Herders Research Articles

Association of Lameness Prevalence and Severity in Early-Lactation Cows with Milk Traits, Metabolic Profile, and Dry Period

This study investigated the prevalence and severity of lameness in dairy cow herds, focusing on its relationship with milk traits, metabolic profile, and dry period management. Lameness was evaluated in 4221 multiparous Holstein dairy cows during early lactation (up to 60 days postpartum) using a 1-to-5 scale. The average lameness score was 1.67, with a prevalence of 10.66% (scores 3 to 5) and 4.55% classified as severe (scores 4 to 5). Severe lameness was associated with energy-corrected milk losses of −11.00 kg/day (p < 0.001) and a decrease in milk lactose concentration by −0.16 percentage points (p < 0.001), alongside a rise in somatic cell scores by +0.11. The incidence of cows with a milk fat-to-protein ratio below 1.2 increased by 21.7 percentage points, while those with a ratio above 1.4 rose by 19.1 percentage points as lameness worsened. Additionally, non-esterified fatty acid concentrations increased by 1.46 times as lameness severity intensified (p < 0.001). Cows without lameness had blood cortisol levels 1.86 times lower than affected cows, with cortisol tripling in those with the highest scores. A dry period of 30 to 60 days was correlated with more healthy cows, whereas periods over 90 days resulted in 1.586 times higher odds of lameness (p < 0.05). This research underscores the need for improved management strategies to enhance dairy cow welfare and productivity.

Targeted reproductive management for lactating Holstein cows: Economic return.

Targeted reproductive management (TRM), employing automated monitoring devices (AMD), is as an alternative to the blanket adoption of ovulation synchronization protocols (OvSP) for first postpartum artificial insemination (AI) and a means of reducing the use of OvSP for re-AI of non-pregnant cows. We hypothesized that a TRM that relies heavily on AI of cows on AMD-detected estrus increases improves reproductive performance and economic return. Early-postpartum estrus characteristics of multiparous (n = 941) cows were evaluated at 40 and 41 DIM (Herds 1and 2, respectively) and early-postpartum estrus characteristics of primiparous (n = 539) cows were evaluated at 54 and 55 DIM (Herds 1 and 2, respectively). Cows in the control treatment were enrolled in the Double-Ovsynch protocol and AI at fixed time (TAI) at 82 and 83 DIM (primiparous cows in Herds 1 and 2, respectively) and 68 and 69 DIM (multiparous in Herds 1 and 2, respectively). Cows enrolled in the TRM treatment were managed according to early-postpartum estrus characteristics as follows: 1. Cows with ≥1 intense estrus (heat index ≥70; 0 = minimum, 100 = maximum) were AI upon AMD detected estrus for 42 d and, if not AI, were enrolled in the Double-Ovsynch, 2. Cows without an intense estrus were enrolled in the Double-Ovsynch at the same time as cows in the control treatment. Control cows were re-AI based on visual or patch aided detection of estrus, whereas TRM cows were re-AI as described for control cows with the aid of the AMD. All cows received a GnRH injection 27 ± 3 d after AI and, if diagnosed as non-pregnant, completed the 5-d Cosynch protocol and received TAI 35 ± 3 d after insemination. The hazard of pregnancy was greater for cows in the TRM treatment [adjusted hazard ratio = 1.17, 95% confidence interval = 1.05, 1.32], resulting in more cows from the TRM treatment starting a new lactation (82.6 vs. 77.2%) and fewer of them sold (15.5 vs. 20.8%). Treatments did not differ regarding total milk yield (control = 12,782.1 ± 130.6 kg, TRM = 13,054.7 ± 136.1 kg). The gross profit ((milk income + sale value + subsequent lactation calf value) - (feed cost + replacement cost + fixed cost + reproductive management cost)) of cows in the TRM treatment was $108 greater than the control treatment ($3,061.6 ± 45.9 vs. $2,953.8 ± 45.2). According to a Monte Carlo stochastic simulation, the mean (±SD) difference in gross profit was $87.8 ± 12.6/cow in favor of the TRM treatment and 95% of the scenarios ranged from $67.2/cow to $108.5/cow (minimum = $30.2/cow, maximum = $141.1/cow). In the conditions of the current experiment, the TRM treatment improved the gross profit of Holstein cows because the increased hazard of pregnancy changed culling dynamics, reducing replacement cost and cow sales and increasing calf value. The findings of the current experiment emphasize the importance of efficient reproductive management and its substantial economic implications, particularly in the context of high-producing Holstein cows.

