Number Of Inseminations Research Articles

Association between serum mineral levels and reproductive performance in primiparous dairy cows during the peripartum period.

To the best of the authors' knowledge, no study has previously investigated whether the concentration of minerals is related to reproductive outcomes in primiparous cows. For this reason, two objectives were set in the present study: (i) to assess serum mineral levels, macrominerals, and trace elements during the transition period (period of high nutritional requirements) in primiparous cows, considering reproductive efficiency, and (ii) to address if the serum mineral levels of primiparous cows are related to reproductive efficiency. Blood samples were taken (i) one month before calving, (ii) one week before calving, (iii) one week postpartum, and (iv) one month postpartum. At the beginning and the end of the study, a body condition score (BCS) was assigned to each lactating cow with no clinical signs of disease. The difference between one month before and one month after calving was the body condition loss (ΔBCS). Optimal prepartum concentrations of K and Cl were associated with fewer days open and a shorter interval calving. Furthermore, macrominerals in the serum decreased immediately after calving (one week) but recovered at one month postpartum. In contrast, the highest concentration of trace elements was found at one week postpartum. Primiparous cows with higher postpartum Se, Mn, Co, and Mo concentrations exhibited better reproductive efficiency, and the concentrations of trace elements in serum were correlated with interval calving and the number of inseminations. Finally, primiparous cows with a greater ΔBCS (at least one point) in period 4 exhibited both a longer calving interval and a greater number of days open. In summary, this study showed, for the first time in primiparous cows, that the concentration of some serum minerals not only plays a crucial role during the transition period but is also related to crucial reproductive parameters, such as interval calving and days open.

Effect of Milk-Feeding Frequency and Calcium Gluconate Supplementation on Growth, Health, and Reproductive and Metabolic Features of Holstein Heifers at a Rearing Farm.

We compared the effects of milk-feeding in 288 Holstein calves (72 per group) which were fed twice (2F) or thrice (3F) daily, with or without the addition of hydrogenated fat-embedded calcium gluconate (G) supplemented in the starter food and in the daily diet up to the age of 9 months, on the calves' metabolism, growth, health, and reproductive efficiency up to first pregnancy. The calves received 6 L of milk replacer (130 g/L) and had ad libitum access to water and textured calf starter with or without gluconate. Gluconate supplementation promoted a "catch-up" in growth in supplemented calves compared to their counterparts that did not receive gluconate. Gluconate appeared to reduce animal metabolic stress during key events, such as weaning and transfer into open-door pens, reducing fructosamine (352.61 vs. 303.06 in 3FG and 3F, respectively; p = 0.028) and urea (3F revealed the highest values compared with the other three groups: 19.06 for 3F vs. 13.9 (2F), 13.7 (2FG), and 14.3 (3FG), respectively, p = 0.002) from weaning onwards. The feeding of dairy calves with milk replacer three rather than two times per day tended to be associated with better health from weaning to 4 months old; parameters such as ultrasound lung score and calf health score improved over time (p < 0.001). Thrice-daily feeding with milk replacer tended to reduce the number of artificial inseminations per pregnancy in heifers by 0.2 points (p = 0.092). We confirmed significant correlations between early health and growth parameters and reproductive efficiency and a positive correlation between body weight and average daily weight gain and the thickness of the back fat layer in young heifers (r = 0.245; p < 0.0001; r = 0.214; p < 0.0001 respectively). Our study was conducted on a commercial farm with reasonably effective animal management, so baseline welfare was likely satisfactory.

Neospora caninum antibodies in bulk tank milk from dairy cattle herds in Italy in relation to reproductive and productive parameters and spatial analysis

