Search Results (23)

In recent years, donkey milk has gained growing interest for its nutritional and therapeutic properties, stimulating both research and commercial interest. Monitoring udder health is essential to reduce production losses and ensure animal welfare. Despite its importance, information about the ultrasonographic anatomy of teat structures in lactating jennies is limited, and normal reference values are not well established. This study aimed to describe the ultrasonographic appearance of the teat and provide reference measurements in healthy lactating standard dairy jennies. Twenty-eight subjects were examined using a 13 MHz linear transducer, and longitudinal and transverse scans were performed to assess teat canal length, teat canal diameter, and cranial and caudal teat wall thickness. All measurements were repeatable and showed high bilateral symmetry. Teat canal diameter was positively correlated with the month of lactation (p < 0.05), whereas no significant associations were found with age or body weight. These findings establish normative ultrasonographic parameters for teat structures in jennies and highlight the progressive adaptation of the teat canal during lactation. Standardized measurements can support early detection of mammary gland pathologies, guide preventive management of mastitis, and improve udder health monitoring in donkey dairy farming. Full article

This study investigated cow longevity, culling reasons, and risk factors influencing culling in South African Holstein and Jersey dairy herds. Lactation records of 1,150,625 Jersey and 1,534,875 Holstein cows from 1864 herds, recorded through the National Milk Recording Scheme during the period 2000 to 2019, were analyzed. Longevity was calculated as length of productive life and number of completed lactations. Logistic binary regression was conducted to estimate the odds ratios (OR) for culling among different calving seasons, parities, and herd sizes. Holstein cows had mean productive life of 739.33 ± 434.31 days and 2.37 ± 1.08 lactations, while Jersey cows averaged 696.81 ± 415.44 days productive life and 2.47 ± 1.13 lactations. Leading reasons for culling were infertility (37.94 ± 0.48% Holstein; 30.46 ± 0.63% Jersey), mastitis (18.15 ± 0.38% Holstein and 18.16 ± 0.53% Jersey), and low milk yield (11.76 ± 0.32% Holstein and 19.76 ± 0.55% Jersey). Summer calving, third parity, and small herd size had the highest odds of culling. These findings suggest that herd management practices and selection objectives in South Africa should place high emphasis on cow fertility and udder health. Furthermore, cows calving in summer and those in third parity or small herds require particular attention to minimize culling. Such measures may help to reduce involuntary culling rates and thus increase herd profitability as well as dairy industry sustainability. Full article

Lipopolysaccharide (LPS) endotoxin is a well-characterized microbe-associated molecular pattern (MAMP) that forms the outer membrane of both pathogenic and commensal Gram-negative bacteria. It plays a crucial role in triggering inflammatory disorders such as mastitis, acidosis, and septicemia. In heifers, an LPS challenge induces a dynamic stress response, marked by elevated cortisol levels, increased body temperature, and altered immune function. Research indicates that LPS administration leads to a significant rise in cortisol post-challenge. Building on this understanding, the present study aimed to estimate genetic parameters for serum cortisol response to LPS challenge in Holstein heifers and its linear associations with production, health, reproduction, and conformation traits. Additionally, a genome-wide association study (GWAS) was conducted to identify genetic regions associated with cortisol response. A total of 252 animals were evaluated for cortisol response, with correlations estimated between cortisol levels and 55 genomic breeding values for key traits. Genetic parameters and heritability for cortisol response were estimated using Residual Maximum Likelihood (REML) in the Blupf90+ v 2.57 software. Single-Step GWAS (ssGWAS) employing a 10-SNP window approach and 42,123 SNP markers was performed to identify genomic regions that explained at least 0.5% of additive genetic variance. Finally, candidate genes and QTLs located 50 kb up and downstream of those windows were identified. The cortisol response showed significant but weak linear associations with cystic ovaries, body maintenance requirements, lactation persistency, milk yield, and protein yield (p-value ≤ 0.05) and showed suggestive weak linear associations with udder texture, clinical ketosis, heel horn erosion, and milking speed (p-value ≤ 0.15). Cortisol response showed significant additive genetic variance, along with moderate heritability of 0.26 (±0.19). A total of 34 windows explained at least 0.5% of additive genetic variance, and 75 QTLs and 11 candidate genes, comprising the genes CCL20, DAW1, CSMD2, HMGB4, B3GAT2, PARD3, bta-mir-2285aw, CFH, CDH2, ENSBTAG00000052242, and ENSBTAG00000050498, were identified. The functional enrichment analysis allowed us to infer two instances where these gene products could interfere with cortisol production: the first instance is related to the complement system, and the second one is related to the EMT (Epithelium–Mesenchymal Transition) and pituitary gland formation. Among the QTLs, 13 were enriched in the dataset, corresponding to traits related to milk (potassium content), the exterior (udder traits, teat placement, foot angle, rear leg placement, and feet and leg conformation), production (length of productive life, net merit, and type), and reproduction (stillbirth and calving ease). In summary, the cortisol response to LPS challenge in Holstein heifers seems to be moderately heritable and has weak but significant linear associations with important production and health traits. Several candidate genes identified could perform important roles, in at least two ways, for cortisol production, and QTLs were identified close to regions of the genome that explained a significant amount of additive genetic variance for cortisol response. Therefore, further investigations are warranted to validate these findings with a larger dataset. Full article