Comparative prevalence assessment of subclinical mastitis in two crossbred dairy cow herds using the California mastitis test

The study was conducted on two herds of Jersey crossbred dairy cows. Samples were taken from two dairy farms to conduct the California Mastitis Test (CMT) during milking. A total of 115 animals were sampled, with 65 animals from Farm 1 and 60 animals from Farm 2. Milk samples were collected from all four quarters of each cow. The study analyzed a total of 460 quarters from the collected milk samples. Among these quarters, 132 quarters (28.69%) were found to be infected. The prevalence of mastitis was 45% in Herd 1 and 25% in Herd 2. The study found that only one quarter of the udder was more affected in both herds. The CMT score (likely a measure of mastitis severity) increased during late lactation. Infected cows had an average milk yield/day of 3.6 liters. Inflammatory (within or under the mammary gland) infections were more common in the first and second parity cows (cows that had given birth to one or two calves, respectively). This could be ascribed to the fact that dairy cows in their starting lactations are more vulnerable to the environmental pathogens because they might not have built up their immunity yet. Overall, this study provides insights into the prevalence, severity, and patterns of mastitis in Jersey crossbred dairy cows located at two different farms. The study highlights factors such as the stage of lactation, parity, and herd differences that can influence the occurrence and severity of mastitis in these animals.

Assessing bull breeding soundness exam parameters following vaccination with modified-live or killed vaccine

Breeding bulls are often placed on a similar herd health plan and vaccinated for the same pathogens as the mature cow herd. The timing of the yearly vaccination is impacted by labor and time constraints with some bulls receiving vaccinations at the time of annual, complete breeding soundness exams or at the time of turnout prior to the breeding season. However, the potential impact of vaccination on spermatogenesis, if any, is unknown. Therefore, the study objective was to determine the impacts on normal sperm morphology through a complete spermatogenic cycle after vaccination of mature beef bulls against bovine herpesvirus 1 and bovine viral diarrhea virus using commercially available modified-live virus (MLV) or killed virus (KV) vaccine. Semen was collected from Bos taurus bulls (n = 11),which were randomly assigned prior to the first breeding soundness exam to vaccine treatment groups: 1) modified-live virus (MLVa); or 2) inactivated/killed virus (KVb). Breeding soundness exams were completed at days -7, 0, 5, 7, 17, 28, 61 following vaccination. No differences were found between vaccine treatment groups MLV and KV (P = 0.46) on the percentage of normal sperm over time (d = -7 through d = 61) as evaluated by two boarded theriogenologists. In conclusion, we found no detrimental effect of the administration of multivalent MLV or KV vaccines on percentage of normal sperm morphology of mature bulls over a 61 – day period.

Effect of sward species diversity combined with a reduction in nitrogen fertilizer on the performances of spring calving grazing dairy cows

The objective of this study was to evaluate the impact of sward diversification combined with a reduction of chemical nitrogen (N) fertilizer on the performance of spring calving grazing dairy cows within a farm systems experiment. Three farmlets were created; a monoculture of perennial ryegrass (Lolium perenne L.; PRG) fertilized with 250 kg N/ha (PRG-250N), a PRG - white clover (Trifolium repens; WC) sward fertilized with 125 kg N/ha (PRGWC-125N) and a multispecies sward (MSS) comprising of grasses, legumes and herbs also fertilized with 125 kg N/ha (MSS-125N). Each farmlet had its own herd of dairy cows on a total area of 18.7 ha divided into 20 paddocks. Each herd was comprised of pure Holstein-Friesian (HF) and HF Jersey crossbred (JFX) animals and randomly assigned through the 3 treatments. For 3 years (2021 to 2023), the performances of both swards (grass yield, botanical composition, nutritive value) and grazing animals (milk production and composition, body weight (BW) and body condition score (BCS)) were recorded. There were no significant differences in pasture production or sward nutritive value between sward systems and grazing season length was also similar (264 d). On average over the 3 years, PRGWC-125N contained 150 g/kg DM of legumes and the MSS-125N contained 160 g/kg DM legumes, 130 g/kg DM plantain and 40 g/kg DM chicory. Both individual cow milk and fat plus protein (Milk solids; MS) yield were lower for PRG-250N (5,018 and 452 kg, respectively), intermediate for PRGWC-125N (5,139 and 463 kg, respectively) and highest for MSS-125N (5,297 and 476 kg, respectively) while milk and MS production per hectare from grazing were similar during the study period (11,523 and 1,016 kg/ha, respectively). Breed also had a significant effect with the JFX having lower milk yield but higher fat and protein concentration compared with HF. This resulted in higher MS production per kg of BW for the JFX compared with HF (0.96 and 0.87 kg MS/kg BW, respectively). The results of this study highlight the possibility for more diverse pastures to reduce chemical N fertilizer input requirements and maintain pasture productivity while increasing animal performance within pasture-based spring calving systems.

