Fertility Of Cows Research Articles

Hybrids Performance Indicators of Black Pied and Holstein Cattle Breeds and Fertility Potential

The presented article discusses the issues of milk productivity in the 2nd lactation of Black Pied cows of different genotypes, their biological indicators in the basic and main comparison farms. Observations were made on the fertility of different groups of animals, the age of insemination of heifers, the live weight of heifers at insemination, as well as breeding criteria, reproductive longevity and lifelong fertility of cows.

Peripartum Supplementation of Rumen Protected Choline and Fat and Se+Vit E in Gir Cows Economically Improves Endocrine Profile and Reproductive Performance

Background: The negative energy balance around calving and in early lactation is the major cause of increased incidence of postpartum metabolic disorders, reduced milk production and impaired reproductive performance. This study was aimed to evaluate the effect of rumen protected choline, fat supplementation and Vit-E and selenium injections on plasma endocrine profile, postpartum productivity, fertility and economics in transitional Gir cows. Methods: Forty advanced pregnant multiprous Gir cows of an organized farm were randomly distributed into five equal groups (T1 to T5; n=8 each) and were fed and managed individually from 30 days prepartum till 60 days postpartum. Cows in T1 (control) group were fed basal diet, while cows in treatment groups received basal diet + supplementation of rumen protected choline-RPC @ 45 g/d/cow (T2), rumen protected fat-RPF @ 80 g/d/cow from -30 to +15 days peripartum and then @ 10 g/kg milk yield (T3), RPC and RPF in combination @ as above (T4) and Inj. E-Care Se(R) 10 ml i/m (Vit-E 500 mg and Se 15 mg) on days -30, -15, 0, +15, +30 and +45 peripartum (T5) along with blood samples for estimation of plasma levels of insulin, IGF1, PGFM, estradiol (E2), progesterone (P4) and cortisol. The puerperal events and fertility parameters were recorded till 10 months postpartum. Result: The fortnightly plasma P4 concentration decreased, while E2, PGFM and cortisol increased gradually and significantly (P less than 0.01) from 30 days prepartum to day of calving and thereafter P4, E2 and cortisol remained basal or very low, while PGFM decreased till 45-60 days postpartum, overall and in all groups. The treatment effect was significant (P less than 0.01) only for E2 and PGFM, with higher values of E2 in T3 and T4 groups and of PGFM in T1 and T2 than in T5 group. The insulin and IGF1 concentrations fluctuated insignificantly during prepartum phase with significantly lowest values till 15 and 30 days postpartum and thereafter only IGF1 increased significantly by day 60 postpartum. The treatment effect was also significant at some intervals with overall highest values of both the metabolic hormones in T1 followed by T5 and T2 than T3 and T4 groups. The uterine involution was significantly earlier in all treatment groups than in control. The first heat postpartum (days) was significantly earlier in group T5 (33.6±3.4), delayed in group T1 (63.5±9.5) and intermediate in Group T2 to T4. The conception rates postpartum were 50.0, 75.0, 62.5, 75.0 and 87.5% in groups T1 to T5, respectively, with significantly reduced service period (days) in T5 (96.3±14.6), followed by T2 (137.3±11.2), than T1, T3 and T4 groups (187 to 214 days). The overall net returns over feed cost of milk yield and reduced service period in T2, T3, T4 and T5 groups over control T1 were Rs. +15898, +6150, +7165 and +24060, respectively. The findings reflected the beneficial and economic role of RPF alone or in combination with RPC and of Se + Vit E supplementation on peripartum endocrine profile and improved postpartum fertility in Gir cows.

126 Effect of oestrus synchronisation protocol with a high dose of oestradiol and an intravaginal progesterone-releasing device on the endometrial epidermal growth factor concentrations and fertility in recipient cows

Reproduction, Fertility and Development is an international journal publishing original research , review and comment in the fields of reproduction and developmental biology in humans, domestic animals and wildlife

163 Genome-wide association study to identify candidate genomic regions for cow fertility in Retinta cattle breed

Reproduction, Fertility and Development is an international journal publishing original research , review and comment in the fields of reproduction and developmental biology in humans, domestic animals and wildlife

