Normal Cows Research Articles

Hormonal Profile Study of Bangladeshi Crossbred Dairy Cows in Relation to Repeat Breeding

The repeat breeding condition affects both the fertility of cows and the economy of farmers and the nation. Normal levels of various biochemical constituents are indispensable for the normal functioning of various body systems of animals, including the reproductive system. The hormonal profile is an indicator of the reproductive status and aids in the prognosis and restoration of animal fertility. The present study explores the implication of four hormones (luteinizing hormone, follicle-stimulating hormone, human chorionic gonadotropin and prolactin) on the normal cycle breeding process of Bangladeshi normal cyclic cows and repeat breeder dairy cows. Among four hormones, the levels of luteinizing hormone and prolactin were significantly different between the normal cyclic cows and repeat breeder cows. The assessment of hormonal profile aids in ameliorating the repeat breeding conditions of the dairy cows. The findings of the present study could be applied in overcoming repeat breeding problems in dairy cows and thus, economic loss could be lessened.

Hormonal Profile Study of Bangladeshi Crossbred Dairy Cows in Relation to Repeat Breeding

The repeat breeding condition affects both the fertility of cows and the economy of farmers and the nation. Normal levels of various biochemical constituents are indispensable for the normal functioning of various body systems of animals, including the reproductive system. The hormonal profile is an indicator of the reproductive status and aids in the prognosis and restoration of animal fertility. The present study explores the implication of four hormones (luteinizing hormone, follicle-stimulating hormone, human chorionic gonadotropin and prolactin) on the normal cycle breeding process of Bangladeshi normal cyclic cows and repeat breeder dairy cows. Among four hormones, the levels of luteinizing hormone and prolactin were significantly different between the normal cyclic cows and repeat breeder cows. The assessment of hormonal profile aids in ameliorating the repeat breeding conditions of the dairy cows. The findings of the present study could be applied in overcoming repeat breeding problems in dairy cows and thus, economic loss could be lessened.

Kinerja birahi pada sapi Aceh yang mengalami kawin berulang

The aim of this study was to determine the difference in the estrous performance of Aceh cows with repeat breeding. In this study, ten Aceh cows were used, consisting of five normal cows (KI) and five repeat breeder cows (KII). The criteria of the cows used were 3-5 years old, had a body weight of 150-250 kg, and had at least two regular cycles. All cows in both groups were estrous synchronized with 5 ml PGF2a intramuscularly. Estrous observation was done visually twice a day at 8 am and 4 pm. Estrous intensity was assessed by scoring. The results showed that the intensity, onset, and duration of estrous (KI vs KII) were respectively (18.00 ± 5.70 vs 17.60 ± 6.65), (40.00 ± 14.96 vs 41.60 ± 30.67 hours), and (78.40 ± 10.43 vs 80.00 ± 40.39 hour). To conclude, there was no difference in the intensity, onset, and duration of estrous between normal Aceh cows and those with repeat breeding.

Effect of Herbal, Homeopathic and Hormonal Drug on Hematology, Ovarian Cyclicity and Conception Rate in Postpartum Anoestrus Cows

The study was designed to assess the effect of herbal, homeopathic, and hormonal drugs namely Janova, Sepia and GnRH-PG-GnRH on hematological parameters, resumption of ovarian cyclicity and conception rate in 40 postpartum anoestrus and 8 normal cyclic cows. The anoestrus cows were randomly divided into five groups as G0, GI, GII, GIII, GIV; 8 cows in each group. Group G0 (untreated anoestrus) and GV (normal cyclic cows) served as positive and negative control, respectively. All cows in GI, GII, GIII and GIV were subjected to dewormer and mineral mixture supplementation for 10 days, while group GII, GIII, and GIV were additionally treated with Janova (herbal heat inducer), Sepia (a homeopathic drug) and GnRH-PG-GnRH (Ovsynch) protocol, respectively. Different therapeutic protocols revealed variable and significant effects on most of the hematological parameters, except differential leucocyte count, before and after treatment. The values were also significantly higher in normal cyclic than anoestrus groups. The oestrus induction response in G0, GI, GII, GIII, GIV, and GV was 0.00, 50.00, 62.50, 75.00, 87.50, and 100.00 %, and corresponding overall conception rates of 3 cycles were 0.00, 75.00, 80.00, 66.66, 57.13 and 75.00 %, respectively. In conclusion, aforesaid therapeutic regimens have definite bearings on oestrus induction as well as on conception and can be used to manage postpartum anoestrus in cows.