Dairy calves' time spent in the cow herd in a calf-driven cow-calf contact system during two-step separation with a nose flap

Although originally developed for weaning of beef calves, nose flaps are also used on dairy farms nowadays to wean calves which are reared with contact to their dam or a foster cow. These calves are often weaned younger than beef calves and the time they wear nose flaps is highly variable, since it is unknown for how long younger calves need to wear the nose flap in order to induce an effective weaning. The aim of our study was therefore to track changes in dam-contact initiated by dairy calves after insertion of a nose flap in order to determine the minimum duration a nose flap needs to be worn to effectively reduce suckling motivation of calves. The study was conducted in two sequential experiments using 3-month-old dairy calves that were reared with full-time dam contact. Calves were weaned with a nose flap over either 14 (experiment I, 9 calves in herd A and 9 calves in herd B) or 7 days (experiment II, 11 calves in herd A and 12 calves in herd B) before they were fence-line separated from their dams. The total time a calf spent within the cow herd (TIC) per day was determined from continuous video recordings during 7 days before nose flap insertion (baseline), as well as during the 7 or 14 days in which calves had free access to the cow area while wearing the nose flap. Statistical analysis was conducted using linear mixed effects models. Results from both experiments showed that calves reduced their TIC at the fourth day of wearing the nose flap compared to their individual baseline (p=0.03 and p=0.001 respectively). In experiment I, calves showed a further numerical reduction in TIC from day 4 to day 5, while in experiment II, calves showed no further reduction in TIC after the 4 days of wearing the nose flap. After these 4 or 5 days respectively, TIC of calves in both experiments stayed at a constant low level of several hours per day. Taken together, these results indicate that in 3-month-old dairy calves it needs at least 4 days until the motivation to spend time with the cow decreases after insertion of a nose flap, while there seems to be no further decrease in motivation when using a nose flap longer than this time. However, results were subject to considerable inter-individual variability already during the baseline week and need replication in a pasture-based setting with less space-restrictions.

Association of Production and Selected Dimensional Conformation Traits in Holstein Friesian Cows.

The objective of this study was to estimate the heritability of dairy production traits and that for dimensional traits and to calculate the correlation between the two heritability values in a Holstein Friesian cow herd bred in Hungary. Data of 15,032 Holstein Friesian cows born in the period 2008-2018 from 666 sires were collected for the study in 6 large dairy herds. Among the conformation traits, stature (ST), chest width (CW), body depth (BD), and rump width (RW), and for production traits, in the first lactation of cows, the 305-day milk yield (MY), milk butterfat yield (FY), and milk protein yield (MY) were evaluated. Heritability estimates of ST, CW, BD, and RW were 0.49, 0.25, 0.31, and 0.30, and those of MY, FY, and PY were 0.40, 0.35, and 0.30, respectively. BD and RW had no phenotypic (b = -0.01) or genetic (b = 0.00-0.01) change. The production traits (MY, FY, PY) increased to a greater extent (b = 2.2-43.3) than the examined conformation traits over time. Consequently, it is indicated that the selection for dairy production did not result in an increase in the studied dimensional traits.

