Breeding Herd Research Articles

Monitoring breeding herd production data to detect PRRSV outbreaks

Porcine reproductive and respiratory syndrome virus (PRRSv) causes substantial economic impact due to significant losses in productivity. Thus, measuring changes in farm productivity before and after PRRS infection enables quantifying the production and economic impact of outbreaks. This study assessed the application of exponentially weighted moving average (EWMA), a statistical process control method, on selected production data (number of abortions, pre-weaning mortality rate and prenatal losses) to supplement PRRS surveillance programs by detecting significant deviations on productivity in a production system with 55,000 sows in 14 breed-to-wean herds in Minnesota, U.S.A. Weekly data from diagnostic monitoring program (available through the Morrison’s Swine Health Monitoring Project) implemented on the same herds was used as reference for PRRS status. The time-to-detect, percentage of early detection of PRRSv-associated productivity deviations, and relative sensitivity and specificity of the production data monitoring system were determined relative to the MSHMP. The time-to-detect deviations on productivity associated with PRRS outbreaks using the EWMA method was −4 to −1 weeks (interquartile range) for the number of abortions, 0–0 for preweaning mortality and −1 to 3 weeks for prenatal losses compared to the date it was reported in the MSHMP database. Overall, the models had high relative sensitivity (range 85.7–100%) and specificity (range 98.5%–99.6%) when comparing to the changes in PRRS status reported in the MSHMP database. In summary, the use of systematic data monitoring showed a high concordance compared to the MSHMP-reported outbreaks indicating that on-farm staff and veterinary oversight were efficient to detect PRRSv, but can be more efficient if they were monitoring closely the frequency of abortions. The systematic monitoring of production indicators using EWMA offers opportunity to standardize and semi-automate the detection of deviations on productivity associated with PRRS infection, offering opportunity to early detect outbreaks and/or to quantify the production losses attributed to PRRS infection.

Investigating the reproductive performance of gilt progeny entering the breeding herd

Objective: To quantify the performance of gilt progeny in the F1 breeding herd at a large swine farm in New South Wales, Australia (Rivalea Australia Pty Ltd). `Materials and methods: Performance data on all gilts selected for entrance to the commercial breeding herd from January 2014 until December 2015 were included in this study. Comparisons were made between gilt and sow progeny in terms of the proportion of animals to reach first breeding, performance to parity 4, and longevity to parity 3. Results: Gilt progeny were lighter than sow progeny at each live weight measurement (P < .001), and had a higher P2 backfat level at selection than sow progeny (P = .02) at the same live weight. Gilt progeny selected into the breeding herd reached first breeding before 220 days of age less often than sow progeny (P < .001) and were 1 day older at first breeding (P = .003). Sow progeny had a lower farrowing rate from this breeding (P < .001). After the first breeding, there were few differences in performance indices between groups for the first four parities. There were no statistically significant differences between the groups in terms of longevity indices. Implications: Fewer gilt progeny may be selected to enter the breeding herd; however, after farrowing their first litter, selected gilt progeny perform just as well as sow progeny. While it is recommended to continue to include gilt progeny in the replacement-gilt selection process, further research in this field is recommended.

Divergent breeding values for fatness or residual feed intake in Angus cattle. 6. Dam-line impacts on steer carcass compliance

