Herders Research Articles

Dairy Producers Who Market Their Surplus Progeny as Calves Use Germplasm With Slightly Lighter and Less-Conformed Carcasses Than Producers Who Rear Their Surplus Progeny Beyond Weaning.

Understanding dairy producer mindset in service sire selection can provide useful information for different junctures along the commercial and extension animal breeding chain. It can aid the targeted marketing of bulls based on farm production systems but also provide useful information for delivering bespoke extension services. The objective of the present study was to examine if differences exist among dairy producers in their choice of dairy and beef service sires depending on the life stage at which the surplus progeny generated from such matings exit the dairy farm. This was predominantly based on evaluating the breed of beef sires used but also their genetic merit for calving difficulty and carcass traits, namely, carcass weight, conformation, and fat score; differences in genetic merit among dairy sires as well as among the dairy cows themselves were also considered. The objective was accomplished through the cross-sectional analyses of progeny fate data from 1,092,403 progeny born in 4,117 Irish dairy herds. Herd-years were categorized into one of four systems based on when the surplus progeny exited the dairy farm: (1) calves sold <70 days of age, (2) cattle sold as yearlings between 250 and 450 days of age, (3) prime cattle sold for finishing (slaughtered between 8 and 120 days of exiting the dairy farm), or (4) prime cattle sold for immediate slaughter (i.e., slaughtered within 7 days of exiting the dairy farm). The mean genetic merit of both the cows and service sires used across the four different systems was estimated using linear mixed models. Of the beef service sires used in herds that sold their surplus progeny as calves, their mean predicted transmitting ability for carcass weight and carcass conformation score was just 2.00 kg and 0.11 scores [scale of 1 (poor) to 15 (excellent)] inferior to the beef service sires used in herds that sold their surplus progeny as prime cattle for immediate slaughter. Similar trends, albeit of smaller magnitude, were evident when comparing the genetic merit of the dairy service sires used in those systems. Cows in herds that sold their surplus progeny as calves were genetically less likely to incur dystocia as well as to have lighter, less-conformed, and leaner carcasses than cows in herds that sold their surplus progeny post-weaning. Hence, results from the present study suggest that diversity in herd strategy regarding when surplus progeny exit the herd influences service sire selection choices in respect of genetic merit for dystocia and carcass attributes. That said, the biological difference based on the current pool of available service sires is small relative to the dairy producers that sell their surplus progeny as young calves; when expressed on a per standard deviation in genetic merit of the beef service sires used across all herds, the difference between extreme systems was, nonetheless, approximately half a standard deviation for carcass weight and conformation.

Randomized controlled trial of reinsemination strategies in dairy cows diagnosed nonpregnant using color flow Doppler ultrasonography on d 21 after insemination

The objective of this study was to quantify the reproductive performance of 4 reinsemination strategies in cows diagnosed nonpregnant using corpus luteum color flow Doppler ultrasonography on d 21 after last insemination. A total of 2,140 color flow Doppler ultrasonography exams from 845 Holstein cows from 10 commercial dairy herds were used in this study. Farms were visited every 2 wk by the research team. On d 7 after insemination, cows were enrolled in a randomized controlled trial to be assigned 1 of 4 treatments if they were subsequently diagnosed nonpregnant on d 21. All cows were then examined on d 21 using Doppler ultrasonography to diagnose nonpregnancy. Treatment A (CON) was the control group: nonpregnant cows were programmed to receive a standard Ovsynch protocol starting on d 32. Nonpregnant cows in treatment B (GnRH) were injected i.m. with GnRH on d 21 after insemination and reinseminated immediately. Cows in treatment C (2×GnRH) received an i.m. injection of GnRH on d 11 after insemination. If diagnosed nonpregnant on d 21 after insemination, they were injected i.m. with GnRH on d 21 after insemination and inseminated immediately. Cows in treatment D (Resynch) received an i.m. injection of GnRH on d 14 after insemination. If diagnosed nonpregnant on d 21 after insemination, they were injected i.m. with PGF2α on d 21 after insemination and injected i.m. with GnRH on d 24. Then, a standard Ovsynch protocol was started on d 32. Statistical analyses were performed using mixed logistic regression models accounting for cow clustering and herd effect. A theoretical simulation was performed for each treatment to quantify the proportion of cows remaining nonpregnant 42 d after initial insemination. Of the 2,140 color flow Doppler ultrasonography exams in the study, 870 (40.6%) had a Doppler score of D0 (n = 444) or D1 (n = 426), which were indicative of nonpregnancy and used for data analysis. Overall, the number of exams assigned to each treatment was as follows: CON = 223 (25.6%), GnRH = 214 (24.6%), 2×GnRH = 220 (25.3%), and Resynch = 213 (24.5%). The final mixed multivariable logistic regression model included treatment, parity, days in milk at enrollment, and herd. Conception risk at first insemination following enrollment was 31.4, 20.6, 31.9, and 48.7% for treatments CON, GnRH, 2×GnRH, and Resynch, respectively. Based on the simulation, if 100 cows were diagnosed nonpregnant at their color flow Doppler ultrasonography exam on d 21 after last insemination, the total number of cows remaining nonpregnant 42 d after the initial insemination would be 69, 72, 58, and 51 for treatments CON, GnRH, 2×GnRH, and Resynch, respectively. Thus, the treatments used in groups 2×GnRH and Resynch for cows diagnosed nonpregnant on d 21 after insemination yielded better results than those used in the other groups.