Background: The German Black Pied Dairy (DSN) cattle is an endangered dual-purpose breed considered an ancestor of the modern Holstein population. DSN is known for its high milk yield, favorable milk composition, and good meat quality. Maintaining a functional body structure is essential for ensuring sustained performance across multiple lactations in dual-purpose breeds like DSN. This study aims to identify candidate genes and genetic regions associated with conformation traits in DSN cattle through genome-wide association studies (GWAS). Methods: The analysis utilized imputed whole-genome sequencing data of 1852 DSN cows with conformation data for 19 linear traits and four composite scores derived from these traits. GWAS was performed using linear mixed models. Results: In total, we identified 118 sequence variants distributed across 24 quantitative trait locus (QTL) regions comprising 74 positional candidate genes. Among the most significant findings were variants associated with “Rump width” on chromosome 21 and “Teat length” on chromosome 22, with AGBL1 and SRGAP3 identified as the most likely candidate genes. Additionally, a QTL region on chromosome 15 linked to “Central ligament” contained 39 olfactory receptor genes, and a QTL region on chromosome 23 associated with “Hock quality” included eight immune-related genes, notably, BOLA and TRIM family members. Conclusions: Selective breeding for favorable alleles of the investigated conformation traits may contribute to DSN’s longevity, robustness, and overall resilience. Hence, continuous focus on healthy udders, feet, and legs in herd management contributes to preserving DSN’s positive traits while improving conformation. Full article

The study aimed to explore if milkability parameters could reliably predict the dimensions of teat structures and their milking-induced changes. Ultrasonography repeatedly measured the teat structures of 48 Holstein cows from mid to late lactation. We found that milking-induced changes in each structure are affected by different milkability parameters. Regression models for teat canal change and length change were significant, and variability was found to be 46.03% and 21.50%, respectively. Similarly, the teat structure’s dimensions significantly affected milkability parameters, which differed for each structure. However, regression models only explained between 3.36% (teat length) and 7.59% (cistern) of variability. The prediction potential, performed based on milkability, is limited if the initial dimensions of structures are not provided. If teat dimensions were measured at the beginning of the production life, automatically collected milkability data could be used to calculate milking-induced changes incurred with each milking and the development of teat dimensions over the production life. If perfected, this tool could provide alerts about critical milking-induced changes and risky teat conformation traits, as they have a proven effect on udder health and are reliable indicators of milking effectiveness. Full article