The present study determined the impact of maternal genetics for estimated breeding values for rib fat (High-Fat, Low-Fat) or residual feed intake (RFI; High-RFI, Low-RFI) on the carcass compliance of Angus steer progeny when reared pre-weaning under High or Low-Nutrition and post-weaning under various finishing system (grazing versus short-term feedlot). The dams were joined to sires of similar genetic background (close to average estimated breeding values) and sires were rotated among all dam genotypes, with herds located at either Struan Research Centre, near Naracoorte in the south-east of South Australia, or Vasse Research Station, in the south-west of Western Australia. The breeding herd was part of the Beef CRC maternal productivity project and cows were managed under either High or Low-Nutrition, achieved by adjustments to stocking rate in rotational grazing systems and supplementary feeding, so as to maintain ~20% difference in cow liveweight. The steer progeny were weaned at ~7 months of age, with individuals from both pre-weaning nutritional treatments being treated the same from then on at each site. Steers from Struan Research Centre in South Australia born in 2008 and 2009 were sold and grown out on pasture on a local commercial property. Steer calves born in 2010 at Vasse remained on the station where they were backgrounded on hay, followed by a short period (111 days) total mixed ration containing 40% grain. In the first year, steers from Struan (n = 58) were slaughtered together at ~2 years of age, and in the second year (n = 85), consigned to six slaughter groups as their ultrasound-scanned subcutaneous P8 (rump) fat reached 7 mm and their liveweight exceeded 550 kg. Steers from Vasse (n = 101) were slaughtered at ~12 months of age, all on the same day. High-Fat-line dams produced steers with carcasses with greater P8 fat than did Low-Fat-line dams at both sites. At Struan, when the 2008-born steers were slaughtered together, more steers from Low-Fat dams failed to meet minimum fat specifications, than steers from High-Fat dams (28% vs 9% respectively). The steers born in 2009 at Struan all met processor fat specifications but steers from the Low-Fat dams took longer to reach the fat threshold, and so had greater carcass weight, but attracted more price penalties because of increased dentition. All steers from Vasse met minimum requirements for fat, with none penalised for dentition. Vasse steers from High- or Low-RFI dams performed in a manner similar to that from High- and Low-Fat dams, respectively, in that the High-RFI group produced fatter carcasses than did the Low-RFI group. Steers reared under low pre-weaning nutrition weighed less at weaning than did those on High-Nutrition, but had higher weight gains after weaning, although insufficient to result in the same carcass weight. The results showed that commercial cattle producers need to be aware of the balance and trade-off among fat breeding value, effect of pre-weaning nutrition and post-weaning growth required to ensure their cattle meet market specifications and to avoid price penalties.

076 Estimation of the effects of mutations causing complex vertebral malformation and brachyspina on milk production, milk composition, and fertility traits in Holstein Friesian dairy cattle

The frequencies of mutations with lethal effects are of significant economic importance in cattle production. The elimination or at least management of such mutations in the national breeding herd is a desirable objective; however, estimation of the potential pleiotropic effects on other traits of economic importance would ascertain if strategic matings of carrier animals would be advantageous. Therefore, the objective of the current study was to estimate the effects of 2 such lethal recessives, complex vertebral malformation (CVM) and brachyspina (BY), on milk and fertility traits in Holstein-Friesian dairy cattle. Complex vertebral malformation and BY SNP genotypes and phenotypes (expressed as predicted transmitting abilities [PTA]) on 10,707 dairy cows were obtained through the Irish Cattle Breeding Federation. The association between each SNP and deregressed PTA was analyzed in ASREML using a weighted mixed animal model. Only cows with an adjusted reliability of >10% were included in the analysis and included n = 6,876 for milk yield and composition traits and n = 1,193, n = 264, n = 4,566, n = 8,564, n = 152, and n = 2,380 cows for calving interval, survival, calving difficulty, gestation length, calf mortality, and maternal calving difficulty, respectively. Complex vertebral malformation (minor allele frequency of 1.7%) was associated with both increased milk protein (0.019 [SE 0.006]; P < 0.01) and increased milk fat concentration (0.039 [SE 0.0132]; P < 0.01) whereas no associations (P > 0.05) were observed between CVM and any of the other milk traits (milk yield, milk fat yield, and milk protein yield) or fertility traits (calving interval, survival, calving difficulty, gestation length, calf mortality, and maternal calving difficulty). Significant associations were observed between BY (<1%) and decreased milk protein concentration (0.024 [SE 0.008]; P < 0.01) and increased milk yield (73.21 kg [SE 30.12]; P < 0.05). No associations (P > 0.05) were observed between BY and any of the fertility traits considered. These results provide additional evidence that carriers of these recessive mutations exhibit effects on milk production and/or composition in Holstein Friesian cattle, however, with no evidence of effects on the fertility traits examined. Cognizance and monitoring of the potential pleiotrophic effects of lethal recessives such as examined in this study will aid livestock breeders when considering elimination of carriers to minimize reduction of the genetic merit of farm enterprises and inform the benefits of strategic matings in controlling these mutations in the population while also sustaining productivity.

Network analysis of pig movements: Loyalty patterns and contact chains of different holding types in Denmark.