Among the available diagnostic techniques, antibody detection in bulk tank milk (BTM) represents a useful tool to estimate and monitor Neospora caninum herd prevalence.To evaluate the prevalence of N. caninum and the effect of parasite infection on herd performances, BTM samples collected from 586 dairy herds located in one of the largest dairy production areas in Italy (Lombardy) were analyzed by an indirect ELISA to detect anti-N. caninum specific antibodies. Generalized linear models (GLMs) were developed. A purely spatial analysis scanning for clusters with high or low rates for N. caninum using the Bernoulli model was performed. A maximum entropy approach was used to estimate the probability of distribution of the parasite based on occurrence records together with environmental variables.Overall, 180 herds resulted positive for N. caninum antibodies on bulk tank milk (P = 30.7 %). A higher risk of seropositivity was evidenced in the provinces of Milano, Cremona, Brescia, and Bergamo (P = 32–40 %); a lower risk was evidenced in Lodi, Pavia, and Mantova (P = 13–24 %). A higher risk of seropositivity was revealed for small-medium farms (101–300 animals) (O.R.=2.8) and for older animals with more than 4 years (O.R.=4.4).Regarding the effect of N. caninum infection on herd performances, the number of inseminations for conception was higher (> 3 inseminations), and the period from calving to conception was longer (> 150 days) for positive farms (O.R.=2.0 and O.R.=2.3, respectively); besides, lower head daily milk production (<20 kg and 21–25 kg) and mature equivalent milk yield (<11,000), and somatic cell counts higher than 300,000 cells/ml were observed for N. caninum positive herds (O.R.=0.4, O.R.=0.4 and O.R.=1.9 respectively).The geographical distribution of N. caninum positive farms with the highest level of probability covers the central sector of the Po Plain where a significant cluster for high risk of parasite infection was shown by spatial scan statistic and Maximum entropy ecological niche modelling. A further significant cluster of low risk occurred in the southern. The climatic and environmental variables with the highest training gain when used in isolation resulted altitude, land use/land cover, and other variables related to temperature and precipitation.Neosporosis is widely distributed in Italian dairy herds and an impact of the parasite on herd performances could be hypothesized. Even if the role of N. caninum in alterations of reproductive and productive parameters should be further explored, veterinarians and farmers should be aware of neosporosis, and control plans should be adopted.

Comparative effectiveness of different methods of using the analogue of gonadotropin-releasing hormone for ovulation stimulation in rabbit does

Modern reproductive technologies require artificial insemination (AI) protocols that are safe for the health of animals and do not violate their welfare. Stress factors arising in the reproduction process of industrial rabbit breeding negatively affect the sexual function and reproductive performance of rabbits and their offspring. In recent years, researchers have focused on alternative methods of ovulation stimulation, including intravaginal introduction of hormonal means of its induction. Therefore, the aim of our study was a comparative evaluation of the effectiveness of the intramuscular method of administration of the gonadotropin-releasing control (GnRH) analogue and its addition to the sperm dose for AI on Hyplus rabbit (n = 30), which were randomly divided into three groups. For this, buserelin acetate was administered intramuscularly at a dose of 1 μg per rabbit immediately after artificial insemination (control group). Experimental animals were inseminated with sperm doses with the addition of a GnRH analogue in the amount of 25 μg (experimental group 1) and 15 μg (experimental group 2). The influence of the method of administration of GnRH analogue on reproductive function was evaluated by indicators of the effectiveness of AI, fertility, and the dynamics of the progesterone level during pregnancy. A decrease in fecundity was observed in females; for example, in experimental group 1, the effectiveness of AI in terms of the number of rabbits was 64.3 %; in animals of experimental group 2 – 41.2 %, and the number of inseminations in this group of rabbits was 41.7% higher compared to control data. The fertility of rabbits of all groups was high, reaching the maximum value in the control group (10.42 ± 0.52 heads/female). Fertility according to live newborns in experimental group 1 was the highest among all groups of rabbits and was 9.67 ± 0.49 heads/female, which showed an increasing trend compared to the control. Also, in the animals of experimental group 1, an increase in the level of progesterone in blood serum was observed (on the 7th day of pregnancy by 13.2 %, on the 14th day by 14.3 %, on the 21st day by 16.4 %). In contrast, in experimental group 2, a significant decrease in the progesterone level was noted. Thus, 25 μg of GnRH analogue added to the extender is optimal. It is worth noting that there were no advantages of intravaginal administration over intramuscular administration in terms of reproductive performance. However, the number of live births and progesterone levels were improved.

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.

Genetic relationship of energy balance predicted from milk traits with fertility in Japanese Holsteins.

