Low-yielding Cows Research Articles

Evaluation of Rumen Microbes For Milk Fat Yield in Cattle Based on 16S rRNA Amplicon Metagenomic Sequencing

Background: Ruminal microbes support growth, lactation and maintenance of animals by providing energy and protein yielding nutrients. Metagenomics is the study of microbial communities directly in their natural environments such as soil, water, gut samples etc. The 16S rRNA gene sequencing is one of the basic genetic markers for the characterisation of prokaryote microorganism community. Current study exploited complex gut microbial communities present in cattle rumen based on variation in milk fat yield. Methods: The study was conducted in cattle reared at University Livestock Farm, Kerala Veterinary and Animal Sciences University. Twelve healthy cattle in the initial stages of lactation (less than three months) were selected and divided into two groups of six each based on high and low milk fat composition. Rumen samples were collected and DNA was isolated. Amplicons of 16S rRNA has been generated from metagenomic DNA targeting V3 and V4 hyper variable regions. Qiime2 was used for analysis for 16S rRNA amplicon sequencing. Result: Results revealed that a total of 38,28,241 sequences were obtained after demultiplexing. Majority of sequence length ranged around 295 to 301 nucleotides for forward reads and 216 to 300 nucleotides for reverse reads. After denoising, a total of 6,62,498 sequences were obtained. Clustering (de-replication) produced 711 unique sequence features. In kingdom level of taxonomy, for bacterial kingdom, there was no significant difference in abundance of organisms for high milk fat yield and low milk fat yield cows. For archaea, significant difference observed between abundance of high milk fat and low milk fat groups at five per cent level in the current study.

Influence of thermal heat load accumulation on daily rumination time of lactating Holstein cows in a zone with temperate climate

In the future, conflicts between animal welfare and climate change will gradually intensify. In the present study, we investigated the daily rumination time (RT) of lactating Holstein-Friesian cows in a zone with temperate climate and the effects of heat load duration and heat load intensity. Responses of individual cows to heat load were assessed, adjusting for milk yield, lactation number, days in milk as well as reproductive status and season. A total of 27,149 data points from 183 cows in a naturally ventilated barn in Brandenburg, Germany, were collected from June 2015 to May 2017. Ambient temperature and relative humidity were recorded at eight positions inside the barn every 5 min, and the temperature-humidity index (THI) was calculated. Based on THI, the degree of heat load was determined, using critical thresholds of THI = 68, 72, and 80. Daily RT was measured with a microphone-based sensor system (collar) on the cow's neck. The analysis models included autocorrelations in time series as well as individual cow-related effects. With each 5 min exposure to contemporaneous heat load, a decrease of approximately 1.17 min d−1 in RT per cow from non-heat stress to heat stress conditions by exceeding THI ≥68 (p < 0.01). This effect was intensified by exceeding the critical THI thresholds of 68 and 72.As heat load duration and intensity increased, daily RT decreased in comparison to daily RT under non-stress conditions. High-yielding (>38.4 kg milk/day) cows were more influenced in rumination time than low-yielding (≤28.8 kg milk/day) cows. With moderate contemporaneous heat load, RT decreased by 0.14 min d−1 per 5 min in high-yielding cows compared to low-yielding cows under moderate heat load. A decrease of 0.1 min d−1 was found in daily RT of mid-yielding cows. However, the delayed effects of heat load (one to three days after the heat stress event) were associated with days in milk and reproduction status. When the heat load duration lasted for several days, the responses were less pronounced than the impacts of contemporaneous heat load (when the heat stress event lasted for one day). Delayed mild heat load resulted in an increase in RT by 0.13 min d−1 in lactating cows ≤60 DIM. This was also found with delayed moderate heat load. Lactating cows ≤60 DIM showed a rise of 0.09 min d−1 in RT. RT also showed interactions with reproduction status of cows under delayed moderate heat stress. Lactating cows with ≤180 days of pregnancy showed an increase of 0.61 min d−1 in RT. Similarly, cows with >180 days of pregnancy had 0.64 min d−1 more RT compared to non-pregnant cows. Further analysis with higher temporal resolution of RT than data accumulation in 24-h blocks as well as the assessment of the correlation between feed composition, intake and rumination will elucidate the influence of heat load on daily RT.

