and it decreased to 0.074, 0.031 and 0.006, when genomic homozygous segments > 8 Mb (FROH>8), >16 Mb (FROH>16) and >32 Mb (FROH>32) were considered. New inbreeding showed the highest correlation with FROH>32, whereas ancestral inbreeding coefficients had the lowest correlations with FROH>32. The correlation between the classical inbreeding coefficient and FROH was 0.572. We found significantly lower FROH, FROH>4, FROH>8 and FIS for US Brown Swiss proportions <60% compared to >80%. Cows surviving to the 2nd, 4th, 6th, 8th, and 10th lactation had lower genomic inbreeding for FROH and up to FROH>32, which was due to a lower number of ROH and a shorter average length of ROH. The strongest ROH island and consensus ROH shared by 50% of the animals was found on BTA 6 at 85-88 Mb. The genes located in this genomic region were associated with longevity (NPFFR2 and ADAMTS3), udder health and morphology (SLC4A4, NPFFR2, GC and RASSF6), milk production, milk protein percentage, coagulation properties of milk and milking speed (CSN3). On BTA 2, a ROH island was detected only in animals with <60% US Brown Swiss genes. Genes within this region are predominantly important for dual-purpose cattle breeds including Original Browns. For cows reaching more than 9 lactations, an exclusive ROH island was identified on BTA 7 with genes assumed to be associated with longevity. The analysis indicated that genomic homozygous regions important for Original Browns are still present and also ROH containing genes affecting longevity may have been identified. The breeding of German Browns should prevent any further increase in genomic inbreeding and run a breeding program with balanced weights on production, robustness and longevity.

Comparative Study of Bacterial Microbiota Differences in the Rumen and Feces of Xinjiang Brown and Holstein Cattle

Xinjiang Brown cattle are a unique and widely distributed breed of dual-purpose cattle in the Xinjiang area of China, whose milk production performance differs from Holstein cattle. It has been known that variations in bacterial species of the gastrointestinal tract influence milk protein, fat, and lactose synthesis. However, the microbiota differences between Xinjiang Brown and Holstein cattle are less known. This study aims to compare the bacterial community composition of the rumen and feces of these two cattle breeds under the same dietary and management conditions. The 16s rRNA sequencing data and milk production of 18 Xinjiang Brown cows and 20 Holstein cows on the same farm were obtained for analysis. The results confirmed differences in milk production between Xinjiang Brown and Holstein cattle. Microbiota with different relative abundance between these two cattle breeds were identified, and their biological functions might be related to milk synthesis. This study increases the understanding of the differences in microbiota between Xinjiang Brown and Holstein cattle and might provide helpful information for microbiota composition optimization of these dairy cattle.

Genetic legacy and adaptive signatures: investigating the history, diversity, and selection signatures in Rendena cattle resilient to eighteenth century rinderpest epidemics

BackgroundRendena is a dual-purpose cattle breed, which is primarily found in the Italian Alps and the eastern areas of the Po valley, and recognized for its longevity, fertility, disease resistance and adaptability to steep Alpine pastures. It is categorized as 'vulnerable to extinction' with only 6057 registered animals in 2022, yet no comprehensive analyses of its molecular diversity have been performed to date. The aim of this study was to analyse the origin, genetic diversity, and genomic signatures of selection in Rendena cattle using data from samples collected in 2000 and 2018, and shed light on the breed's evolution and conservation needs.ResultsGenetic analysis revealed that the Rendena breed shares genetic components with various Alpine and Po valley breeds, with a marked genetic proximity to the Original Braunvieh breed, reflecting historical restocking efforts across the region. The breed shows signatures of selection related to both milk and meat production, environmental adaptation and immune response, the latter being possibly the result of multiple rinderpest epidemics that swept across the Alps in the eighteenth century. An analysis of the Rendena cattle population spanning 18 years showed an increase in the mean level of inbreeding over time, which is confirmed by the mean number of runs of homozygosity per individual, which was larger in the 2018 sample.ConclusionsThe Rendena breed, while sharing a common origin with Brown Swiss, has developed distinct traits that enable it to thrive in the Alpine environment and make it highly valued by local farmers. Preserving these adaptive features is essential, not only for maintaining genetic diversity and enhancing the ability of this traditional animal husbandry to adapt to changing environments, but also for guaranteeing the resilience and sustainability of both this livestock system and the livelihoods within the Rendena valley.

