Cortisol regulates insulin-like growth-factor binding protein (igfbp) gene expression in Atlantic salmon parr.

The growth hormone (Gh)/insulin-like growth-factor (Igf)/Igf binding protein (Igfbp) system regulates growth and osmoregulation in salmonid fishes, but how this system interacts with other endocrine systems is largely unknown. Given the well-documented consequences of mounting a glucocorticoid stress response on growth, we hypothesized that cortisol inhibits anabolic processes by modulating the expression of hepatic igfbp mRNAs. Atlantic salmon (Salmo salar) parr were implanted intraperitoneally with cortisol implants (0, 10, and 40 µg g-1 body weight) and sampled after 3 or 14 days. Cortisol elicited a dose-dependent reduction in specific growth rate (SGR) after 14 days. While plasma Gh and Igf1 levels were unchanged, hepatic igf1 mRNA was diminished and hepatic igfbp1b1 and -1b2 were stimulated by the high cortisol dose. Plasma Igf1 was positively correlated with SGR at 14 days. Hepatic gh receptor (ghr), igfbp1a, -2a, -2b1, and -2b2 levels were not impacted by cortisol. Muscle igf2, but not igf1 or ghr, levels were stimulated at 3 days by the high cortisol dose. As both cortisol and the Gh/Igf axis promote seawater (SW) tolerance, and particular igfbps respond to SW exposure, we also assessed whether cortisol coordinates the expression of branchial igfbps and genes associated with ion transport. Cortisol stimulated branchial igfbp5b2 levels in parallel with Na+/K+-ATPase (NKA) activity and nka-α1b, Na+/K+/2Cl--cotransporter 1 (nkcc1), and cystic fibrosis transmembrane regulator 1 (cftr1) mRNA levels. The collective results indicate that cortisol modulates the growth of juvenile salmon via the regulation of hepatic igfbp1s whereas no clear links between cortisol and branchial igfbps previously shown to be salinity-responsive could be established.

Vertebrate seed dispersers maintain the composition of tropical forest seedbanks.

The accumulation of seeds in the soil (the seedbank) can set the template for the early regeneration of habitats following disturbance. Seed dispersal is an important factor determining the pattern of seed rain, which affects the interactions those seeds experience. For this reason, seed dispersal should play an important role in structuring forest seedbanks, yet we know little about how that happens. Using the functional extirpation of frugivorous vertebrates from the island of Guam, together with two nearby islands (Saipan and Rota) that each support relatively intact disperser assemblages, we aimed to identify the role of vertebrate dispersers in structuring forest seedbanks. We sampled the seedbank on Guam where dispersers are absent, and compared this with the seedbank on Saipan and Rota where they are present. Almost twice as many species found in the seedbank on Guam, when compared with Saipan and Rota, had a conspecific adult within 2 m. This indicates a strong role of vertebrate dispersal in determining the identity of seeds in the seedbank. In addition, on Guam, a greater proportion of samples contained no seeds and overall species richness was lower than on Saipan. Differences in seed abundance and richness between Guam and Rota were less clear, as seedbanks on Rota also contained fewer species than Saipan, possibly due to increased post-dispersal seed predation. Our findings suggest that vertebrate seed dispersers can have a strong influence on the species composition of seedbanks. Regardless of post-dispersal processes, without dispersal, seedbanks no longer serve to increase the species pool of recruits during regeneration.

Erythropoietin attenuates loss of potassium chloride co-transporters following prenatal brain injury.

