Onset of normal cycles in postpartum anovulatory dairy cattle treated with kisspeptin

The efficacy of a long-acting synthetic derivative of kisspeptin (Kp) to initiate normal estrous cycles was tested in 24 mixed-aged, Holstein-Friesian cows that were 18 to 25 d postpartum on day of treatment (D0). Groups of eight received saline (Sal) vehicle by intramuscular injection at 0800 and 1600 h (Sal-Sal), Kp at 800 h and vehicle at 1600 h (Kp-Sal) or Kp on both occasions (Kp-Kp). The Kp dose was 15 nmol per 60 kg body weight. The cows ovaries were examined daily by ultrasonography between D-4 and D14. Blood samples were collected from a tail vessel 0, 2, 4, 8, 10 and 12 h relative to the time of first injection for LH and FSH assay. Additional samples were collected daily from D-4 until D14 and D19, 22, 26 and 29 for progesterone assay. An LH surge-like response were observed in cows treated with Kp at 0800 h. Ovulation was consistently induced by Kp within 48 h when there was a dominant follicle of at least 10 mm in diameter on the ovaries (8/14), but in no cases (6/14) during a new wave of ovarian follicular development consisting of follicles <10 mm diameter. The subsequent ovulatory cycle was of normal length in most cases, as compared with short 8 to 12 d cycles observed in spontaneously ovulating cows. We conclude that Kp treatment can induce ovulation in postpartum dairy cows, with ensuing estrous cycles of normal length, if administered when a mature dominant follicle is present on the ovaries.

Host Serum Proteins as Potential Biomarkers of Bovine Tuberculosis Resistance Phenotype

Eradication of bovine tuberculosis (bTB) continues to be a worldwide challenge. The lack of reliable vaccines dampens the control and eradication programs of Mycobacterium bovis infection and spread. Selection and breeding of cattle resistant to M. bovis infection would greatly enhance the effectiveness of bTB eradication programs. Here, we have evaluated the potential of serum proteins as biomarkers of cattle resistance to bTB in Holstein-Friesian cows, 6–8-year-old, born and raised in similar conditions in herds with bTB prevalence &gt;30%. Serum proteins obtained from uninfected cows (bTB-resistant; R) were compared to those from infected cows (bTB-susceptible; S), defined by a negative or positive bTB diagnosis, respectively. bTB diagnosis included: (i) single intradermal (caudal fold) tuberculin test, (ii) whole blood IFN-gamma test, (iii) gross visible lesions in lymph nodes and lungs by inspection at the abattoir, and (iv) a bacteriological culture for M. bovis. Using 2D-GE and LC-ESI-MS/MS, we found higher expression levels of primary amine oxidase (AO), complement component 5 (C5), and serotransferrin (TF) in R cattle than S cattle. In-house developed and standardized ELISAs for these novel biomarkers showed the best sensitivities of 72, 77, 77%, and specificities of 94, 94, 83%, for AO, C5, and TF, respectively. AUC-ROC (95% CI) values of 0.8935 (0.7906–0.9964), 0.9290 (0.8484–1.010), and 0.8580 (0.7291–0.9869) were obtained at cut-off points of 192.0, 176.5 ng/ml, and 2.1 mg/ml for AO, C5, and TF, respectively. These proteins are involved in inflammatory/immunomodulatory responses to infections and may provide a novel avenue of research to determine the mechanisms of protection against bTB. Overall, our results indicate that these proteins could be novel biomarkers to help identify cattle resistant to bTB, which in turn could be used to strengthen the effectiveness of existing eradication programs against bTB.

Therapeutic Effects of Levocarnitine or Vitamin B Complex and E With Selenium on Glycerin-Treated Holstein Friesian Cows With Clinical Ketosis

Currently, ketosis has no fully satisfactory resolution in dairy cows. Here, we investigated the effect of levocarnitine or vitamin B complex and E with selenium on clinically ketotic cows (β-hydroxybutyrate ≥ 3.0 mmol/L and decreased milk yield), fed glycerin. In total, 18 cases of Holstein cows with clinical ketosis during the postpartum transition period were randomly assigned to three treatments (6 cases per group): (1) levocarnitine (C+G), (2) vitamin B complex and E with selenium (VBES+G), and (3) levocarnitine and vitamin B complex and E with selenium (C+VBES+G). All groups were administered glycerin. Treatments were administered daily for 4 days. Blood sampling was performed on the onset day of ketosis (day 0), day 4, and day 6. β-Hydroxybutyrate (BHBA), milk yield (MY), and serum biochemical values were measured. Half of the animals in C+G failed to overcome clinical ketosis. VBES+G treatment ameliorated BHBA (p &lt; 0.05), MY, and glucose on day 4. However, ketosis was exacerbated following the discontinuation of the treatment. C+VBES+G treatment improved BHBA, glucose (p &lt; 0.05), and MY and reduced ketotic cases on days 4 and 6 with greater improvements compared to the others. In conclusion, combined treatment with levocarnitine, vitamin B complex and E with selenium, and glycerin may have the therapeutic effect on clinical ketosis.