Financing Beef Cow Herd Building for Beginning Ranchers

Intensive capital requirements relative to cash flows available inhibit the entry of beginning producers into the cattle industry. Here, we propose and analyze a strategy for beginning ranchers to build a herd. Over a three-year cycle, new producers borrow cash needed to purchase 450- pound heifers in the first year, breed heifers, sell open heifers and bull calves, retain heifer replacements, rebreed the two- year-old cows, and eventually sell bred two-turning-three cows 27 months after the initial heifer purchase. The goal is to retain a group of debt-free heifers. Analyses conducted over 14 cycles of 27 months each across three cattle markets, Oklahoma, Nebraska, and North Dakota, indicate that this herd- building strategy appears to be financially feasible for new producers, in most cycles. Positive net cash flows occurred for producers in Oklahoma for 13 of 14 cycles, 11 of 14 cycles in North Dakota, and 10 of 14 cycles in Nebraska. Positive net returns were realized in at least 12 cycles in each location. Sensitivity analyses were conducted on revenues and costs to evaluate the robustness of the strategy.

In Vitro and In Vivo Evaluation of the Effects of a Compound Based on Plants, Yeast and Trace Elements on the Ruminal Function of Dairy Cows

The high production levels reached by the dairy sector need adjustment in nutritional inputs and efficient feed conversion. In this context, we evaluated a compound (QY—Qualix Yellow) combining optimized inputs in trace elements and 20% MIX 3.0. In a first step, the effects of MIX 3.0 on ruminal function were assessed in vitro by incubating ruminal fluid with the mixture at a ratio of 20:1. The results obtained encouraged us to test QY in vivo, on a herd of dairy cows. The herd was divided into one group of 19 dairy cows receiving the compound and a control group of 20 animals conducted in the same conditions, but which did not received the compound; the production performance and feed efficiency of the two groups were compared. In vitro experiments showed improved digestion of acid and neutral detergent fibres by 10%. The propionate production was enhanced by 14.5% after 6 h incubation with MIX 3.0. The plant mixture decreased the production of methane and ammonia by 37% and 52%, respectively, and reduced the number of protozoa by 50%. An increase in milk yield by 2.4 kg/cow/d (p &lt; 0.1), combined with a decrease in concentrate consumption of 0.27 kg DM/cow/d (p &lt; 0.001), was observed in vivo after consumption of the compound. Sixty-six days after the beginning of the trial, methane emissions per kg of milk were significantly lower in the group receiving QY. In conclusion, MIX 3.0 induced change in ruminal function in vitro and, when it entered into the composition of the QY, it appeared to improve feed efficiency and production performance in vivo.

Heat synchronization and the effectiveness of insemination of cows of Holstein breed under the conditions of the dairy complex

The food security of country is largely determined by the development of animal husbandry branches. Dairy cattle breeding is of particular importance, which has been actively developing in recent years due to the modernization of farms and complexes, the introduction of innovative technologies and the formation of a highly productive breeding herd. The most important link in the development of dairy cattle breeding is the reproduction of the herd. Modern technologies make it possible to use hormonal drugs in order to optimize the reproductive traits of animals. The results of clinical and experimental studies have shown the important role of hormones in the regulation of physiological functions, as well as the possibility of their use for directed changes in metabolism, productivity and fertility of animals. The purpose of the research was to assess the influence of methods of synchronization of heat of cows on the pregnancy rate under the conditions of the dairy complex. The research data on the effectiveness of insemination when identifying animals in visually heat and using Heatime neck strips, as well as when using heat synchronization programs such as Presynch and Double Ovsynch have been presented in the article. The research has been carried out under the conditions of a modern dairy complex on a highly productive herd of cows of Holstein breed. Differences in the effectiveness of insemination by using the studied methods were revealed from 49,1 to 72,5 %. The highest conception rate has been observed in first-calf heifers (83,0 %) and cows (62,5 %) inseminated using the Double Ovsynch protocol. The dependence of the level of conception rate on the presence of diseases suffered by cows during the newcalving period and until the moment of insemination has been noted. In sick animals, the conception rate for groups of first-calf heifers and cows was significantly lower than in healthy animals. Thus, according to the Double Ovsynch insemination protocol, the conception rate in healthy animals was 83,7 %, and in those who were ill – 65,2 %. The research results confi rmed the validity of stopping the use of the Presynch protocol and completely transferring the dairy herd of cows to synchronization and insemination using the Double Ovsynch protocol.

