Short communication: Genetic lag represents commercial herd genetic merit more accurately than the 4-path selection model.

Expectation of genetic merit in commercial dairy herds is routinely estimated using a 4-path genetic selection model that was derived for a closed population, but commercial herds using artificial insemination sires are not closed. The 4-path model also predicts a higher rate of genetic progress in elite herds that provide artificial insemination sires than in commercial herds that use such sires, which counters other theoretical assumptions and observations of realized genetic responses. The aim of this work is to clarify whether genetic merit in commercial herds is more accurately reflected under the assumptions of the 4-path genetic response formula or by a genetic lag formula. We demonstrate by tracing the transmission of genetic merit from parents to offspring that the rate of genetic progress in commercial dairy farms is expected to be the same as that in the genetic nucleus. The lag in genetic merit between the nucleus and commercial farms is a function of sire and dam generation interval, the rate of genetic progress in elite artificial insemination herds, and genetic merit of sires and dams. To predict how strategies such as the use of young versus daughter-proven sires, culling heifers following genomic testing, or selective use of sexed semen will alter genetic merit in commercial herds, genetic merit expectations for commercial herds should be modeled using genetic lag expectations.

Comparison of Holstein-Friesian and Norwegian Red dairy cattle for estrus length and estrous signs.

This study addressed the effect of breed on estrus length and estrous behavior by observing 20 Holstein-Friesian (HF) and 20 Norwegian Red (NRF) cows on an outdoor wood-chip pad through 1 estrous cycle (22d). Detailed behavioral data were collected by continuous (24 h) video monitoring of all cows. Accurate estimation of duration of estrous periods, behavioral signs (sum per period and counts per hour), and duration and number of sexually active groups were reported through all stages of mount estrus (prestand, standing estrus, and poststand). These dependent variables were analyzed with a basic statistical model that included fixed effects for breed and lactation group. Other independent variables (milk yield, body condition score, and number of cows in standing estrus) were added to the basic model one by one and included in an expanded model if they had an effect on the respective dependent variables. Estrus duration was considerably shorter in HF compared with NRF cows for all the major periods: mount estrus (11.2 ± 3.0 vs. 21.3 ± 2.7 h), standing estrus (7.1 ± 1.4 vs. 11.7 ± 1.3 h), mounting period (6.9 ± 2.7 vs. 18.2 ± 2.4 h), and mounted period (9.2 ± 2.8 vs. 17.5 ± 2.6 h). Additionally, the NRF cows spent more time in sexually active groups (36.1 ± 4.0 vs. 17.6 ± 4.8%) during standing estrus compared with HF cows. The NRF cows participated in a greater number of sexually active groups (9.6 ± 1.3 vs. 5.5 ± 1.3) with longer average duration (0.42 ± 0.04 vs. 0.20 ± 0.04 h) and continued to be more active in these groups through late stages of estrus (poststand) compared with the HF breed. Mounting activity differed between breeds as NRF mounted more times in total (46.3 ± 6.2 vs. 18.1 ± 6.3) and per hour (2.6 ± 0.4 vs. 1.5 ± 0.5) during mount estrus. In addition, NRF tended to express the primary estrous sign, standing when mounted, more often during standing estrus (32.4 ± 5.0 vs. 18.5 ± 5.2). The HF initiated more unsuccessful mounts (1.6 ± 0.3 vs. 0.6 ± 0.3) per hour than did NRF during mount estrus. A significant effect of milk yield was demonstrated only on this behavior. For other estrous signs, HF cows initiated chase-up (2.0 ± 0.5 vs. 0.5 ± 0.4) and anogenital sniff (3.7 ± 0.6 vs. 2.0 ± 0.5) more frequently (counts per hour), whereas NRF expressed more total head butt behavior (32.3 ± 4.7 vs. 14.2 ± 4.8) during mount estrus. Body condition score had a significant effect on receptive behavior. Measures of estrus duration, sexually active group activity, and behavior related to estrus should be subjected to larger studies for improved heat detection and possible implementation in breeding programs.