Detailing the chemical composition of roasted soybeans and the effect for its use in the diet of dairy cows

Roasted soybeans are a complete source of indigestible protein in the rumen, have high sanitary and hygienic indicators, are devoid of non-nutritional substances of ordinary raw soybeans. The SoyPass and RaPass technology provides all the advantages of roasting soybeans and creates prerequisites for prolonged storage of beans for up to two years without prior drying. The introduction of full-fat flattened soybeans roasted by the Roast-A-Matic roaster into the diet of dairy cows leads to an increase in their milk productivity. Certified results of chemical research show that after frying, the percentage of crude protein significantly increased (by 2.92 points, P &lt; 0.05) and the content of total digestible nutrients (by 8.1 %, P &lt; 0.05), urease activity decreased to 0.06 ± 0.007 units of pH. The biological value of soy protein after frying corresponds to the indicators of the reference protein. Two groups of cows were involved in the study: № 1 – high-yielding cows with a daily milk yield of 30.69–35.96 L (n = 307) and № 2 – medium- and low-yielding cows with a yield of 19.05–28.88 L (n = 377). Group № 1 was given 300 g of roasted soybeans (111 g of protein) daily in their diet instead of 250 g of a high-protein supplement (200 g of protein); group No. 2 – gradually replaced 230 g of the supplement (184 g of protein) and 1500 g of 51 % meal (765 g of protein) with 1700 g of roasted soybeans (629 g of protein). In both groups, the 65-day observation period should be divided into 2 periods: 1) a 30-day period of intensive growth with a rapid increase in milk yield (up to +24.2–25.0 %); 2) the period of stabilization (from the 31st to the 65th day), characterized by some fluctuations in the % increase in milk, but in general by reliable maximum values (up to +25.0–36.7 %). The maximum daily volume in group № 1 reached 41.83 ± 1.04 and 41.83 ± 0.3 L (Р &lt; 0.01) on the 32nd and 38th days, respectively. At the same time, the range of the indicators of the individual yield in the group ranged from 10.7 to 11.7 L. Similar indicators for group № 2 were: 32.56 ± 2.74 L (Р &lt; 0.025) on the 58th day and 10.4–23.8 L. So, in the first 30 days of feeding full-fat fried soybeans, there is a rapid but unstable (with fluctuating peaks) increase in milk productivity of cows. During the 2nd month of soy consumption, the maximum milk yield is reached, when the increase in added milk is not rapid, but stable. Thus, it is advisable to introduce 1.5–2.0 kg/day of roasted soybeans (equivalent to 0.3–0.4 kg of fat/day) into the diet of dairy cows.

How does a beef × dairy calving affect the dairy cow's following lactation?

For beef semen usage on dairy cows, much of the research has focused on the performance of the crossbred calves, yet little focus has been given to the subsequent performance of the cow herself. This study aimed to evaluate the performance of dairy cows for milk yield, fertility, and survival traits after giving birth to beef x dairy crossbred calves and compare this with the performance after giving birth to purebred dairy calves. Further, we aimed to study if the effect of a difficult calving was the same regardless of whether the calf was purebred dairy or beef x dairy crossbred. Phenotypic records from 587,288 calving events from 1997 to 2020 were collected from the Swedish milk recording system from cows of the dairy breeds Swedish Red (SR) and Swedish Holstein (SH). The sire beef breeds studied were Aberdeen Angus, Hereford (combined in category LIGHT), Charolais, Limousin, and Simmental (category HEAVY). Sixteen traits were defined and grouped in 3 categories: cumulative and 305-d milk, fat, and protein yield, daily milk yield, and 75-d milk yield as yield traits; calving to first insemination interval, calving to last insemination interval, first to last insemination interval, calving interval, and number of inseminations as fertility traits; and survival to 75 d or to next calving and lactation length as measures of survival. The data were analyzed for all traits for first and second parities separately using mixed linear models, with a focus on the estimates of cow breed by service sire breed combinations. All traits in parity 2 were adjusted for previous 305-d milk yield based on the expectation that low-yielding cows would more likely to be inseminated with beef semen. Overall, milk yield was lower after beef x dairy calvings compared with the purebred dairy calvings. The largest effects were found on cumulative yields and in second parity, with lower effects for yields early in lactation and yields in first parity. The largest decrease was 13-14 kg (0.12 phenotypic SD) for cumulative fat yield when breeding beef breed sires with purebred SR dams. For fertility traits, for most breed combinations, the effects were not large enough to be significant. Conversely, all beef x dairy crossbred combinations showed significantly lower results for survival to the next lactation, and mostly also for lactation length. There was some indication that dairy cows with beef x dairy calvings in parity 2 that were the result of maximum 2 inseminations in parity 1, had lower survival than corresponding calvings resulting from more than 2 inseminations. This could indicate that the former cows were marked for culling already when inseminated. There was generally an unfavorable effect of a difficult calving on all traits, however, there were almost no significant interactions between calving performance and dam by sire breed combination, and these interactions were never significant in first parity.