PSIV-27 Effects of organic complexed or inorganic trace mineral supplementation on cow performance and herd longevity

Abstract Records for Angus-crossbred cows (n = 219) that were born during a 3-yr project to investigate the effects of trace mineral source on beef cow performance were reviewed. For the 3-yr cow project, cows were initially assigned to 1 of 4 groups within spring and fall calving herds. Groups within each herd were assigned randomly to 1 of 2 supplemental trace mineral treatments 1) inorganic sources as Cu, Zn, and Mn in sulfate forms and Co carbonate (ING), or 2) organic sources as Cu, Zn, and Mn amino acid complexed and Co glucoheptonate (ORG). Free choice minerals were provided with appropriate mineral treatments while cattle were maintained on fescue-bermudagrass pastures that were rotated monthly. When forage or hay was limited, treatments were delivered via grain supplements. At weaning, heifer calves remained on their respective dietary treatments through their first breeding season (approximately 15 mo of age). The cow project began with pregnant cows, thus, all heifers weaned in the first year and some in other years (n = 86) were conceived before their dams received the dietary treatments. Most heifers weaned in yr 2 and 3 were conceived while their dams were on their respective dietary treatments (n = 133). After heifers were confirmed pregnant, they re-entered the cow herd. At the conclusion of this project the Cow-Calf Unit continued to keep performance records. Natural breeding occurred after artificial insemination and open cattle were culled annually. Year of performance data (calving, culling, and death records) were analyzed to determine the long-term effects of trace mineral source. MIXED procedures were used of SAS 9.4 with herd (spring/fall calving) and year weaned as random effects and individual heifer as the subject. Previously reported, heifers supplemented with organic trace mineral sources had a tendency for improved reproductive performance (P = 0.09; ING = 66%, ORG = 76.8%) and a decreased percentage of heifers culled (P = 0.07; ING = 33.7%, ORG = 22.1%) compared with heifers receiving inorganic supplementation. However, in subsequent year previous trace mineral supplementation did not influence (P = 0.65) when cows were culled (ING = 3.01 yr, ORG = 3.20 yr). The number of calves produced per cow did not differ (P = 0.45) between previous trace mineral source supplementation (ING = 2.45 calves, ORG = 2.78 calves). With heifers that were conceived on the study, there were no differences when they were culled (P = 0.25; ING = 2.83 yr, ORG = 3.51 yr) or the total calves produced (P = 0.18; ING = 2.24 calves, ORG = 2.95 calves). To conclude, supplementation of heifer calves with different sources of trace mineral did not affect their longevity in the herd, but results suggest further investigation.

PSLBII-1 Enhancing cattle health and performance through targeted supplement optimization and evaluation

Abstract Our objective is to evaluate and optimize Bovi-MV formulation through its effect on serum mineral/vitamin (M/V) concentrations in cattle and develop a systems approach to oral M/V supplementation through the lifecycle of beef cattle to determine the best management strategy to help reduce M/V deficiencies in young and mature animals. Cow/calf pairs (n = 300 over 2 yr) and follow the calves to harvest late in yr 2. The research is timed to coincide with typical management handling processes (e.g., vaccination of cows before calving and calf processing after birth, before pasture, at weaning time, on induction to the feedlot, and at reimplanting). The calf herd will be divided at birth into treatment (calves whose dams received BoviMV supplement) and control (~150 calves per group). Vitaferst-Care will be provided to the treatment group at processing (vaccination, antiparasitic application) before going to grass (~ 3 mo of age). Bovi-MV will only be given to the treatment group. All calves will be administered a tracer vaccine to assess their immune response. Blood samples will be collected from all calves for antibody titer testing at weaning (~ 6 mo of age). The treatment calves will also receive a booster dose of Bovi-MV at that time. Approximately 90 d after weaning (~ 9 mo of age) antibody titer will be determined immune response was. Calf morbidity, mortality, and performance (average daily gain) will be monitored in the feedlot. An accredited lab will conduct M/V blood analysis; antibody titer testing will be done at a Lakeland College lab. Based on MV and titer to the Bovi-MV supplement and tracer vaccine, the formulation of the Bovi-MV will be evaluated, and recommendations will be made. Based on results from two previous studies evaluating M/V blood concentrations in cattle (Neonatal supplement and Itchy Cow) in Western Canada, vitamin and mineral concentrations tended to be below optimum values, especially in herds provided supplementation free choice. All cows were deficient in vitamin A at calving, averaging 66.27 ± 2.51 ppb, with 50% having nondetectable concentrations. With vitamin E, 8 animals had nondetectable concentrations, only 8 had sufficient concentrations, and those with detectable concentrations averaged 3.16 ppm ± 2.17. Cows had sufficient iron ug/mL averaging 2.14 ± 1.02 and selenium ug/mL 0.09 ± 0.02. As Cheryl Waldner et al. (2023) reported, 24 to 43% copper deficiency is prevalent in cattle in the southern halves of the three prairie provinces. Armed with this information, this study is the first step in developing a systems approach to year-round management of the cow herd’s vitamin and mineral supplementation.