Potent inhibition by ropivacaine of metastatic colon cancer SW620 cell invasion and NaV1.5 channel function.

BACKGROUND: Metastatic breast and colon cancer cells express neonatal and adult splice variants of NaV1.5 voltage-activated Na(+) channels (VASCs). Block of VASCs inhibits cell invasion. Local anaesthetics used during surgical tumour excision inhibit VASC activity on nociceptive neurones providing regional anaesthesia. Inhibition of VASCs on circulating metastatic cancer cells may also be beneficial during the perioperative period. However, ropivacaine, frequently used to provide analgesia during tumour resection, has not been tested on colon cancer cell VASC function or invasion. METHODS: We used reverse transcription-polymerase chain reaction and sequencing to identify NaV1.5 variants in the SW620 metastatic colon cancer cell line. Recombinant adult and neonatal NaV1.5 variants were expressed in human embryonic kidney cells. Voltage-clamp recordings and invasion assays were used to examine the effects of ropivacaine on recombinant NaV1.5 channels and the metastatic potential of SW620 cells, respectively. RESULTS: SW620 cells expressed adult and neonatal NaV1.5 variants, which had similar steady-state inactivation profiles, but distinctive activation curves with the neonatal variant having a V1/2 of activation 7.8 mV more depolarized than the adult variant. Ropivacaine caused a concentration-dependent block of both NaV1.5 variants, with IC50 values of 2.5 and 3.9 µM, respectively. However, the reduction in available steady-state current was selective for neonatal NaV1.5 channels. Ropivacaine inhibited SW620 invasion, with a potency similar to that of inhibition of NaV1.5 channels (3.8 µM). CONCLUSIONS: Ropivacaine is a potent inhibitor of both NaV1.5 channel activity and metastatic colon cancer cell invasion, which may be beneficial during surgical colon cancer excision.

Eukaryotic translation initiation factor 4AIII (eIF4AIII) is functionally distinct from eIF4AI and eIF4AII.

Eukaryotic initiation factor 4A (eIF4A) is an RNA-dependent ATPase and ATP-dependent RNA helicase that is thought to melt the 5' proximal secondary structure of eukaryotic mRNAs to facilitate attachment of the 40S ribosomal subunit. eIF4A functions in a complex termed eIF4F with two other initiation factors (eIF4E and eIF4G). Two isoforms of eIF4A, eIF4AI and eIF4AII, which are encoded by two different genes, are functionally indistinguishable. A third member of the eIF4A family, eIF4AIII, whose human homolog exhibits 65% amino acid identity to human eIF4AI, has also been cloned from Xenopus and tobacco, but its function in translation has not been characterized. In this study, human eIF4AIII was characterized biochemically. While eIF4AIII, like eIF4AI, exhibits RNA-dependent ATPase activity and ATP-dependent RNA helicase activity, it fails to substitute for eIF4AI in an in vitro-reconstituted 40S ribosome binding assay. Instead, eIF4AIII inhibits translation in a reticulocyte lysate system. In addition, whereas eIF4AI binds independently to the middle and carboxy-terminal fragments of eIF4G, eIF4AIII binds to the middle fragment only. These functional differences between eIF4AI and eIF4AIII suggest that eIF4AIII might play an inhibitory role in translation under physiological conditions.

Variability in Holstein heifer heart-girth measurements and comparison of prediction equations for live weight.