Therapeutic agents that restore the inhibitory actions of γ-amino butyric acid (GABA) by modulating intracellular chloride concentrations will provide novel avenues to treat stroke, chronic pain, epilepsy, autism, and neurodegenerative and cognitive disorders. During development, upregulation of the potassium-chloride co-transporter KCC2, and the resultant switch from excitatory to inhibitory responses to GABA guide the formation of essential inhibitory circuits. Importantly, maturation of inhibitory mechanisms is also central to the development of excitatory circuits and proper balance between excitatory and inhibitory networks in the developing brain. Loss of KCC2 expression occurs in postmortem samples from human preterm infant brains with white matter lesions. Here we show that late gestation brain injury in a rat model of extreme prematurity impairs the developmental upregulation of potassium chloride co-transporters during a critical postnatal period of circuit maturation in CA3 hippocampus by inducing a sustained loss of oligomeric KCC2 via a calpain-dependent mechanism. Further, administration of erythropoietin (EPO) in a clinically relevant postnatal dosing regimen following the prenatal injury protects the developing brain by reducing calpain activity, restoring oligomeric KCC2 expression and attenuating KCC2 fragmentation, thus providing the first report of a safe therapy to address deficits in KCC2 expression. Together, these data indicate it is possible to reverse abnormalities in KCC2 expression during the postnatal period, and potentially reverse deficits in inhibitory circuit formation central to cognitive impairment and epileptogenesis.

Factors associated with frequency of abortions recorded through Dairy Herd Improvement test plans.

Frequency of abortions recorded through Dairy Herd Improvement (DHI) testing was summarized for cows with lactations completed from 2001 through 2009. For 8.5 million DHI lactations of cows that had recorded breeding dates and were >151 d pregnant at lactation termination, the frequency of recorded abortions was 1.31%. Effects of year, herd-year, month, and pregnancy stage at lactation termination; parity; breed; milk yield; herd size; geographic region; and state within region associated with DHI-recorded abortion were examined. Abortions recorded through DHI (minimum gestation of 152 d required) were more frequent during early gestation; least squares means (LSM) were 4.38, 3.27, 1.19, and 0.59% for 152 to 175, 176 to 200, 201 to 225, and 226 to 250 d pregnant, respectively. Frequency of DHI-recorded abortions was 1.40% for parity 1 and 1.01% for parity ≥ 8. Abortion frequency was highest from May through August (1.42 to 1.53%) and lowest from October through February (1.09 to 1.21%). Frequency of DHI-recorded abortions was higher for Holsteins (1.32%) than for Jerseys (1.10%) and other breeds (1.27%). Little relationship was found between DHI-recorded abortions and herd size. Abortion frequencies for effects should be considered to be underestimated because many abortions, especially those caused by genetic recessives, go undetected. Therefore, various nonreturn rates (NRR; 60, 80, …, 200 d) were calculated to document pregnancy loss confirmed by the absence of homozygotes in the population. Breeding records for April 2011 US Department of Agriculture sire conception rate evaluations were analyzed with the model used for official evaluations with the addition of an interaction between carrier status of the service sire (embryo's sire) and cow sire (embryo's maternal grandsire). Over 13 million matings were examined using various NRR for Holstein lethal recessive traits (brachyspina and complex vertebral malformation) and undesirable recessive haplotypes (HH1, HH2, and HH3) as well as >61,000 matings for a Brown Swiss haplotype (BH1), and 670,000 matings for a Jersey haplotype (JH1). Over 80% of fertility loss occurred by 60 d after breeding for BH1, HH3, and JH1, by 80 d for HH2, by 100 d for BY, and by 180 d for HH1. For complex vertebral malformation, fertility loss increased from 40 to 74% across gestation. Association of undesirable recessives with DHI-recorded abortions ranged from 0.0% for Jerseys to 2.4% for Holsteins.

Consequence of alternative standards for bulk tank somatic cell count of dairy herds in the United States.