Investigations on cytokines and proteins in lactating cows with and without naturally occurring mastitis

ASTRACT Mastitis an inflammation of mammary gland in dairy herds is a key concern of economic losses worldwide caused by bacteria and its toxins. In this study, we investigated pro-inflammatory and anti-inflammatory cytokines (IL-2, IL-1β, IL-6, TGF-β, IL-10, TNF-α), lactoferrin and albumin, and milk composition in normal dairy cows and lactating cows with symptoms of sub-clinical and clinical mastitis. Lactating cows with clinical mastitis showed marked increase in IL-2, IL-6, IL-1β, TNF-α and a decrease in anti-inflammatory levels of TGF-β, IL-10, milk parameters fat, protein, SNF, lactose and increase in pH compared to normal lactating cows. Subclinical lactating cows showed significant alteration in TNF-α, IL-1β when compared to normal lactating cows. There was no significant difference between IL and 2 and IL-6 in normal and subclinical lactating cows. The subclinical cows also did not exhibit significant difference in TGF-β, albumin, milk fat, protein and pH when compared with normal lactating cows. Findings in the present study indicate that cytokines together with proteins lactoferrin and albumin can be considered as prospective markers in early detection of subclinical and clinical mastitis.

Metabolic Profiling of Normal and Lame Karan Fries Cows and its Association with Lameness during Transition Period

Metabolic Profiling of Normal and Lame Karan Fries Cows and its Association with Lameness during Transition Period

Identification and characterization of urinary peptides using Q-TOF mass spectrometry in cow

Cow urine has been found to be the most effective secretion of animal origin with innumerable therapeutic values. It has potent antimicrobial activity which may be attributed to the presence of urinary peptides in it. Lack of evidence for the presence of such antimicrobial peptides (AMPs) in cow urine lead to the present study. Using a technique of membrane filtration, ion exchange chromatography, acid-urea poly-acrylamide gel electrophoresis (AU-PAGE), reverse phase high performance liquid chromatography (RP-HPLC) and ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-QTOF-MS/MS), we successfully extracted and characterized cationic peptides from the urine of healthy, normal cycling indigenous cow. We could identify two urinary peptides which were reported to contain antimicrobial properties. These identified peptides were 97 and 99 amino acids long Neutrophil defensin-4 and β-defensin-127 of defensin class. These peptides may be responsible for the innate immunity and serve as an alternative to the conventional antibiotics in the time to come.

Untargeted Metabolomic Analysis of Gestationally Matched Human and Bovine Milk Samples at 2-Weeks Postnatal

Abstract Objectives Human breast milk is the ideal nutrition source for infant development during the first year of life. Epidemiological data demonstrates that bovine whole milk is often substituted for human milk during the first 12-months of life and may be associated with adverse infant outcomes. The goal of this project is to interrogate the human and bovine milk metabolome at 2-weeks postnatal to identify unique and overlapping metabolites that may impact infant health outcomes. Methods Human milk (n = 10) was collected at 2-weeks postpartum from normal weight mothers (pre-pregnant BMI <25 kg/m2) that vaginally delivered term infants and planned to exclusively breastfeed for at least 2-months. Similarly, bovine milk (n = 10) was collected 2-weeks postpartum from normal weight primiparous Holstein dairy cows. Dairy cattle were housed in sand-bedded, shaded barns with access to fans and water soakers and fed a common transition cow total mixed ration. Untargeted metabolomics was completed on all milk samples using high-resolution mass spectrometry. Metabolomic analysis was implemented using an open-source containerized metabolomics pipeline. Data processing was completed using MZmine, mummichog and Python were used for statistical analysis. Results We detected 716 metabolomic features in human and bovine milk samples after quality control. Our analysis also revealed that 43% (312) of metabolomics features were present in both human and bovine milk, 23% (167) of metabolomics features were unique to human milk and 33% (237) of metabolomics features existed only in bovine milk samples. Pathway analysis revealed that sialic acid and glycosphingolipid metabolism (P < 0.0009) were common to human and bovine milk samples. We also found that amino acid (tryptophan, tyrosine, purine) metabolism (P < 0.005) was unique to bovine samples and vitamin B3 pathways (P = 0.03) was unique to human samples. Conclusions Our analysis revealed a core milk metabolome shared between human and bovine samples. Collectively, these results highlight untargeted metabolomics as a potential strategy to identify unique and overlapping metabolites in bovine and human milk that may impact infant health outcomes. Funding Sources Research was supported by NIDDK/K01; SECIM P&F; CTSI Pilot Award; Robin Hood Foundation; NIH Loan Repayment Program.