Measurement of heart-girth (chest circumference) is commonly used to estimate dairy heifer body weight from previously derived equations or tables. In this experiment, variability of heart-girth measurements as they are taken in the field was analyzed to determine the standard deviation within a group of 26 Holstein heifers of various ages weighing 42-590 kg. Standard deviations were 2.19 cm among 26 observers and 2.74 cm within any one observer. Repeatability between two heart-girth measurements by an individual observer on the same animal using a blind heart-girth tape was >0.99. Correlation coefficients between two measurements by different observers using blind measuring tapes on the same animal also were >0.99, with 99% of total differences due to observer and heifer, indicating very little random variation. A second part of this study was the validation of the most recently derived equation to calculate body weight from heart-girth. The equation was validated with data sets from universities across the United States and field data collected specifically for this study. Experimental and field data comprised of heart-girth and body weight measurements upheld the previously derived equation and support its continued use. These results allow more precise interpretation of heart-girth data collected from field studies with Holstein dairy heifers and provide more complete validation of existing body weight-prediction equations.

A three-dimensional magnetometer for motion sensing of a balloon-carried atmospheric measurement package.

An instrument is described which carries three orthogonal geomagnetic field sensors on a standard meteorological balloon package, to sense rapid motion and position changes during ascent through the atmosphere. Because of the finite data bandwidth available over the UHF radio link, a burst sampling strategy is adopted. Bursts of 9 s of measurements at 3.6 Hz are interleaved with periods of slow data telemetry lasting 25 s. Calculation of the variability in each channel is used to determine position changes, a method robust to periods of poor radio signals. During three balloon ascents, variability was found repeatedly at similar altitudes, simultaneously in each of three orthogonal sensors carried. This variability is attributed to atmospheric motions. It is found that the vertical sensor is least prone to stray motions, and that the use of two horizontal sensors provides no additional information over a single horizontal sensor.

Short communication: Effect of vacuum and ratio on the performance of a monoblock silicone milking liner.

The vacuum and teat-cup chamber ratio are important operating parameters that affect milking performance by milking machines. In addition, the design and composition of materials are major elements affecting the performance characteristics of (teat-cup) milking machine liners. The objective of this experiment was to determine the effects of vacuum and teat-cup chamber ratio on the performance of a unique mono-block silicone milking machine liner that is round in the open position and triangular in the collapsed position. System vacuum settings (set at receiver) were 40.6, 43.9, and 47.3 kPa, whereas teat-cup chamber ratios were 60:40, 65:35, and 70:30. Milk yield was greatest at a vacuum of 43.9 kPa. Manual adjustments and kickoffs were very low (<2%) at all vacuum levels and for all ratios. The interaction of vacuum level and ratio was significant for milking duration, peak flow rate, and average flow rate, but not for milk yield. Average and peak milk flow rates increased at each increasing vacuum level and each wider ratio, whereas milking duration decreased.

Milk, fat, protein, somatic cell score, and days open among Holstein, Brown Swiss, and their crosses.

The objectives of this study were to compare Holstein (HO), Brown Swiss (BS), and their crosses for milk, fat, and protein yields, somatic cell score (SCS), days open (DO), and age at first calving (AFC), and to estimate the effects of heterosis and recombination. First through fifth lactation records were obtained from 19 herds milking crosses among BS and HO. The edited data set included 6,534 lactation records from 3,473 cows of the following breed combinations: 2,125 pure HO, 926 pure BS, 256 BS sire x HO dam (SH), 105 backcrosses to BS (SX), 18 HO sire x BS dam, and 43 backcrosses to HO. Least squares means for daily milk, fat, and protein yields, mature-equivalent milk, fat, and protein yields, SCS, DO, and AFC were calculated for breed combinations with a model that included fixed effects of age within parity (except for AFC), days in milk for daily yield and SCS, herd-year-season of calving, and breed combination. Cow and error were random effects. Breed combination was replaced with regressions on coefficients for heterosis and recombination in a second analysis. Last, data were analyzed with a 5-trait animal model that included a single pedigree file for both breeds and coefficients for heterosis and recombination. The least squares means for fat production were 1.21, 1.15, 1.27, and 1.16 kg for HO, BS, SH, and SX, respectively, which corresponds to a heterosis estimate of 7.30% and a recombination estimate of -3.76%. Heterosis and recombination estimates for protein production were 5.63% and -3.31%, respectively. Heterosis estimates increased for fat yield (10.38%) and protein yield (7.07%) when maternal grandsire identification from a known artificial insemination sire was required. Regression coefficients indicated an 11.44-d reduction in DO due to heterosis. Heterosis estimates for SCS were inconsistent. Regression on heterosis for SCS was significant and favorable (-0.22) when the breed of sire was BS, but nonsignificant and unfavorable when sire breed was HO (0.43). Heterosis estimates were favorable for all traits, whereas recombination effects tended to be unfavorable for yield traits. Reduced performance of future generations did not appear to be the result of inseminating crossbred cows with inferior sires. Results indicated that first-generation crosses among BS and HO compared favorably with HO. Yield in subsequent generations was somewhat below expectations, perhaps due to recombination loss in HO.