The effect of first-lactation calving season, milk production, and morphology on the survival of Simmental cows

Longevity in dairy and dual-purpose cattle is a complex trait which depends on many individual and managerial factors. The purpose of the present study was to investigate the survival (SURV) rate of Italian Simmental dual-purpose cows across different parities. Data of this study referred to 2 173 primiparous cows under official milk recording that calved between 2002 and 2020. Only cows linearly classified for type traits, including muscularity (MU) and body condition score (BCS) were kept. Survival analysis was carried out, through the Cox regression model, for different pairwise combinations of classes of milk productivity MU, BCS, and calving season. Herd-year of first calving was also considered in the model. SURV (0 = culled; 1 = survived) at each lactation up to the 6th were the dependent variables, so that, for example, SURV2 equal to 1 was attributed to cows that entered the 2nd lactation. Survival rates were 98, 71, 63, 56, and 53% for 2nd, 3rd, 4th, 5th, and 6th lactation, respectively. Results revealed that SURV2 was not dependent on milk yield, while in subsequent parities, low-producing cows were characterized by higher SURV compared to high-producing ones. Additionally, cows starting the lactation in autumn survived less (47.38%) than those starting in spring (53.49%), suggesting that facing the late gestation phase in summer could increase the culling risk. The present study indicates that SURV in Italian Simmental cows is influenced by various factors in addition to milk productivity. However, it is important to consider that in this study all first-calving cows culled before the linear evaluation - carried out between mid- and late lactation in this breed - were not accounted for. Finding can be transferred to other dual-purpose breeds, where the cows’ body conformation and muscle development - i.e. meat-related features - are often considered as important as milk performance by farmers undertaking culling decisions.

Assessment of runs of homozygosity, heterozygosity-rich regions and genomic inbreeding estimates in a subpopulation of Guzerá (Bos indicus) dual-purpose cattle.

For decades, inbreeding in cattle has been evaluated using pedigree information. Nowadays, inbreeding coefficients can be obtained using genomic information such as runs of homozygosity (ROH). The aims of this study were to quantify ROH and heterozygosity-rich regions (HRR) in a subpopulation of Guzerá dual-purpose cattle, to examine ROH and HRR islands, and to compare inbreeding coefficients obtained by ROH with alternative genomic inbreeding coefficients. A subpopulation of 1733 Guzerá animals genotyped for 50k SNPs was used to obtain the ROH and HRR segments. Inbreeding coefficients by ROH (FROH ), by genomic relationship matrix based on VanRaden's method 1 using reference allele frequency in the population (FGRM ), by genomic relationship matrix based on VanRaden's method 1 using allele frequency fixed in 0.5 (FGRM_0.5 ), and by the proportion of homozygous loci (FHOM ) were calculated. A total of 15,660 ROH were identified, and the chromosome with the highest number of ROH was BTA6. A total of 4843 HRRs were identified, and the chromosome with the highest number of HRRs was BTA23. No ROH and HRR islands were identified according to established criteria, but the regions closest to the definition of an island were examined from 64 to 67 Mb of BTA6, from 36 to 37 Mb of BTA2 and from 0.50 to 1.25 Mb of BTA23. The genes identified in ROH islands have previously been associated with dairy and beef traits, while genes identified on HRR islands have previously been associated with reproductive traits and disease resistance. FROH was equal to 0.095 ± 0.084, and its Spearman correlation with FGRM was low (0.44) and moderate-high with FHOM (0.79) and with FGRM_0.5 (0.80). The inbreeding coefficients determined by ROH were higher than other cattle breeds' and higher than pedigree-based inbreeding in the Guzerá breed obtained in previous studies. It is recommended that future studies investigate the effects of inbreeding determined by ROH on the traits under selection in the subpopulation studied.

PSXII-2 Lactation Persistence Analysis and Its Genetic Correlations with Productive, Reproductive, and Health Traits in the First Two Parities in Lucerna Cattle