Noncompliance with current US and European Union (EU) standards for bulk-tank somatic cell count (BTSCC) as well as BTSCC standards recently proposed by 3 US organizations was evaluated using US Dairy Herd Improvement Association (DHI) herds and herds supplying milk to 4 Federal Milk Marketing Orders (FMO). Herds with 15 to 26 tests (frequently monthly) from January 2009 through October 2010 were included. Somatic cell scores (SCS) from 14,854 herds and 164,794 herd-tests were analyzed for DHI herds with ≥10 cows for all tests. Herd test-day SCC was derived as a proxy for BTSCC and was the basis for determining noncompliance and percentage of the milk it represented. For FMO herds, actual milk marketed and BTSCC were available from 27,759 herds and 325,690 herd-tests. A herd was noncompliant for the current EU BTSCC standard after 4 consecutive rolling 3-test geometric means (geometric method) were >400,000 cells/mL. A herd was noncompliant for the current US BTSCC standard after 3 of 5 consecutive monthly BTSCC shipments (frequency method) were >750,000 cells/mL. Alternative proposed standards (600,000, 500,000, or 400,000 cells/mL) also were examined. A third method designated noncompliance when a single 3-mo geometric mean of >550,000 or >400,000 cells/mL and a subsequent test exceeded the same level. Results were examined based on herd size or milk shipped by month. Noncompliance for the current US standard for the 12 mo ending October 2010 in DHI and FMO herds was 0.9 and 1.0%, respectively, compared with 7.8 and 16.1% for the current EU standard. Noncompliance was always greater for the frequency method than for the geometric method and was inversely related to herd size or milk shipped. Using the frequency method at 400,000 cells/mL, noncompliance was 19.1% for DHI herd-tests in herds with <50 cows compared with 1.1% for herds with ≥ 1,000 cows. For FMO herds shipping <900 t, noncompliance was 44.5% using the frequency method at 400,000 cells/mL compared with 8.0% for herds marketing >9,000 t. All methods proposed increased the percentages of herds and shipped milk that exceeded the regulatory limit. Producers will need to place more emphasis on reducing the incidence and prevalence of subclinical mastitis through known management practices such as proper milking techniques, well-functioning milking machines, postmilking teat disinfectant, dry cow treatment, and culling of problem cows to meet any of the proposed new standards.

Mechanically adaptive intracortical implants improve the proximity of neuronal cell bodies.

The hypothesis is that the mechanical mismatch between brain tissue and microelectrodes influences the inflammatory response. Our unique, mechanically adaptive polymer nanocomposite enabled this study within the cerebral cortex of rats. The initial tensile storage modulus of 5 GPa decreases to 12 MPa within 15 min under physiological conditions. The response to the nanocomposite was compared to surface-matched, stiffer implants of traditional wires (411 GPa) coated with the identical polymer substrate and implanted on the contralateral side. Both implants were tethered. Fluorescent immunohistochemistry labeling examined neurons, intermediate filaments, macrophages, microglia and proteoglycans. We demonstrate, for the first time, a system that decouples the mechanical and surface chemistry components of the neural response. The neuronal nuclei density within 100 µm of the device at four weeks post-implantation was greater for the compliant nanocomposite compared to the stiff wire. At eight weeks post-implantation, the neuronal nuclei density around the nanocomposite was maintained, but the density around the wire recovered to match that of the nanocomposite. The glial scar response to the compliant nanocomposite was less vigorous than it was to the stiffer wire. The results suggest that mechanically associated factors such as proteoglycans and intermediate filaments are important modulators of the response of the compliant nanocomposite.

Genome sequences of Mycoplasma alligatoris A21JP2T and Mycoplasma crocodyli MP145T.

Mycoplasma alligatoris and Mycoplasma crocodyli are closely related siblings, one being highly virulent and the other relatively attenuated. We compared their genomes to better understand the mechanisms and origins of M. alligatoris' remarkable virulence amid a clade of harmless or much less virulent species. Although its chromosome was refractory to closure, M. alligatoris differed most notably by its complement of sialidases and other genes of the N-acetylneuraminate scavenging and catabolism pathway.

Potential consequences of selection to change gestation length on performance of Holstein cows.