We predicted the energy balance of cows from milk traits and estimated the genetic correlations of predicted energy balance (PEB) with fertility traits for the first three lactations. Data included 9,646,606 test-day records of 576,555 Holstein cows in Japan from 2015 to 2019. Genetic parameters were estimated with a multiple-trait model in which the records among lactation stages and parities were treated as separate traits. Fertility traits were conception rate at first insemination (CR), number of inseminations (NI), and days open (DO). Heritability estimates of PEB were 0.28-0.35 (first lactation), 0.15-0.29 (second), and 0.09-0.23 (third). Estimated genetic correlations among lactation stages were 0.85-1.00 (first lactation), 0.73-1.00 (second), and 0.64-1.00 (third). Estimated genetic correlations among parities were 0.82-0.96 (between first and second), 0.97-0.99 (second and third), and 0.69-0.92 (first and third). Estimated genetic correlations of PEB in early lactation with fertility were 0.04 to 0.19 for CR, -0.03 to -0.19 for NI, and -0.01 to -0.24 for DO. Genetic improvement of PEB is possible. Lower PEB in early lactation was associated with worse fertility, suggesting that improving PEB in early lactation may improve reproductive performance.

INFLUENCE OF PARATYPIC FACTORS ON THE FERTILITY OF DAIRY COWS AND REPLACEMENT HEIFERS

The results of researching the influence of the season, air temperature, age, stage of lactation, insemination number and daily milk yield on the fertilization of heifers and cows under different housing technologies are presented. It was established that the best fertilization was demonstrated by heifers kept in tethered housing at PE Agroprogres. Nevertheless, the fertilization rate of cows among the farms under study was the highest under free housing (p&lt;0.001). By months of the year, in general, on all farms, a trend of a greater number of inseminations of heifers was observed in spring and summer, although no clear dependence was established. The share of fertile inseminations of heifers of PE Agroprogress varied from 56% in October to 92% in June. Fertilization of heifers at SE EFs named after Dekabrists and Kutuzivka had less variability: from 47% in February to 70% in May in the first farm and from 46% in May to 60% in July in the second farm, respectively. At PE Agroprogres and SE EF named after Dekabrists, there was a tendency to increase the fertilization of heifers at the air temperature above 20 ºС. Cows of PE Agroprogres and SE EF named after Dekabrists had the lowest fertilization rate at temperatures below -10 ºC. There was also a trend of its increase with an increase in air temperature above 20 ºC. It was established that at PE Agroprogres (tethered housing) a clear trend of increasing the fertility of cows was observed during the period of summer open air housing, at SE RF named after Dekabrists this trend is almost imperceptible, and the opposite dependence has been established at SE EF Kutuzivka (year-round free housing keeping with feeding on walking platforms). At all studied farms, there was a clear tendency in decrease of the fertilization of cows during the period of high milk productivity. Cows of PE Agroprogres and SE EF Kutuzivka with a daily milk yield of more than 40 kg of milk were fertilized worse by 1-4% (р&lt;0.1) and 5-6% (р&lt;0.001) than animals with a lower milk yield. Cows of the SE EF named after Dekabrists with a daily milk yield of more than 30 kg also had 8-9% (p&lt;0.001) worse fertilization compared to animals with lower productivity. At all studied farms, the highest percentage of fertilization was characterized by heifers at their first insemination, and among cows were animals of the first and second calving. According to all inseminations, the average day of lactation of cows with their artificial insemination was 38-54 days longer at SE EF named after Dekabrists in comparison with PE Agroprogres and SE EF Kutuzivka (p&lt;0.001). The share of fertilized cows during the breeding period up to 90 days after calving was lower by 6% At PE Agroprogres, and by 9% at SE EF named after Dekabrists, and by 6% at SE EF Kutuzivka than in the mid-lactation period (91-180 days) (р&lt;0.001).

SPERM PARAMETERS' PREDICTIVE VALUE IN INTRAUTERINE INSEMINATION SUCCESS: A SINGLE-CENTER EXPERIENCE

Although intrauterine insemination is a widely used assisted reproductive technique there is no consensus on sperm parameters that affect the probability of pregnancy. Therefore, the purpose of this study was to determine whether semen parameters affect intrauterine insemination success. A total of 403 couples (345 negative pregnancies, and 58 positive pregnancy) that underwent 549 intrauterine insemination treatment cycles for heterogenous indications were included in the study. Clomiphen citrate, letrazole and/or gonadotropins were used for ovarian stimulation in women in this study. The spermiogram tests of the spouse of receiving IUI tretment were examined. Clinical pregnancy occurred in 58 of 549 intrauterine insemination (10.56%). Unexplained infertility, polycystic ovary syndrome, and cervical-tubal factors were higher in positive pregnancy group compared to negative pregnancy group while male factor was more prevalant in negative pregnancy group comparison to positive pregnancy group (p=0.03). There was no statistical difference between women with positive and negative pregnancy in terms of age (≤ 35 and &gt; 35), body mass index, infertility type, infertility time, endometrial thickness on HCG day, stimulation protocol, cycle numbers, number of insemination, estradiol, prolactin, LH, FSH, and TSH levels (p&gt;0.05). The sperm characteristics in males [ejaculate volum, sperm concentration, total sperm count, motility, immotility, and total progressive motile sperm count] did not significantly differed between positive and negative pregnancy groups (p&gt;0.05).&#x0D; Briefly, the present study found that the conception probability of intrauterine insemination did not correlate with the spermiogram parameters.