The Overall Situation of the Livestock and Evaluation of the Quantity of Beef Production in Batna City (Algeria)

Background: This study aims to determine the evolution of beef production during the last five years (2019-2023) in Batna city (Algeria) Methods: For the realization of this work we carried out an investigation at the municipal slaughterhouse of the city. During this investigation, we also took slaughter data. These include the weight of the carcasses and the classification of the slaughterhouse according to the categories of animals slaughtered. Moreover, a study was conducted to gather data from the Directorate of Agricultural Services (DSA) and the Ministry of Agriculture and Rural Development (MADR) regarding the number of cow herds in the studied city. The goal of this strategy is to comprehend the general state of the city’s livestock, including those destined for fattening and slaughter. Result: The animals intended for slaughter are mainly male cattle; of the young bulls and calves, the females admitted are cull dairy cows ( greater than 8 years). The results of this investigation showed that the beef production has experienced a remarkable drop from 1262560 kg in 2019 to 473430 kg in 2022, a slight change observed in 2023 but which still remains weak.

Recipients' and Environmental Factors Affecting the Pregnancy Rates of a Large, Fresh In Vitro Fertilization-Embryo Transfer Program for Dairy Cows in a Commercial Herd in China.

The main objective of this study was to determine the influence of the recipient dairy cows' breed, lactation number, estrus condition, the type, location and volume of the corpus luteum (CL) and the time of year that the embryo transfer (ET) was performed on the pregnancy rates of a large, fresh in vitro fertilization-embryo transfer program for dairy cows in a commercial herd in China. The recipients were from a herd of dairy cows in Ningxia, a province in northwest China, and we statistically analyzed the data of 495 cows from 2021 to 2023. Cumulus oocyte complexes (COCS) were isolated from follicular fluid obtained through ovum pick-up (OPU) and oocytes were incubated 20-22 h for in vitro maturation (IVM). Embryos were obtained after 10-12 h of in vitro fertilization (IVF) and six days of in vitro culture (IVC). Embryos at the morula or blastocyst stage were transferred to randomly chosen recipients (n = 495). The influence of recipients' breed (Holstein or other), recipients' lactation number (heifers or cows), estrus type (natural or synchronized), CL type (homogeneous, CLhom or cavitary, CLcav), CL side (left or right), volume of the CL and season of transfer (spring, autumn or winter) on pregnancy rates were determined. The pregnancy rates were analyzed by binomial logistic regression with IBM SPSS statistics software, version 26. Pregnancy rates after ET to Holstein cows and other breeds were 43.49% and 42.68%, respectively (p > 0.05). Regarding age, pregnancy rates were 45.56% for heifers and 30.77% for cows (p < 0.05). Pregnancy rates following ET during natural and synchronized estrus were 44.41% and 41.5%, respectively (p > 0.05). Pregnancy rates with a left- or right-side CL were 40.18% and 45.65%, respectively (p > 0.05). The pregnancy rates achieved with a CLhom and CLcav were 44.44% and 39.68%, respectively (p < 0.05). The rates obtained in spring, autumn and winter were 49.26%, 46.02% and 34.64%, respectively (p < 0.05). Moreover, it was found that pregnancy rates were higher in recipients with a CL volume measuring greater than 10 cm3 compared with those with a CL volume measuring less than 10 cm3 (p < 0.05). The comparisons showed that recipients' breed, estrus type or side of the CL had no effect, but the recipients' lactation number, ET season and the type and volume of the CL have significant effects on pregnancy rates during ET.