Genetic evaluations for gestation length (GL) for Holstein service sires were studied to determine their effectiveness in predicting GL in an independent data set. Consequences of selection on GL were also assessed by examining correlated changes in milk and fitness traits. Holstein bulls with ≥ 300 calvings between 1998 and 2005 were stratified into the following 7 groups using predicted transmitting ability (PTA) for service sire GL: <-3.00, -3.00 to -2.01, …, 1.00 to 1.99, and ≥ 2.00 d. An independent set of 261,598 first-parity cows mated later to the same bulls and calving between 2006 and 2009 were segregated by the service sire PTA GL groups (group had 8,317 to 73,324 gestations), and these mates' GL were examined to determine effectiveness of service sire PTA GL. The model included fixed effects for herd-year and service sire group, plus covariates for conception dates to account for time opportunity among mates. Mean GL for mates by service sire group (from lowest to highest PTA GL) were 275.3, 276.5, 277.8, 278.6, 279.5, 280.6, and 281.7 d. Thus, service sire PTA GL was effective in identifying bulls that modified GL. Subsequent yield and fitness traits were also examined for the (independent) mates with the same service sire groups. Intermediate service sire PTA GL was optimal for yield traits and days open; performance for productive life and culling generally became less favorable as service sire PTA GL increased. A second examination was made by replacing service sire PTA GL groups in the model with phenotypic cow GL groups. Relationships between GL and subsequent performance for milk yield and fitness traits were examined using 9 phenotypic cow GL groups: ≤ 271, 272-273, …, 284-285, and ≥ 286 d. Performance generally improved for subsequent lactation yield as cow GL increased; however, intermediate GL was optimal for productive life, calving ease, stillbirth, culling, and days open. Results indicated that neither shortening nor increasing the mean for GL in the Holstein breed provided much overall benefit when all traits were considered. The same traits examined in the cows for the correlated effect from various GL were also examined in their offspring to determine whether the GL producing the calf had any influence on these same traits when the offspring reached their own productive period. Little carryover occurred from GL on the dam to the other traits observed on the offspring when examined a generation later.

Use of sexed semen and its effect on conception rate, calf sex, dystocia, and stillbirth of Holsteins in the United States.

Use of sexed semen for artificial insemination of US Holstein heifers (1.3 million breedings) and cows (10.8 million breedings) in Dairy Herd Improvement herds was characterized by breeding year, parity, service number, region, herd size, and herd milk yield. Sexed semen was used for 1.4, 9.5, and 17.8% of all reported breedings for 2006, 2007, and 2008, respectively, for heifers, and for 0.1, 0.2, and 0.4%, respectively, for cows. For 2008 sexed semen breedings, 80.5 and 68.6% of use was for first services of heifers and cows, respectively. For cows, 63.1% of 2008 sexed semen use was for first parity. Mean sexed semen use within herd was the greatest for heifers in the Southwest (36.2%) and for cows in the Mideast (1.3%). Mean sexed semen use increased for heifers but changed little for cows as either herd size or herd mean milk yield increased. Availability of sexed semen was examined for Holstein bulls in active AI service; of 700 bulls born after 1993, 37% had sexed semen marketed by mid August 2009. Active AI bulls with marketed sexed semen were superior to average active AI bulls for evaluations of yield traits, productive life, somatic cell score, daughter pregnancy rate, service-sire calving ease, service-sire stillbirth, final score, sire conception rate, and lifetime net merit. The effect of sexed semen use on conception rate, calf sex, dystocia, and stillbirth also was examined for heifers and cows. Mean conception rate for heifers was 56% for conventional and 39% for sexed semen; corresponding conception rates for cows were 30 and 25%. For single births from sexed semen breedings, around 90% were female. Dystocia and stillbirth were more frequent for heifers (6.0 and 10.4%, respectively, for conventional semen; 4.3 and 11.3%, respectively, for sexed semen) than for cows (2.5 and 3.6%, respectively, for conventional semen; 0.9 and 2.7%, respectively, for sexed semen). Difficult births declined by 28% for heifers and 64% for cows with sexed semen use. Stillbirths were more prevalent for twin births except for sexed semen heifer breedings. Stillbirths of single male calves of heifers were more frequent for breedings with sexed semen (15.6%) than conventional semen (10.8%); a comparable difference was not observed for cows, for which stillbirth frequency of single male calves even decreased (2.6 vs. 3.6%). Overall stillbirth frequency was reduced by sexed semen use for cows but not for heifers.

Response to alternative genetic-economic indices for Holsteins across 2 generations.