Investigating anogenital distance and antral follicle count as novel markers of fertility within a herd of cows with positive or negative genetic merit for fertility traits

Using early-in-life markers of reproductive characteristics may enhance the speed and success of genetic improvement in fertility. We investigated 2 phenotypes that can be measured early in life and are moderately heritable to determine their association with traditional measures of reproductive success and genetic variation under a seasonal-calving, pasture-based system. Cows were bred to be divergent in the New Zealand Fertility Breeding Value, which estimates genetic merit for fertility. Cows consisted of 2 groups with an average positive (+5%) or negative (-5%) genetic merit for fertility traits and were expected to have large diversity in reproductive outcomes. Calves were genotyped at 41 ± 3.1 d of age (mean ± SD; n = 538), and antral follicle counts (AFC) were measured when they were postpubertal heifers before their first breeding (416 ± 15 d old; 92-d range; n = 520). The anogenital distance (AGD) was measured in 478 primiparous cows of this same population 50 to 60 d after the breeding start date when they were 881 ± 25 d old (145-d range). The AGD was shorter in animals with a positive genetic merit for fertility traits (based on parent averages). An indicator of herd reproductive success in a seasonal-calving system (recalving by 6 wk in lactation 2) was chosen for logistic regression with cross-validation, and if significant, a cut-off was calculated that categorized animals into groups. Both linear and quadratic regression was undertaken, and the model with the greatest sensitivity for detection of nonpregnant cows used. The AGD linear model was significant with a sensitivity of 64% and a specificity of 48%. This model resulted in a cut-off of 102 mm, which we used to classify cows as short (≤102 mm) or long (>102 mm) AGD animals. Primiparous cows with a short AGD were more likely to be pregnant within the first 3 and 6 wk of mating, and become pregnant as a primiparous cow, than those with a long AGD. The time from calving to conception was 20 d earlier in short AGD compared with long-AGD cows. None of the models tested for AFC were significant; therefore cows were categorized into 3 groups based on previous work in seasonal systems. However, associations between fertility phenotypes and AFC group were limited. Genomic regions of interest for AGD and AFC did not overlap, indicating phenotypes were genetically independent. Overall, AGD appears as a promising early marker of fertility in seasonal grazing systems.

Effect of an integrated veterinary herd health program on fertility performance and incidence of reproductive disorders in five dairy herds.

The study was carried out in 5 dairy herds of Polish Holstein-Friesian cows. The average milk yield was about 9000 kg per year. For each herd, the following fertility parameters were calculated at the start of the program and 4 years later: first- service conception rate, services per conception, length of inter-calving period and culling rate due to infertility. The incidence of silent heat, ovarian cysts, ovarian afunction, retained placenta and clinical endometritis was also recorded. Four years after implementation of the program, the average first-service conception rate increased from 43.2% to 51.2%. In three herds the differences were statistically significant (p⟨0.05). There was also a decrease in the number of services per pregnancy and in the culling rate due to infertility. Fertility performance was maintained in two herds. The average incidence of silent heat decreased from 38.1% to 29.7% and the difference was statistically significant (p⟨0.05) in three herds. There was no significant reduction in incidence of other reproductive disorders during the 4 years except for clinical endometritis in one herd. The average milk yield increased from 9300 kg to 9530 kg milk per cow per year. In conclusion, the results indicate that the implementation of the integrated veterinary herd health program improved or maintained fertility performance despite an increase in milk yield.

Improving the selection of cows according to a complex evaluation indicator

The expediency of improving the indicators of judgment assessments of individual breeding characteristics of the Hereford cattle breed is justified. The proposed method of selecting cows according to a complex evaluation indicator is based on the principle of a point assessment with the correction of the selection significance of the absolute value of some economically useful characteristics that are definitely related to the economy of animal breeding. At the same time, it is characterized by the Breeding Value Index (BVI), which allows you to complete a selection group of cows in breeding herd with breeding value from 70 points and above. The main values of constructed index must select or create such genotypes that would combine the most important and desirable combinations of breeding traits. The method is universal for cows of different breeds, types, herds, provides breeding and formation of more highly productive and technological animals on the basis of meat productivity.

Black-and-White Cow Herd Consolidation Ways by Breeding Traits

In the context of large-scale selection and the widespread use of methods of initial genomic evaluation of stud bulls, a careful selection of breeding pairs is of particular importance when it is necessary to consolidate animals in dairy herds according to the traits of conformation, body composition and dairy type intensity. The method of linear evaluation of physique features, adopted in Russia, coincides with the standard method system approved by the ICAR in the main approaches and characteristics. According to the results of a linear evaluation of bulls used in a herd of black-and-white cattle, it was found that the average score on the main parameters of the conformation for technologically significant traits (dairy type intensity, the condition of the animal’s limbs) has been within 5.00…5.90 (points). At the same time, the traits that characterize the main parameters of the udder of cows, depth and breadth measurements, need to be improved. Based on the results of evaluating the prepotent properties of the bulls by linear traits, the optimal structure of the dairy herd has been determined, in accordance with the presence of the main lines in the Holstein breed.