The Association of Calcium Profiles at Calving with Health and Performance of Holstein Cows and Their Calves

The aim of this study was to assess the association of hypocalcemia at calving with health and performance of Holstein cows and their calves. Data were collected January 1st 2017 to December 31st 2020. A total of 431 lactating Holstein Friesian cows (118 primiparous and 313 multiparous) from a research of hypocalcemia was 2 groups (hypo and non-hypo). The overall prevalence of hypocalcemia was 3.4% for first-lactation cows and 18% for multiparous cows. Lactating dairy cows with hypocalcemia had greater proportion of cows with Retained Fetal Membranes (RFM) metritis and culling within 60 days in milk (DIM), compared with non-hypocalcemia respectively. For the first 2 official milk tests milk yield and components (% fat, % protein on SCC) did not differ between hypo and non-hypo cows. The days in milk at first service, mastitis, dystocia and pregnancy at first service were not different between hypo and non-hypo groups. The proportion of stillbirth, survival at 60 days of age in calves did not differ between calves born from hypo or non-hypo cows. Calves born from Hypo cows had greater incidence of diarrhea (38.3%) than calves born (22.3%) from non-hypo cows. The results of this study show that hypocalcemia in calving has significant health implications for both dams and their calves.

Relationship of Cytokines Concentration With Mastitis Infection Degree in Holstein Cows Reared in The Middle of Iraq

The study conducted by using ninety-five Friesian cows in the 3rd parity reared in private ruminant’s farm in the middle of Iraq (AL-Dewanya province) during the year 2020. All cows that used in this study were infected with mastitis in different degree to investigate the relationship between TNFa and IL-6 cytokines with the degree of mastitis. Results showed a significant relationship (P≤0.01) of mastitis degree with TNF-α concentration, the highest concentration of TNFa was recorded in cows with acute infection in whole udder namely, 102.11 Pg/ml while the lowest concentration was noticed in cows with simple mastitis infection. Results showed a significant difference (P≤0.01) in IL-6 concentration according to the degree of mastitis infection, the highest IL-6 level was in cows suffered from acute mastitis to reached as 58.3 pg/ml compared with the lowest level which noticed in cows with simple mastitis infection which was 15.82 pg/ml.

Effects of Milk Urea Nitrogen (MUN) and Climatological Factors on Reproduction Efficiency of Holstein Friesian and Jersey Cows in the Subtropics

This study investigated the effects of MUN and climatological factors on the inter calving period (ICP), reproductive performance (RP%), and reproductive index (RI) in Holstein Friesian (n = 1177) and Jersey cows (n = 3305) in different seasons in the subtropics. Threshold values for MUN on the reproduction of dairy cows in the subtropics remain controversial due to complex environmental interactions, especially with high environmental temperatures. A retrospective analysis was conducted of data obtained from the National Milk Recording scheme of the Agricultural Research Council (ARC) in South Africa. The results confirm that MUN influences the reproduction of dairy cows in the subtropics. MUN concentrations exceeding 18.1 ± 4.28 mg/dL in Holstein Friesian cows and 13.0 ± 4.70 mg/dL in Jersey cows extended the inter calving period (ICP), and decreased RP% and RI. Jersey cows have a lower threshold MUN concentration compared to Holstein Friesian cows, but they are not adversely affected by high humidity or temperatures, while Holstein Friesian cows are.

Combinations of Linear Type Traits Affecting the Longevity in Hungarian Holstein-Friesian Cows

Several research studies confirm the association of the linear type traits with longevity, but only with one trait at a time. The aim of our study was to analyse the influence of combinations for linear type traits on longevity in the Hungarian Holstein-Friesian cows. Data were provided by four herds; the filtered dataset consisted of 17,717 cows. From the 14 available linear type traits, the most important combinations were identified based on principal components and cluster analysis. From the six identified combinations, only three (chest width-body depth, fore udder attachment-udder depth, angularity-rear udder height) proved to have a significant effect on longevity. A wide chest and deep body caused a high-risk ratio of culling. The lowest risk ratio was observed with cows having intermediate chest width and intermediate body depth. Very angular cows having low rear udder height were at the highest risk of culling. The lowest culling risk was found in cows with a lack of angularity and high rear udder height. Weak and loose fore udder along with deep udder had increased culling risk. Strong and tight fore udder subclasses were the most favourable as their risk ratios decreased towards the shallowing of udder depth.

Emissions of carbon dioxide and methane from dairy cattle manure

There is an increasing interest in reducing production and emissions of greenhouse gases to combat global warming. Greenhouse gases can be produced through animal production operations. One of the major sources of greenhouse gases emitted from the animal farming is dairy cattle barns. This study measured the CH4 and CO2 emissions from dairy cattle manure decomposition trapped inside the static chambers through anaerobic digestion process by bacteria and at regular intervals by focusing on animal age and manure storage method. Samples were analyzed using gas chromatography for the estimation of CH4 and CO2 emissions. Four Friesian cows were used representing two stages of cow age (3 and 10 years old) and 1 kg of fresh manure samples were collected (feces and mixture of feces with urine). It was found that CH4 and CO2 emissions produced by cattle at the age of 3 years were higher than age of 10 years. In addition, gases emitted from fresh slurry feces were higher than liquid manure for both ages (3 and 10 years). This is due to the fact that the organic matter degradation in the feces and amount of fresh slurry feces is twice the amount of fresh slurry feces used in the liquid manure, as well as the organic matter in the manure mass for the age of 3 years is higher than for the age of 10 years. The findings from this study can provide information for improving manure management practices in animal farms.