Investigation of the Effect of Disinfectant and Antioxidant Intrauterine "Anionic Oxygen" Application on Fertility after Artificial Insemination in Dairy Cows

In the study, a total of 30 clinically healthy fertile Holstein cows (aged 3-8 years old; with 500-700 kg average live weight and 28 litres average daily milk) were used in a private dairy farm in Milas district of Muğla province. Randomly selected cows were divided into two groups (control and treatment) (n=15 cows/group) with almost similar body condition scores (BCS) (as all having approximately BCS of 2.75±0.25 units, 1-5 scale). Cows were monitored for natural oestrus, especially during the 2 months postpartum. Control cows (n=15) showing oestrus were inseminated (throughout the 3 consecutive occasions at maximum) by routine AI via recto-vaginal intrauterine route using frozen bull semen (0.25 ml dose; 7.5 x 106 total motile sperm) and thawing at 37 °C for 30 seconds. Inseminations were carried out for 7 months (from December 2021 to June 2022). For the treatment group, the cows were given the antimicrobial agent (UB20 O8®) intrauterine 30 minutes after each AI. The disinfectant dose, given to the corpus uteri region after the AI, was used as a total of 50 ml mixture (40 ml warm saline and 10 ml disinfectant). Throughout the study, animals were routinely given a farm-specific "dairy cow" diet (with 23% protein/concentrated feed). In addition, cows were provided regularly with clean drinking water, shade, and free movement in paddocks. Total pregnancy rates of cows and the 'pregnancy index' (the number of inseminations per pregnancy) of 35-60-day post-insemination as checked via ultrasound examination were analysed statistically by using Chi-Square and Wilcoxon tests. The possible difference between the groups based on pregnancy rate and pregnancy index data was considered significant at the P&amp;lt;0.05 level. According to the results obtained, numerical differences observed due to local treatment after all insemination periods were not statistically significant (P&amp;gt;0.05). Pregnancy rates following the 1st, 2nd, and 3rd inseminations in the treatment and control groups were 60.00% vs. 46.66%, 86.66% vs. 66.66%, and 93.33% vs. 80.00%, respectively. The total pregnancy indexes in the groups were 1.57 (14 pregnancies/22 inseminations; treatment) and 2.25 (12 pregnancies/27 inseminations; control). Briefly, it was observed that the pregnancy rate and pregnancy index in the treatment group were consistently but only numerically higher than those in the control group, indicating that anionic oxygen could be an effective alternative for intrauterine treatment leading to high fertility early postpartum.

Uncovering genetic parameters and environmental influences on fertility, milk production, and quality in autochthonous Reggiana cattle

Reggiana is a local cattle breed from northern Italy known for its rusticity and profitability, due to the production of branded Parmigiano Reggiano cheese. To ensure the persistence of such profitability in the long term, an adequate breeding program is required. To this aim, in the present study we estimate the genetic parameters of the main productive and reproductive traits, and we evaluate the effect of genotype by environment interaction (GxE) on these traits using 2 environmental covariates: (1) productivity and (2) temperature-humidity index (THI). Milk, fat, protein, and casein yield were considered as daily production traits, whereas protein, fat, casein percentage, casein index, and somatic cell score were considered as milk quality traits. Finally, reproductive traits such as the number of inseminations, days open, calving interval, and calving-to-first-insemination interval were evaluated. Reggiana cattle produce an average of 19 kg of milk per day with 3.7% fat and 3.4% protein content and have excellent fertility parameters. Compared with other breeds, they have slightly lower heritability for production and quality for production traits (e.g., 0.12 [0.09; 0.15] for milk yield), but similar heritability for fertility traits. Milk, protein, and fat daily yields are highly correlated but negatively correlated with the percentage of protein, fat, and casein, whereas fertility traits have an unfavorable genetic correlation with daily production traits. When considering productivity, a consistent amount of variability due to GxE was observed for all daily production traits, somatic cell count, and casein index. A modest amount of GxE was observed for fertility parameters, while the percentage of solid content showed almost no GxE effect. A similar situation occurred when considering the THI, but no GxE interaction was observed for reproduction traits. In conclusion, this study provides useful information for the implementation of accurate selection plans in this local breed, accounting for environmental plasticity measured through the consistent GxE interaction observed.