Understanding animal movements is an important factor for the development of meaningful surveillance and control programs, but also for the development of disease spread models. We analysed the Danish pig movement network using static and temporal network analysis tools to provide deeper insight in the connection between holdings dealing with pigs, such as breeding and multiplier herds, production herds, slaughterhouses or traders. Pig movements, which occurred between 1st January 2006 and 31st December 2015 in Denmark, were summarized to investigate temporal trends such as the number of active holdings, the number of registered movements and the number of pigs moved. To identify holdings and holding types with potentially higher risk for introduction or spread of diseases via pig movements, we determined loyalty patterns, annual network components and contact chains for the 24 registered holding types. The total number of active holdings as well as the number of pig movements decreased during the study period while the holding sizes increased. Around 60–90% of connections between two pig holdings were present in two consecutive years and around one third of the connections persisted within the considered time period. Weaner herds showed the highest level of in-loyalty, whereas we observed an intermediate level of in-loyalty for all breeding sites and for production herds. Boar stations, production herds and trade herds showed a high level of out-loyalty. Production herds constituted the highest proportion of holdings in the largest strongly connected component. All production sites showed low levels of in-going contact chains and we observed a high level of out-going contact chain for breeding and multiplier herds. Except for livestock auctions, all transit sites also showed low levels of out-going contact chains. Our results reflect the pyramidal structure of the underlying network. Based on the considered disease, the time frame for the calculation of network measurements needs to be adapted. Using these adapted values for loyalty and contact chains might help to identify holdings with high potential of spreading diseases and thus limit the outbreak size or support control or eradication of the considered pathogen.

Serological survey of lentivirus infection in goats and sheep slaughtered in the State of Paraíba, semiarid of Northeastern Brazil

The objective of this study was to determine the frequency of antibodies against small ruminant lentivirus (SRLV) in goats and sheep slaughtered in the state of Paraiba, in the Northeast semiarid region of Brazil. Blood was collected from 500 goats and 500 sheep in slaughterhouses in the municipalities of Alhandra, Guarabira, Esperanca, Picui, Monteiro, Sume, Patos, Pianco, Catole do Rocha, and Sousa. The agar gel immunodiffusion (AGID) test was used for the diagnosis of SRLV infection. Of the 1,000 animals analyzed, 28 (2.8%) were seropositive, with a frequency of 3% (15/500) in goats and 2.6% (13/500) in sheep. It was also observed that no significant difference was present in seropositivity among the different municipalities. The low frequency of seropositive animals can be explained by the fact that most of the sampled animals came from extensive breeding herds consisting of meat production native breeds and crossbred animals.

Serological survey of lentivirus infection in goats and sheep slaughtered in the State of Paraíba, semiarid of Northeastern Brazil

The objective of this study was to determine the frequency of antibodies against small ruminant lentivirus (SRLV) in goats and sheep slaughtered in the state of Paraíba, in the Northeast semiarid region of Brazil. Blood was collected from 500 goats and 500 sheep in slaughterhouses in the municipalities of Alhandra, Guarabira, Esperança, Picuí, Monteiro, Sumé, Patos, Piancó, Catolé do Rocha, and Sousa. The agar gel immunodiffusion (AGID) test was used for the diagnosis of SRLV infection. Of the 1,000 animals analyzed, 28 (2.8%) were seropositive, with a frequency of 3% (15/500) in goats and 2.6% (13/500) in sheep. It was also observed that no significant difference was present in seropositivity among the different municipalities. The low frequency of seropositive animals can be explained by the fact that most of the sampled animals came from extensive breeding herds consisting of meat production native breeds and crossbred animals.

Characteristics and risk factors for severe repeat-breeder female pigs and their lifetime performance in commercial breeding herds