Determination of some serum macroelement minerals levels at different lactation stages of dairy cows and their correlations

Minerals levels in blood affects animal performance, such as reproduction, immunity, and lameness. Minerals blood levels are recorded for all world tropics to be affected by lactation yield. This study aims to determinate the effects of different lactation stages of dairy cows on the serum Ca, P, Mg, Na and K minerals levels.The study involved 37 dairy cows, of parity order ranging between 2 to 6, at different stages of lactation. The animals were divided into four groups based on their stage of lactation, including postpartum, early, mid, and late stage cows. At the different lactation stages, serum profiles of Ca, P, Na, K and Mg as well as average daily milk yield were estimated. The data of serum profile was analyzed for the significance of stage of lactation by analysis of covariance, taking parity order as a covariate.The descriptive statistics of the studied traits showed that calcium serum level showed the most discrepancies among observations (coefficient of variation of 73.39%), whereas sodium serum level had the lowest level of discrepancies (coefficient of variation of 2.41%). The average daily milk yield was significantly higher at mid stage of lactation than those at the other stages of lactation. Serum level of all of the studied macro minerals were not statistically variable among stages of lactation, however, calcium showed statistically insignificant high levels during the early and mid of lactation, whereas, showed the lowest level at prepartum and postpartum stages. Calcium positively correlated with daily milk yield and negatively with potassium serum level.Results offer a base-line data concerning minerals levels during different lactation stages specially during prepartum and postpartum for normal healthy cows. Different lactation stages may affect and determinate macro-elements minerals levels. prepartum and postpartum periods are the most important stages that affects minerals levels. Some minerals showed tendency to correlate positively or negatively with other.

Plasma proteomic profiling and pathway analysis of normal and overconditioned dairy cows during the transition from late pregnancy to early lactation

This study applied a quantitative proteomics approach along with bioinformatics analyses to investigate changes in the plasma proteome of normal and overconditioned dairy cows during the transition period. Fifteen weeks before their anticipated calving date, 38 multiparous Holstein cows were selected based on their current and previous body condition scores (BCS) and allocated to either a high or a normal BCS group (19 cows each). They received different diets until dry-off to reach targeted differences in BCS and back fat thickness (BFT) until dry-off. At dry-off, normal BCS cows had a BCS <3.5 (minimum, 2.75) and BFT <1.2 cm (minimum, 0.58), and the high BCS cows had a BCS >3.75 (maximum, 4.50) and BFT >1.4 cm (maximum, 2.90). The proteomics study used a subset of 5 animals from each group. These cows were selected based on their circulating concentrations of fatty acids (FA) on d 14 postpartum and β-hydroxybutyrate (BHB) on d 21 postpartum, representing the greater or the lower extreme values within their BCS group, respectively. The high BCS subset (HE-HBCS) had 4.50 < BCS > 3.75, FA = 1.17 ± 0.46 mmol/L, and BHB = 2.15 ± 0.42 mmol/L (means ± SD), and the low BCS subset (LE-NBCS) had 3.50 < BCS > 2.75, FA = 0.51 ± 0.28 mmol/L, and BHB = 0.84 ± 0.17 mmol/L. Plasma samples from d -49, +7, and +21 relative to parturition were used for proteome profiling by applying the quantitative tandem mass tags (TMT) approach. Nondepleted plasma samples were subjected to reduction and digestion and then labeled with TMT 10plex reagents. High-resolution liquid chromatography-tandem mass spectrometry analysis of TMT-labeled peptides was carried out, and the acquired spectra were analyzed for protein identification and quantification. In total, 254 quantifiable proteins (criteria: 2 unique peptides and 5% false discovery rate) were identified in the plasma samples. From these, 24 differentially abundant proteins (14 more abundant, 10 less abundant) were observed in the LE-NBCS cows compared with the HE-HBCS cows during the transition period. Plasma α-2-macroglobulins were more abundant in HE-HBCS versus LE-NBCS cows at d +7 and +21. Gene Ontology enrichment analyses of differentially abundant proteins revealed that the acute inflammatory response, regulation of complement activation, protein activation cascade, and regulation of humoral immune response were the most enriched terms in the LE-NBCS group compared with the HE-HBCS group. In addition, we identified 24 differentially abundant proteins (16 in the LE-NBCS group, and 8 in the HE-HBCS group) during the transition period. The complement components C1q and C5 were less abundant, while C3 and C3d were more abundant in LE-NBCS compared with HE-HBCS cows. Overall, overconditioning around calving was associated with alterations in protein pathways related to acute inflammatory response and regulation of complement and coagulation cascades in transition cows.