Short communication: genetic correlation between test-day electrical conductivity of milk and mastitis.

Electrical conductivity (EC) of milk is an indicator of mastitis. If EC shows genetic variation and is genetically correlated to mastitis, it could be used in a breeding program that includes selection for improved mastitis resistance. In this study, daily records of EC and mastitis from about 1,500 Holstein cows were analyzed. A bivariate animal model was used for estimation of (co)variance components, including fixed effects of age of calving, herd-test-day, and days in milk, in addition to random additive genetic effects and permanent environmental effects. For EC, the estimated heritability was moderate (0.22 to 0.39), whereas for mastitis, the heritability was low (0.013). The genetic correlation between EC and mastitis was estimated to be 0.75, and genetic improvement of mastitis resistance should be feasible through selection for reduced EC.

A prospective study of calf factors affecting age, body size, and body condition score at first calving of holstein dairy heifers.

Data were collected prospectively on parameters related to first calving on 18 farms located in Northeastern Pennsylvania. This project was designed to study possible residual effects of calf management practices and events occurring during the first 16 wk of life on age, BW, skeletal growth, and body condition score at first calving. Multiple imputation method for handling missing data was incorporated in these analyses. This method has the advantage over ad hoc single imputations because the appropriate error structure is maintained. Much similarity was found between the multiple imputation method and a traditional mixed model analysis, except that some estimates from the multiple imputation method seemed more logical in their effects on the parameter measured. Factors related to increased age at first calving were increased difficulty of delivery, antibiotic treatment of sick calves, increased amount of milk or milk replacer fed before weaning, reduced quality of forage fed to weaned calves, maximum humidity, mean daily temperature, and maximum ammonia levels in calf housing areas. Body weight at calving tended to increase with parity of the dam, increased amount of grain fed to calves, increased ammonia levels, and increased mean temperature of the calf housing area. Body condition score at calving tended to be positively influenced by delivery score at first calving, dam parity, and milk or milk replacer dry matter intake. Withers height at calving was positively affected by treatment of animals with antibiotics and increased mean temperature in the calf area. This study demonstrated that nutrition, housing, and management factors that affect health and growth of calves have long-term effects on the animal at least through first calving.

Milk urea nitrogen concentration: heritability and genetic correlations with reproductive performance and disease.

