Genus (United Kingdom)

Abstract Breeding for improved sow longevity will contribute to directly improving animal welfare, production efficiency, and environmental sustainability in the swine industry. Sow longevity is a complex trait that can be defined by different indicators, including length of productive life (LPL), removal age (RA), and removal parity (RP). Genetic selection for improved sow longevity is also more challenging due to the time taken for obtaining the phenotypic measurements for each animal, censored nature of the records due to voluntary culling, and potential genotype-by-environment interactions between nucleus and commercial farm conditions. Therefore, the primary objectives of this study were to estimate variance components and genetic parameters for LPL, RA, and RP in purebred and crossbred pig populations incorporating genomic information in the analyses. Data from 26,441 sows were analyzed, including 14,787 Landrace and 11,654 Landrace x Large White crossbreed sows. Pedigree and genotype data were incorporated into the analyses, including information from 5,378,363 animals in the pedigree and 22,925 genotyped animals. Variance components and genetic parameters were estimated using the Restricted Maximum Likelihood (REML) method implemented in the BLUPF90+ software. The fixed effects included in the models were contemporary group (concatenation of herd, season, and year of birth) and age at first parity as a linear covariate. For the analyses combining purebred and crossbred animals, line was also added as a fixed effect. The average (SD) LPL was 242.10 (242.22) days for Landrace and 352.56 (289.29) days for the crossbred sows, with maximum values of 1,592 and 1,258 days, respectively. The average (SD) RA was 587.50 (241.89) days for Landrace and 674.60 (291.78) days for the crossbred sows. A total of 81.32% of the sows, considering both purebred and crossbred animals, were removed by the fourth parity. The heritability estimates for the Landrace sows were 0.20 (0.02) for LPL and RA, and 0.22 (0.02) for RP. For the crossbred population, the heritability estimates were 0.11 (0.02) for all three traits. For the complete dataset (i.e., combining both lines), the heritability (SE) estimates were 0.28 (0.02) for LPL and RA, and 0.30 (0.02) for RP and the genetic correlation between LPL and RP, as well as between RA and RP, was 0.99 (0.0003). The observed heritability estimates suggest that genetic selection can effectively improve sow longevity. Additionally, the high genetic correlation (0.99) between them indicates that these traits are essentially the same from a genetic perspective. This suggests that only one of them may be needed as selection criteria.

Abstract This preliminary study aimed to estimate the heritability of liver abscess incidence in fed, beef on dairy crossbred progeny. Liver abscesses affect approximately 20% to 30% of livers at slaughter. They are commonly identified during viscera inspection at slaughter due to difficulty with antemortem diagnosis. All livers with abscesses are condemned, causing a profit loss for producers. This loss is increased when the abscesses are ruptured or adhered to the gut due to additional condemnation of the gut. The most common prevention techniques include antimicrobial feed additives and nutritional management; however, mitigation has not been highly effective. Few studies have attempted to ascertain if a genetic component for liver abscess incidence exists. Determining if there is a genetic component to liver abscess occurrence could enable the ability to utilize genetic selection as a preventative measure. Liver abscess scores were collected on 1,492 crossbred beef on dairy heifers at slaughter. Cattle were harvested in Kansas. Individual livers were scored using the Elanco scoring system of 0, A-, A, A+. Scores of A+, A+AD, and A+O were combined into the A+ category. A score of 0 indicates a normal liver, as scores of A-, A, and A+ indicate increasing severity of abscesses. Scores of A+AD and A+O represent animals with adhesion to the gut or ruptured abscesses, respectively. In the dataset, the distribution was 903, 168, 69, and 352 for scores of 0, A-, A, and A+, respectively. Overall, the prevalence of liver abscesses was 39.5% in this sample. All 1,492 heifers had recorded sire information, but no dam information existed other than knowing they were of dairy origin. In total, 19 unique sires were represented in the data, with six of the sires producing 89.4% of the heifers. A 3-generation sire pedigree was built from the data, and heritability was estimated using a sire model and the statistical software package ASReml 3.0. Fixed effects included the number of bovine respiratory disease treatments, age in days, and a contemporary group consisting of kill lot and treatment type. These cattle were part of an additional study evaluating the effectiveness of various treatment regimens for mitigating the incidence of liver abscesses. There were three treatment groups, one control and two treatments. Genetic and phenotypic variation for this model was estimated to be 2.70 × 10-7 ± 9.99 × 10-9 and 1.58 ± 5.86 × 10-2, respectively. With such a small genetic variance estimate, the heritability of liver abscesses was effectively 0 (1.70 × 10-7), which suggests the lack of a genetic component for liver abscesses in these data. This was a preliminary study that had limited sire variation. Currently, dam information is being accumulated in an attempt to account for dam genetic variation.