This observational study explored the early-life challenges of intra-uterine growth restricted (IUGR), low birth body weight (LBW), and normal birth body weight (NBW) piglets. The aim was to understand the impact of birth weight and intra-uterine growth restriction phenotype on neonatal survival and behavior. Based on weight and phenotype, piglets were classified as IUGR (n = 32), LBW (n = 34), and NBW (n = 29) immediately after birth. The piglets were litter- and sex-matched. Vitality scores were assigned based on motor activity and breathing and complemented with an assessment of umbilical cord condition, rectal temperature, crown–rump length (CRL), time to reach the udder, time to suckle, colostrum intake, and weight gain over 24 h. Beyond the lower birth weight, reduced CRL, and higher mortality rate, IUGR piglets faced several other challenges compared with LBW and NBW piglets. Growth-impaired piglets often struggled to engage in early feeding behaviors and displayed consistently lower rectal temperatures at 1, 3 and 24 h after birth. IUGR piglets showed inadequate colostrum intake and weight loss, which were also observed for LBW counterparts. In contrast, no significant differences were observed in vitality scores and umbilical cord conditions across the groups. In conclusion, our findings underscore the impact of intra-uterine growth restriction on neonatal piglets, emphasizing the need for specialized care strategies to improve survival and health outcomes in IUGR. Full article

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 F_ROH was 0.122 ± 0.032 and it decreased to 0.074, 0.031 and 0.006, when genomic homozygous segments > 8 Mb (F_ROH>8), >16 Mb (F_ROH>16) and >32 Mb (F_ROH>32) were considered. New inbreeding showed the highest correlation with F_ROH>32, whereas ancestral inbreeding coefficients had the lowest correlations with F_ROH>32. The correlation between the classical inbreeding coefficient and F_ROH was 0.572. We found significantly lower F_ROH, F_ROH>4, F_ROH>8 and F_IS 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 F_ROH and up to F_ROH>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. Full article

The objective of this study was to evaluate the association between dry period (DP) length and various indicators of productivity, reproduction, and udder health in cows managed with an automatic milking system. We analyzed records from 3861 cows, categorizing them into three groups based on their DP duration: (1) <40 days, (2) 40–70 days, and (3) DP > 70 days. Cows with a DP of 40–70 days had an average energy-corrected milk production that was 8.2 kg greater than that of cows with a short DP and 5.0 kg greater than that of cows with a long DP (p < 0.001). Milk from the 40–70-day DP group exhibited the highest lactose concentration (4.64 ± 0.01%). Additionally, cows with the longest DP had the smallest proportion of animals with a milk fat-to-protein ratio of 1.2 to 1.4. Cows with a DP of 40–70 days also showed the lowest milk electrical conductivity across all udder quarters, whereas cows with the shortest DP had the highest conductivity. The highest conception rates were observed in the group with the shortest DP. These results suggest that a DP of 40–70 days is optimal for maximizing milk production and improving both udder health and reproductive performance under AMS. Proper management of DP duration can be an effective strategy for sustainable dairy herd management. Full article

The present review aims to analyze the anatomical and physiological characteristics of the mammary gland and udders of water buffalo by making an anatomofunctional comparison with dairy cattle. It will also discuss the knowledge generated around the physiological regulation of milk ejection in the water buffalo. It was found that buffalo’s average udder depth and width is approximately 20 cm smaller than Bos cattle. One of the main differences with dairy cattle is a longer teat canal length (around 8.25–11.56 cm), which highly influences buffalo milking. In this sense, a narrower teat canal (2.71 ± 0.10 cm) and thicker sphincter muscle are associated with needing higher vacuum levels when using machine milking in buffalo. Moreover, the predominant alveolar fraction of water buffalo storing 90–95% of the entire milk production is another element that can be related to the lower milk yields in buffalo (when compared to Bos cattle) and the requirements for prolonged prestimulation in this species. Considering the anatomical characteristics of water buffalo’s udder could help improve bubaline dairy systems. Full article