Survey on Serum Amyloid A and Haptoglobin Concentrations in Normal or Sensitive to Rumen Acidosis Holstein Dairy Cows

BACKGROUND: Diagnosis and prognosis of inflammatory conditions based on acute phase proteins (APPs) level in blood has been exploited for a long time in human medicine and their changes in SARA condition is considered in veterinary medicine. OBJECTIVES: To evaluate the variations of serum amyloid A (SAA) and haptoglobin (Hp) as main acute phase proteins in cow with normal pH or cows that experienced rumen pH ≤5.8 during first days after parturition. METHODS: A total of 106 multiparous Holstein dairy cows were randomly selected after parturition in two different seasons of winter and summer 2017. Cows were divided into 2 groups as normal cows with pH >5.8 or rumen pH ≤5.8. Ruminal fluid samples were collected through stomach tube for rumen pH and blood samples were taken from the coccygeal vein of cows concurrently once per day at days 4, 11 and 18 post-partum. SAA and Hp were determined in blood samples. The PROC MIXED of SAS (2003) was used for all determined variables with repeated measures. BCS, parity and milk yield were included as fixed and cows as random effect. The significant level was declared at P≤0.05, and tendency toward significance was considered at 0.05 5.8. For all examined cows, SAA concentration was greater in winter than summer (P 5.8. CONCLUSIONS: Results showed that rumen pH ≤5.8 seems not to stimulate the APPs production

Concentration of serum estradiol, progesterone and cortisol during biological stress period of normal cyclic and silent Oestrous crossbred cows of Assam

The present study was planned to compare the concentration of serum estradiol, progesterone and cortisol level during biological stress period of normal cyclic and silent oestrous cycles of crossbred cows of Assam. Jugular blood samples were collected from ten normal cyclic and ten silent oestrous cows on day 0, 10, 17 and 20 of cycles for the present study. These 3 hormones were estimated by using ELISA kit manufactured by LDN GmbH& Co.KG, Germany, by solid phase enzyme-linked immunosorbent assay. Both estradiol and progesterone concentrations in serum were varied significantly (P< 0.01) between days of oestrous cycles of normal and silent oestrous cows. Lowest level of progesterone with concomitant highest level of estradiol was recorded on the day of oestrus. On the other hand, highest concentration of progesterone was found on the day 10 of cycles with lowest concentration of estradiol on day 17 of cycle. The mean levels of cortisol varied significantly between days of cycles with highest level on the day of oestrus.

Interleukins’ expression profile changes in granulosa cells of preovulatory follicles during the postpartum period in dairy cows

The postpartum period in dairy cows is associated with a state of temporary negative energy balance and could induce functional changes into ovarian granulosa cells (GC) resulting in significant impact on the ovarian function and fertility. Yet, the regulation of interleukin receptors (ILRs) in GC as well as ILs expression profile during the postpartum period have not been fully investigated. We hypothesized that the postpartum period is associated with changes in ILs expression profile that could affect follicular development and ovulation rate. First, we aimed to investigate the expression and regulation of different IL and IL receptors in GC at different stages of follicular development and then analyse the changes in target ILs expression profile induced during the postpartum period. In the first objective, normal cycling cows were selected and GC were collected from small follicles (SF), dominant follicles at day 5 of the estrous cycle (DF), and ovulatory follicles, 24 h following hCG injection (OF). In the second objective, dairy cows between 50 and 70 days postpartum were randomly selected, and β-hydroxybutyrate (BHB) concentrations were measured in blood samples in order to assign cows to the BHB+ group (>1.4 mmol/L) or BHB− group (<1.2 mmol/L). GC were collected from preovulatory follicles by transvaginal aspiration. Total RNA was extracted from GC of all groups for analysis of target ILs and ILRs expression. Steady-state mRNA levels of IL4R was strongest in the DF, while IL15R expression was greatest in the OF, and IL21R showed increased steady-state mRNA levels in the corpus luteum as compared to the different groups of follicles. Overall, expression of IL1A, IL1B, IL8, IL15, IL23 and TNFα was stronger in OF as compared to DF, while IL4 and IL10 expression was stronger in SF than in DF. Similarly, expression of IL1A, IL1B, IL8, IL15, IL23, and TNFα were significantly stronger in GC of BHB+ cows than in the control, while IL4 expression was significantly reduced in BHB+ as compared to control cows. We have established an IL expression profile, which suggest a correlation with BHB levels during the postpartum period. Additionally, we have demonstrated a differential regulation of target ILRs in GC at different stages of follicular development. Overall, these data provide a better understanding of the changes that could affect follicular development and ovulation during the postpartum period and lay the ground for further investigations.