BackgroundRepeat-breeder females increase non-productive days (NPD) and decrease herd productivity and profitability. The objectives of the present study were 1) to define severe repeat-breeder (SRB) females in commercial breeding herds, 2) to characterize the pattern of SRB occurrences across parities, 3) to examine factors associated with SRB risk, and 4) to compare lifetime reproductive performances of SRB and non-SRB females. Data included 501,855 service records and lifetime records of 93,604 breeding-female pigs in 98 Spanish herds between 2008 and 2013. An SRB female pig was defined as either a pig that had three or more returns. The 98 herds were classified into high-, intermediate- and low-performing herds based by the upper and lower 25th percentiles of the herd mean of annualized lifetime pigs weaned per sow. Multi-level mixed-effects logistic regression models with random intercept were applied to the data.ResultsOf 93,604 females, 1.2% of females became SRB pigs in their lifetime, with a mean SRB risk per service (± SEM) of 0.26 ± 0.01%. Risks factors for becoming an SRB pig were low parity, being first-served in summer, having a prolonged weaning-to-first-mating interval (WMI), and being in low-performing herds. For example, served gilts had 0.81% higher SRB risk than served sows (P < 0.01). Also, female pigs in a low-performing herd had 1.19% higher SRB risks than those in a high-performing herd. However, gilt age at-first-mating (P = 0.08), lactation length (P = 0.05) and number of stillborn piglets (P = 0.28) were not associated with becoming an SRB female. The SRB females had 14.4–16.4 fewer lifetime pigs born alive, 42.8–91.3 more lifetime NPD, and 2.1–2.2 lower parities at culling than non-SRB females (P < 0.05).ConclusionsWe recommend that producers closely monitor the female pig groups at higher risk of becoming an SRB.

Effect of immunologic solutions on sows and gilts on time to stability, and production losses in breeding herds infected with 1-7-4 PRRSv

Porcine reproductive and respiratory syndrome virus (PRRSv) is an economically significant swine pathogen causing production losses in the global swine industry. Clinical impact depends on many factors including the virus itself. One method to sub-type PRRSv is using restriction fragment length polymorphism (RFLP). The RFLP pattern 1-7-4 emerged within the United States swine industry in 2014 and has become prevalent since then. This was a field study that prospectively followed 1-7-4-infected breeding herds (n=107) and compared time to stability (TTS), time to baseline production (TTBP) and total loss per 1000 sows between herds using modified-live virus vaccine (MLV) on sows and gilts (MLV-MLV), MLV on sows and MLV in addition to field virus exposure on gilts (MLV–MLV/FVE) or not deliberately exposing sows or gilts to PRRSv (Natural-Natural). Analyses were done in SAS 9.4 and results were adjusted by selected co-variates (duration of herd closure, number of previous PRRSv outbreaks of last 3 years, weaning frequency/week, gilt development unit location, herd size and production system). Survival analysis was conducted on TTS and TTBP and regression analysis on total loss. Herds in the Natural–Natural group achieved TTS and TTBP before other herds. Herds in the MLV-MLV/FVE had the longest TTS and TTBP. The total loss was numerically least in MLV–MLV herds (1194 pigs/1000 sows) compared to MLV/MLV-FVE (1810/1000 sows) and Natural–Natural (2671/1000 sows). This study provided additional information to assist veterinarians deciding between methods of exposure to manage PRRSv infection from breeding herds.

Milk protein concentration, estimated breeding value for fertility, and reproductive performance in lactating dairy cows

Milk protein concentration in dairy cows has been positively associated with a range of measures of reproductive performance, and genetic factors affecting both milk protein concentration and reproductive performance may contribute to the observed phenotypic associations. It was of interest to assess whether these beneficial phenotypic associations are accounted for or interact with the effects of estimated breeding values for fertility. The effects of a multitrait estimated breeding value for fertility [the Australian breeding value for daughter fertility (ABV fertility)] on reproductive performance were also of interest. Interactions of milk protein concentration and ABV fertility with the interval from calving date to the start of the herd's seasonally concentrated breeding period were also assessed. A retrospective single cohort study was conducted using data collected from 74 Australian seasonally and split calving dairy herds. Associations between milk protein concentration, ABV fertility, and reproductive performance in Holstein cows were assessed using random effects logistic regression. Between 52,438 and 61,939 lactations were used for analyses of 4 reproductive performance measures. Milk protein concentration was strongly and positively associated with reproductive performance in dairy cows, and this effect was not accounted for by the effects of ABV fertility. Increases in ABV fertility had important additional beneficial effects on the probability of pregnancy by wk 6 and 21 of the herd's breeding period. For cows calved before the start of the breeding period, the effects of increases in both milk protein concentration and ABV fertility were beneficial regardless of their interval from calving to the start of the breeding period. These findings demonstrate the potential for increasing reproductive performance through identifying the causes of the association between milk protein concentration and reproductive performance and then devising management strategies to capitalize on them. Research should be conducted to understand the component of the relationship not captured by ABV fertility.