A narrative review of factors affecting the welfare of dairy cows in larger Australasian pasture-based production systems

On the basis of current growth trajectories, pasture-based dairies of the future are likely to be bigger, have higher stocking rates and feed more concentrate to cows. This review uses the five-domains framework to consider risks to the welfare of dairy cows in these larger intensified pasture-based production systems. The factors considered in this review can be broadly categorised as (1) emerging welfare risks that can be managed, (2) emerging welfare risks that require research to be managed, or (3) persisting and/or exacerbated welfare risks. First, large herds could be subject to welfare risks associated with more stock per labour unit, longer milking times and longer distances walked to and from the dairy. To counter this, the time that cows in large herds spend off pasture can be reduced by splitting the herd into several more manageable groups, and animal-monitoring technologies can help identify health challenges with a reduced stockperson to animal ratio. Cow body condition and productivity can be maintained at high stocking rates by improving pasture production and feeding a higher proportion of concentrate. The risk of ruminal acidosis may then be reduced by appropriate transition feeding regimes and rumen buffers. Second, ensuring social stability and reducing competition may become difficult as herd sizes increase and feeding becomes more intensive. The resulting variability in feed intake, increased agonistic behaviour and social stress present emerging risks to cow welfare. Research is needed to better understand the social behaviour of cows in large intensive pasture-based herds, and how the design of the pre-milking area, the feeding pad and pasture feeding regimes (i.e. quantity and timing of pasture allocation) can improve accessibility for more vulnerable animals. Finally, intensive pasture-based dairies of the future will continue to face welfare challenges relating to lameness, mastitis and cull-cow management, whereas risks due to environmental exposure may be exacerbated by the removal of shelterbelts to facilitate irrigation. These require continued efforts in research (e.g. ways of incorporating shelter into intensive grazing systems), development (e.g. pathway to market for aged beef) and extension (e.g. improved record keeping and benchmarking of lameness and mastitis).

Продуктивные особенности коров голштинской породы разных генетических линий

Abstract. The purpose of the study is to investigate the productive features of Holstein cows of different genetic lines. Methods. The research was carried out in two breeding enterprises of the Sverdlovsk region on the livestock of Holstein cows. Groups of animals were formed by the method of pairs of analogues, taking into account the age of animals in lactation, physiological condition, live weight, lines of breeding bulls. The coefficient of milk content was estimated by the calculation method. The lactose, fat and protein content in milk was determined using a “Bentley 150” device. Somatic cells were determined on the “Somatos-M” device. Bacterial contamination was studied using a reductase assay. Prolactin was determined by enzyme immunoassay, cortisol by immunochemiluminescent method. Results. In terms of milk yield for 305 days of lactation and protein content in milk, Montwick Chieftain cows had an advantage with a significant difference between the groups (P &lt; 0.05). The animals of the Reflection Sovering line were the best in terms of fat content, the difference between the groups was insignificant. The lowest content of somatic cells in milk and bacterial contamination was found in animals of the Reflection Sovering and Vis Back Idial lines. The best indicators of the leukocyte profile were determined in animals of the Vis Back Idial and Montwick Chieftain lines. In terms of glucose and total protein content in the blood, cows of the Montwick Chieftain line had an advantage, in terms of the amount of urea, animals of the Montwick Chieftain and Vis Back Idial line affiliation. The highest level of total lipids in the blood is typical for cows of the Reflection Sovering line. Scientific novelty. The research results indicate the relationship of biological characteristics and milk productivity with different lines of breeding bulls. The leukocyte profile of this herd of cows of different genetic lines in breeding enterprises of the Sverdlovsk region was studied for the first time. Practical significance. The results of the research can be used in breeding enterprises in order to increase the milk productivity of cows.

Polish Dairy Farm Transformations and Competitiveness 20 Years after Poland's Accession to the European Union.

Poland is one of the leading milk producers in the EU, being the fifth largest after countries such as Germany, France, Italy, and the Netherlands. From Poland's accession to the European Union in 2004 up to 2022, Polish milk production experienced dynamic development. In this, there occurred a strong decline in the number of dairy farms (by -78%) and the number of cows (by -21%), an increase in dairy herd size (3.5 times) and increase in milk production (+60%) and milk yield per cow (by +62%). These were among the highest growth dynamics among the analysed countries. As a result of this significant transformation, Poland maintained an important position in milk exports, with a 31% export share in production in 2022. The scale of milk production was the basic factor determining the efficiency and competitiveness of dairy farms in Poland. Milk yield, farmland productivity, labour productivity, milk price, and the Corrected Competitiveness Index (based on labour and land opportunity costs) all showed a positive relationship with cow herd size on the farm. Milk production is highly uncompetitive for smaller farms (<15 cows). Despite substantial public support, the smaller farms, where subsidies equal up to 47% of total production value, could not earn sufficient income to cover the cost of capital, risk, and management in 2008, and even more so in 2021. This is because the farm income is too small to cover the extremely high opportunity cost of labour. The larger farms (with 30 cows and more) are competitive and responsible for the majority (~60-70%) of milk produced and delivered to the market. The most challenging from the sectoral policy point of view are medium farms (10-29 cows), whose share in production and deliveries is still important. To survive as economically viable units, these farms have to increase in scale and improve productivity. Otherwise, they will be gradually supplanted by larger farms.