Mass Spectrometry-Based Identification of Urinary Antimicrobial Peptides in Dairy Cows.

Urine is considered one of the biological fluids in which antimicrobial peptides are secreted or expressed. Cow urine has not been investigated for the presence of these peptides using MALDI-TOF-MS. The aim of this study is to isolate, identify and assess the antimicrobial activity of urinary antimicrobial peptides from healthy normal cycling cows. We analyzed the urine sample using diafiltration, ion exchange chromatography, Reverse Phase High-Performance Liquid Chromatography (RP-HPLC), acid urea polyacrylamide gel electrophoresis (AU-PAGE) coupled with identification through Peptide Mass Fingerprinting (PMF) by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDITOF- MS). The in vitro antimicrobial effects of purified fractions were assessed using Radial Diffusion Assay (RDA) and microtitre broth dilution assay against Gram-positive and Gramnegative bacteria. Proteins corresponding to the peaks were identified using SWISSPROT protein database. This study revealed constitutive expression of β-Defensin-1 (DEFB1), β-Defensin-4A (DFB4A), Neutrophil Defensin-1 (DEF1), Neutrophil Defensin-3 (DEF3) in cow urine. The identified peptides are cationic antimicrobial peptides of the defensin family. The purified fractions exhibited antimicrobial effects in radial diffusion assay and MIC values in the range of 2.93-29.3 µM/L. This study concludes that cow urine, previously unexplored with regard to antimicrobial peptides, would be a promising source of highly potent AMPs and an effective alternative to the resistant antibiotics.

Metabolic biomarkers, body condition, uterine inflammation and response to superovulation in lactating Holstein cows

The objective was to determine associations between response to superovulation and body condition, subclinical endometritis and circulating metabolic biomarkers [adiponectin, leptin, insulin, IGF1, tumor necrosis factor (TNF) α, interleukin (IL) 1β, IL6, and urea] in lactating dairy cows. Ten multiparous lactating Holstein cows in each body condition score (1–5; 1 emaciated; 5 obese) category (BCSC) 2.00 to < 2.50 (BCSC1), 2.50 to < 3.00 (BCSC2), 3.00 to <3.50 (BCSC3), 3.50 to <4.00 (BCSC4) and 4.00 to 5.00 (BCSC5) groups (total n = 50) were randomly selected and superovulated, timed artificially inseminated with frozen-thawed semen from three sires and embryos collected (n = 50 collections). At embryo collection, blood samples and embryo recovery fluid were collected for determination of metabolic markers and presence of subclinical endometritis (lavage technique; > 6% PMN). In total, 379 embryos were collected (average of 7.6 embryos per superovulation). Mean numbers of total ova and embryos was greater for cows in BCSC2, BCSC3 and BCSC4 groups compared with cows in BCSC1 and BCSC5 groups (P < 0.01). Total number of transferrable embryos were greater for cows in BCSC 2 and BCSC3 groups compared with cows in BCSC1, BCSC4 and BCSC5 groups (P < 0.01). Mean number of total ova and embryos and of transferrable embryos was higher for cows with 0 or 1–6% PMN compared to cows with >6% PMN (P < 0.01). In addition, there was a quadratic association between blood urea nitrogen concentrations and % transferrable embryos (r2 = 0.85; P < 0.05) and between BCS and % transferrable embryos (r2 = 0.73; P < 0.05). Circulating adiponectin, leptin, insulin, IGF1 and TNFα were greater in cows with moderate to good body condition compared to thin or obese cows (P < 0.05). Circulating adiponectin, leptin, IGF1 and insulin were greater in normal cows (≤6% PMNs), whereas, TNFα and IL1β and IL6 were greater in cows with subclinical endometritis (P < 0.05). In conclusion, BCS and subclinical endometrial inflammation were associated with superovulatory response and embryo quality. Further, circulating metabolic biomarkers were associated with superovulatory response and embryo quality, likely due to donor’s metabolic status and uterine environment. Optimizing superovulatory responses and embryo quality in lactating dairy cows requires management of nutrition and uterine health.