Division of Cow Production Groups Based on SOLOv2 and Improved CNN-LSTM

Udder conformation traits interact with cow milk yield, and it is essential to study the udder characteristics at different levels of production to predict milk yield for managing cows on farms. This study aims to develop an effective method based on instance segmentation and an improved neural network to divide cow production groups according to udders of high- and low-yielding cows. Firstly, the SOLOv2 (Segmenting Objects by LOcations) method was utilized to finely segment the cow udders. Secondly, feature extraction and data processing were conducted to define several cow udder features. Finally, the improved CNN-LSTM (Convolution Neural Network-Long Short-Term Memory) neural network was adopted to classify high- and low-yielding udders. The research compared the improved CNN-LSTM model and the other five classifiers, and the results show that CNN-LSTM achieved an overall accuracy of 96.44%. The proposed method indicates that the SOLOv2 and CNN-LSTM methods combined with analysis of udder traits have the potential for assigning cows to different production groups.

Effects of mothers of different productivity on the body weight and metabolic profile of daughters

The results of the study conducted at the “Pchany-Denkovych” stud farm of the Stryi district of the Lviv region on heifers of the Simmental breed obtained from cows with different productivity are described. The dynamics of animal growth and the biochemical composition of the blood of heifers obtained from low-productive and high-productive mothers were studied. In the process of studying the dynamics of the live weight of calves from birth to 6 months of age, a tendency to increase the body weight of calves of the first group, obtained from highly productive mothers, at the age of 2, 4, and 6 months, respectively, was established – by 1.2 kg, 5.3 kg and 4.8 kg to the body weight index of heifers obtained from low-yielding cows. Experimental groups of heifers at the age of 6 months corresponded to the live weight of the Simmental breed standard. It was established that the total protein content in the blood serum of heifers obtained from cows with different milk productivity from birth to 6 months of age was within the physiological norm and increased gradually with the advantage of its level in analogs obtained from highly productive cows. Comparing the indicators of total protein in the dynamics from the first to the sixth month, it was found that it increased by 33.9 % in the first group and 25.5 % in the second group, respectively. The level of total cholesterol in the blood serum of experimental heifers during six months increased with age, with a slight advantage of indicators in heifers from the first group, which came from highly productive mothers (Р &gt; 0.05). The increase in total cholesterol from one month to 6 months of age in the first and second groups of heifers was 38.5 % and 20.0 %, respectively. A higher concentration of total lipids was noted in the blood of experimental daughters of highly productive cows. The minimum indicators of the level of total lipids were established in the first month of life of experimental heifers of the first and second groups, respectively – at 2.7 and 2.6 g/l, with the same level (3.5 g/l) in the second month and an increase in indicators in the third-month life (4.5 vs. 4.1 g/l) (Р &gt; 0.05). It was established that the activity of aspartate aminotransferase in all periods of growth of Simmental breed heifers significantly exceeds the activity of alanine aminotransferase. Characteristic features of the dynamics of this indicator are the maximum activity of AST and ALT in the first two months of the animal's life, which then gradually decreases.

Addressing stray animal population through alteration of sex ratio

Livestock plays a significant role in rural economy and livelihood by providing milk, meat, hide, drought power, etc. India’s livestock sector is one of the largest in the world with a holding of 11.6% of world livestock population. But due to economic reasons, dairy farmers have a strong preference for female calves for milk production and hence there is a very limited demand for male calves. Apart from that, there are several other reasons such as negligence of the indigenous populations and excessive focus on crossbreeding in the past few decades, increased mechanisation and the national policy to ban on cow slaughter have further added to the problem. In the common parlance, stray cattle include low-yield cows, bulls or calves that are abandoned and free to roam about in the open during the daytime because they are unproductive and creating traffic nuisance in cities, they also attack crops in villages. Therefore, techniques for gender selection and skewing of sex ratio towards female are demand of the hour. Flow cytometric sorting of spermatozoa is one of the best approaches to select the sexed semen for desire sex of calf, but its cost and patented technology is a definite disadvantage of this technology. In the present review, we will discuss in detail about the techniques available for skewing of sex ratio to address the stay animal population.

Factors affecting length of productive life of Brazilian Holstein cows assessed using survival analysis