A randomized study on the effect of an extended voluntary waiting period in primiparous dairy cows on fertility, health, and culling during first and second lactation

When the voluntary waiting period (VWP), defined as the days between calving and when the cow is eligible to receive the first insemination, is extended, high-yielding dairy cows may have better opportunities to regain energy balance before first insemination. This study investigated the effect of an extended (145-215 days in milk [DIM], n = 280) or conventional (25-95 DIM, n = 251) VWP treatment on fertility, disease incidence, and culling rate in cows during their first lactation. The cows were also followed through a second lactation without intervention regarding VWP, during which the farmers could decide when they wished to start the inseminations. This was done in a randomized-controlled study on 16 high-yielding commercial herds in southern Sweden, containing a total of 531 primiparous cows of the Holstein and Red Dairy Cattle breeds. Data from the Swedish national dairy herd recording scheme collected between August 2018 and September 2021 were used in the analysis, including records on breed, calvings, estrus intensity, inseminations, disease, somatic cell count, culling date, and culling reason. During first lactation, more cows receiving the extended VWP treatment showed strong estrus intensity (score 4-5, 55% vs. 48%) and fewer showed moderate estrus intensity (score 3, 35% vs. 43%) at first insemination, compared with cows receiving the conventional VWP treatment. First service conception rate (FSCR) was higher (67% vs. 51%) and number of inseminations per conception (NINS) was lower (1.6 vs. 2.0) during the first lactation for cows receiving the extended compared with the conventional VWP treatment. For disease incidence rate or culling rate expressed as number of events per cow-time in the study, we found no differences between the cows receiving the 2 VWP treatments in any lactation. Calving to first service interval during second lactation was longer (86 vs. 74 d) for cows with extended compared with conventional VWP. In conclusion, primiparous cows with extended VWP showed improved reproductive functions, in the form of higher estrus intensity, greater FSCR, and lower NINS, during the first lactation. However, we observed no apparent effect on these fertility measures during the following lactation (without VWP intervention) and no differences in disease prevalence or culling between cows receiving the 2 different VWP treatments in either lactation. Compliance with the planned VWP treatment was lower for cows with planned extended compared with planned conventional VWP treatment. We studied the "intention-to-treat" effect (i.e., the results for all cows randomized to each treatment regardless of whether the planned VWP was achieved or not) to identify any bias arising due to degree of compliance. However, we found no difference in culling rate between cows randomized to an extended VWP compared with those randomized to a conventional VWP. These findings can be used to support management decisions on VWP length in high-yielding dairy herds.

Evaluation of the productive and reproductive performance of Holstein dairy cows reared in a warm Tunisian (Mediterranean) climate.

This work consists in studying the productive and reproductive performance of Holstein dairy cows (n=77) reared in an intensive production system in a Mediterranean climate, as well as the factors of their variations. Meteorological data collected between 2017 and 2020 for the region of Beja, North-West of Tunisia, revealed that the average monthly values ​​of ambient temperature (Ta), relative humidity (HR) and temperature-humidity index (THI), are respectively 19.97 ±1.24°C, 73.69±3.42%, and 66±1.74. During the 3 years of study, the cows were exposed to a hot summer season which began in Jun (THI= 76) and persisted until September (THI =77). On average, milk production at 305 days of lactation, milk fat (MG) and protein (MP) content, as well as somatic cell count (SCC) were respectively 5782 ± 358 Kg, 3.36 ± 1.65%, 3.12 ± 0.42% and 489 ± 305 x 103 cells/ml. Several factors significantly (P &lt; 0.05) affect milk production. Indeed, the highest milk production is observed during the year 2020. When the THI increases, the drop of milk production is greater (-0.18kg/d, per THI point). Multiparous cows produce more milk than primiparous cows, with higher yields at peak lactation (30.0 kg/d) and a lower persistence coefficient (95.6%). Cows calved in winter produced more milk (+22%; P&lt;0.05) than cows calved in summer. The interval between calving to the first insemination (IV-IA1), calving to fertilizing insemination (IV-IAF) and calving interval (IVV) were 87.4 ± 28.2 days, 134 ± 71 days and 425 ±75 days respectively. The success rate in 1st insemination (TRIA1) and three or more insemination, as well as number of inseminations per conception were respectively 29.1±18.5%, 9.7±5.5% and 2.11±1.6. In conclusion, control of breeding conduct, in particular the heat detection technique, is essential to improve the productivity of the Holstein cow raised in an intensive production system in a hot Tunisian climate.