Four US genetic-economic indices for dairy cattle were retrofitted to illustrate differences in phenotypic response observed for retrospective selection over 2 generations for currently evaluated traits, even though producers did not have evaluations available at the time for direct selection for those traits. Differences among cows were compared based on ranking of their sires and maternal grandsires (MGS) for the 4 retrofitted indices. Holstein artificial insemination bulls (106,471) were categorized by quintile for each index, and 25 cow groups were formed based on quintiles for sire and MGS (2 generations). Data included records from 1,756,805 cows in 26,106 herds for yield traits, productive life, pregnancy rate, and somatic cell score; 692,656 cows in 9,967 herds for calving difficulty; and 270,564 cows in 4,534 herds for stillbirths. For each index, least squares differences between the 25 cow groups were examined for 8 first-parity traits (milk, fat, and protein yields; productive life; somatic cell score; pregnancy rate; calving difficulty; and stillbirth) that had been standardized for age. Analysis removed effects of herd and cow birth year. Seven of 25 cow groups were consolidated into 3 groups based on index ranking for their male ancestors (low, medium, and high). The cow group with high sire and MGS rankings for the 2006 net merit index produced more milk (219 kg), fat (21 kg), and protein (11 kg) and had longer productive life (6.3 mo), lower somatic cell score (0.21), higher pregnancy rate (1.2 percentage units), fewer difficult births in heifers (3.8 percentage units), and lower stillbirth rate (4.6 percentage units) than did the group with low sire and MGS rankings. For cow groups based on sire and MGS rankings for 1971 (milk and fat) and 1977 (milk, fat, and protein) indices, advantages for the group with high sire and MGS rankings were much larger for yield traits but smaller (and sometimes even unfavorable) for other traits. Cow groups based on sire and MGS rankings for the 1994 net merit index generally had differences that were intermediate to groups based on sire and MGS rankings for the 1977 and 2006 indices. Phenotypic differences revealed retrospectively between genetic-economic indices indicate that genetic improvement should be made for all traits included in recent net merit indices.

Bilateral retinochoroiditis caused by an atypical strain of Toxoplasma gondii.

BACKGROUND: A 53-year-old man presented with an acute bilateral posterior uveitis with extensive necrotising retinochoroiditis but without chorioretinal scarring. A thorough workup did not reveal any underlying disease. The possibilities of atypical ocular toxoplasmosis as well as herpetic retinal necrosis were considered and specific therapy instituted, with little improvement. The patient died within 2 months as result of an undifferentiated squamous cell carcinoma. METHODS: Histopathological examination, immunohistochemistry and multilocus polymerase chain reaction confirmed Toxoplasma gondii infection of the retina RESULTS: Macroscopic examination of enucleated globe showed extensive retinal necrosis and vitreous detachment. Histological examination of retinal tissue identified numerous round-to-elliptical toxoplasmic cysts within the retina, with retinal necrosis and minimal choroidal inflammation. Immunohistochemical analyses confirmed that the cysts were due to T gondii. DNA extracted from formalin-fixed, paraffin-embedded tissue sections was subjected to multilocus polymerase chain reaction (PCR) analysis at the following typing loci: SAG1, SAG2, SAG3, SAG4, B1, NTS2, GRA6 and GRA7. DNA sequencing of positive PCR products at the NTS2, SAG1 and GRA7 loci confirmed the presence of a non-archetypal strain of T gondii infecting the eye of the patient experiencing a severe, atypical ocular toxoplasmosis CONCLUSION: A highly divergent, non-archetypal strain of T gondii was responsible for causing a severe, atypical bilateral retinochoroiditis in a patient from Brazil.

Inhibition of CXCR2 signaling promotes recovery in models of multiple sclerosis.

Multiple sclerosis (MS) is a neurodegenerative disease characterized by demyelination/remyelination episodes that ultimately fail. Chemokines and their receptors have been implicated in both myelination and remyelination failure. Chemokines regulate migration, proliferation and differentiation of immune and neural cells during development and pathology. Previous studies have demonstrated that the absence of the chemokine receptor CXCR2 results in both disruption of early oligodendrocyte development and long-term structural alterations in myelination. Histological studies suggest that CXCL1, the primary ligand for CXCR2, is upregulated around the peripheral areas of demyelination suggesting that this receptor/ligand combination modulates responses to injury. Here we show that in focal LPC-induced demyelinating lesions, localized inhibition of CXCR2 signaling reduced lesion size and enhanced remyelination while systemic treatments were relatively less effective. Treatment of spinal cord cultures with CXCR2 antagonists reduced CXCL1 induced A2B5+ cell proliferation and increased differentiation of myelin producing cells. More critically, treatment of myelin oligodendrocyte glycoprotein peptide 35-55-induced EAE mice, an animal model of multiple sclerosis, with small molecule antagonists against CXCR2 results in increased functionality, decreased lesion load, and enhanced remyelination. Our findings demonstrate the importance of antagonizing CXCR2 in enhancing myelin repair by reducing lesion load and functionality in models of multiple sclerosis and thus providing a therapeutic target for demyelinating diseases.