The objectives of this study were to estimate the heritability of milk urea nitrogen (MUN) concentration and describe the genetic relationship between MUN and reproductive performance and between MUN and diseases in Holsteins. Dairy Records Management Systems (Raleigh, NC) provided lactation data. The Danish Agricultural Advisory Center provided breeding value estimates for diseases. Infrared (IR) and wet chemistry (WC) data were analyzed separately. Heritabilities and genetic correlations for 2 different measures of MUN and reproductive performance were estimated with an animal model using ASREML. Heritabilities for MUN were estimated using all lactations combined (lactations 1 through 5) and separately for first lactation and second lactation. Genetic correlations with reproduction and health were estimated separately for parities 1 and 2. Herd-test-day or herd-year-season along with age at calving and days in milk were included as fixed effects in all models. Heritability estimates for all lactations combined were 0.15 for WC MUN and 0.22 for IR MUN. Genetic correlations between WC MUN and 2 measures of reproductive performance, days to first service, and first service conception were not different from zero. In contrast, the genetic correlation between WC MUN and days open of 0.21 in first lactation and 0.41 in second lactation indicated that higher WC MUN values were associated with increased days open. Correlations among estimated breeding values for MUN and estimated breeding values for Danish diseases identified no significant relationships. Although the results of this study indicate that heritable variation for MUN exists, the inability to identify significant genetic relationships with several measures of disease or reproductive performance appears to limit the value of MUN in selection for disease resistance and improved reproduction.

The application of fractal analysis to mammographic tissue classification.

As a first step in determining the efficacy of using computers to assist in diagnosis of medical images, an investigation has been conducted which utilizes the patterns, or textures, in the images. To be of value, any computer scheme must be able to recognize and differentiate the various patterns. An obvious example of this in mammography is the recognition of tumorous tissue and non-malignant abnormal tissue from normal parenchymal tissue. We have developed a pattern recognition technique which uses features derived from the fractal nature of the image. Further, we are able to develop mathematical models which can be used to differentiate and classify the many tissue types. Based on a limited number of cases of digitized mammograms, our computer algorithms have been able to distinguish tumorous from healthy tissue and to distinguish among various parenchymal tissue patterns. These preliminary results indicate that discrimination based on the fractal nature of images may well represent a viable approach to utilizing computers to assist in diagnosis.

Polymorphic forms of the epithelial mucin, PAS-I (MUC1), in milk of Holstein cows (Bos taurus).

The polymorphic epithelial mucin, PAS-I (also known as MUC1), in individual milk samples from 119 Holstein cows was resolved into bands on SDS-gels. Mobility indices established for these bands provided evidence of four and possibly five polymorphic forms. Sialic acid, a major component of the oligosaccharide portion of PAS-I, was removed from the mucin by treatment of milk samples with neurominidase. This reduced the mobility of the mucin bands but did not alter their mobility relationships within a sample or among samples. Consideration of evidence from this and other studies indicates that the four or five polymorphic forms correspond to alleles, which are inherited, one each from sire and dam, and co-dominantly expressed. It appears that the Holstein population may carry several more alleles for PAS-I than do Ayrshire, Jersey or Brown Swiss cattle. In addition to these breed differences, some remarkable molecular differences have been noted between MUC1 (PAS-I) of human and mouse suggesting that research regarding molecular evolution of this mucin could provide another approach to understanding relationships among species.

Computer graphics in the assessment of severity of spasmodic torticollis: potential role in the evaluation of surgical treatment.

There is a need for objective evaluation of the effectiveness of treatment of spasmodic torticollis so that comparisons can be made between different therapies. Video tape recordings of patients undergoing surgery for spasmodic torticollis were digitized and the movement of a reference marker was tracked by computer. A graphic presentation of oscillation of the marker around a mean position was obtained. Comparison of preoperative and postoperative recordings enabled assessment of the effectiveness of surgery. The results can be tabulated, facilitating accurate documentation of large series of results in publication. This should enable easier comparison of the effectiveness of different therapies.

Comparison of balloon-carried atmospheric motion sensors with Doppler lidar turbulence measurements.

Magnetic sensors have been added to a standard weather balloon radiosonde package to detect motion in turbulent air. These measure the terrestrial magnetic field and return data over the standard uhf radio telemetry. Variability in the magnetic sensor data is caused by motion of the instrument package. A series of radiosonde ascents carrying these sensors has been made near a Doppler lidar measuring atmospheric properties. Lidar-retrieved quantities include vertical velocity (w) profile and its standard deviation (sigma(w)). sigma(w) determined over 1 h is compared with the radiosonde motion variability at the same heights. Vertical motion in the radiosonde is found to be robustly increased when sigma(w)>0.75 m s(-1) and is linearly proportional to sigma(w).