EFFICIENCY OF SELECTION BY EXTERIOR TYPE IN THE BREEDING HERDS DAIRY BREEDS

The need to study constitutional-exterior features of dairy cattle is due, of course, established in many studies to their positive connectivity with performance and lasting economic use. The vast majority of scientists-breeders thinks, that breeding cattle by technological features should determine the basic direction of work in farming on the threshold of XXI century. Based from the above, the aim of the research was to evaluate the productive and technological features cattle of dairy breeds combined with linear estimation from the body type. The study focused on linear estimation of cattle dairy breeds by the type of body structure and study their impact on economically useful traits – don’t have any doubts.The study was conducted in pedigree cattle breeding farms of Holstein, Ukrainian black- and red-white dairy breeds in stock of 1300 cows. Linear evaluation of cows by external type carried from the method of Hmelnychyi L.M. developed by employees of Institute to breeding and animal genetics. Comparative evaluation of animals for productive characteristics held within the breeding herds and genealogical groups. In the course of the work done was applied genealogical, population, genetics and mathematical methods Study of frequency heritability, variability, estimation of genotype of animals and other classical research methods. A statistical analysis result of research was conducted on algorithms N.A. Plohinskyi.Cows first calves Ukrainian red- and black-white dairy breeds are characterized by the following measurements articles: the height at the withers and sacrum 132.7&amp;132,2 and 141,1 &amp; 140,8 cm, with well-developed breasts in depth (72.0 and 71.5 cm), width (44.6 and 43.1 cm) and girth (189.9 and 187.9 cm), with extensive backwards in tubers of Ilium (51.3 and 50.9 cm) and in buttocks (34.6 and 35.2 cm). Spit length of rump was 52.5 and 51.8 cm, and body length - 162.4 and 161.2 cm. First-born Holstein breed exceeded peers Ukrainian dairy breeds by the withers height on (1.4 and 1.9 cm) and a sacrum (1.2 and 1.5 cm), by breast depth 1.1 and 1.6 cm, but they are inferior on the basis of the width of the breast, especially in comparison with cattle Ukrainian red-white milk breed (1.8 cm). Holstein animals differed broader backwards in tubers of Ilium (0.3 and 0.7 cm), in the hipbone (0.3 and 0.4 cm) and in buttocks (by 2.0 and 1.1 cm), and longer by 1.2 and 2.4 cm trunk, by chest girth of 2.4 and 4.4 cm.Large coefficients of variation measurements describing the distance from the bottom of the udder to hock (Cv = 33,2 - 42,3%), between the front (Cv = 24,2 - 28,1%), back (Cv = 33,3 - 53,9%) and side teat (Cv = 19,1 - 27,0%) indicate the level of not consolidation studied animal herds on these characteristics. Comparative characteristics of the firstborn cow’s udder Ukrainian red- and black-white dairy breeds shows, that animal’s udder great and makes for girth - 132.4 and 135.3 cm, length - 38.7 and 40.0 cm and width - 29.9 and 32.3 cm with advantage of reliable peers Ukrainian black-white dairy cattle for the circumference of 2.9 cm (TD = 2.41), length - 1.3 cm (td = 1,74) and width - 2.4 cm (td = 4,56). Most of the morphological features of the udder is in the positive connection with the largest yield per lactation. These include the circumference (r = 0,430 and 0.335) length (r = 0,376 and 0.353), width (r = 0,347 and 0.232) and depth of the front quarters (r = 0,160 and 0.166).The estimated population of the first-calves is characterized by rather high rates, then ranging within 1.85 - 1.90 kg / min. exceeding the maximum target standards for Ukrainian dairy breeds 0.05 - 0.10 kg / min. During the breeding to improve dairy breeds is important to know and take into account the relationship between the magnitude and intensity of milking yield. When examined the effect of daily yield on the intensity of milk found, that the highest daily yield, the more intense cow milk off. This high correlation coefficients (r = 0,438 - 0,511) in large samples with high reliability (td = 6.11 – 7.87). Share heredity influence the total variability measurements articles of udder varies widely. Most udder traits are positive in relation to the size of yield and total yield of milk fat. A high level of heritability coefficients udder morphological characteristics sufficient for efficient breeding of dairy cattle and there was a positive correlation between the main floors of the udder and the largest yield provide breeding aimed at improvement.