Context Length of productive life is defined as the number of days from first calving to the last day of milking records, when the cow is no longer sufficiently productive. Although it has economic implications, length of productive life has not yet been included in Brazilian dairy cattle breeding programs because it depends on other traits such as age at first calving, milk production level and disease occurrence. In addition, its evaluation occurs later in life, and heritability coefficients are low. Aims The aim of this study was to identify the effects of both age at first calving and accumulated 305-day milk yield in the first lactation on length of productive life in Holstein cows. Methods Official dairy control data of 31 562 Holstein cows, calved from 2010 to 2014, in 321 herds from Paraná state, Brazil, were analysed by using the Kaplan–Meier estimator and Cox regression model. Key results First calving at &lt;21 months was associated with shortest productive life (1197.01 ± 232.40 days), whereas first calving at 24 months was associated with the lowest hazard ratio (0.572), suggesting that this is the most suitable age of first calving for a longer productive life. Low-yielding cows (first lactation yield &lt;6392 kg) had the second lowest survival probability (47.20%), the shortest productive life (1150.60 ± 234.51 days) and the highest voluntary hazard ratio (1.30) and were prematurely culled from the herds. High-yielding cows (first lactation yield &gt;12 024 kg) had lower culling risk at the first lactation. Conclusions Cows that started their reproductive life ∼16 months of age (first calving at 24 months) had the longest productive life and an average first lactation milk yield ∼9000 kg. Implications Reproductive management practices could affect length of productive life through effects on age at first calving and first lactation milk yield. Most of the Holstein semen used in Brazil comes from countries where longevity has already been included in selection indexes; thus, early identification of cow longevity could be used for culling decisions.

Economic and management considerations in two dairy systems grazed and arable crops based

On the Hungarian dairy farms grazing is not a common practice presently. What are the reasons for this situation? Necessary conditions are not available for grazing, or the technical considerations about grazing are not favourable in practice. These questions were investigated on two dairy farms with methods of farm visits and technical interviews. Farm 1 still has grazing, Farm 2 used to graze its animals, presently it does not graze its animals, but it plans to establish pasture for grazing. Summarizing results of the investigations:&#x0D; - Non of the farm has got enough pasture/land area to meet the requirements of grazing. This situation fits to the national situation known from literature and statistics.- The time of substantial herbage allowance is relatively short, it is maximum 2 month in the season.- The nutritive value of grass decreases sharply in Spring. It is the reason why only animals requiring less intensive feeding can be grazed (first of all dry cows, than heifers and perhaps low yield cows).- Grazing can result in remarkable savings regarding inputs and costs.- Grazing does not need specific labour, present staff of the farms. Can manage grazing at the necessary technical level.- Asset security of outdoor animals we not considered as a real obstacle against grazing on the farms. This situation is different of that reported about the national situation.

The reaction of the thyroid gland to the thyrotropic hormone “load” in high and low-yielding cows

The studies were carried out on cows of Holstein black-and-white breed. 2 groups of 10 heads each were formed. The milk yield for lactation was 10 thousand kg in the first group, and - 5 thousand kg in the second group. Blood was collected from the subcaudal vein monthly during lactation. T3 and T4 were determined in the blood serum. The functional “load” on the thyroid gland was performed at the peak of lactation (3 months) and at its end - at 9 months. The TSH preparation at a dose of 0.5 u/kg of live weight was administered intramuscularly on an empty stomach before morning feeding. T3 and T4 hormones in the blood were determined before the injection of TSH and 0.5 one and two hours after the injection. Kath was calculated using the formula Т1 – Т0 / Т0 where Kath is the coefficient of activity of thyroid hormones. T0 – T3 and T4 levels before TSH injection T1 – T3 and T4 levels 2 hours after TSH injection. During lactation, the level of milk production and thyroid hormones varies inversely with the average daily milk yield. During the period of high milk productivity (2,3,4 months of lactation), the concentration of T3 and T4 in both groups was low, and later increased and was maximum in the 8th month of lactation. The functional reserves of the thyroid gland in high-yielding cows in 3 and 9 months of lactation are lower in relation to low-yielding cows.

Assessment of the influence of the maternal genotype on the realization of the productive potential of Holstein cattle in the conditions of the Novosibirsk region

An analysis of the productive qualities of mothers cows and their offspring, obtained from different fathers, showed that the contribution of parents to the formation of milk productivity is unequal. Intensive selection of bulls-producers leads to fixation of homozygotes at the loci associated with traits of milk production, which increases their influence on offspring. The strength of the influence of the father’s factor on milk yield, milk protein and live weight of daughters was 6, respectively; 14 and 16%. The productivity level of mothers did not significantly affect the productivity of their daughters. High-yielding offspring can be obtained from low-yielding cows. Daughters surpassed their mothers in milk yield, but inferior in fat milk. The proportion of deviation from the theoretically expected productivity of daughters (milk yield per 305 days), which is caused by the influence of the maternal genotype, in the groups of Auckland No. 426436885, Showman No. 831842 and Euclid No. 831491, respectively, was 15.8; 27.5 and 30.4%. The correlation coefficient between the milk yield of mothers and daughters was + 0.25 (p &lt;0.05), and body weight correlated at the level of +0.3 (p &lt;0.01). In the groups of daughters, butterfat is associated with milk yield (r = - 0.5) and milk protein (from +0.34 to +0.67). For mothers, the relationship between these indicators was lower. It is possible that half-siblings have stronger genetic links between traits than unrelated mothers. Genetic diversity in milk yield (h2 = 0.6) and live weight (h2 = 0.5) was established. Repeatability coefficients for fat and milk protein were at the level of 0.35. The productive potential of the breed depends on the combinational compatibility of the parents, their contribution to the formation of complex quantitative characteristics of productivity.