Abstract Our objective was to determine the effects of increasing daily dietary standardized ileal digestible (SID) lysine (Lys) intake during d 35 to 112 of gestation on sow and litter performance. A total of 704 gilts and sows (PIC Camborough) were used. Females were group-housed after d 35 of gestation and individually fed with electronic sow feeders (ESF). At d 35 of gestation, females were balanced for body weight (BW) and caliper scores within parity categories, and randomly allotted to 1 of 4 treatments. Treatments consisted of increasing daily dietary SID Lys intake (11.1, 13.5, 16.1, and 18.5 g/d). Both gilts and sows received 2.37 kg/d of a gestation diet containing 3.17 Mcal of ME/kg, which was estimated to avoid feeding females below their maintenance requirements throughout the entire gestation. Treatments were achieved by different blend of low (0.47% SID Lys) and high (0.78% SID Lys) Lys diets via ESF based on the set feed allowance for females. Sow was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmerfunctions of R, considering treatment, parity, and their interaction as fixed effects. There was no evidence (P > 0.10) of treatment and parity interaction for any response criteria. Body weight at d 112 of gestation and BW change from d 35 to 112 of gestation increased (linear; P < 0.05) with increasing daily dietary SID Lys intake (Table 1). No evidence for SID Lys treatment differences were observed for BW at weaning or BW change during lactation (P > 0.10). There was no evidence (P > 0.10) for treatment differences on caliper score (CS) at d 35 of gestation, d 112 of gestation, at weaning, or CS changes during gestation and lactation. There was no evidence for treatment difference on total born, percentage stillbirth and percentage of mummified fetuses (P > 0.10). However, there was a marginal reduction in percentage born alive piglets (quadratic, P = 0.056), with the least proportion of piglets born alive observed in females receiving 16.1g of daily SID Lys intake from d35 to d112 of gestation. Increasing daily dietary SID Lys intake during d 35 to 112 of gestation did not affect piglet birth weight, piglet average daily gain during lactation, proportion of removed pigs, and proportion of dead pigs during lactation. In summary, increasing daily dietary SID Lys intake during d35-to-112 of gestation increased female BW; however, no evidence of benefits was observed for female reproductive performance and litter performance during lactation.