Relation between body condition score and conception rate of Japanese Black cows.

This study analyzes interactions of body condition score (BCS) with other factors and the effect of BCS on estimates of genetic paremeters of conception rate (CR) in Japanese Black cows. Factors affecting CR were analyzed through the linear mixed model, and genetic parameters of CR were estimated through the threshold animal model. The interactions between BCS and each season and the number of artificial inseminations (AI) was significant (p<0.05), but that between BCS and parity showed no significance for CR. High CR was observed with BCS 3 in autumn (0.56±0.01) and BCS 4 in summer (0.56±0.02). The highest CR with BCS 3 (0.56±0.02) and BCS 4 (0.55±0.01) was observed at first AI. With BCS 5, however, the highest CR (0.55±0.08) was observed at second AI. The model with BCS was notably conducive to the estimation of genetic parameters because of a low deviance information criterion of heritability that, nevertheless, was slightly lower than the model without BCS.

Genetic Evaluation of Gir Cattle for Success Rate to Conception using GLIMMIX Model

Background: The objective of this study was to assess the genetic and phenotypic parameters associated with the success rate to conception using 90-days non-return rate (NRR90F), conception Rate (CR) and number of insemination to conception (INS) traits in service bull. Methods: A total of 2590 insemination including 1776 first time insemination was carried out during the period of 2018-2020 in the Gir cattle distributed in the semi-arid region of RajasthanNRR90F and CR were analysed as binary variable and INS as multi-nominal trait. Generalized linear models were used to for the evaluation of non-genetic factors and generalized linear mixed models for genetic effects. Result: The average success rate of artificial insemination was estimated as 0.35 for NRR90F and 0.41 for CR. Further, cumulative logit link function was used to analyse the number of successful insemination to conception (INS) and cumulative estimates was observed as 0.95 for two number of insemination to conception. Period and season were the non-genetic factors that influenced the traits studied. Decreasing trend was observed over the period for success of insemination for all studied traits. Summer season showed highest odd ratio and estimated as 1.213 for NRR90F, 1.388 for CR and 1.440 for INS with reference to autumn season. Heritability was estimated as 0.015 for NRR90F, 0.028 for CR and 0.086 for INS.

Genetical analysis of mastitis and reproductive traits in first-parity Holstein cows using standard and structural equation modelling

The present study aimed to investigate the causal relationships between clinical mastitis and some reproductive traits, including success at first insemination (SFI), the number of inseminations to pregnancy (INS), the interval from calving to first service (CTFS), first and last service interval (IFL), and open days (OD) in first-parity Holstein cows. For this purpose, the records of 58 281 first parity Holstein cows were analysed. These data sets were collected from 17 large dairy herds from 2008 to 2017. Recursive Mixed Models (RMMs) were applied and compared with the estimations under Standard Mixed Models. Then, one trivariate and three bivariate Gaussian-threshold models were used for the analyses. Recursive models were applied, considering that clinical mastitis can influence fertility traits. Mastitis is considered a covariate for the reproductive traits to determine their causal relationship. The results of this study indicated that causal effects of mastitis on SFI (on the observed scale, %), CTFS, IFL, OD, and INS were −5.7%, 3.3 days, 12.27 days, seven days, and 0.26 services, respectively. The estimated structural coefficients of the recursive models in the first parity imply that mastitis significantly lengthened the fertility interval and decreased the conception rate. In addition, genetic, residual, and phenotypic correlations between mastitis and the reproductive traits under both models were statistically significant. Results of genetic correlations between mastitis and fertility traits suggest that more incidence of mastitis during lactation is related to the delays in the heat show and pregnancy rate after insemination. In summary, considering the causal effects under RMMs may be advantageous to comprehend complicated relationships between complex traits better.