THE MAIN REQUIREMENTS FOR THE GENOCATION OF THE GENE-FOUND STAIN IN POVERTY IN THE CONTEXT OF THE ACTIVITY OF THE GENE-FUNDING ECONOMY

THE MAIN REQUIREMENTS FOR THE GENOCATION OF THE GENE-FOUND STAIN IN POVERTY IN THE CONTEXT OF THE ACTIVITY OF THE GENE-FUNDING ECONOMY

Patterns of calving and young stock movement in Ireland and their implications for BVD serosurveillance

The Republic of Ireland has a national eradication programme for bovine viral diarrhoea virus (BVDv) based on tissue-tag testing of calves to identify persistently infected animals (PIs). It has been proposed that serological testing of a sample of home-bred young stock would be a more cost effective surveillance mechanism than continued tissue-tag testing in herds which have previously been found to be BVD-free. These animals would have to be at least 6 months of age to avoid interference from maternal antibodies in test results. To examine the potential practicality of this system, we identified birth profiles and movements of calves born in Ireland during 2014 and 2015. We found that birth profiles for both beef and dairy animals were more evenly distributed throughout the year than often assumed, which should be borne in mind when evaluating the suitability of a single round of serological testing in the autumn for every herd. A large amount of movement was identified, with approximately 43% of calves experiencing a move before they reached 10 months of age, including moves to another Irish herd, to a knackery, to export, or to slaughter. Approximately 19% of calves had moved to other breeding herds in Ireland within this period. There were distinct patterns according to movement type, month of birth and herd type. The majority of herds moved either all or none of their calves in the first 10 months of life. These results indicate that young stock serological testing is unlikely to be an appropriate surveillance mechanism for all BVDv-free herds, as (i) many herds would not be able to supply a large enough sample of suitably aged home-bred young stock at a single point in time and (ii) PIs which would have been picked up by tissue-tag testing soon after birth would have moved from their home herd, to infect other herds, before serological testing could be conducted.

Impacts of on farm management factors on herd fertility of commercial beef breeding herds in Northern Ireland

SUMMARYTo assess the impact of farm management on herd fertility, a survey of 105 beef farms in Northern Ireland was conducted to establish the relationship between management variables and fertility. Each herd's average calving interval (CI) and the proportion of cows with a CI &gt; 450 days (extended calving interval, ECI) was calculated to establish herd fertility. The relationship between each response variable (CI and proportion ECI) and each explanatory variable (respondents’ answers to questionnaire) was examined using univariate linear regression analyses. All response variables found to be associated with the explanatory variables were modelled against each group in turn using a fully automated multivariate stepwise regression algorithm employing the method of forward selection with backward elimination. The optimum 365-day CI and a proportion of 0 cows per hundred calved ECI targets were not widely attained in the current study. The distribution of CI and proportion ECI in the current study suggests more realistic targets would be a 379-day CI and 5 cows per hundred calved with ECI in commercial beef breeding herds. Six management factors were found to be associated with herd fertility: herd vaccination, bull selection, fertility management, breeding female management, perception of extension service (rural education provided by the government) and record keeping. It was found that respondents who vaccinated cows had a reduction of 5 cows per hundred calved in the proportion of cows with ECI, and as the number of vaccines administered to a cow increased, the CI decreased. Regular vaccination of breeding bulls was associated with a 9-day reduction in CI. Bull selection strategy had several associations with herd fertility; most notable was that respondents who used visual selection rather than estimated breeding values (EBVs) to select bulls were found to have a 15-day longer CI and 7 cows per hundred calved higher proportion of cows with ECI. For each 0·01 increase in the proportion of cows served by artificial insemination, CI increased by 0·16 days. Respondents who rated their beef breeding herd fertility as ‘very good’ had lower ECI and CI than those who rated beef breeding herd fertility as poor or satisfactory. Condition scoring of cows at weaning lowered ECI by 5 cows per hundred calved. Those who perceived the extension service to be very useful had the lowest CI and lowest ECI. Respondents who did not keep a record of CI to assess herd fertility had an 11-day longer CI and 6 cows per hundred calved higher proportion ECI than those who did not. In conclusion, the survey found a number of important variables linked to improved fertility including selecting sires based on EBVs and using a robust vaccination programme.