Reproductive status of Holstein and Jersey cows in the United States.

Reproductive information since 1995 from the USDA national dairy database was used to calculate yearly Holstein and Jersey means for days to first breeding after calving (DFB), 70-d nonreturn rate, conception rate (CR), number of breedings per lactation (NB), interval between first and last breedings during the lactation, days to last breeding after calving (DLB), pregnancy rate (PR), calving interval (CI), and interval between consecutive breedings. Data were from nearly 20 million breedings during >8 million lactations of >5 million cows in >23,000 herds. Means were also calculated for some traits by parity and breeding number for both breeds and by geographical region and synchronization status for Holsteins. The DFB declined for Holsteins from 92 d in 1996 to 85 d in 2007; the trend in yearly differences was not as consistent for Jerseys. First- and all-breeding 70-d nonreturn rate declined 5 to 9 percentage units over time. First- and all-breeding CR declined 2 to 4 percentage units. The DFB were longer for later parities of Holsteins than for early parities. Second- and third-breeding CR were sometimes 1 to 2 percentage units above first-breeding CR for Holsteins but lower (1 to 7 percentage units) for Jerseys. The CR within breeding number declined across parities for both breeds. The NB increased by 0.3 to 0.4 breedings over time but remained constant (2.5 or 2.6 breedings) across parities for Holsteins and increased (from 2.2 to 2.4 breedings) for Jerseys. Holstein DFB were fewest in the Northwest (78 d) and greatest in the Mountain region (92 d). Regional CR was highest for the Northeast and Southwest (33%) and lowest for the Southeast (26%); NB was fewest for the Northeast (2.3) and greatest for the Southeast (2.7). Mean DLB was fewest for the Southwest (127 d) and greatest for the Mountain region (157 d); CI was shortest for the Southwest (406 d) and longest for the Mideast (434 d). Mean PR was highest for the Southwest (28.3%) and lowest for the Mideast and Southeast (22.2%). Use of timed artificial insemination following synchronized estrus appears to have reduced DFB, lowered CR, and increased NB while reducing DLB and CI. However, synchronized breeding was not a primary cause of Holstein regional differences for reproductive traits. Since 2002, phenotypic performance for CR, DLB, and CI as well as genetic merit for daughter PR have stopped their historical declines and started to improve.

Impact of genetic merit for milk somatic cell score of sires and maternal grandsires on herd life of their daughters.

A retrospective study of the impact of the estimated breeding values of sires and maternal grandsires for somatic cell score (SCS) on productive life (PL) of Holsteins and Jerseys was conducted. Data included records from 2,626,425 Holstein and 142,725 Jersey cows. The sires and maternal grandsires of cows were required to have been available through artificial insemination and to have predicted transmitting ability (PTA) SCS evaluations based on 35 or more daughters. A weighted function (WPTA) of sire and maternal grandsire PTA for SCS was used: (sire PTA + 0.5 maternal grandsire PTA)/1.5. The 3 dependent variables were PL, frequency of cows culled for mastitis, and first-lactation SCS. The model included effects of herd, birth year, and WPTA (WPTA was categorized into groups: <2.70, 2.70 to 2.79, ..., 3.20 to 3.29, > or =3.30). For analysis of first-lactation SCS, calving year and calving month were substituted for birth year. Differences among WPTA groups were highly significant: as WPTA increased, PL decreased, whereas percentage culled for mastitis and first-lactation SCS increased. The range in PL from lowest to highest WPTA was 5.07 mo for Holsteins and 4.73 mo for Jerseys. Corresponding differences for percentage culled for mastitis were 7.0 and 5.6% and for SCS were 0.95 and 1.04 (for Holsteins and Jerseys, respectively). Although phenotypic studies suggest that cows with extremely low SCS were less resistant to mastitis, our results showed consistent improvements in PL, percentage culled for mastitis, and SCS of daughters when bulls were chosen for low PTA SCS.