A field investigation of the impact of the interaction between IBR vaccination and insemination time in cow herd: Reproductive and economic perspectives

A field investigation of the impact of the interaction between IBR vaccination and insemination time in cow herd: Reproductive and economic perspectives

POLIMORFIZM W GENIE UCP3 A CECHY UŻYTKOWOŚCI MLECZNEJ BYDŁA

The protein UCP3 can perform several different functions such as regulating lipid metabolism in mitochondria, protecting against oxidative stress, and regulating energy metabolism, and proper metabolism is crucial in cows during lactation. The aim of the study was to determine the frequency of genes and alleles and their influence on milk production traits for four SNP (rs467440799, rs446854207, rs444645335, and rs440638775) polymorphisms in the UCP3 gene. The experiment was conducted in a herd of Polish Holstein-Friesian black and white cows, and genotypes were determined using the PCR-RFLP method. The conducted research showed that the analyzed SNPs significantly (p ≤ 0.05) influence milk production traits such as milk yield, fat yield, and protein yield.

Glycal Forte® (calcium-stabilized glycerol), a novel feed ingredient, promotes rumen function in dairy cows

Abstract Good nutritional practices are essential to support the high milk production of modern dairy cows. This requires an active rumen microbial biomass which supplies microbial protein and short-chain fatty acids to the cow. Glycal Forte® (GF) a calcium-stabilised glycerol product, increased microbial biomass in an in vitro gas production study, by some 37%. The efficacy of GF was substantiated in a trial with high-producing dairy cows fed a TMR with or without GF for 28 d. Cows fed GF showed behaviour differences. Chewing was reduced from 710 GF vs 769 for the control (CON) min/d; P=0.01 and they spent more time in an inactive state (429 GF vs 383 CON min/d; P=0.01). There was a statistically significant improvement in feed efficiency with GF (2.19 CON vs 2.34 GF kg ECM/kg dry matter intake (DMI); P=0.03). Feed efficiency has an important bearing on costs and profitability of a dairy operation. Cows fed GF yielded an improved profit of $1.45 per cow per day over 28 d with an ROI of 2.23. Extrapolated to a 100 dairy cow herd for 28 d gave an additional profit of $4,060. Milk yields continued to show benefits for 70 d in milk (DIM) after the GF treatment was stopped, showed a numerical increase in milk yield of 3.2 kg/d. The benefits in rumen function continues after the feeding of GF had ceased. In summary, this trial with high-producing dairy cows was consistent with the in vitro trial data and showed that GF can improve rumen function manifested as less time chewing, more inactive time and most importantly, improved feed efficiency. This has both economic and environmental advantages in that dairy cow productivity can be enhanced solely by nutritional means

Bovine Digital Dermatitis: Treponema spp. on trimming equipment and chutes – effect of washing and disinfection