PREVALENCE AND ETIOLOGICAL FACTORS CAUSING THE RETENTION OF THE PLACENTA IN COWS

Among the main reasons for the retention of the membranes, weakening of the contractile function of the uterus, as well as fusion of caruncles with cotyledons as a result of inflammatory processes arising in them. At the same time, hemodynamic disorders and hypotonia of the uterus, according, noticeably prevail over the rest. The reason for the retention of the membranes, should be considered the blood circulation in the maternal part of the placenta, due to the high concentration of unbound heparin in it and the low concentration of ascorbic acid. Hyperkinesia, allocated by a number of authors animals, in all likelihood, does not play such a big role. Purpose. To study the prevalence and etiological factors responsible for the retention of membranes in cows. Materials and methods. For the period from 2015 to 2021, in the herds of cows belonging to the Krasnodarskoe EF and the Kuban EF and were under supervision, 194 cases of pathogenic process due to the retention of membranes in cows. The number of dairy cows in the herd in different years ranged from 795 to 845, and averaged 830 heads. Of these, in 2015, the retention of membranes was registered in 22 cows (2.65%), in 2016 in 19 (2.29%), in 2017 in 32 (3.86%), in 2018 in 35 (4 , 2%), in 2019 for 29 (3.5%), in 2020 for 26 (3.02%) and in 2021 for 31 cows (3.73%). The research results were subjected to mathematical processing using standard statistical analysis programs for the IBM PC. The reliability of the results was determined by the parametric Student’s test. Results. The results of processing the obtained data indicate that from the second half of April to August, the rate of retention of membranes in cows, in relation to the average annual, increases markedly and reaches 12.35% of all calving cows. Meanwhile, many studies carried out in the conditions of farms and complexes indicate that in the warm season, the pathology of childbirth associated with the retention of the membranes is significantly reduced. In this regard, we made an attempt to analyze the conditions of keeping, feeding and insemination of cows prior to the development of this pathology in animals in training and experimental farms. Conclusion. Analyzing the etiological factors that determine the retention of the membranes in cows of educational and experimental farms, it can be concluded that the development of this pathology of the birth period in cows is in close connection with the state of the fodder base in farms and with the presence of helminth infestation in animals. A regularity was revealed between the presence of traumatic foreign objects in the cows’ net, causing traumatic reticulitis, and the subsequent occurrence of chronic placentitis in them, leading to the retention of the membranes.

Genetic Parameters for Maternal Performance Traits in Commercially Farmed New Zealand Beef Cattle.

Simple SummaryEnhancing maternal performance in a beef cattle enterprise can increase overall profitability. Knowledge of the degree of genetic variation in relevant traits is required to inform breeding decisions in commercial environments. The objective of this research was to examine the inheritance of maternal performance traits and to evaluate the trait complementarity among reproduction, live weight, hip height, body condition score and maternal weaning weight in 15-month-old heifers, 2-year-old cows and mature cows using data collected on commercial New Zealand hill country farms. Results from this study indicate that almost no genetic variation exists for pregnancy outcomes in 15-month-old heifers and mature cows under New Zealand farming conditions but there is potential to improve reproductive performance in 2-year-old cows through genetic selection. Cows with greater genetic potential for rebreeding performance after their first calving season were more likely to have greater live weight, hip height and body condition score as heifers but were unlikely to become larger cows at maturity. Cows with genetics for greater maternal weaning weight were more likely to carry lower body condition and those animals tended to show greater reproductive performance.Maternal performance is a major driver of profitability in cow-calf beef cattle enterprises. The aim of this research was to evaluate the inheritance of maternal performance traits and examine the intercorrelation among reproduction, live weight, hip height, body condition and maternal contribution to calf weaning weight in 15-month-old heifers, 2-year-old cows and mature cows in New Zealand beef herds. Data were collected on a total of 14,241 cows and their progeny on five commercial New Zealand hill country farms. Heritabilities were low for reproductive traits in heifers and mature cows (0–0.06) but were greater in 2-year-old cows (0.12–0.21). Body condition scores were lowly (0.15–0.26) and live weights (0.42–0.48) and hip heights (0.47–0.65) highly heritable in heifers, 2-year-old cows and mature cows. Results indicate that 2-year-old cows with higher genetic potential for rebreeding ability may have greater genetic merit for live weight, hip height and body condition as heifers (rg = 0.19–0.54) but are unlikely to be larger cows at maturity (rg = −0.27–−0.10). The maternal genetic effect on weaning weight had a heritability of 0.20 and was negatively genetically correlated with body condition score in lactating cows (rg = −0.55–−0.40) but positively genetically correlated with rebreeding performance (rg = 0.48).