Genetic differences in oestrous signs and oestrogen metabolism-related genes between Chinese Mi and European Landrace-Large White pigs.

Oestrous signs affect timely mating and reproductive efficiency in swine breeding herds. To study the genetic difference of oestrous signs between Chinese and European pigs, 100 Landrace-Large White (LLW) cross gilts and 50 Chinese Mi gilts were assessed for oestrous signs and the concentrations of serum estradiol-17β and progesterone were determined. The genotype of 39 single nucleotide polymorphisms (SNPs) in 11 oestrogen metabolism and function-related genes was determined by Sequenom iPLEX platform. Compared with LLW gilts, Mi gilts had longer time of standing reflex (p<.001), higher scores of vulva reddening (p=.001) and greater serum estradiol-17β concentration (p<.01). Gilts with greater serum estradiol-17β concentrations also had greater (p<.05) scores for oestrous signs. Genetic polymorphisms of nine genes in oestrogen metabolism pathways had significant differences (p<.05) between LLW and Mi gilts. There were three and six haploblocks of SNPs in LLW and Mi, respectively. Compared with LLW, the distribution of haplotypes was more centralized in Mi pigs. Genetic polymorphisms of oestrogen metabolism-related genes have considerable differences between Chinese Mi and European LLW pigs. Because of the important roles of oestrogen during the oestrus, some genes of oestrogen metabolism pathway could be considered as candidate genes for oestrous signs.

Novel effects of identified SNPs within the porcine Pregnancy-Associated Glycoprotein gene family (pPAGs) on the major reproductive traits in Hirschmann hybrid-line sows

This is the first study describing identification of SNPs within the multiple and polymorphic Pregnancy-Associated Glycoprotein gene family (PAGs) in the genome of the domestic pig (pPAGs). We identified pPAG-like (pPAG-L) genotypes in primiparous and multiparous farmed hybrid-line JSR Hirschmann (Hrn) sows (N=159), in which various novel associations with their phenotypes for the major reproductive traits have been discovered. Genomic DNA templates were isolated from the blood and different pPAG-L primers were used to amplify various regions by PCR. Electrophoretically-separated amplicons were selected, purified and sequenced.All identified SNPs were verified for possible pPAG2-L genotype associations with the major reproductive traits. In total, 196 SNPs were identified within the entire structure of the pPAG2-Ls, encompassing 9 exons and 8 (A–H) introns, resembling all aspartic proteinases. It was discovered that among all SNPs, one diplotype localized in exon 6 (657C>T/749G>C; pPAG2 ORF cDNA numbering; L34361) caused amino acid substitutions (Asp220→Asn and Ser250→Thr) in the polypeptide precursors and was associated with an increase in the number of live-born piglets (P≤0.05) in Hrn sows. In turn, co-localized SNP (504g>a; KF537535 numbering) in the intron F of the pPAG2-Ls, but only in the homozygotic genotype (gg), was associated with an increased number of live-born (P≤0.01) and weaned (P≤0.05) piglets in the Hrn sows. These results qualify the pPAG2-Ls as candidate genes of the main QTLs. The novel pPAG SNP profiles provide the basis for a diagnostic genotyping test required for early pre-selection of female/male piglets, presumably mainly useful in various breeding herds.

Mortality and Survival Probability of Female Pigs in Southern European Commercial Breeding Herds

This retrospective cohort study characterized death occurrences in female pigs in commercial herds, examined the survival probability for served females, and quantified factors associated with by-parity mortality risks for farrowed sows. The cohort data from herd entry to removal included 558,486 first service records of 113,517 females in 121 herds, served between 2008 and 2013. Two herd categories were defined on the basis of the lower 25th percentiles of herd means of annualized lifetime pigs weaned per sow: low-performing herds and ordinary herds. Two-level survival analysis was performed for served females to obtain by-parity survival probabilities (gilts and parity 1-6 sows). Also, log-binomial regression models were used to examine risk factors and ratios associated with mortality risks for the seven parity groups farrowed in either spring, summer, autumn or winter. Overall mean mortality incidence rates were 1.22 and 5.30 pigs per 100 pig-days of observation for pregnant females and farrowed sows, respectively. Survival probabilities for served females rapidly decreased by 2.3%-3.7% around farrowing in all parity groups. The lower survival probabilities were associated with increased age at first-mating, females in low-performing herds, sows farrowing more stillborn piglets and sows having weaning-to-first-mating interval of 7 days or more (P &lt; 0.05). Mortality risks were assessed for herds, served month, WMI and stillborm piglets. Increased risks were associated with summer farrowing, low-performing herds and more stillborn piglets (P &lt; 0.05). We recommended that producers individually monitor high risk female groups, and provide prompt treatment to any females with problems.