Genetic and nongenetic variation of heifer fertility in Italian Holstein cattle

Excellent fertility performance is important to maximize farmers' profit and to reduce the number of culled animals. Although female fertility of adult cows has been included in Italian Holstein breeding objectives since 2009, little has been done to quantify genetic variation of heifer fertility characteristics so far. The aim of the present study was to estimate genetic parameters of 4 fertility traits in nulliparous Italian Holstein heifers and to develop an aggregate selection index to improve heifer fertility. Data were retrieved from the national fertility database and included information on insemination, calving, and pregnancy diagnosis dates. The investigated phenotypes (mean ± standard deviation) were age at first insemination (AFI, mo; 17.25 ± 2.89), nonreturn rate at 56 d from the first insemination (NRR56, binary; 0.78 ± 0.41), conception rate at first insemination (CR, binary; 0.61 ± 0.49), and interval from first to last insemination (IFL, d; 26.09 ± 51.85). Genetic parameters were estimated using a 4-trait animal model that included the following fixed effects: herd-year of birth and month of birth for AFI, and herd-year-season of birth and month-year of insemination for IFL, NRR56, and CR; the animal additive genetic effect (fitted to the pedigree-based relationship matrix) was considered as a random term. An aggregate index was developed from the estimated additive genetic (co)variance matrix by considering CR as the breeding goal and AFI, NRR56, and IFL as selection criteria. Heritability estimates from average covariance matrices ranged from 0.012 (CR) to 0.015 (IFL), with the exception of AFI (0.071). Conception rate at first insemination was strongly correlated with both IFL (−0.730) and NRR56 (0.668), and weakly to AFI (−0.065), and the relative emphasis placed on each selection criteria in the aggregate index was 10%, 47%, and 43% for AFI, IFL, and NRR56, respectively. The results of the present study suggest that heifer fertility should be considered as an additional trait in the breeding objectives of Italian Holstein.

Direct transfer of a single frozen-thawed in vitro-produced embryo to avoid twin pregnancy in dairy cows.

Fertility of cow receiving fixed-time artificial insemination (FTAI) was compared with cow in which a single frozen-thawed in vitro-produced (IVP) embryo was fixed-time transferred (FTET) to avoid twin pregnancy. The study population was comprised of 596 lactating dairy cows synchronized for oestrus: 440 were fixed-time inseminated (AI cows), and 156 were given GnRH treatment at the time of embryo transfer (ET cows) 8 days post-oestrus. Of the 596 cows, 235 (39.4%) became pregnant: 175 (39.8%) AI cows and 60 (39.8%) ET cows. Twin pregnancy was recorded in 16% of the AI pregnant cows (28/175), whereas no ET cows had twins (0/60). Significant interaction (p < .01) was observed between breeding technique (FTAI vs FTET) and repeat (RB) or not repeat breeding (NRB) for the likelihood of pregnancy. This meant that using RB AI cows as reference, the odds ratio for pregnancy in RB ET cows was 2.2 (p=.04). In conclusion, transfer of a frozen IVP embryo proved useful to prevent the risk of twin pregnancy without affecting fertility.

The Study of Biodive and Cow Fertilizer Composition on Bean Growth and Production (Phaseolus Vulgaris L.)

In agricultural cultivation technology, there are very influential limiting factors on plant growth and yield, one of which is the presence of fertilization. This research aims to study the composition of Bio fertilizer and Cow manure fertilizer application bean’s growth and yield. This research was conducted from February 25th, 2022 to May 22th, 2022 at Seed Garden of Food Crops and Horticulture Tawangmangu (TPH) Tawangmangu, Karangpandan District, Karanganyar Regency with an altitude place of 1100 meters above sea level and Latosol soil. This research method uses a single factor randomized complete block design (RCBD) consisting of 6 kinds of experiments and each was repeated 4 times in order to obtain 24 kinds trial. The variables used are length of plant, number of leaves, length of root, fresh weight of biomass, dry weight of biomass, the number and weight of pods. The results of this research showed that the composition of biofertilizer and cow fertilizer application has no effect on bean’s growth and yield.

What are the factors associated with pregnancy loss after timed-artificial insemination in Bos indicus cattle?