Evaluation of highly productive cows by selection and genetic parameters

Under the conditions of intensive technologies used in production of livestock products, the main selection feature that characterizes the economic feasibility of dairy farming and breeding value of animals is milk productivity. One of the factors that affects, not only the economy of production, but also the improvement of herds and breeds of cattle, is the use of highly productive cows. Therefore, the aim of our research was to assess the level of development of productive traits in Holstein cows under the conditions of intensive milk production technology, according to selection and genetic parameters. To conduct the study, a group of 1089 first-born cows was formed with the help of the Dairy Comp program and Microsoft Excel. The material for the research was the milk productivity of Holstein cows during the first three lactations. The level of development of selection traits in animals was determined by selection and genetic parameters. It was found that from the sample n = 1089 to the group of highly productive animals (“&gt;10560”) were included 266 cows, and low-productive animals (“&lt;8706”) – 249 first-borns. They had an average milk yield for the first lactation, 11439 kg of milk with a fat content of 3.96 % and 7737 kg of milk and 3.95 %, respectively. There is a difference in milk yield, milk fat and protein between the groups of cows “&gt;10614” and “&lt;8706”, but there is a general tendency towards changes in productivity with age. Based on the data of milk recurrence and the amount of milk fat of high-yielding cows (group “&gt;10614”), it was found that higher values of the coefficient are characteristic of lactations I–III (rw= 0.105; rw= 0.135). As a result of comparative analysis it was found that low-yielding animals (group “&lt;8706”) were characterized by higher recurrence rates for I–II and I–III lactation (rw = 0.345;rw = 0.316;rw = 0.320 and rw = 0.664;rw = 0.646;rw = 0.651, respectively). Higher rates of recurrence of traits of milk productivity are the characteristic of low-yielding cows (group “&lt;8706”), i.e. they had more consistency of traits during different lactations and animals with a high level of productivity did not differ in age constancy. At a high level of milk yield in cows of group “&gt;10614” appeared a negative correlation of low and medium level (r = -0.423). It was also found a negative correlation of low and medium level between milk yield and protein content in milk (r = -0.007… -0.332). At lower milk yields, there is no negative correlation between milk yield and fat content in milk. Thus, the existence of a negative correlation between milk yield and fat content in milk at a high level of animal productivity, and between milk yield and protein content in milk at both high and low levels of cow productivity was proved.

Effect of automatic cluster remover settings on milkability, milk quality and milking irregularities of crossbred cows.

Automatic cluster remover (ACR) settings regulate the end of milking by detaching the clusters based on milk flow dropping below a preset level, which needs to be standardised for different breeds of dairy animals based on their production. A study was conducted to find out the best ACR setting for milking Indian crossbred cows based on milkability, milking irregularities and milk quality. Fifty six crossbred dairy cows in lactations 1 to 4 were categorised into three groups based on the level of production; low (N = 16; 18 kg/d). The ACR settings tested were 0.1, 0.2, 0.3 and 0.4 kg/min, keeping the vacuum level and pulsation settings constant. The ACR settings significantly (P &lt; 0.01) affected the milk yield at all levels of production with a significant effect (P &lt; 0.01) on machine-on time at 0.4 kg/min. The yield during the first 2 min of milking, average flow and peak flow rates were not affected at any level of production. The average electrical conductivity in milk was significantly (P &lt; 0.01) lower for the low and medium yield cows without affecting the mean somatic cell count. At 0.4 kg/min, more cluster reattachments were needed because of significant amount of milk remaining in the udders post-cluster removal.

Short communication: Relationship of blood DNA methylation rate and milk performance in dairy cows

The objective of this study was to investigate the global methylation rate in blood DNA and its relationship with lactation performance. A total of 196 mid-lactation dairy cows were fed the same diet under the same management. Milk yield was recorded and blood samples were collected from the jugular vein before morning feeding. The blood global DNA methylation rates were quantified using a methylation quantification kit. Overall, the average blood global DNA methylation rate of all cows was 12.4%. When DNA methylation rates were compared between cows with high (n = 40; 37.0 to 42.0 kg/d) and low (n = 33; 24.0 to 30.0 kg/d) milk yield, DNA methylation rates in the lower-yield cows (14.1 ± 0.7%) were significantly higher than those in the higher-yield animals (11.6 ± 0.7%). Our results indicated an association of milk and protein yields with global DNA methylation rates in lactating dairy cows. However, further research is needed to determine whether this association reflects the true influence of epigenetic mechanisms on yield or whether other factors, such as different proportions of blood cell types in high- and low-yielding cows, affect apparent global DNA methylation levels.