Abstract The objective of the study was to evaluate the daily thermoregulatory pattern of Duroc boars with and without electronically controlled floor cooling pads (ECP) during the summer season in a boar stud at Scottsville, Kentucky. Thirty boars were placed in two rows of pens (2.06 x 0.66 m) of a 350 head tunnel ventilated barn and were randomly assigned to either CONTROL (n = 15; no ECP) or PAD (n = 15; 4.25 L cold water flushed when sensors reached 27°C or every 4 min, whichever occurred first, through a group of 5 pads connected to each other) treatments. Boars experienced natural seasonal heat stress (daily mean temperature = 25.7°C; hourly high temperature = 28.8°C, corresponding relative humidity = 85.4%, corresponding dew point = 26°C) during the period of 4 d wherein the ECP remained on, and flushing based on the setpoints mentioned above. Rectal temperature (RT) and respiration rate (RR) were taken at 600, 830, 1100 1330, 1600, 1830 and 2100 h daily for all 4 d. Two statistical analyses were conducted. The first was a mixed model including the fixed effects of ECP, day, time of measurement and their interactions with boar included as a random effect. Secondly, mixed model periodic regressions were fitted to the RR and RT data. Both RT and RR were impacted by ECP, day, time, and all two and three factor interactions (P < 0.001). The final periodic regression model for RR included the random effect of boar, main effect of ECP, interaction of ECP and day, single phase sine/cosine and 2-phase cosine variables, the interaction with the single 2 and 3 phase sine/cosine variables with day (P < 0.001). The periodic regression results indicate that the response of the ECP to reduce RR were consistent relative to the time of the day (mean of 57.5 breaths/min versus 18.9 breaths/min, P < 0.001) but the overall response in RR relative to time of day was variable for the four days. The final model for RT using periodic regression included the random effect of boar, ECP, single-phase sine and cosine and three-phase sine variables (P < 0.001) and interaction of single-phase sine by ECP (P = 0.001) and interaction of the three-phase sine with day. The interaction of the ECP by single phase sine interaction was due to an increase in temperature from 600 to 1330 for control boars (0.21°C) versus no change for boars on the ECP. The ECP reduced RT at all measurement times, a lesser extent from 600 to 1100 (0.31°C to 0.37°C) and greater extent from 1330 (0.59°C) and 1600 h (0.63°C) and 2100 (0.67°C). The impact of the ECP to reduce RR and RT varied from day to day with greater effects on the days with higher barn temperatures.

Abstract The objective of the study was to evaluate the flushing management trends of the electronically controlled grouped floor cooling pads (ECP) during the summer heat stress in a boar stud at Scottsville, Kentucky. Four groups of 5 ECPs connected to each other were placed in 15 boar crates (2.06 x 0.66 m) in a 350 head evaporative cooled, tunnel ventilated barn. One set of ECP (Zone 1) had temperature sensors placed on the 5th pad which triggers flushing of 4.25 L cold water (over 80 sec interval) when sensors reached 27°C. The other two sets of ECP (Zones 2 and 5) had temperature sensors on the first pad and flushing the same cold-water volume when sensors reached 24°C (based on the first pad averaging 3°C lower temperature than the last pad) or every 4 min, whichever occurred first. Cold water for Zone 1 and 2 came from cooling tank 1 (Mean = 17.35°C) while Zone 5 cold water came from cooling tank 2 (Mean = 15.7°C). The water in both tanks was cooled using a 2 HP Hydro Frost Chiller. Daily ECP temperatures (PT), ECP flushing rate (FR), barn temperature (BT) barn relative humidity (RH) barn dewpoint (DP) and cooling tank temperature (TT) were collected every 10 min for the ECP variables and 30 mins for the environmental variables. Boars experienced varying natural summer heat stress (temperature and corresponding relative humidity and dewpoint: Mean = 25.3°C, 87.2%, 23.2°C; high: 29.0°C, 84.5%, 26.1°C), July 29, 2023. A mixed model was used for statistical analysis in SAS including fixed effects of zone and hour. FR and PT readings were affected by the zone, hour of day and all two- and three-way interactions (P < 0.001). All of the zones flushed more frequently late morning to afternoon (Mean: 64.6%) from 1100 to 1600 h and gradually the FR decreased in the evening (1900 h onwards). Zone 1 flushed more frequently (47.7%) than the 2 other zones (Zone 2 = 39.9%, Zone 5 = 33%). Zone 1 ECP temperature averaged 26.7°C (hourly mean range 26.1°C to 27.3°C). Zone 2 ECP temperatures averaged 22.1°C (hourly mean range 19.7°C to 24.1°C). Zone 5 ECP temperature patterns averaged 20.7°C (hourly mean range 19.1°C to 22.4). Zone 1 flushed less frequently (30.3%) at between 2100 to 0400 h. The following day and PT stayed cooler (Mean = 26.7°C) compared with the PT during the middle of the day (27.1°C).The set temperature (27°C; 24°C) or set time every 4 min kept the temperature of the ECP at desirable temperature, below 27°C for the last boar pad or below 24°C for the first of 5 pads (with approximate 3°C difference between the first and last of the of the 5 pads).