Effect of bromelain on milk yield, milk composition and mammary health in dairy goats.

A 7 month prospective cohort study was designed to determine if feeding bromelain to dairy goats influenced the MSCC, milk yield, milk composition and the incidence of IMI. Forty-four clinically normal goats from 2nd to 6th parities were studied. Daily bromelain dosage was 7.4 grams/animal (185-mg/Kg weight). Samples for diagnostic bacteriology were collected from each udder half every 2 weeks. Samples for MSCC and composition were obtained every 42 days. Milk yield was also recorded every 42 days. Bromelain affected milk protein and fat but not MSCC, milk yield or milk lactose. Bromelain did not decrease the MSCC in healthy goats. Milk protein and fat increased in the bromelain treated group (P < 0.01), which is important for dairymen because premiums are paid milk fat and protein content. No clinical mastitis was detected in the goats for the total study period and incidence rate of subclinical IMI was 5.7%. Relative risk was 1.50 (0.28 < RR < 8.12) which means that the bromelain had no significant effect on IMI (P > 0.05). In addition, the use of pineapple by-products could be especially important in tropical countries were pineapple waste seems to be a pollution problem.

Foamy virus as a gene transfer vector to the central nervous system.

Engineered foamy virus (FV) vectors have been lauded for their superior safety profiles and stable integration patterns compared to their gammaretroviral counterparts. The drawback has been the belief that FV incorporation is cell cycle-dependent, thereby limiting its utility in post-mitotic tissues such as the central nervous system. In this brief communication, we challenged this theory by examining FV in vivo. We injected equal titers of FV and lentivirus (LV) into the adult rat brain and found that at 1 week, FV transduced a significantly greater volume of bromodeoxyuridine (BrdU)-negative brain parenchyma than did LV. By 8 weeks, however, the volume of transduced tissue was greatly reduced--comparable to LV-and restricted to BrdU+. Taken together, these data implicate a role for FV in short-term gene delivery strategies to the CNS.

Death losses for lactating cows in herds enrolled in dairy herd improvement test plans.

Factors that affect frequency of death of lactating cows were studied for cows with records that terminated from 1995 through 2005. Analyses included effects of herd, year, month, parity, and lactation stage at lactation termination as well as cow breed and milk yield. A national data set (15,025,035 lactations in 45,032 herds) was analyzed with PROC GLM. Overall death frequency was 3.1% per lactation (5.7% per cow). Death frequency increased by 1.6% from 1995 to 2005, with a sudden increase of 0.9% from 2003 to 2004, probably because of a USDA requirement in late 2003 for euthanizing downer cows. Death frequency was 16.5% greater for lactations that terminated at or=251 d. Death frequency increased with parity (2% greater for eighth parity and later than for first parity) and with lactation milk yield (0.4%/1,000 kg for Holsteins and Jerseys and 0.5%/1,000 kg for other breeds). Deaths were most frequent in July and least frequent in November. Within-herd breed differences (Holstein, Jersey, and other breeds) were small. The heritability of likelihood of death estimated from a sample of 79,162 Holstein cows was 1.3%. Death losses are increasing, perhaps partly because of increased milk yield and more intensive management regimens.

Stillbirth (co)variance components for a sire-maternal grandsire threshold model and development of a calving ability index for sire selection.