The evaluation of an artificial intelligence system for estrus detection in sows

BackgroundGood estrus detection in sows is essential to predict the best moment of insemination. Nowadays, a technological innovation is available that detects the estrus of the sow via connected sensors and cameras. The collected data are subsequently analyzed by an artificial intelligence (AI) system. This study investigated whether such an AI system could support the farmer in optimizing the moment of insemination and reproductive performance.M&MThree Belgian sow farms (A, B and C) where the AI system was installed, participated in the study. The reproductive cycles (n = 6717) of 1.5 years before and 1.5 years after implementation of the system were included. Parameters included: (1) farrowing rate (FR), (2) percentage of repeat-breeders (RB), (3) farrowing rate after first insemination (FRFI) and (4) number of total born piglets per litter (NTBP). Also, data collected by the system were analyzed to describe the weaning-to-estrus interval (WEI), estrus duration (ED) and the number of inseminations used per estrus. This dataset included 2261 cycles, collected on farms B and C.ResultsIn farm A, all parameters significantly improved namely FR + 4.3%, RB − 3.75%, FRFI + 6.2% and NTBP + 1.06 piglets. In farm B, the NTBP significantly decreased with 0.48 piglets, but in this farm the insemination dose was too low (0.8 × 109 spermatozoa per dose). In farm C, only the NTBP significantly increased with 0.45 piglets after the implementation of the system. The WEI as determined by the system varied between 78 and 90 h, being 10–20 h shorter in comparison with the WEI as determined by the farmer. The ED, determined by the system ranged from 48 to 60 h, and was less variable as compared to the ED as assessed by the farmer. The mean number of inseminations per estrus remained similar over time in farm B whereas it decreased over time from approximately 1.6–1.2 in farm C.ConclusionThe AI system can help farmers to improve the reproductive performance, assess estrus characteristics and reduce the number of inseminations per estrus. Results may vary between farms as many other variables such as farm management, genetics and insemination dose also influence reproductive performance.

Effect of Timing of Artificial Insemination on Fertility of Cows and Calf Sex Ratio in Arsi Cows

An on-station study was conducted to investigate the effect of the interval between artificial insemination (AI) and the beginning of estrus on the fertility and sex ratio of offspring in Arsi cows. Standing to be mounted was considered the beginning of estrus, and artificial inseminations were made 6 h (Group 1), 12 h (Group 2), 18 h (Group 3) and 24 h (Group 4) after the onset of estrus in the cows. Overall, 50 cows with parity between 2 and 4, body weight ranging from 250 to 300 kg were used for the purpose of this study. Ovulation was synchronized by administration of PGF2α hormone. Pregnancy diagnosis was performed by rectal palpation at 90 to 120 days post AI. Pregnancy rates were 60%, in each of the Groups 1, 2, 3 and 50% in group 4. The highest female to male ratio (P=0.041) of calves was obtained in Group 1. Whereas the highest male to female ratio was recorded in group 4. The number of artificial inseminations per pregnancy was within the economical limits in all groups. In conclusion, the results of this study indicated that the variation in time interval between the onset of estrus and artificial insemination alters the sex ratio of offspring in Arsi cows without affecting fertility parameters.

Comparison of calf morbidity, mortality, and future performance across categories of passive immunity: A retrospective cohort study in a dairy herd

Four categories of transfer of passive immunity (TPI) were recently proposed in response to the widespread high preweaning morbidity and mortality risks in calves with adequate TPI when a dichotomous classification was used. Hitherto, however, the risks of preweaning morbidity and mortality and future performance among these TPI categories have not been compared. Thus, the objective of this retrospective cohort study was to compare dairy calf morbidity, mortality, growth until weaning, and reproductive efficiency until first calving among the categories of poor (<5.1 g/dL total protein), fair (5.1-5.7 g/dL), good (5.8-6.1 g/dL), and excellent (>6.2 g/dL) TPI. For this, the records from 4,336 dairy calves (2,272 female, 2,064 male) born January 2014 to April 2017 on a commercial dairy farm in Michigan were analyzed. These calves had been randomly selected for weekly serum total protein determination on calves 2 to 7 d old. Data from both sexes were used to evaluate preweaning health and mortality, whereas only the female's data were used to investigate average daily gain (ADG), reproductive performance, and first-lactation milk yield. For each calf, data regarding disease status, growth, and reproductive parameters were obtained from the farm's software database. Associations of TPI categories with disease events (diarrhea or pneumonia), reproduction indices (age at first insemination, successful insemination, and calving, and number of inseminations), first-lactation milk yield and ADG at weaning were evaluated by survival analysis and mixed models. Compared with calves with excellent TPI, calves in the inferior TPI categories showed increased risk of diarrhea: poor [hazard ratio (HR) = 1.49; 95% CI: 1.22-1.82], fair (HR = 1.32; 95% CI: 1.16-1.51), good (HR = 1.14; 95% CI: 1.02-1.29). However, the risk of pneumonia differed only between the calves in the poor and excellent TPI groups (HR = 1.39; 95% CI: 1.05-1.84). The preweaning mortality risk was also higher in calves with poor TPI (HR = 4.29; 95% CI: 1.98-9.27) compared with excellent TPI. However, mortality risks were not statistically different between calves with fair or good TPI and those with excellent TPI. Similarly, calves with poor TPI had a 64, 55, and 24% lower risk of reaching first insemination, successful insemination, or first calving, respectively. However, there were no differences in ADG, number of inseminations, or first-lactation 305-d mature equivalent milk production across TPI groups. Our results confirm the positive effects of optimal TPI in calf preweaning health and postweaning reproductive efficiency. The 4 proposed categories of TPI can assist in decreasing the incidence of diseases that occur in the first weeks of life (i.e., diarrhea), but their effect on other diseases or future performance might be more limited. Although conducted in one herd, this study can be used to illustrate the effect of TPI on future calf performance.