Curent state and futyre of using the biotechnological methods of reproduction in sheeps breeding

The analysis of publication related to the usage of embryo transplantation method in breeding sheep had been conducted. It is proved that the theoretical basis of the method of embryo transplantation is the large number of germ cells in the ovaries of females, most of which during the usual method of reproduction does not participate in these processes, and the high probability of inheriting genetic characteristics of embryos after transplantation by recipient. On this basis, from females throughout her life we can get a few dozen of descendants. The main aspects of embryos transplantation technology is to development of new methods that will ensure obtaining of the greatest number of good-quality embryos with desirable genotypes, both by the induction of multiple ovulation and by cultivation of follicular oocytes outside the body. It has been defined, that its usage is limited by a number of factors that are not well studіed and many of them are contradictional, in particular unpredictable results of the multiple ovulation induction. The development of the method of predicting the results of polyovulation will significantly increase the efficiency of embryos transplantation and significantly reduce the cost of labor and financial resources. It has been shown, that one of the main factors of making transplantation more practical is to develop the methods of embryos cryopreservation. This will simplify the selection of recipients and donors by the sexual cycle, will further long distance transportation and will enable the transplantation in the planned breeding herds. The further of the method, along with modern advances of genetics, embryology, endocrinology, will in the near future lead to develop a comprehensive method for the accelerated creation in sheep breeding flocks of high performance animals.

Neospora caninum in beef herds in New South Wales, Australia. 1: seroprevalence study.

To determine the seroprevalence of Neospora caninum antibodies in beef breeding herds across New South Wales (NSW) and to determine if there are any differences associated with geographic location and other herd-level factors. Cross-sectional survey of beef breeding cows (n = 3298) from 63 properties (approximately 55 cows per herd) sampled randomly from six regions in NSW using a multistage survey design. Samples were tested by ELISA for N. caninum. Seroprevalence was determined at animal and herd levels, using an analysis approach to account for stratification, sample weighting and within-herd clustering. Animal-level seroprevalence ranged from 1.8% to 11.3% across regions and the overall animal seroprevalence for NSW was 5.9%. The mean within-herd seroprevalence was 5.2%. The herd seroprevalence ranged from 50% to 92%, with an overall point estimate for NSW of 63.8% (using ≥ 1 animal positive = herd positive). The within-herd seroprevalence ranged from 1.6% to 32.7% Prevalence and associated confidence limits were adjusted for the design of the survey. Overall, about two-thirds of all herds in NSW showed evidence of infection, but the seroprevalence of N. caninum in individual beef cattle in NSW was low to moderate (1.8-11.3%). Significant differences occurred between regions. The risk for herds being positive for N. caninum was associated with geographic factors, particularly in the Mid-North Coast Region.

Water provisioning in Kruger National Park alters elephant spatial utilisation patterns

Water provisioning is a controversial yet common practice and its consequences for wildlife and vegetation have fuelled well-worn debates. Contradictory opinions exist on the effect of water provisioning on elephant abundance and distribution. Here, we evaluated how water utilisation patterns, water source type, and availability affect the spatial utilisation patterns of elephants in Kruger National Park. We segmented the seasonal movement paths of 26 elephant breeding herds into trips, defined as segments of the trajectory that occur between two consecutive visits to water sources. We classified the trips as natural or artificial depending on the start and end water source. Elephants visited rivers more often than artificial waterholes. The probability of visiting water was highest during the hot afternoon and most trips lasted less than 36 h. Artificial waterholes made trips further from rivers potentially less costly, and for a third of the total area traversed by elephants, they visited waterholes instead of rivers. Additionally, artificial waterholes may increase the intensity of use in some areas. Water provisioning in Kruger alters elephant spatial utilisation patterns. Removing artificial waterholes in Kruger might reduce the area traversed and educe spatio-temporal variability in how elephants utilise space, a desirable outcome for conservation management.