Pregnancy loss (PL) has important impacts on the profitability of livestock production systems, although it is not widely reported, particularly in Bos indicus cattle. The present study retrospectively evaluated PL after timed-artificial insemination (TAI) in Bos indicus (Nelore) beef cows corresponding to several factors, such as parity, body condition score (BCS), presence of corpus luteum (CL) at the beginning of TAI protocols, expression of estrus, and hormonal manipulations during the TAI protocol. Data from two experiments performed during three breeding seasons (BS) were reanalyzed. Both experiments evaluated adding GnRH treatment at TAI in a 7-d estradiol (E2) plus progesterone (P4)-based protocol, with intravaginal P4 implant removal on Day 7 combined with treatment with 0.5 or 1.0 mg E2 cypionate and 300 IU eCG, and TAI on Day 9. In addition, during BS 2 and 3 (Exp 2), cows were randomized to receive or not a PGF treatment on Day 0 (beginning of the TAI protocol). In all BS, presence of CL and BCS were evaluated at the beginning of TAI protocols, follicle size and expression of estrus were evaluated at TAI. The PL was assessed between the first pregnancy diagnosis (∼35d) and parturition. There were no effects of hormonal manipulations within TAI protocols of different BS on PL. There was no interaction between GnRH treatment at TAI and the other variables within BS, and there was no main effect of GnRH treatment on PL (without = 10.1% [102/1007] vs. with = 10.4% [114/1100]). The addition of PGF on Day 0 had no effect on PL (11.5% [102/886] vs. 10.5% [89/850]), as well as EC dose to induce final ovulation (10.8% [89/827] vs. 11.2% [102/909] for 0.5 and 1.0 mg, respectively). Primiparous had greater PL than multiparous cows (14.0% [77/550] vs. 8.9% [139/1557]), and cows not expressing estrus near TAI had greater PL than those expressing estrus (13.5% [57/422] vs. 9.7% [156/1617]). There was no interaction between follicle size at TAI and GnRH treatment on PL. However, probability of PL decreased linearly as follicle size at TAI increased. There were no effects of service number (first TAI or resynchronization), BCS, or presence of CL on D0 on PL. In addition, PL was not affected by sire within any of the BS. In conclusion, some factors that are known to impact pregnancy per AI also influenced PL, such as parity and expression of estrus, although, other aspects such as BCS, number of services, and presence of CL on D0 did not affect PL. Moreover, commonly implemented treatments to increase fertility (e.g., PGF on Day 0 and increasing EC dose to 1.0 mg) did not affect PL. Finally, the GnRH treatment at TAI had no effect on PL and did not interact with any of the variables, an important result, since GnRH at TAI also increases fertility in Bos indicus beef cows.

Fertility of dairy cows milked once daily or twice daily in New Zealand.

The objective of this study was to evaluate the reproductive performance of New Zealand dairy cows with different milking regimens. A total of 2,562 herds calving in 2017 met the criteria for inclusion in this study. The herds were classified into 5 different milking regimens: 260 herds with cows milked once daily (OAD) during the entire lactation, 1,206 herds with cows milked twice daily (TAD) during the entire lactation, 94 herds that were switched to OAD milking from TAD milking during the mating period (OAD-M), 700 herds that were switched to OAD milking from TAD milking after peak lactation (OAD-P), and 302 herds that switched to OAD milking from TAD milking at end of the lactation (OAD-E). Time from the start of mating to first service (SMFS), start of mating to conception (SMCO) and first service to conception (FSCO) were analyzed using survival analysis. Time from SMFS, SMCO and FSCO was significantly shorter in cows milked OAD compared with cows milked TAD. Also, cows milked OAD had fewer services per conception and higher mean 3-wk submission (SR21), in calf by 3 wk (PR21), in calf by 6 wk (PR42), conception to the first service (PRFS), 3-wk calving (CR21) and 6-wk calving (CR42), and lower not in calf (NIC) than herds with TAD, OAD-M, OAD-P, OAD-E milking cows. Fertility performance differed with parity; first-parity cows had lower SR21, 6-wk submission (SR42), PR21, PR42, PRFS, CR21, and CR42 values, and higher NIC values than second-parity cows. Third parity cows had the highest values for SR42, PR21, PR42, PRFS, CR21, and CR42, and lowest value for NIC compared with cows of other parities. Significant but minor interactions between milking regimen and parity existed for SMFS, SMCO, FSCO, SR21, SR42, PR21, PR42, PRFS, NIC, and CR21.

Genetic analysis of fetal loss in Holstein cattle.