Absence of quadratic relationships between genetic evaluations for somatic cell scores and udder linear traits.

Sire genetic evaluations for lactation average somatic cell scores from first and second lactation daughters were regressed in separate models on genetic evaluations for udder linear traits. Somatic cell scores were from Pennsylvania DHIA, and udder linear scores were from the Holstein Association of America classifications of first lactation cows in the northeastern US excluding Pennsylvania. The independent data files for calculation of genetic evaluations included 108,632 cows from 301 sires with udder linear scores and 58,235 cows from the same 301 sires with somatic cell scores. Sire genetic evaluations for higher udders, stronger fore udder attachments, closer teat placement, and shorter teats were associated with lower somatic cell scores. Quadratic relationships between genetic evaluations for the udder traits and somatic cell scores were not important. Quadratic components were significant only for somatic cell scores and teat length. Evaluations for intermediate teat length tended to be associated with higher somatic cell score evaluations. Selection and mating for intermediate udder depth, fore udder attachment, and front teat placement scores are not as effective in reducing somatic cell scores as selection for higher udders, stronger fore udders, and closer front teats.

Relationship among udder and teat morphology and milking characteristics.

Teat cup liner slips, manual milking machine adjustments, milk yields, and milking times were recorded during both morning and evening milkings for 8 d on 97 Holstein cows in The Pennsylvania State University dairy herd. Fore and rear udder heights (distance from floor to udder), udder levelness, distances between teats (before and after milking), teat lengths, teat diameters, and teat end shapes were measured on the same cows. Product-moment correlations among the morphological characteristics, linear slips, manual adjustments, milk yields, and milking times were determined. Residual correlations from a model including lactation number and DIM (linear and quadratic) were also calculated. The variation among cows in machine liner slips and manual adjustments within and across lactation number and DIM can be partially explained by udder and teat morphology. Wider teats were associated with increased linear slips and increased manual adjustments. More tilted udders (rear quarters lower than front quarters) were associated with increased liner slips and tended to be associated with increased manual adjustments. In addition, larger teat diameters and longer teats tended to be associated with increased liner slips.

Heritabilities and correlations among body condition scores, production traits, and reproductive performance.

The objectives of this study were to estimate the heritability of body condition scores (BCS) from producer and consultant-recorded data and to describe the genetic and phenotypic relationships among BCS, production traits, and reproductive performance. Body condition scores were available at calving, postpartum, first service, pregnancy check, before dry off, and at dry off from the Dairy Records Management Systems in Raleigh, NC, through the PCDART program. Heritabilities, genetic correlations, and phenotypic correlations were estimated assuming an animal model using average information REML. Herd-year-season effects and age at calving were included in all models. Prior calving interval was included in models for second and third lactations. Analyses that included reproductive traits were conducted with and without mature equivalent milk as a covariable. Heritability estimates for BCS ranged from 0.09 at dry-off to 0.15 at postpartum in first lactation. Heritability estimates ranged from 0.07 before dry-off to 0.20 at pregnancy check in second lactation and from 0.08 before dry-off to 0.19 at first service in third lactation. Genetic correlations between adjacent BCS within first lactation were greater than 0.96 with the exception of calving and postpartum (0.74). In second lactation, adjacent genetic correlations were 1.0 with the exception of calving and postpartum (0.84). Genetic correlations across lactations were greater than 0.77. Phenotypic correlations between scoring periods were highest for adjacent scoring periods and when BCS was lowest. Phenotypic correlations were lower than genetic correlations, i.e., less than 0.70. Higher BCS during the lactation were negatively related to production, both genetically and phenotypically, but the relationship was moderate. Higher BCS were favorably related genetically to reproductive performance during the lactation.