Relationship between biochemical analytes and milk fat/protein in Holstein cows

The aim of this study was to assess the relationship between biochemical analytes and milk fat/protein in high-yield (DIM: 42 ± 10 d postpartum) and low-yield (DIM: 91 ± 11 d postpartum) Holstein cows. Stepwise regression analysis was used to evaluate the relationships of biochemical analytes with the fat and protein content of the milk from 126 Holstein cows belonging to nine intensive housed dairy farms. The comparison between the two groups showed differences ( P< 0.05) in the milk yield, milk fat and milk fat/protein ratio, with the higher values in high-yield cows. The correlations between milk fat, milk protein, milk fat/protein ratio and biochemical analytes concentrations, were assessed within each group. Milk fat level was positively correlated to cholesterol, triglycerides, β-hydroxybutyrate and albumin in high-yield cows. Milk protein level was positively correlated to urea, and negatively correlated to sodium ion, potassium ion and chlorine ion in high-yield cows. A virtually linear dependence has also been found between milk fat and triglycerides, between milk protein and urea, and between milk fat/protein ratio and cholesterol, and triglycerides in low-yield cows. The metabolic profiles provide a practical tool, to present an insight into the underlying physiological mechanisms of lactation, and the identification of relationships between key analytes and components of milk, such as protein and fat content. Key words : dairy cow, blood chemistry, milk fat, milk protein.

Metabolism and immune status during transition period influences the lactation performance in Zebu (Bos indicus) cows

We evaluated the changes in the concentration of innate immune molecules (haptoglobin: Hp, serum amyloid A: SAA, IL-6, TNF-α, IL-1β, and IL-8), energy indicators [NEFA, dry matter intake (DMI) and body condition scoring (BCS)] during the transition period in dual-purpose Zebu (Deoni breed) cows in relation to milk yield. Blood collection was done at weekly intervals (–21±2, –14±1, –7±1, d pre-partum, day 0 (date of calving) and 3±1, 7±1, 14±1, 21±2 d postpartum period) for estimation of above plasma variables using commercially available bovine specific ELISA kits. We also recorded DMI and BCS during the corresponding period. Transition cows were classified based on their milk yield during the study period as high (6), medium (6) and low (6) yielding cows and data were analyzed by using Mixed-model repeated measure analysis. High yielding (HY) cows had significantly higher concentrations of SAA, TNF-α, and IL-6 during pre-partum and early postpartum period than low yielding (LY) cows. DMI was significantly higher in HY cows than MY (3rd and 7th d) or LY cows (21st d) while, BCS was significantly higher in HY than LY cows during pre-partum period (-7th d). LY cows had significantly higher concentration of NEFA during the postpartum period (14th and 21st d). It is concluded that the active functioning of the immune system and more dry matter intake in transition Deoni cows enabled to synthesise more milk during the postpartum period.

SELECTION OF THE SITUATION IN SEEF «OLEKSANDRIVSKE» FOR BREEDING UKRAINIAN RED-AND-WHITE DAIRY CATTLE AND UKRAINIAN BLACK-AND-WHITE DAIRY CATTLE AND ITS IMPROVING