Pregnancy loss is recognized as one of the major factors contributing to poor reproductive performance in dairy cattle. Here, we performed a comprehensive genetic analysis of fetal loss, defined as a pregnancy loss that occurs after detection of a viable embryo around 42 d of gestation. The objectives of this study were to reveal (1) whether fetal loss is heritable and, hence, whether it will respond to selection, and (2) to what extent current fertility traits, such as daughter pregnancy rate, are associated with fetal loss. Data consisted of 59,308 confirmed pregnancy or fetal loss records distributed across nulliparous heifers and primiparous and multiparous cows. We defined fetal loss as a binary trait (yes vs. no) or as an ordinal trait (pregnancy maintenance, early fetal loss ≤150 d of gestation, and late fetal loss >150 d of gestation), and we assessed both linear and threshold models. Heritability estimates for fetal loss ranged from 1 to 18%, depending upon parity, trait definition, and statistical model used. Heritability estimates were greater for lactating cows than for nonlactating nulliparous heifers. Threshold models were able to capture more additive genetic variance and, thus, yielded higher heritability estimates than linear models. Notably, fetal loss traits were highly genetically correlated with each other but only weakly correlated with current fertility traits included in the national genetic evaluation. Overall, our study provides evidence that fetal loss is heritable enough to make genetic selection for reducing fetal loss and improving pregnancy maintenance feasible. In addition, our results suggest that fetal loss is largely independent from current traits used to select for cow fertility, and thus current breeding efforts have unfortunately little effect on reducing the incidence of fetal loss.

Efektivitas Aplikasi Pupuk Organik Cair Urine Sapi Terhadap Pertumbuhan Vegetatif Bibit Kelapa Sawit (Elaeis guineensis Jacq.) di Pre Nursery

This study was conducted to determine the effect of the application of liquid organic fertilizer in cow urine on the vegetative growth of oil palm seedlings in early nurseries. This research was conducted in the experimental garden of ITSI Medan. This research was conducted for 3 months. Starting from August 2021–October 2021. This study used a non-factorial Randomized Block Design (RAK) method consisting of 5treatments with 5 replications, so the number of samples was 25 seeds. Parameters observed were plant height, stem diameter, number of leaves, shoot dry weight, root dry weight, shoot wet weight and root wet weight. The data obtained were statistically analyzed by DMRT and ANOVA tests. The results of this study indicate that the application of liquid organic fertilizer cow urine has an effect on the vegetative growth of oil palm seedlings in early nurseries with the best dose of 20 ml cow urine. The standard gave some significant and very significant effects on stem height, stem diameter, number of leaves, but had no effect on wet weight and dry weight. Keywords:urine, pre nursery, poc

Relationship Between Globulins in the Late Dry Period with Biochemical Parameters, Fertility and Culling of Cows within 90 Days after Calving

Diseases of the transit period in cows and their culling after calving attract considerable attention. Therefore, early diagnosis and prediction of pathological processes during the transition period in cows using biochemical markers stays relevant. The purpose of this study was to find the relationship of globulin levels in the late interlactation period with biochemical parameters and the level of fertilisation and culling of cows within 90 days after calving. The blood serum of cows of the main herd was investigated 10-15 days before calving, based on which the animals were conditionally divided into three groups (with signs of hypogammaglobulinemia (less than 30 g/l)), as well as with normal and elevated (more than 40 g/l) globulin levels. Apart from indicators of protein-nitrogen metabolism, enzymatic activity was also found in the blood serum and the state of carbohydratelipid, mineral, and vitamin metabolism was assessed using biochemical, chromatographic, and spectrophotometric research methods. It was found that cows with hypoglobulinemia showed substantially lower activity of asparagine transaminase, as well as differences in carbohydrate-lipid metabolism (high glucose levels and reduced concentration of high-density lipoproteins). Furthermore, these cows were found to have a decrease in the content of magnesium, as well as copper. It was discovered that within 90 days after calving, the highest level of culling was observed among cows with reduced globulin levels, and the lowest – in animals with normoglobulinemia. Therefore, a direct relationship between the level of globulins in the blood serum 10-15 days before calving with the reproductive capacity and the level of culling of cows was proved. This allows promptly diagnosing and predicting the development of post-partum pathology and reproductive disorders. The results obtained can be used by practical specialists and scientists to plan and investigate the effectiveness of preventive measures to improve the safety of cows and their reproductive capacity in the post-calving period