Abstract Our objective was to determine the effects of fiber supplementation during gestation on sow and piglet performance. A total of 200 PIC Camborough P1+ sows were used. At breeding, sows were balanced by body weight (BW) within parity and randomly allotted to 1 of 2 dietary treatments, which consisted of 1) Control; corn-soybean meal gestation diet; and 2) Fiber; inclusion of soybean hulls in the formulation at a level to yield a dietary crude-fiber content 6%. Females were housed in individual stalls throughout the entire gestation. At d 90 of gestation, serum glucose, fecal dry matter, fecal volatile fat acids (acetate, propionate, butyrate, isovalerate, and valerate), urinary traits (color, turbidity, density, pH, and presence of nitrate or blood), and frequency of stereotypic behavior (sham chewing, teeth grinding, bar biting, and floor licking) was accessed. Perineal scoring was visually evaluated at d 105 and 110 of gestation. Farrowing traits (farrowing length, and number of piglets born alive, stillborn, and mummified fetuses) and piglet vitality (meconium presence, umbilical cord integrity, oxygenation, and heart rate) were individually monitored. Individual piglet BW was obtained within 12 h of birth and after 24 h for colostrum intake, and at weaning. Sow daily lactation feed intake was registered. Data were analyzed using generalized linear mixed models with the Glimmix procedure of SAS with sow serving as the experimental unit. There was no evidence (P > 0.10) for differences in sow BW at d1, d112 of gestation, and at weaning. Sows fed the greater fiber diet showed lower levels of post-prandial glucose (-6%; P < 0.10), darker urine (+33%; P < 0.10) with greater pH (+5%; P < 0.05), and greater levels of fecal butyrate (+62%; P < 0.05) and isovalerate (+15%; P < 0.10) at the end of gestation (d 90). Feces from sows fed the control diet were drier (P < 0.05) at d 90 of gestation. Fiber supplementation reduced the frequency of teeth grinding (-52%; P < 0.10), bar biting (-74%; P < 0.05), and floor licking (-65%; P 0.10) behaviors. There was no evidence for treatment differences (P > 0.10) for perineal scores. Piglet vitality was not affected by the treatments, except for a marginal increase in blood oxygen saturation for piglets from sows fed the greater fiber diet (+1%; P < 0.10). Treatment did not impact (P > 0.10) farrowing duration, number of total piglets born, born alive, stillborn, and mummified, nor average piglet birth weight and colostrum intake. Sows fed diet with fiber supplementation during gestation had a marginal increase in average daily feed intake during lactation (+0.50kg/d; P = 0.08), which resulted in improved piglet BW gain (P < 0.05) and weaning weights (+0.20kg; P < 0.05). In summary, providing increased level of fiber supplementation via soybean hulls to gestating diets did not impact sow reproductive performance. Beneficial effects were observed for welfare lactation feed intake, piglet BW gain and weaning weights.