BackgroundDigital dermatitis (DD) is a contagious bovine foot disease causing reduced animal welfare and negative economic consequences for the farmer. Treponema spp. are the most important causative agents. Studies indicate that trimming equipment can transfer DD-associated treponemes between cows. The aim of this observational study in 22 DD-positive Norwegian dairy herds was to investigate the risk of transferring Treponema spp. with trimming equipment and chutes after claw trimming, and after washing and disinfection. Swabs from the trimming equipment and chutes were collected from nine different locations, at five different time points. Bacterial DNA was extracted from 647 swabs and analysed by qPCR for Treponema spp. In addition, 172 swabs taken immediately after trimming, were analysed by a multiplex qPCR targeting T. phagedenis, T. pedis and T. medium/vincentii. Biopsy sampling from DD lesions was performed on cows in the same herds during trimming. Altogether 109 biopsies were analysed by FISH for confirmation of the DD diagnosis and identification of Treponema phylotypes (PTs).ResultsHigh numbers of Treponema spp. were detected from all nine locations on the trimming equipment and chutes immediately after trimming, and T. phagedenis was detected on two or more locations in all but two herds, 1 and 19. There was a decline in the amount of Treponema spp. after washing and disinfection. The belly belt, the cuff, and the footrest on the chute had the highest proportion of positive samples after disinfection. The belly belt had the highest copy numbers of all nine locations (median = 7.9, max = 545.1). No Treponema spp. was detected on the hoof knives after disinfection. Treponema phagedenis, T. pedis, and Treponema phylotype 3 (T. refringens) were detected by FISH analysis of the biopsies. Treponema phagedenis was detected in biopsies from all herds except 1 and 19.ConclusionThis study shows that DD-associated Treponema spp. were present on the trimming equipment and chutes after trimming cows in DD-positive herds. Washing and disinfection reduced the load of Treponema spp. However, large differences in Treponema spp. between different locations were documented. High copy numbers on the grinder and the chute after disinfection, indicates that sufficient cleaning and disinfection of these locations is difficult, and that passive transfer of DD-associated treponemes (viable or not) is possible.

The Past, Present and Future of chimazambi instrument of the Ndau people of Zimbabwe

This research investigated the factors leading to the decline of the chimazambi musical instrument of the Ndau people of Rusitu Valley in Chimanimani District of Chief Ndima area, Manicaland Province in Zimbabwe. Chimazambi is a Ndau indigenous string instrument which is slightly similar to the chipendani of the Karanga people. While the instrument was performed by the Ndau people in the past, there is no adequate scholarship regarding the origin, use of instrument in the modern times and the future of chimazambi. The study therefore traces the origin of chimazambi instrument. It investigates ways in which the instrument was played as well as its purpose within the Ndau culture. The research adopted a qualitative method, an ethnographic field work. In depth interviews, participant observation, focus group discussions and document analysis were utilized to collect data. The study was mainly informed by postcolonial theory, supported by Ndau epistemologies. The findings indicate that chimazambi is central in the lives of the Ndau people. It has been revealed that chimazambi was well known for entertaining herd boys. The study further discovered that some identified elders were engaging chimazambi for spiritual healing purposes. Christianity, modernization and migration were discovered to be the major effects responsible for the decline of chimazambi. The study recommends the revitalization of the instrument through digitalizing, archiving and commercializing it. There is also a need to include the instrument in various modern ceremonies and festivals.

Comparison of different methods for monitoring of acid base status in dairy cow herds

Acid-base disorders in dairy herds can be diagnosed by determining urinary net base excretion (NBE). Modifications of this method are the differential NBE (dNBE) with determination of the urinary concentration-independent base-acid ratio (BAR) and the simplified NBE test with reduced urine volume (sNBE). The aim of this study was to compare these methods among themselves and as a pooled test, in their assessment of cow group acid base status as well as to derive recommendations for practical use. The concentrations of NBE, dNBE, and sNBE were measured in urine samples derived from 855 German-Holstein cows in 127 cow groups at different stages of lactation. BAR was then calculated. dNBE and BAR were determined both individually per cow and as a pool of a group. Mixed linear models were used to examine the relationship between the mean of the individual animal values and the pool sample result of a group for these two parameters. In addition, all groups were evaluated with respect to acidotic or alkalotic load based on their single animal results of the respective methods, the mean values formed from them, and the measured pool result. By using the single animal BAR as reference, the sensitivity and specificity of the different methods were calculated. The calculated mean values of the individual measurements of dNBE and BAR differed from the measured value in the pool sample, especially in low and high measurement ranges. In the group assessment, NBE showed the best combined sensitivity and specificity for the detection of acid base disorders. The dNBE pool assay showed satisfactory specificity with respect to acidosis and alkalosis, while the sNBE on an individual animal basis and the BAR determination in the pool showed satisfactory sensitivity with respect to acidosis. It was shown that NBE determined in individual animal samples is well suited for the assessment of acid base status of cow groups and can therefore be recommended for practical use. The determination of dNBE as well as BAR as a pool test is not sufficient for the detection of alkalotic load in cow groups but may help to confirm an existing acidotic load.