Diagnosing postpartum endometritis in dairy cattle

#### What you need to know Postpartum endometritis is a common cause of infertility in dairy cattle, and most vets can discriminate between a normal cow and a cow with...

Full genomic characterization of a porcine rotavirus strain detected in an asymptomatic piglet in Accra, Ghana

BackgroundThe introduction of rotavirus A vaccination across the developing world has not proved to be as efficacious as first hoped. One cause of vaccine failure may be infection by zoonotic rotaviruses that are very variable antigenically from the vaccine strain. However, there is a lack of genomic information about the circulating rotavirus A strains in farm animals in the developing world that may be a source of infection for humans. We therefore screened farms close to Accra, Ghana for animals sub-clinically infected with rotavirus A and then sequenced the virus found in one of these samples.Results6.1% of clinically normal cows and pigs tested were found to be Rotavirus A virus antigen positive in the faeces. A subset of these (33.3%) were also positive for virus RNA. The most consistently positive pig sample was taken forward for metagenomic sequencing. This gave full sequence for all open reading frames except segment 5 (NSP1), which is missing a single base at the 5′ end. The virus infecting this pig had genome constellation G5-P[7]-I5-R1-C1-M1-A8-N1-T7-E1-H1, a known porcine genotype constellation.ConclusionsFarm animals carry rotavirus A infection sub-clinically at low frequency. Although the rotavirus A genotype discovered here has a pig-like genome constellation, a number of the segments most closely resembled those isolated from humans in suspected cases of zoonotic transmission. Therefore, such viruses may be a source of variable gene segments for re-assortment with other viruses to cause vaccine breakdown. It is recommended that further human and pig strains are characterized in West Africa, to better understand this dynamic.

The potential interaction between body condition score at calving and dietary starch content on productive and reproductive performance of early-lactating dairy cows

Improving reproductive performance is one of the most important factors affecting the profitability of dairy herds. This study investigated the effect of feeding a high starch (HS) diet and body condition score (BCS) at calving on blood metabolites, fertility and ovarian function and milk production in Holstein dairy cows. One hundred seventy-four multiparous cows were fed common close-up and early lactation diets during the first 15 days in milk (DIM). Cows were randomly assigned to 1 of 2 experimental diets from 16 until 50 DIM (n = 87 per group); normal starch (228 g/kg diet DM; NS) or HS (270 g/kg diet DM; HS) diets. Each treatment group was further subdivided based on BCS at calving as normal BCS (BCS ⩽ 3.5; normal BCS (NBCS); n = 45) or high BCS (HBCS) (BCS ⩾ 3.75; HBCS; n = 42). A significant difference was detected for increased milk production (47.24 v. 44.55 kg/day) and decreased milk fat (33.93 v. 36.33 g/kg) in cows fed HS or NS, respectively. Plasma glucose and insulin concentrations were significantly higher in cows fed the HS compared to the NS diet. Diets significantly affected DIM at first artificial insemination (AI, 79.51 ± 3.83 v. 90.40 ± 3.83 days for cows fed HS and NS diets, respectively). High BCS groups had greater milk fat content and elevated plasma nonesterified fatty acids (NEFA), β hydroxybutyrate (BHB) and bilirubin concentrations. In general, feeding higher starch diets to normal BCS cows during the first 50 DIM improved productive and reproductive performance of early-lactating dairy cows.

On-farm risk factors associated with Leptospira shedding in New Zealand dairy cattle.