Abstract In beef cattle, for a single pregnancy opportunity, only 60% of cows will remain pregnant. It is possible that uterine dysfunction prevents adequate embryo signaling and subsequent placentation. Our aim was to compare the abundance of molecular markers associated with pregnancy retention among embryo recipients classified for fertility. The hypothesis was that expression of interferon-stimulated genes (ISG15 and RSAD2) in lymphocytes and concentration of pregnancy associated glycoproteins (PAGs) in serum increase according to cow fertility. Cyclic, Bos Indicus-influenced, primiparous cows (n = 50) were submitted to five consecutive rounds of estrus synchronization, embryo transfer (ET), pregnancy termination and recovery. The ET was conducted 7 days after estrus (D7). Each cow received two embryos per transfer from a randomly assigned bull pair (BP) containing one embryo from each bull A, B or C (BP1 = A+B; BP2 = A+C; BP3 = B+C). Pregnancy diagnostic was conducted on D32 and D45 using B-mode ultrasonography. Blood samples were collected on D20 to quantify expression of ISG15 and RSAD2 in peripheral blood mononuclear cells and on D25, D32, and D39 to quantify serum concentration of PAGs. Based on D45 pregnancy outcome (pregnant or open), cows were classified as Fertile (Fert; n = 14), Sub-fertile (SF; n = 16) or Infertile (IF; n = 15) if they were pregnant 3, 2, or 1 out of the 5 experimental rounds, respectively. Five cows that never sustained a pregnancy until D45 were excluded. The overall prevalence of twin-pregnancies was 7.8% (n = 13/166). Expression of ISG15 was increased in Fert compared to IF cows (P = 0.01; 0.0196 ± 0.0042 vs 0.0164 ± 0.0052, respectively). There was no effect of fertility classification on the expression of RSAD2. Serum concentrations of PAGs increased over time (P < 0.0001), regardless of fertility classification (day x fertility classification; P > 0.4). There was an effect of BP on the probability of pregnancy on D32 and D45 (P < 0.05). For D32, BP2 (84%) was 3 times more likely to maintain a pregnancy than BP1 (52%), while BP3 (74%) was not significantly different. On D45, BP2 (80%) was 2.8 times more likely to remain pregnant than BP1 (50%), and BP3 (62%) was not different than either BP1 or BP2. The interaction bull pair by fertility classification on the probability of pregnancy on D45 approached significance (P = 0.1). While pregnancy to BP2 was similar across all fertility classifications (80%), pregnancy to BP1 decreased dramatically as classifications changed from Fert to IF (88% vs. 14%, respectively). In conclusion, IF cows were less able to respond to IFN-t, likely because of a reduced secretion of IFN-t from the elongating conceptus. Also, IF cows are more susceptible to the genetics of the embryo than FERT cows.

Abstract In beef cattle, 40% of cows that display estrus do not remain pregnant after embryo transfer (ET). Estrus is a physiological behavior influenced by the concentration of sex-steroids. The use of accelerometer devices for estrus detection is a common practice in dairy operations. It remains unclear if this same artificial intelligence software can accurately measure reproductive behavior in beef females. We hypothesized that estrous variables detected by an accelerometer are associated with ovarian, hormonal, pregnancy outcome, and fertility-related variables measured in the cow. Fifty Bos indicus-influenced, cyclic, primiparous cows were fitted with an accelerometer collar (SCR Engineers, Israel) and a breeding indicator (Estrotectâ) to detect estrus after a synchronization protocol in five subsequent experimental replicates (n = 50*5 = 250). Only cows that showed estrus (d 0) remained in the study. The following variables were used from the accelerometer software: Activity Peak, Rumination Nadir, Estrus Duration, and Heat Index, calculated by proprietary algorithms. Dominant follicle (DF) diameter and plasma concentration of estradiol were measured on d -2 (day of progesterone device removal) and on d 0. On d -1 and d 4, endometrial thickness and luminal fluid accumulation were measured by ultrasonography. On d 7, two embryos were transferred/cow. Pregnancies were diagnosed on d 45 and terminated. After 30 d, a new replicate started. Cows included in at least two replicates that remained pregnant 100%, 99-50%, or less than 50% were classified as fertile, sub fertile, and infertile, respectively. Estrus display was recorded for 166 cows (66%). Estrus detection by accelerometer and Estrotect had excellent agreement rate (kappa coefficient 0.76). Cows detected in estrus only by Estrotect had 66% less pregnancy/ET than cows in estrus by both (9/21 vs. 97/145; P = 0.01). The DF diameter on d 0 was not associated with accelerometer variables. Cows with greater and moderate Activity Peak had a greater growth rate of the DF from d -2 to d 0 than lower Activity Peak cows (interaction day*Activity Peak; P = 0.06). Estradiol on d -1 was positively associated with the Activity Peak (P < 0.0001). Cows with lower Activity Peak had a thicker endometrium on both d -1 and d 4 (P=0.02), and greater uterine luminal fluid score on d -1 (P=0.03). Fertility status was not associated with any accelerometer variables. In conclusion, the Activity Peak is associated positively with estradiol concentration and DF growth, however no association was found with pregnancy outcome and fertility. Therefore, the main advantage of accelerometers in beef ranches is the ability to detect estrus at a similar accuracy as breeding indicators, using less labor. Future enhancements in hardware and software to allow prediction of pregnancy outcomes are expected to increase reproductive efficiency in cow-calf operations.