Created Ukrainian Red-and-White Dairy and Ukrainian Black-and-White Dairy cattle have a desirable level of reproductive and productive qualities. These breeds are competing successfully with animals of the European selection, so comparative study of pedigree and productive qualities of animals at one of the farms has practical value.&#x0D; The studies were conducted in the herd of “Oleksandrivske” SE RF at the animals of Ukrainian Red-and-White Dairy and Ukrainian Black-and-White Dairy breeds of Vinnytsia region. The animals of both breeds were kept under the same technological conditions in housing for livestock.&#x0D; It was taken into account milk production (milk yield, fat content in milk and milk fat) for 305 days of lactation. Expert evaluation of the exterior of first-calf heifers has been conducted for 2015-2016. Assessment of type of body structure of cows was conducted on 100-point scale. Fatness of cows was determined on 5-point scale. The analysis of genealogies of 37 bulls which had progeny in the herd was conducted by breeding index, discharge of breeding values and milk production of ancestors.&#x0D; Milk production of the animals of the herd was more than 6000 kg of milk for 305 days of lactation. Comparing milk yields, it was found that the animals of Ukrainian Black-and-White Dairy breed dominated Ukrainian Red-and-White Dairy cows of the same age.&#x0D; It is noteworthy that biological feature of cows to increasing milk yield with each subsequent lactation is positive. Thus, the Ukrainian Black-and-White Dairy cows after the second calving in comparison with the first calving increased milk yield by 380 kg and the animals after the third calving and older comparatively with the second one – by 425 kg more. Also the Ukrainian Red-and-White Dairy cows increased milk yield, respectively, by 348 and 358 kg.&#x0D; The average body measurements of the first-calf heifers were inferior by targeted parameters of Ukrainian Red-and-White Dairy and Ukrainian Black-and-White Dairy cattle from -0.3 cm (girth of metacarpus) to -7.8cm (height in the sacrum) in most cases. &#x0D; The total number of points for type of body structure was 87.9 at the animals of Ukrainian Black-and-White Dairy cattle and, respectively, 87.0 at the Ukrainian Red-and-White Dairy cows; it corresponds to the assessment "very good". This indicates the high estimation of individual parts of the exterior.&#x0D; The cows of the herd had the required fatness. The average of this trait at animals of Ukrainian Black-and-White Dairy breed was 3.0 points and at the cows of Ukrainian Red-and-White Dairy cattle was respectively 3.4 points.&#x0D; The genealogical structure of the current herd of “Oleksandrivske” SERF consists of two female contingents. The animals of Ukrainian Black-and-White Dairy cattle were derived from 18 bulls belonging to 8 bloodlines. Most of animals belong to R.O.R.Elevation 1491007 bloodline – 45.4%, H.H.Starbuck 352790 and P.F.A.Chief 1427381 bloodlines – 14.4%.&#x0D; Qualitative characteristic of bulls used for the female livestock of the herd, shows that in the vast majority they are valuable breeding bulls. However, it should be noted that there are progeny derived from bulls with low breeding value in the herd. Thus, bull Matrix Red 136549448 had SI-7 and H- and Trubadur 343643346 had SI-50 and H-. The use of bulls for female livestock of the herd with low breeding value is unacceptable for further breeding work. Expectation of improving the breeding traits in progeny from such fathers is unlikely.&#x0D; It is planned to accelerate the reproduction of valuable genotypes and increase the rate of genetic progress at the herd using embryos transplantation this year. Donors of embryos will be their own breeding resources. Using this method will make it possible to exclude from the selection process animals with exterior defects and low-yielding cows.&#x0D; The considered aspects of selective breeding work indicate prospects of using Ukrainian Red-and-White Dairy and Ukrainian Black-and-White Dairy cattle. This applies particularly to increase of milk yield to 8000 kg and more per lactation.&#x0D; Bulls which will be used for breeding stock should have high rates of breeding values (SI +1000 and P4 and more). Especially it applies such features as fat content in milk and some exterior defects.

Pregnancy outcome is influenced by luteal area during diestrus before successful insemination but not by milk production level

The objective was to compare luteal area (LA), luteal blood flow (LBF), and progesterone (P4) concentration before and after artificial insemination (AI) in pregnant and open cows in the diestrus preceding insemination and during the first 21 d after insemination. A number of 119 multiparous German Holstein cows were examined using B-mode and color Doppler sonography in diestrus (15–5 d before AI) and on days 7, 14, and 21 post insemination (pi). Blood samples for determination of P4 concentration were collected at each examination. In pregnant cows, P4 was measured in the diestrus before AI and on days 7, 14, and 21 of pregnancy, and in open cows, in the diestrus preceding the first AI and 7, 14, and 21 d later. Cows were retrospectively allocated into two groups according to the mean daily milk yield in the first 42 d (high milk yield [HMY], ≥39 kg/d; low milk yield [LMY], <39 kg/d). Pregnant cows had larger LA than open cows during diestrus before insemination (5.69 ± 1.85 vs. 4.94 ± 1.66 cm2, P < 0.05), on days 7 (5.34 ± 1.83 vs. 4.52 ± 1.93 cm2, P < 0.05) and 21 pi (5.92 ± 1.60 vs. 4.97 ± 1.44 cm2, P < 0.05). On day 14 there was a tendency towards larger LA in pregnant cows (P = 0.09). Luteal blood flow (1.72 ± 0.74 vs. 1.22 ± 0.67 cm2) and P4 concentration (8.97 ± 4.37 vs. 6.49 ± 4.32 ng/mL) were higher in pregnant cows than in open cows on day 21 (P < 0.05). At day 150, 69% of the LMY cows and 56% of the HMY cows were pregnant (P > 0.05). Pregnant HMY cows had larger LA during diestrus before insemination and on days 7 and 21 pi than open HMY cows (P < 0.05) and tended to result in larger CLs on day 14 (P = 0.06). Pregnant HMY cows had higher LBF on days 14 and 21 (P < 0.05) and higher P4 concentration on day 21 than open HMY cows (P < 0.05). The main finding of this study was a larger LA during diestrus in cows that conceived in the ensuing estrous cycle compared to cows that did not conceive. Luteal area, LBF, and P4 concentration were greater in pregnant cows compared to open cows, and further studies should be conducted on the usefulness of these variables to detect open cows as early as possible after breeding. High-yielding cows appear to require larger LA, LBF, and higher P4 concentration than low-yielding cows to maintain pregnancy. In conclusion, larger LAs were established in pregnant cows in the diestrus before successful insemination regardless of their milk yield. Further studies are needed to verify whether LA in the diestrus before insemination might be used to predict probabilities in reproductive performance.