Assessment of the genetic parameters and breeding value of bulls-producers of the Ukrainian black speckled milky breed by the main characteristics

Evaluation and selection of breeding bulls based on economically important characteristics is the main tool in modern systems of genetic improvement of dairy cattle. The purpose of the study was to analyse the influence of environmental and genetic factors on the traits of milk productivity, reproduction, productive longevity, and the difficulty of calving, to assess the genetic parameters and breeding value of breeding bulls based on these traits. The research material was data on the indicators of productivity, reproduction, and productive longevity of cows of the Ukrainian black speckled milky breed of the agricultural cooperative “Vostok” of the Kharkiv region. A multidimensional linear-threshold model was used to calculate genetic parameters (heritability coefficients and genetic correlations) and breeding values of breeding bulls. A probable phenotypic negative association was identified between calving difficulty and milk yield for 305 days (r= -0.2244±0.0266, P&gt;0.999); an increase in calving difficulty by 1 point leads to a decrease in milk yield for 305 days of lactation by 1281.0 kg. Calculated estimates of genetic correlation indicate the presence of a fairly high relationship between milk yield for 305 days of lactation and the service period (over +0.5), a negative relationship between the service period and productive longevity (about -0.37), and a positive relationship between the service period and calving difficulty (about +0.26). This data indicates the presence of genetic antagonism between milk productivity and the level of reproduction of dairy cows, the negative impact of the extended service period on the length of stay of cows in the dairy herd, and the impact of calving difficulty on the deterioration of cow fertility. Estimates of the breeding value of breeding bulls by milk yield, service period, productive longevity, and calving difficulty were calculated. The results obtained indicate the expediency of including traits of reproduction, productive longevity, and difficulty of calving cows in the breeding index, which is used to evaluate and select bulls-producers of the Ukrainian black speckled milky breed

PSV-A-1 Estrus Response and Pregnancy Rates of Beef Cows Enrolled in two Fixed-Time Artificial Insemination Protocols, with or without pre-Synchronization

Abstract Pre-synchronization strategies with prolonged exposure to exogenous progesterone have the potential to alter estrus expression and improve fertility in beef cows. The objective of this study was to evaluate the estrus response and pregnancy rate of suckled beef cows enrolled in two fixed-time artificial insemination (TAI) protocols. A total of 1,216 cows (angus-crossed) at 10 locations across VA were enrolled in the study. Within location, cows were ranked by body weight, and days postpartum and randomly assigned to one of two treatments: 1) 7&amp;7 (n = 610), cows were administered prostaglandin F2α (PGF; 25 mg) and a controlled internal drug releasing (CIDR) insert [Day -14], an injection of GnRH (100 μg [Day -7]), PGF injection and CIDR removal [Day 0], and a second injection of GnRH concurrently with TAI 64 ± 2 h later [Day 2]; 2) 7-day CO-Synch+CIDR (7-day; n = 606), cows were administered GnRH (100 μg) and a CIDR insert [Day -7], PGF (25 mg) injection and CIDR removal [Day 0], and a second injection of GnRH concurrently with TAI 64 ± 2 h later [Day 2]. All cows received an estrus alert patch (ESTROTECT) on Day 0 and were evaluated for patch activation at TAI on Day 2. Pregnancy was diagnosed by transrectal ultrasonography between 45 and 65 days after TAI. The percentage of cows exhibiting estrus between Day 0 and 2 was greater (P &amp;lt; 0.001) for 7&amp;7 compared with 7-day cows (72.8% and 55.9%, respectively). However, pregnancy rate to TAI was similar (P = 0.328) between treatments (63.8% and 61.1%, for 7&amp;7 and 7-day, respectively). We conclude that suckled beef cows enrolled in the 7&amp;7 TAI protocol had increased estrus expression, but similar pregnancy rate when compared with cows enrolled in the 7-day CO-Synch+CIDR TAI protocol.

Increased luteal tissues after secondary corpus luteum formation leads to enhanced progesterone concentrations and improved fertility in repeat-breeder dairy cows during heat stress condition in tropical climate.