Lameness in Early Lactation Is Associated with Lower Productive and Reproductive Performance in a Herd of Supplemented Grazing Dairy Cows.

Simple SummaryIt has been reported that the detrimental impact of clinical diseases, such as mastitis, on lactation and reproduction is highest when the first clinical case occurs in early lactation. Therefore, we run an observational study on 7156 lactations from highly supplemented grazing dairy cows to evaluate the association of the timing of lameness case occurrence in lactation with productive and reproductive performances in dairy cows. We found that cows getting lame before the first service produced less milk than cows getting lame later in lactation (i.e., after the first service), and that both groups of lame cows produced less milk than healthy ones. We also found that cows becoming lame after the first service had an 87 d longer calving to pregnancy interval than healthy herd mate cows and that cows turning lame before the first service had an 38 d longer calving to pregnancy interval than healthy herd mates. In conclusion, the timing of lameness case occurrence in lactation is associated with its impact on productive and reproductive performances in dairy cows.The main aim of this study was to assess the associations between the timing of lameness clinical case occurrence in lactation with productive and reproductive performances in grazing Holstein cows. A cohort study was carried out on a dataset with records from a commercial dairy herd (Buenos Aires, Argentina) for cows that calved and were dried off from January 2010 through June 2017. The first recorded event of lameness per lactation was considered for the study. Criteria for lactation inclusion included not having uterine diseases, mastitis, or anovulatory cysts during the studied risk period (i.e., up to 200 DIM). Therefore, a total of 7156 out of 20,086 lactations were included in the statistical analysis. The association between lameness case occurrence in lactation (cows not lame (LG0) vs. lame cows between parturition and first service (LG1) vs. lame cows between first service and first pregnancy (LG2)) with productive (i.e., accumulated milk yield to 150 DIM (MILK150) and 300 DIM (MILK305)) and reproductive performances (hazard of insemination and pregnancy) was analyzed with linear regression models and proportional hazard regression models, respectively. Lame cows produced 161 and 183 kg less MILK150 and MILK305 than non-lame herd mates, respectively. Moreover, LG1 cows produced 216 kg less MILK150 and 200 kg less MILK305 than LG0 cows, and LG2 cows also produced 58 kg less MILK150 and 158 kg less MILK305 than LG0 cows. The LG1 cows had a lower hazard of service than LG0 cows (HR = 0.43, 95%CI = 0.39–0.47). Furthermore, LG1 cows had a lower hazard of pregnancy than LG0 cows (HR = 0.52, 95%CI = 0.46–0.59) and took longer to get pregnant than LG0 cows (median [95%CI], 139 [132–144] vs. 101 [99–103]). Moreover, LG2 cows had a much lower hazard of pregnancy than LG0 cows (HR = 0.08, 95%CI = 0.05–0.12) and much longer calving to first pregnancy interval than LG0 cows (188 [183–196] vs. 101 [99–103]). In conclusion, cows that become lame in early lactation produce less milk and have lower hazards of insemination and pregnancy than herd mates that are healthy or become lame later in lactation. In addition, cows that become lame immediately after the voluntarily waiting period have the poorest reproductive performance (i.e., they have the lowest hazard of pregnancy and the longest calving to pregnancy interval).

SOURCES OF FINANCING AGRICULTURAL ACTIVITIES IN DAIRY FARMS WITH DIFFERENT SCALES OF COW REARING

The aim of the research was to evaluate the sources of financing agricultural activities in farms specialized in milk production. The subject of research was a group of family farms located in the Podlaskie and Mazowieckie voivodeships (provinces). The criterion for farm division was the number of cows in the basic herd. There was also an assessment of the most important factors conducive to the development of dairy farms. To do so, the opinions of dairy farmers were used, and their views in this regard were expressed on a five-point Likert scale. The research was conducted on a sample of 100 farms in 2021. The interpretation of the results was made in relation to the criterion adopted in the division of farms into quartiles. It was found that the main source of financing activities in dairy farms was own funds. The highest share of farms using commercial loans was in the group of farms with the largest number of cows. With an increase in the number of cows in a herd, the area of farms increased, which is understandable due to the need to produce roughage. The most important factors influencing the development possibilities of agricultural holdings were the uninterrupted collection of raw material and a stable milk purchase price, which guaranteed the farmers’ financial liquidity.

Comparison of efficacy of Ovsynch protocol to single PGF2α administration in treatment of individual dairy cows with post-service subestrus.