Alterations in the relative abundance of Haptoglobin (Hp) transcripts in total milk somatic cells during different stages of lactation cycle in high yielding cross-bred cows

The expression profile of Haptoglobin (Hp) gene in total milk somatic cells (SCC) of high-yielding cross-bred Karan Fries (KF) was studied during early, mid, and late lactation cycle. Milk samples (200 ml/animals) were collected from 10 high-yielding and 10 low-yielding cows throughout the lactation cycle (from day 7 to day 300) with an interval of one month. Relative mRNA expression profiles of Hp by RT polymerase chain reaction was studied in high-yielding cows, whereas low-yielding cows were taken as control. The folds of induction of Hp was significantly (p < 0.001) downregulated by a mean factor of 0.207 in milk SCC during early lactating cows. Whereas, it was significantly (p < 0.01) upregulated by a mean factor of 20.888 during mid lactation. The expression was unaltered during the late lactation. The study demonstrates that Hp is synthesized within the mammary gland and significantly upregulated during mid-lactation period compared to other stages of lactation cycle.

Influence of breed, milk yield, and temperature-humidity index on dairy cow lying time, neck activity, reticulorumen temperature, and rumination behavior

The objective of this study was to compare weekly mean lying time (LT), neck activity (NA), reticulorumen temperature (RT), and rumination time (RU) among 3 breed groups, milk yield (MY), and temperature-humidity index (THI). Cows (n = 36; 12 Holstein, 12 crossbred, and 12 Jersey) were blocked by parity group (primiparous or multiparous), days in milk, and MY. Lying time, NA, RT, RU, and MY were recorded and averaged by day and then by week for each cow. For study inclusion, each cow was required to have 10 wk of LT, NA, RT, and RU data. Maximum THI were recorded and averaged daily. Mean (±SE) days in milk, LT, MY, RT, RU, NA, and maximum THI were 159.0 ± 6.0 d, 11.1 ± 0.1 h/d, 28.7 ± 0.5 kg/d, 38.8 ± 0.0°C, 6.4 ± 0.1 h/d, 323.8 ± 3.8 activity units, and 56.5 ± 0.6, respectively. The MIXED Procedure of SAS (SAS Institute Inc., Cary, NC) was used to evaluate fixed effects of breed, MY, parity, THI, and their interactions on LT, NA, RT, and RU with cow nested within breed as subject. All main effects remained in each model regardless of significance level. Stepwise backward elimination was used to remove nonsignificant interactions. The interactions of breed × parity group and maximum THI × parity group were associated with RT. Increasing THI coincided with increasing RT. Least squares means LT for multiparous cows was significantly greater than LT for primiparous cows (11.4 ± 0.3 and 10.5 ± 0.5 h/d, respectively). Least squares means NA for primiparous cows was greater than for multiparous cows of all breeds (372.1 ± 10.9 and 303.4 ± 7.8, respectively). The CORR Procedure of SAS was used to evaluate relationships among RT, RU, LT, NA, and MY. Rumination time was positively correlated with MY (r = 0.30) and negatively correlated with LT (r = -0.14). Reticulorumen temperature was negatively correlated with MY (r = -0.11). Rumination time was positively correlated with NA (r = 0.18) and negatively correlated with LT (r = -0.14). Lying time and NA were negatively correlated (r = -0.43). Neck activity was positively correlated with MY (r = 0.14). Lying time was negatively correlated with MY (r = -0.25). Milk yield was associated with RU, which may be related to cows with greater MY also having a greater feed intake. Lying time increased and NA decreased with increasing parity, which may be effects of social hierarchy, where primiparous cows are more susceptible to being pushed away from the feed bunk and freestalls. Milk yield was positively associated with RU. Greater milk production requires greater feed intake, which may result in longer RU than for low-yielding cows. Lying time decreased as milk yield increased. The behavioral and physiological differences observed in this study provide new insight into the effects that breed, parity, MY, and THI have on cows.