Crossbreeding in dairy cattle with exotic breeds continues to be an appealing practice to the dairy farmers of Bangladesh. However, there is limited knowledge regarding the impact of crossbreeding on both the physical attributes and milk quality traits of crossbred cattle in Bangladesh. Therefore, the primary objective of this study was to evaluate the impact of crossbreeding Bangladeshi local cattle with the exotic Holstein breed on their body characteristics and milk quality. To achieve the goal, data pertaining to body traits and milk samples were gathered from a total of 981 cows from 19 dairy farms located in the northwestern region of Bangladesh. A trained evaluator measured body condition score (BCS), udder score, locomotion score, and body conformation traits. Milk yield information was acquired from official records, while milk composition details were determined through milk analysis. Notably, crossbred cows (Holstein × Local cattle) exhibited greater values for wither height (141 vs. 135, cm), body length (157 vs. 153, cm), heart girth (211 vs. 204, cm), BCS (3.69 vs. 3.27), and udder score (3.29 vs. 2.08) than their Bangladeshi local counterparts. Furthermore, crossbred cows produced 42.4% and 35.3% more milk (10.89 vs. 7.65, kg/d) and fat-corrected milk (10.35 vs. 7.54, kg/d) than Bangladeshi local cattle. However, milk from crossbred cows displayed lower fat and protein content, although their somatic cell score (SCS) and energy-corrected milk remained similar. Additionally, milk from crossbred cows exhibited a longer coagulation time when compared to that of Bangladeshi local cattle. In conclusion, crossbred cows (Holstein × Local cattle) had improved body characteristics with greater milk yield than Bangladeshi local cattle; however, lower fat and protein contents in milk with longer coagulation time were noted. Full article

Reproductive traits are the basic economic traits of goats and important indicators in goat breeding. In this study, Dazu black goats (DBGs; n = 150), an important Chinese local goat breed with excellent reproductive performance, were used to screen for important variation loci and genes of reproductive traits. Through genome-wide association studies (GWAS), 18 SNPs were found to be associated with kidding traits (average litter size, average litter size in the first three parity, and average litter size in the first six parity), and 10 SNPs were associated with udder traits (udder depth, teat diameter, teat length, and supernumerary teat). After gene annotation of the associated SNPs and in combination with relevant references, the candidate genes, namely ATP1A1, LRRC4C, SPCS2, XRRA1, CELF4, NTM, TMEM45B, ATE1, and FGFR2, were associated with udder traits, while the ENSCHIG00000017110, SLC9A8, GLRB, GRIA2, GASK1B, and ENSCHIG00000026285 genes were associated with litter size. These SNPs and candidate genes can provide useful biological information for improvement of the reproductive traits of goats. Full article

A recent study on the population structure of the German Brown population found increasing levels of classical and ancestral inbreeding coefficients. Thus, the aim of this study was to determine the effects of inbreeding depression and purging on longevity traits using classical and ancestral inbreeding coefficients according to Kalinowski (2002) (F_{a_Kal}, F_New), Ballou (1997) (F_{a_Bal}), and Baumung (2015) (Ahc). For this purpose, uncensored data of 480,440 cows born between 1990 and 2001 were available. We analyzed 17 longevity traits, including herd life, length of productive life, number of calvings, lifetime and effective lifetime production for milk, fat, and protein yield, the survival to the 2nd, 4th, 6th, 8th, and 10th lactation number, and the culling frequencies due to infertility, or udder and foot and leg problems. Inbreeding depression was significant and negative for all traits but for culling due to udder and to foot and leg problems. When expressed in percentages of genetic standard deviations, inbreeding depression per 1% increase in inbreeding was −3.61 to −10.98%, −2.42 to −2.99%, −2.21 to −4.58%, and 5.13% for lifetime production traits, lifetime traits, survival rates, and culling due to infertility, respectively. Heterosis and recombination effects due to US Brown Swiss genes were positive and counteracted inbreeding depression. The effects of F_New were not significantly different from zero, while F_{a_Kal} had negative effects on lifetime and lifetime production traits. Similarly, the interaction of F with F_{a_Bal} was significantly negative. Thus, purging effects could not be shown for longevity traits in German Brown. A possible explanation may be seen in the breed history of the German Brown, that through the introgression of US Brown Swiss bulls ancestral inbreeding increased and longevity decreased. Our results show, that reducing a further increase in inbreeding in mating plans is advisable to prevent a further decline in longevity due to inbreeding depression, as purging effects were very unlikely in this population. Full article