The aim of this study was to evaluate the efficacy of the Ovsynch protocol in the treatment of post-service subestrus in individual dairy cows compared to a single administration of PGF2α. The study was performed on 517 Polish Friesian Holstein cows with post-service anestrus over four years in 3 dairy herds under a herd health program. Cows (n=240) diagnosed ultrasonographically as non-pregnant and with a mature corpus were treated with a single PGF2α administration and inseminated at detected estrus. Cows without corpus (n=277) were treated with the Ovsynch protocol. The estrus detection rate after PGF2α administration, percentages of cows pregnant after the treatment and at day 260, intervals from parturition to treatment and from treatment to conception and pregnancy loss rates were calculated. The overall percentage of cows pregnant after treatment did not differ between animals treated with the Ovsynch protocol and with PGF2α (38.9% vs. 42.5%; p>0.05). In herd A the percentage of cows pregnant after treatment was significantly lower (p⟨0.05) for the Ovsynch group than for the PGF2α group (30.2% vs. 61.2%). In contrast, in herd C the percentage of cows pregnant after treatment was significantly higher (p⟨0.05) in the Ovsych group than in the PGF2α group (39.6% vs. 28.8%). The overall estrus detection rate after administration of PGF2α was 59.6%. However, it was significantly lower (p⟨0.05) in herd C (44.7%) than in herds A (79.6%) and B (76.3%). The overall pregnancy loss rate ranged from 5.1% to 13.3% and did not differ significantly between herds and treatment groups (p>0.05). In conclusion, Ovsynch protocol can be a useful alternative for treatment of post-service suboestrus in individual cows in dairy herds with insufficient oestrus detection.

Outbreak of Pseudomonas aeruginosa mastitis in a dairy cow herd in northern Greece and its control with an autogenous vaccine.

In a dairy cow herd consisted of herd of 200 lactating Holstein-Friesian cows and heifers, clinical signs of mastitis in 40 out of 170 animals were observed. Treatments with antibiotics were proved ineffective. Milk bacterial cultures from 15 affected animals revealed Pseudomonas aeruginosa. An autogenous vaccine was administered subcutaneously, twice in a month period, to all adults. Cases of clinical mastitis declined significantly (p⟨0.0001) during next 3 months.

МОЛОЧНАЯ ПРОДУКТИВНОСТЬ ГОЛШТИНОВ РАЗНЫХ СЕЛЕКЦИЙ В УСЛОВИЯХ МОЛОЧНО-ТОВАРНЫХ ФЕРМ

This work aims to identify the level of productivity of Holstein cows of different breedings. The experimental studies were performed using purebred Holstein animals imported from Germany, Hungary, and Finland. When studying the exterior-constitutional features of livestock raised on the farm, it was found that Holstein cows as a whole were characterized by a relatively strong constitution, a proportionally developed and slightly elongated body with average live weight, deep chests with well-defined milk veins, glandular and properly attached bath-like and cup-shaped udder, with an average intensity of milk yield (2.12-2.4 kg/min). According to the expressiveness of dairy forms, the best indicators were for animals of Hungarian breeding with the linear affiliation of Reflection Sovering, and in cows of German and Finnish breedings - Montwik Chieftain. A study of the dairy productivity of cows showed that the greatest milk yield over 305 days for three lactations, depending on the linear affiliation, was for Hungarian cows: during the 1st lactation - 6465.9- 6951.2 kg, the 2nd lactation - 7463.5-7706.2 kg, according to the 3rd lactation - 8254.2-8297.7 kg of milk. A comparative evaluation of the dairy production of cows showed that the highest dairy productivity was noted in cows of the Reflection Sovering line. Thus, the average milk yield in cows of this line in the first three lactations was higher than in analogs of the Finnish breeding by 885 kg (13.02%) and German one - by 892 kg or 13.1% (P&lt;0.05), Vis Beck Ideal by 444.5 kg (6.2%) and 807 kg or 12.0% (P&lt;0.01) respectively. The animals of the Montwik Chieftain line of the Hungarian breeding exceeded in the milk yield of the German cows by 176.5 kg (2.4%) and the Finnish cows by 238.2 kg or 3.3%. Indicators of the coefficient of variation in milk yield show that the herd of Holstein cows in the first and third lactations is very heterogeneous. According to the second lactation, the representatives of the Vis Beck Ideal line of the German selection and the Montwik. It was established that in the coefficient of consistency of lactation, cows of German breeding exceeded the analogs of the Finnish and Hungarian breedings by 4.7 and 6.7%, respectively. Herewith, in the Hungarian cows, the lactation full value indicator was higher by 18.3% and 1%, which indicates higher stability of milk yield of cows of this group for the entire lactation. In such a way, our analysis of the morphofunctional properties of the udder showed that the investigated groups of animals correspond to the technological requirements for industrial keeping technology and organizing machine milking.