Abstract Lactation persistency (LP) is a trait of economic relevance in dairy cattle since persistent cows are more profitable by presenting fewer diseases, requiring fewer inputs, and having better reproductive performance. Therefore, the main objective of this study was to estimate genetic relationships between lactation persistency for mastitis (MT), calving interval (CI), and 305–day milk yield (305M) in first and second Lucerna cattle lactations. Records from 67,952 test–day milk, 7,100 CI, and 1,074 clinical-mastitis evaluations from two Colombian farms of Creole dual-purpose cattle were considered. Five three-parameter equations, as reported in previous literature, were graphically and statistically evaluated for fitting a lactation curve (LC) for each parity. The goodness-of-fit criteria included AIC, BIC, RSS, and R2. The most appropriate equation was identified and implemented for predicting 305M for 4,620 lactations (2,716 and 1,904 from first and second parity, respectively) for which LP was estimated. Bi-trait animal models between LP-MT, LP-CI, and LP-M305 for each parity were executed in the BLUPF90+ software (AI-REML algorithm) to estimate heritabilities (h2) and genetic correlations (GC). Fixed effects of herd, year of calving, season of calving, b0 lactation parameter, and age at calving were included. Estimates of goodness-of-fit criteria for all LC equations varied between R2 (0.29 – 0.68), BIC (132,322 – 207,415), AIC (132,289 – 207,389), and RSS (188,231 – 414,007). The incomplete gamma equation best satisfied the goodness-of-fit-criteria and drew the most accurate LC in both parities. Due to the low data density in this work, estimates involving MT and CI had increased standard deviations; therefore, the interpretation should be considered cautiously. The h2 estimates were 0.0 and 0.24 for MT, 0.02 and 0.09 for CI, 0.18 and 0.36 for M305, and 0.14 and 0.15 for LP, for the first and second parity, respectively. The GC estimates were -0.24 and -0.41 for LP–M305, 0.31 – 0.35 for LP–CI, and -0.76 for LP–MT for each parity, respectively. The results of this study suggest that LP could be considered as a selection target in the farms’ breeding program since desirable relationships were found with all evaluated traits for the first and second parity.

Effect of tree shade on behavior and haircoat temperature of grazing dual-purpose cows in a hot and humid tropical environment

We evaluated the behavior and skin temperature of dual-purpose cattle that grazed pastures having high (HC), low (LC), and no (NC) tree cover during the rainy and dry seasons in the hot and humid tropics of Mexico. We observed twenty-four adult cows (eight per treatment) over 24 days during each season, recording skin temperature and the time related to different daily activities. Across treatments, cows spent the same amount of time foraging during the rainy season (P > 0.05), but cows under HC spent less time during the dry season (P < 0.0001). During the rainy season, cows under HC showed more motivation to continue grazing than becoming restless or beginning rumination (P < 0.001) or roaming more than in other treatments (P < 0.001). During the dry season, cows under HC and LC also had less probability of initiating rest than NC (P < 0.001). Cows under HC had greater motivation to transition from grazing to roaming and less incentive to pass from rumination to rest than cows under LC and NC (P < 0.001). The frequency of water consumption was greater during the dry season (P < 0.001) and consistently high under NC (P < 0.0001). Skin temperature did not differ among treatments during the rainy season (P = 0.261), but during the dry season, it was greater under NC (P < 0.001). Tree cover improves cow behaviors by increasing the impetus to graze and perform daily activities, which contributes to reduced skin temperature during hotter seasons.

The future of surplus dairy calves – an animal welfare perspective

An important obstacle toward sustainably produced animal-source food is the existence of so-called ‘surplus animals’, which are by-products of the production of dairy products and eggs, and ‘unwanted’ due to their perceived low value. Although this depends on the country, in Europe many surplus dairy calves are transported to veal farms to be raised for 6 months until slaughter. The aim of this article is to present ideas for alternative future systems for the dairy-veal chain, including an overview of current challenges and improvement strategies for calf welfare. This dairy-veal chain presents a number of potential concerns for calf welfare, including transportation of young animals, high risk of disease and barren housing. Many incremental changes have been suggested in past literature to lift the welfare of veal calves, including reducing transportation, transporting calves at an older age, better health screening, and pens with enrichment and bedding. The Netherlands is at the centre of the veal sector import-export flow in Europe and is one of the main veal producers in the world. The Dutch government has recently presented a report with three alternative ‘scenarios’ for the raising of these surplus dairy calves, which are expected to lead to improvements in animals welfare. The first scenario is a restriction on transport of &amp;lt;100km, leading to more local production of dairy-veal. The second scenario is a delay on the transportation of surplus calves from 2 weeks to 3 months of age, handing dairy farmers a much larger role in the raising of these calves. This delay would ensure that calves are more robust and less vulnerable to disease at the time that they are transported to the veal farm. The third scenario proposes an alternative system, where the veal sector is eradicated and surplus dairy calves are raised at the dairy farm of origin until slaughter. We, like others before us, question the impact of small incremental changes on calf welfare, arguing that improvements at one end could potentially lead to worsening of welfare at the other end, and prefer to focus on system changes, such as the use of dual-purpose cattle breeds. We do not however believe that system changes can be created and implemented with the sole input of animal welfare scientists. This work is hence just one piece of the puzzle towards the sustainable production of milk and meat, and more specifically the sustainable rearing of surplus calves.