This study aimed to evaluate risk factors associated with shedding of pathogenic Leptospira species in urine at animal and herd levels. In total, 200 dairy farms were randomly selected from the DairyNZ database. Urine samples were taken from 20 lactating, clinically normal cows in each herd between January and April 2016 and tested by real-time polymerase chain reaction (PCR) using gyrB as the target gene. Overall, 26.5% of 200 farms had at least one PCR positive cow and 2.4% of 4000 cows were shedding Leptospira in the urine. Using a questionnaire, information about risk factors at cow and farm level was collected via face-to-face interviews with farm owners and managers. Animals on all but one farm had been vaccinated against Hardjo and Pomona and cows on 54 of 200 (27%) farms had also been vaccinated against Copenhageni in at least one age group (calves, heifers and cows). Associations found to be statistically significant in univariate analysis (at P < 0.2) were assessed by multivariable logistic regression. Factors associated with shedding included cattle age (Odds ratio (OR) 0.82, 95% CI 0.71-0.95), keeping sheep (OR 5.57, 95% confidence interval (CI) 1.46-21.25) or dogs (OR 1.45, 95% CI 1.07-1.97) and managing milking cows in a single as opposed to multiple groups (OR 0.45, 95% CI 0.20-0.99). We conclude that younger cattle were more likely to be shedding Leptospira than older cattle and that the presence of sheep and dogs was associated with an increased risk of shedding in cows. Larger herds were at higher risk of having Leptospira shedders. However, none of the environmental risk factors that were assessed (e.g. access to standing water, drinking-water source), or wildlife abundance on-farm, or pasture were associated with shedding, possibly due to low statistical power, given the low overall shedding rate.

162 Detection of ovulation disorders and normal ovulation using wireless sensors of ventral tail surface temperature and neck acceleration data in Japanese Black cows

The present study aimed to clarify the possibility of detection of ovulation disorders and normal ovulation in Japanese Black cows using wearable wireless sensors based on continuous measurements of body surface temperature (ST) and neck acceleration data. For cows with normal ovulation (n=19, 8.5 years old, 476.2kg), controlled internal drug release (CIDR) and gonadotrophin-releasing hormone were administered on arbitrary days of the oestrous cycle (Day −10), and oestrus was induced by CIDR removal and prostaglandin F2α administration (Day −3). Ovulation (Day 0) was induced by gonadotrophin-releasing hormone administration on estimated oestrus day (Day −1) and was detected based on the disappearance of ≥8mm follicles using ultrasonography at 1- to 2-h intervals. For cows with spontaneous ovarian cysts (n=11, 8.6 years old, 471.2kg), oestrus and the next day were defined as Days −1 and 0, respectively. Plasma concentrations of progesterone (P4) and oestradiol-17β (E2) were measured on Days −9, −6, −2, −1, 0, 1, 5, and 8. The body ST sensor was attached to the ventral tail base (Day −16), and ST was measured every 10min for 24 days. For analysis of ST, after extracting hourly maximum ST values, the values were expressed as residual ST (RST; ST − mean ST for the same hour on the previous 3 days) for removal of circadian rhythm (Miura et al. 2017 Anim. Reprod. Sci. 180, 50-57; https://doi.org/10.1016/j.anireprosci.2017.03). The acceleration sensor (Farmnote Color, Farmnote Inc.) was attached to the neck (Day −16). Hourly oestrus level (amount of oestrus activity) was obtained from the amount of activity; the difference between the residual oestrus level (REL; same calculation as RST) and measured values of each day was used. To identify RST and REL of cows with normal ovulation and cows with ovarian cysts, the mean values and standard deviations for the same hours for 3-7 days before oestrus were calculated. Mean RST and REL for 3-7 days before oestrus were assumed according to the normal distribution. The 95% confidence range was determined using×1 standard deviation of all hours. Values over the 95% confidence range for ≥5h were considered to be different from the mean 4 days and the 5% level. For RST, no difference was found in both groups due to the large influence of environment, particularly low temperature. However, for REL, a difference was indicated for oestrus in all cows (P&amp;lt;0.05). A large peak of REL appeared once on oestrus (&amp;gt;14.4 REL for 20h) in normal cows, and three peaks occurred in &amp;lt;21 days (&amp;gt;16.2 REL for 21, 15, and 15h) in cows with ovulation disorders (P&amp;lt;0.05). The REL rapidly increased following peaking E2 and decreasing P4 to oestrus (Day −1) in normal cows. In cows with an ovulation disorder, REL increased on oestrus; however, E2 and P4 remained high and low stable to oestrus, respectively. In conclusion, oestrus activity and the characteristics of normal cows and those with an ovulation disorder can be detected by the neck acceleration sensor using the correction value. This research was supported by The Research Project for the Future Agriculture Production Utilising Artificial Intelligence.