Reproductive traits of cows of Holstein breed and dynamics of their changes during productive life

In order to obtain maximum milk productivity of cows, it is necessary to constantly maintain a high level of reproduction traits of cows in the herd to ensure timely eff ective insemination of them for the annual production of calves. The economy of dairy farming, the level of breeding work, the longevity of animals depends on the state of reproduction of the herd. The purpose of the research was to study the reproductive traits of cows of Holstein breed and the dynamics of their changes during productive life. The research was carried out on the basis of the Agricultural Production Cooperative “Plamya”, a milk production enterprise where Holstein cattle are bred. In order to conduct the study, the indicators of the reproductive traits of cows of the entire productive herd were evaluated in dynamics over 5 years of production use. The material for the analysis of the dynamics of change was taken from the database of the information and analytical system “SELEX-Dairy cattle”. Thus, it was found that during the study period the annual calf crop increased by 102,4 % or by 2 calves. The average number of inseminations per effective one was 2,1 doses over the period. In the period from 2017 to 2021, in the herd the duration of the open days period ranged from 128 to 140 days. The best indicator was noted in 2019. On average, for the herd over a fi ve-year period, there was an increase in the duration of the open days period by 12 days compared to 2017 data. As a result of a comprehensive analysis of the state of reproduction traits of cows in the herd, it was found that the indicators of reproductive trais of cows had a slight deviation from the threshold (normative) values, which indicates a fairly high level of breeding work carried out by specialists of the farm.

Pegbovigrastim use in periparturient embryo-recipient cows: Effects on health and reproduction

The objective of this randomized clinical study was to evaluate the effects of periparturient administration of pegbovigrastim (recombinant bovine granulocyte colony stimulating factor; PEG) on postpartum health and reproductive outcomes in dairy cows carrying transferred embryos. A total of 60 multiparous Jersey cows (second parity n = 21, >second parity n = 39) that were in vitro-fertilized embryo recipients were enrolled. Animals were selected from a commercial herd and assigned to 1 of 2 treatments: (1) PEG (n = 31), which received a subcutaneous injection of 15 mg of PEG 7 d before expected calving and a second dose within 1 h of parturition; or (2) CON, untreated control (n = 29). Parturition was induced pharmacologically in all cows at 280 d of pregnancy with 500 μg of cloprostenol and 25 mg of dexamethasone intramuscularly. Cow health was monitored daily during the periparturient period and included assessment for retained fetal membranes within 24 h after calving and metritis until 20 d in milk. Descriptive statistics were calculated, to determine the incidence of postpartum diseases, causes of culling, and early-lactation reproductive outcomes, including number of inseminations, days to first heat, days to first service, and interval from calving to conception. The Wilcoxon rank sum test was used to assess treatment effects on early-lactation reproductive performance outcomes. The overall incidence of metritis in this cohort of cows was 17.14%. Animals treated with PEG tended to have more cases of metritis (25%) compared with CON (8.8%). Mastitis incidence in PEG was 19.35% compared with CON at 27.59%. These data suggest that in this dairy, with embryo-recipient cows induced to calve at 280 d of pregnancy, the administration of 2 doses of PEG tended to increase postpartum metritis but had no effect on mastitis incidence, culling rate, or early-lactation reproductive outcomes.