The objective of this study was to explore the effect of dam body conformations on birth traits including stillbirth, dystocia, gestation length and birth weight of Chinese Holstein calves and to provide a reference for improving cow reproductive performance. We collected phenotype data on 20 conformation traits of Chinese Holstein cows and analyzed the impact of dam conformation trait linear scores on stillbirth, dystocia, gestation length and calf birth weight. The feet angle, set of rear legs, fore udder attachment and rear attachment height traits of the dairy cows significantly affected the risk of stillbirth. The risk of dystocia decreases with the increase in stature and pin width. The bone quality of dairy cows had a significant positive correlation with gestation length. There was a significant positive correlation between fore udder attachment and calf weight at birth. The birth weight of calves from cows with high body conformation traits was significantly higher than that of calves with a low composite score. These results suggest that improving the body conformation traits, especially the selection of mammary system and body shape total score, will be beneficial in improving the reproductive performance of dairy cows. Full article

The study examined the relationship between milk yield and udder morphology traits in White Fulani cows. Fifty-eight apparently healthy cows in early lactation at 2nd, 3rd, and 4th parity were used in the study. The data obtained from the cows were test day milk yield (TDMY) from single milking and udder morphology traits comprising udder length (UL), udder width (UW), udder depth (UD), fore teat length (FTL), rear teat length (RTL), fore teat diameter (FTD), and rear teat diameter (RTD). There was no significant effect of parity on TDMY or the udder morphology traits. Phenotypic correlations between TDMY, UL, UW, and UD were positive and significant. Notably, phenotypic correlations between UL and TDMY at different parities were the strongest. Teat measurements had no significant correlation with TDMY. Stepwise and principal component regressions were implemented to assess the relationship between milk yield and udder morphology traits. Interestingly, UL was the only trait that entered the reduced models. The results suggest a probable genetic correlation between milk yield and udder length. Therefore, since udder conformation traits are heritable, when selecting for udder length in White Fulani cows, a correlated response in milk yield is expected. Full article

In this study, the authors focused on the evaluation of the genetic parameters of longevity, milk yield traits, and type traits in dairy cattle populations in the Republic of Serbia. The total dataset used consisted of production records and pedigree data for 32,512 Holstein cows that calved from 1981 to 2015. The animal model was applied to determine the variance and covariance components and genetic parameters of the analyzed traits by applying the restricted maximum likelihood (REML) approach and using the programs VCE6 and PEST. The heritability of longevity traits was estimated using the Survival Kit V6.0 software package. Variance and covariance were estimated for five production traits: milk yield (MY), fat yield (FY), protein yield (PY), milk fat content (MC), and protein content (PC), and three longevity traits: length of productive life (LPL), lifetime milk yield (LMY), and the number of lactations achieved (NL) as well as for 18 standard type traits. Heritabilities for the milk, fat, and protein yield traits were 0.20 (MY), 0.15 (FY), and 0.19 (PY), respectively. The estimated coefficients of heritability for the longevity traits were higher when using the Weibull proportional hazards model compared to the traditional linear methods and ranged from 0.08 for NL to 0.10 for LPL. Heritability values for the type traits varied from a low of 0.10 (RLSsv—rear legs set–side view) to medium values of 0.32 (ST-stature). Genetic correlations were found between MY and the following longevity traits: LPL, LMY, and NL with values of −0.18, −0.11, and −0.09, respectively. Genetic correlations were found between MY and a number of linear type traits and varied from 0.02 (between MY and RUH-rear udder height) to 0.28 (between MY and FUA-fore udder attachment). Genetic correlations between the 18 investigated type traits ranged from −0.33 between TL (top line) and RTP (rear teats position) to 0.71 between AN (angularity) and RUH (rear udder height). Genetic correlations between most linear type traits and longevity traits (LPL, LMY, and NL) were generally negative and very low. The highest positive genetic correlation was found between UD and LPL (r_xy = 0.38). Full article