(Co)variance components for stillbirth in US Holsteins were estimated under a sire-maternal grandsire threshold model using subsets of data from the national calving ease database, which includes over 6 million calving records with associated stillbirth scores. Stillbirth was coded as a binomial trait indicating whether the calf was alive 48 h postpartum. Records were selected for calves whose sire and maternal grandsire (MGS) were among the 2,600 most frequently appearing bulls (2,578 sires and 2,586 MGS). Herd-years were required to contain at least 20 records and only single births were used. After editing, the data set included 2,083,979 calving records from 5,765 herds and 33,304 herd-years. Six sample datasets of approximately 250,000 records each were created by randomly selecting herd codes. Quasi-REML and Bayesian approaches were used to estimate (co)variance components from each sample. The model included fixed year-season, parity-sex, birth year group of sire, and birth year group of MGS effects and random herd-year, sire, MGS, and residual effects. Quasi-REML and Bayesian analyses produced similar results, although the Bayesian estimates were slightly larger. Marginal posterior means (and standard deviations) from the Bayesian analysis averaged 0.0085 (0.0015), 0.0181 (0.0020), 0.0872 (0.0538), and 0.00410 (0.0001) for sire, MGS, and herd-year variances and the sire-MGS covariance, respectively. Mean direct and maternal heritabilities were 0.030 (0.003) and 0.058 (0.005), respectively, and the mean genetic correlation between the 2 effects was -0.02 (0.16). A calving ability index combining stillbirth (SB) and calving ease (CE) was developed for inclusion in the Lifetime Net Merit index. The index was calculated as -4(sire CE)-3(daughter CE)-4(sire SB) -8(daughter SB).

Voluntary waiting period and adoption of synchronized breeding in dairy herd improvement herds.

Voluntary waiting period and adoption of synchronized breeding (ovulation synchronization followed by timed artificial insemination) were characterized from 33 million services of Holsteins and Jerseys in Dairy Herd Improvement herds. Calving month, calving year, and parity had large effects on days to first service for both breeds. Holstein cows that calved during March and April were bred later than those that calved during other months (February and March for Jerseys), whereas cows that calved during September and October were bred earlier. First-parity cows had longer days to first service than did second-parity cows. Herd-year voluntary waiting period was measured as the days postpartum by which 10% of cows had received a first insemination. Median days to reach 10% of cows bred were 55.5 d. Over 65% of herds had 10% of cows inseminated by 60 d postpartum, the voluntary waiting period assumed for national evaluations for daughter pregnancy rate. Herd-years with synchronized breeding at first insemination were identified through chi2 analysis based on deviation of observed frequency of first inseminations by day of the week from an expected equal frequency and by the maximum percentage of cows inseminated on a particular day of the week. Herds that were identified as having synchronized breeding had fewer days to first service (17.0), more services (0.16/cow), and fewer days open (9.1) than did herds that were classified as having traditional estrus detection. Synchronized herds also had a standard deviation for days to first service that was only 38% as large as that for herds that bred on observed estrus. Adoption of synchronized breeding for first services steadily increased from 1.9% of herd-years (2% of cows) for 1996 to 19.9% of herd-years (34.9% of cows) for 2005. Procedures for genetic evaluation of daughter pregnancy rate should be examined to determine if herd regimen for reproductive management affects results.

Effects of nonadditive genetic interactions, inbreeding, and recessive defects on embryo and fetal loss by seventy days.

Lethal recessive genes that cause early embryo loss are difficult to detect. Nonreturn rate at 70 d after first insemination (NR) was evaluated as a trait of the embryo using 1,739,055 first-service records from 1,251 Holstein bulls represented as both service sires and sires of cows. Effects modeled included herd-year-season, parity of cow, sire of cow, service bull, interaction of service bull with sire of cow, and regression on inbreeding of embryo. Variances of service bull and sire of cow were estimated using REML and estimated effects were removed from the data. Interaction variance was estimated from the residuals using the tilde-hat approximation to REML. An additive relationship matrix was used for sire of cow and a dominance relationship matrix for the interaction term. Service bull effects were assumed constant across time and unrelated. For each 10% increase in inbreeding, NR percentage declined by an estimated 1%. A regression of this size could be explained by > 20% of animals carrying defects that cause early embryo loss. Of the total variance, service bull contributed 0.36%; sire of cow, 0.24% (heritability of 1.0%); and interaction, 0.18% (dominance variance of 2.8%). Numbers of records exceeded 500 for 50 bull pair subclasses. Predicted interactions that included effects of inbreeding ranged from - 3.6% to +2.9%, compared with the mean NR of 56%. The largest negative interactions were not caused by known recessive defects. Complex vertebral malformation generally causes loss of pregnancies later in gestation, and few current bulls carry the gene for deficiency of uridine monophosphate synthase. Further study of the families with largest negative interactions could uncover new recessive defects.