THE EFFICIENCY OF INDEX SELECTION OF SIMMENTAL LIVESTOCK HERDS IN ORGANIC AND CONVENTIONAL MILK PRODUCTION

The article highlights the results of studies of the effectiveness of index selection in herds of Simmental cattle in organic and conventional milk production using the selection index of R. Teinber, indicating the feasibility of its use, because the indicators of dairy productivity of animals of different groups are significantly different.&#x0D; The improvement of the quantitative indicators of milk productivity of cows in the herd of the Simmental breed, both in conventional and organic dairy production, largely depends on the value of the selection index. The strength of the influence of the selection index in the herd of Miroslavel-Agro on milk yield for 305 days of lactation of cows was 67%, milk fat – 88, milk protein – 77, total production of fat and protein – 86%, in the herd of "Galeks-Agro", respectively: 71, 87, 74 and 84% (P &lt; 0.001).&#x0D; The first-calf cows of the Simmental breed under the conditions of organic milk production were somewhat dominated by animals of the conventional herd in terms of milk productivity - in terms of milk yield per 305 days of lactation per 114 kg, with an insignificant difference. First-calf cows under conditions of organic milk production had worse reproduction parameters (service period – 136 days, reproductive rate – 0.89), compared to conventional milk production (127 days and 0.91), which is associated with the prohibition of the use of artificial vitamins, hormonal veterinary drugs to stimulate hunting, and shorten the duration of biological periods.&#x0D; The lowest milk productivity among the experimental groups were characterized by animals of the fifth group of both herds – their yield for 305 days of the first lactation amounted to 5042 and 4912 kg of milk, fat milk 4.08 and 4.11%, protein milk 3.37 and 3.46%. With a decrease in the selection index in animals has been established a decrease in dairy yield from 6767 (first group) to 5452 kg (fifth group), milk fat – from 290.7 to 204.8, milk protein – from 244.4 to 177.8 kg in the herd "Myroslavel-Agro" and from 7170 (first group) to 4912 kg (fifth group), milk fat – from 303.5 to 201.3, milk protein – from 252.8 to 169.5 kg in stage of "Halex-Agro".&#x0D; We recommend to use for repair of a herd of cows whose referred to the first two groups with the value of the selection index not lower than +23.0 (for "Myroslavel-Agro") and +26.3 (for "Galex-Agro"). The worst in terms of milk productivity, with the lowest value of the selection index (respectively: -44.9 and -51.7), it is desirable to sell to subsidiaries or other farms.&#x0D; It was found that when selecting animals according to the Tainber`s index, animals in organic and conventional herds are characterized by a lack of harmonious interaction with their habitat - cows are characterized by high dairy yields with simultaneous deterioration of their reproductive capacity, which confirms the well-known inverse relationship between these traits.&#x0D; The first-calf cows of the Simmental breed in the conditions of organic milk production slightly outnumber the animals of the conventional herd in terms of dairy productivity - in terms of milk yield for 305 days of lactation by 114 kg (P &gt; 0.05). The first-calf cows in the conditions of organic milk production had worse reproduction parameters (service period – 136 days, reproductive rate – 0.89), compared to conventional milk production (127 days and 0.91). In our opinion, this is due to the peculiarities of the dairy industry in organic milk production and the ban on the use of artificial vitamins, hormonal veterinary drugs to stimulate hunting and reduce the duration of biological periods of reproduction.

Sanitary and hygienic condition of the microclimate parameters of the premises of light-frame and reconstructed cowsheds in the spring with loose housing of the dairy herd

A comparative evaluation of the main parameters of the air microclimate for the maintenance of a dairy herd of cows in the reconstructed and light frame cowsheds in the spring was carried out. It was found that the average daily air temperature in the cowshed of light frame type of metal structures in the spring ranged from 5.48 to 16.42 ° C. Relative humidity in the spring ranged from 67.32 (third decade, at 12 o'clock) to 72.54% (at 6 o'clock in the morning in the first decade of research). Air velocities during the study period ranged on average from 0.29 (first decade at 15th hour) to 0.52 m/s (at 18 o’clock in the second decade of the study). On average, during the first, second and third decades, the level of natural light in the light frame cowshed was: 1981.05; 1942.72 and 2414.89 lux. In the reconstructed cowshed for the period of researches the lowest air temperature (° C) was fixed at the beginning of research as of 6 o'clock in the morning - 6,28 ° C, and the highest for the third decade - 17,86 ° C, at 15 o'clock. The relative humidity ranged from 67.74 to 74.12% (at 6 a.m. in the first decade of the study). The air velocity ranged from 0.39 to 0.42 m/s. The average rate of acceleration of air movement for the first, second and third decades was, respectively: 0.35; 0.41 and 0.34 m/s. The difference between the highest average (second decade) and the lowest (third decade) was 20.58%. In the reconstructed cowshed, the lowest indicator of natural light was recorded at the beginning of the research in the first decade at 6 o'clock in the morning - 1245.38 lux, and the highest in the third decade - 2481.51 lux, at 15 o'clock. On average for the first, second and third decades, the level of natural light in the reconstructed barn, respectively, was: 2000.06; 2075.15 and 2236.74 lux. It is established that the formation of the parameters of the air microclimate both in the room as a whole and in some of its individual parts is influenced by a number of factors, both external and internal. As a result, it was concluded that the parameters of the air microclimate in both cowsheds, although they had some differences, but in general met the established hygienic standards. Key words: microclimate parameters, air temperature, relative humidity, air movement, natural light, light frame cowshed, reconstructed cowshed, spring period, loose boxes of the dairy herd.