Relatively, little is known about the corpus luteum (CL) function in early pregnancy after the successful treatment of luteal phase deficiency in repeat-breeder dairy cows when exposed to extreme environments under tropical climate. To investigate the influence of increased tissues of corpora lutea (CLs) by inducing secondary CL based on progesterone (P4) concentration and fertility in repeat-breeder dairy cows undergoing the fixed-time artificial insemination (FTAI) protocol, 32 cows were treated with gonadotropin releasing hormone (GnRH) on day 5 post-induction (experiment 1). In experiment 2, 213 cows were bred using the short-term FTAI protocol. On day 5 post-FTAI, cows were divided into two groups: treatment with (GnRH5-treated group) or without (GnRH5-untreated group) GnRH. The temperature-humidity index ranged from 77.3 to 82.8. Cows bearing two CLs had greater P4 concentrations than cows bearing only one CL on their ovaries (P < 0.05). Pregnancy rates were greater in GnRH5-treated group than the GnRH5-untreated group (P < 0.01). Moreover, repeat-breeder cows bearing two CLs had a greater likelihood of pregnancy (odds ratio = 20.86) than cows bearing only one CL on their ovaries (P < 0.01). Under heat stress condition, the results highlighted that increasing luteal tissues by creating secondary CL leads to enhanced peripheral P4 concentrations and improved pregnancy outcomes in repeat-breeder dairy cows.

Fertility of Holstein cows and heifers submitted to timed artificial insemination and receiving one or two doses (12 h apart) of semen.

The objective of this retrospective study was to assess the effect of receiving a single (n=50,285) or double (n=4392) artificial insemination (AI), 12 h apart, within a timed artificial insemination protocol on pregnancy per AI (P/AI) in nulliparous heifers (inseminated with either sex-sorted or conventional semen) and pluriparous Holstein cows in a commercial dairy herd. Also, this study aimed to investigate the relationship between temperature-humidity index (THI) and time of the first AI and fertility. Fertility of cows receiving two AI with normothermia (THI <68) was higher (p<.05) than cows receiving a single AI (42.9% vs. 36.4%). P/AI of cows receiving two AI with severe heat stress (THI >85) was higher (p<.05) than cows receiving a single AI (21.0% vs. 12.6%). Regardless of heat stress conditions, applying the first AI in the morning increased (p<.05) P/AI in cows with double AI than in cows whose first AI occurred in the afternoon (38.4 vs. 33.3%). With moderate heat stress, and sexed-sorted semen, P/AI to timed AI was higher (65.0 vs. 51.9%; p<.05) in heifers receiving double AI than those serviced once. It was concluded that double AI, 12 h apart, enhanced fertility at timed AI than herd mates with a single AI, particularly with heat stress at breeding.

Simultaneous free fatty acid elevations and accelerated desaturation in plasma and oocytes in early postpartum dairy cows under intensive feeding management

A severe negative energy balance and high circulating free fatty acids (FFA) in postpartum cows impair fertility. The lipotoxicity of FFA has been shown to decrease the quality of bovine oocytes in vitro. Therefore, excess FFA in cells is converted to triacylglycerol (TAG), a non-toxic form, to avoid lipotoxicity. We recently reported that the TAG content in oocytes was higher in postpartum lactating cows subjected to grazing management than in heifers (Theriogenology 176: 174–182, 2021). The present study investigated the compositions of the energy metabolism-related lipids, FFA and TAG, in the plasma and oocytes of cows at different lactation stages under indoor intensive feeding management in order to obtain insights into lipotoxicity in oocytes, particularly those in early postpartum cows. Blood and oocytes were collected from 20 lactating cows categorized into the following lactation groups: 20–30 days in milk (DIM) (n = 5), 40–50 DIM (n = 5), 60–80 DIM (n = 5), and 130–160 DIM (n = 5). Daily energy balance data were obtained for 3 weeks prior to oocyte collection using the ovum pick up (OPU) method. The contents and compositions of FFA and TAG in plasma and oocytes were analyzed using liquid chromatography-mass spectrometry. As expected, plasma FFA was high at 20–30 DIM, decreased by 50 DIM, and was maintained at a low level for the remainder of the experimental period. Similar changes were observed in oocyte FFA and TAG with DIM as plasma FFA. Oocyte FFA positively correlated with plasma FFA (P < 0.05), but negatively correlated with the mean energy balance 1 and 21 days before OPU (P < 0.05). Relationships were noted between the composition and content of FFA in plasma and oocytes, with the FFA 16:1/16:0 and 18:1/18:0 ratios positively correlating with the total amount of FFA (P < 0.05). Elevated oocyte FFA in cows in the early postpartum period under intensive feeding management suggested that oocytes were at a high risk of FFA lipotoxicity. Furthermore, the present results implied that the severe negative energy balance in the previous few weeks was closely related to increases in oocyte FFA, which supports the importance of long-term cow feeding management for preserving the quality of oocytes in the early postpartum period. The present results provide insights into the effects of high circulating FFA on the fertility of postpartum cows.