Proteolytic activation of the hemagglutinin (HA) glycoprotein by host cellular proteases is pivotal for influenza A virus (IAV) infectivity. Highly pathogenic avian influenza viruses possess the multibasic cleavage site of the HA which is cleaved by ubiquitous proteases, such as furin; in contrast, the monobasic HA motif is recognized and activated by trypsin-like proteases, such as the transmembrane serine protease 2 (TMPRSS2). Here, we aimed to determine the effects of TMPRSS2 on the replication of pandemic H1N1 and H3N2 subtype IAVs in the natural host, the pig. The use of the CRISPR/Cas 9 system led to the establishment of homozygous gene edited (GE) TMPRSS2 knockout (KO) pigs. Delayed IAV replication was demonstrated in primary respiratory cells of KO pigs in vitro. IAV infection in vivo resulted in significant reduction of virus shedding in the upper respiratory tract, and lower virus titers and pathological lesions in the lower respiratory tract of TMPRSS2 KO pigs as compared to WT pigs. Our findings could support the commercial use of GE pigs to minimize (i) the economic losses caused by IAV infection in pigs, and (ii) the emergence of novel IAVs with pandemic potential through genetic reassortment in the "mixing vessel", the pig.

Abstract Our objective was to determine the effects of two different dietary energy concentrations and diet forms on growth performance of nursery pigs. Barrows and gilts (n = 1,300 PIC337×Camborough, initial BW = 6.7±1.40 kg) were used in a 35-day growth trial with 52 pens in two rooms, 13 pens per treatment, and 25 pigs per pen. At the beginning of the trial, pens within each room were formed by segregating pigs into three body weight (BW) categories and gender, and then randomly allotted to one of four treatments in a randomized complete block design. Pigs were fed in three dietary phases and phase changes occurred based on assigned feed budget (Phase 1: 2 kg/pig, Phase 2: 4 kg/pig, and Phase 3: ad libitum until 35d post-weaning). Treatments consisted of a 2 x 2 factorial arrangement with one factor being the energy concentration of the diets with 2 levels (low and high) and the other factor being the diet form with 2 plans (mash throughout phases 1 to 3 or mash in phase 1 and 2 then pelleted in phase 3). Pellet size was 4 mm, and PDI measurements averaged 84.0 and 83.4% in the low and high energy diets, respectively. Growth performance data were analyzed using a generalized mixed model in Minitab and considered pen as the experimental unit. The statistical model considered fixed effects of BW category, energy, diet form, and their interaction, and random effects of room. All data are reported as least square means and considered statistically significant at P < 0.05. There was no evidence for a significant interaction between energy level and diet form (P > 0.10) for any response criteria. Increasing energy of the diet fed to nursery pigs did not result in significant differences (P > 0.10) in overall average daily gain (ADG; 356 and 367 g/d), average daily feed intake (ADFI; 501 and 510 g/d), or feed efficiency (G:F; 711 and 719 g/kg) between low and high energy, respectively. Feeding a pelleted diet in the last nursery phase resulted in increased (P = 0.004) overall ADG (368 vs 355 g/d), increased (P = 0.018) final BW (19.6 and 19.2 kg), and improved (P = 0.002) overall G:F (727 and 702 g/kg) compared with pigs fed mash diets throughout the entire nursery period. There was no evidence for differences in ADFI due to diet form. In addition, no evidence for treatment differences were observed for overall removal and mortality rates. In conclusion, under the conditions of this study, there was no evidence for an energy impact in nursery pig growth performance. Feeding a pelleted diet in the last nursery phase resulted in improvements in overall ADG, G:F, and final BW of nursery pigs.