Evaluation of a povidone-iodine and chitosan-based barrier teat dip in the prevention of mastitis in dairy cows

Postmilking teat dip is an important tool used to prevent mastitis in the modern dairy industry. In this study, we evaluated the in vitro and in vivo efficacies of a barrier teat dip containing povidone-iodine and chitosan for the prevention of mastitis. In experiment 1, we evaluated the antibacterial effects of chitosans with different molecular weights against six mastitis-causing bacteria based on the minimal inhibitory concentration test. The results showed that 50 kDa chitosan had the maximum antibacterial activity compared with 5, 150 and 350 kDa chitosans. In experiment 2, the inhibition zone test indicated that the barrier teat dip with 4.0% povidone-iodine and 1.0% chitosan had higher (P<0.05) in vitro antibacterial efficacy against most tested mastitis-causing bacteria than the barrier teat dip with 4.0% povidone-iodine and no chitosan. In experiments 3 and 4, we evaluated the efficacies of two postmilking teat dips, 1) a barrier teat dip containing 1.0% chitosan and 4.0% povidone-iodine and 2) a conventional nonbarrier product containing 10% povidone-iodine in a field trial at two commercial dairy herds (1 and 2). A 56-d split-udder experiment (experiment 3) was conducted using 47 lactating Chinese Holstein cows in herd 1. Both left teats were immersed in barrier postmilking dip, and both right teats were dipped with nonbarrier postmilking dip. During a 56-d split-herd experiment (experiment 4), a total of 139 lactating Chinese Holstein cows from herd 2 were allocated to two groups: 1) all teats of 67 cows were dipped in the nonbarrier teat dip, and 2) all teats of 72 cows were dipped in the barrier teat dip. Milk samples were collected and analyzed for somatic cell count (SCC), fat content, protein content, and fat-to-protein ratio prior to the start of sampling (0 d), and at 28 and 56 d after initiation. Bacteriological analysis was only performed on milk samples with SCC≥200 000 cells mL−1. In experiment 3, no differences (P>0.05) in SCC, somatic cell score (SCS) or other milk quality indicators were observed between nonbarrier and barrier teat dip treatment teats throughout the experiment. At the end of experiment 4, compared with nonbarrier teat dip group, a reduction (P<0.05) of 29% was observed for subclinical mastitis infection prevalence in the barrier teat dip group. In the barrier teat dip group, the subclinical mastitis infection prevalence on 56 d was lower (P<0.05) than 0 d. No differences (P>0.05) in milk qualities or clinical mastitis incidence were detected between groups. Bacteriological analysis demonstrated that the barrier product containing povidone-iodine and chitosan reduced the subclinical mastitis infection prevalence induced by mastitis pathogens. This effect was mainly due to the reductions in Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia fergusonii infections. Overall, the data indicated that a barrier teat dip containing 4% povidone-iodine and 1% chitosan was more effective than 10% povidone-iodine in preventing subclinical mastitis.

Вітчизняний досвід застосування схрещування в стадах корів українських червоно-рябої та чорно-рябої молочних порід

Goal. To study the influence of selection of breeders of Montbeliard, Holstein, and Norwegian red breeds in herds of cows of Ukrainian red-spotted and black-spotted dairy breeds on the productivity of dairy cattle. Methods. Analysis of experimental research in the application of efficient breeding methods, theoretical analysis, formulation of hypotheses, genealogical, biometric and statistical methods, assessment of productive qualities of animals. Results. Higher milk yields were obtained from local first-born cows for the first 100 and 200 days of lactation: by 240 kg and 517 kg (P>0.999) from crossbreeds of Ukrainian red-spotted dairy and Montbeliard breeds; by 338 kg (P>0.99) and 883 kg (P>0.999) from crossbreeds of Ukrainian black-spotted dairy breed and Norwegian. Similarly, the predominance of mixtures as to the fat and protein content in milk was observed. Crossed first-born cows outnumbered purebred peers in terms of smaller service period — for 24 days (P>0.99) among crossbreeds of Ukrainian red-spotted dairy and Montbeliard breed; for 32 days (P>0.999) among crossbreeds of Ukrainian black-spotted dairy breed and Norwegian, the number of inseminations per 1 fertile (less than 1.4 times among crossbreeds of Ukrainian red-spotted dairy breed and Montbeliard breed; and 1.69 times among crossbreeds of Ukrainian black-spotted dairy breed and Norwegian), the safety of the number of first-born cows in the herd increased by 94.4 and 96.7%. Conclusions. Crossed first-borns obtained from the selection of breeders of Montbeliard and Norwegian red breeds outnumbered their peers obtained from Holstein bulls: by milk yield — on 324–425 kg (P>0.999), by fat content in milk — on 0.14–0.61% (P>0.95), and by protein — on 0.09–0.13%, by the coefficients of milk yield, constancy of lactation, reproductive capacity and safety of first-borns for the 1-st lactation.