In Vitro Effects of Short-Term and Long-Term Heat Exposures on the Immune Response and Prostaglandin Biosynthesis in Bovine Endometrial Cells.

Worldwide heat stress (HS) conditions have a negative impact on dairy cow fertility. However, understanding of the effect of heat stress on endometrial functions is still unclear. The present study aimed to investigate the effects of differential heat exposure conditions on the immune response and prostaglandin biosynthesis of bovine endometrium challenged with bacterial lipopolysaccharide (LPS). Cultures of endometrial cells were grown to confluence at 37 °C (control) and 40.4 °C for 24 h after confluence (short-term heat exposure) and 40.4 °C for 8 days from the beginning of the culture (long-term heat exposure), prior to a challenge by 100 ng/mL LPS for 12 h. LPS altered ALOX12, IL8, IL1B, S100A8, PTGES and AKR1B1 expressions, as well as secretory IL8 and PGF2α. Short-term heat exposure decreased S100A8, IL8 and PGF2α compared with the control temperature, while long-term heat exposure decreased S100A8 and PGF2α. In contrast, HSPA5 expression was not altered by heat exposure or LPS. Indeed, the short-term heat treatment was insufficient for accomplishing the responses of the endometrium to LPS treatment for IL8, S100A8 and PTGES expressions when compared with other temperature conditions. Our findings showed that heat exposure could compromise endometrium immune response and prostaglandin biosynthesis in different ways based on elevated temperature duration, which could reduce subsequent fertility.

Estimation of Genetic Parameters for Heifer and Cow Fertility Traits Derived from On-Farm AI Service Records of South African Holstein Cattle.

Simple SummaryFemale fertility has gained significant attention and is incorporated in dairy cattle breeding objectives worldwide. Currently, age at first calving (AFC) and calving interval (CI) are the only traits used as indicators of fertility in the genetic evaluations of South African dairy cattle, but these traits are greatly affected by the breeder’s decisions and calving interval is available late in an animal’s life which delays selection decisions. This study investigated the possible use of additional fertility traits derived from artificial insemination records. The fertility traits examined in this study could be used in addition to age at first calving and calving interval to select for improved fertility in dairy cattle.This study aimed to derive additional fertility traits from service data and estimate their genetic parameters for their possible inclusion in the South African Holstein cattle breeding programs. Service records (n = 64,464) were collected from 18 South African Holstein herds using on-farm automated milk recording systems. Using a multivariate model, the data were used to estimate heritabilities and correlations among several fertility traits. The pedigree data consisted of information on 18,592 animals born between 1981 and 2013. Heritability estimates observed were low to moderate (0.02 ± 0.00 to 0.24 ± 0.00), indicating that there is some genetic basis for the explored fertility traits to warrant selection. The genetic correlations observed between fertility traits were generally favorable, with some high correlations between age at first service (AFS) and services per conception for heifers (SPCh) (0.73 ± 0.00) and between days from calving to first service (CFS) and services per conception for cows (SPC) (0.90 ± 0.01). Positive genetic correlations indicate that improvement in one trait is coupled with a correlated genetic increase in another trait. The studied fertility traits could be used in addition to AFC and CI to serve as a basis for the selection of reproduction in dairy cattle to minimize selection bias.

DAIRY PRODUCTIVITY OF COWS OF UKRAINIAN RED-AND-WHITE DAIRY BREED OF DIFFERENT GENOTYPES IN NATURAL AND CLIMATE ZONES OF UKRAINE

DAIRY PRODUCTIVITY OF COWS OF UKRAINIAN RED-AND-WHITE DAIRY BREED OF DIFFERENT GENOTYPES IN NATURAL AND CLIMATE ZONES OF UKRAINE