Effects of the reproductive cycle and age on calcium and phosphorus metabolism and bone integrity of sows

The purpose of this study was to determine the effects of stage of the reproductive cycle and age on Ca and P metabolism and bone integrity of sows. Five-day balance studies were conducted with first- and fifth-parity sows, and sows were slaughtered during the last trimester of gestation, at the end of lactation, or during the last trimester of the subsequent gestation. First-parity sows were studied during their first gestation (n = 11), first lactation (n = 10), or second gestation (n = 10). Fifth-parity sows were examined during their fifth gestation (n = 10), fifth lactation (n = 9), or sixth gestation (n = 9). All sows were fed 1.9 kg/d of a common diet (.76% Ca and .63% P) during gestation and were allowed ad libitum access to the same diet during lactation. Digestibilities of Ca and P were much greater during lactation than during gestation. During gestation, young sows absorbed and retained more Ca and P than did mature sows. However, during lactation, mature sows consumed more feed, and therefore Ca and P, and retained more Ca and P than did young sows. Bones of mature sows were larger, more mineralized, and stronger than the bones of young sows. Bone weight and strength decreased during lactation and increased during the subsequent gestation. Changes in weight and strength were greater in young sows than in mature sows.

Genetic discrimination in the workplace

Author argues that the Americans with Disabilities Act prohibits discrimination against workers based on their genetic makeup. He also examines state legislation and recently proposed federal legislation prohibiting genetic discrimination.

Influence of sample orientation on prediction of fresh ham lean content by electromagnetic scanning

To evaluate the effect of orientation of hams during electromagnetic scanning on the estimation of dissected lean content, hams were scanned horizontally, posterior first (POS) or dorsal first (DOR), and vertically, medial side (aitchbone) first (MED; standing on the butt face). Weight and percentage of dissected lean were estimated using scan peak for each orientation, ham weight, and fat thickness. The mean scan peak for the MED orientation was approximately twice as great as peaks for the POS and DOR orientations, which suggests that this orientation may offer greater predictive accuracy by reducing the signal to noise ratio. Results, however, indicated that all orientations were equally effective at predicting lean weight and percentage, with R2 values of .95 and .75 and root mean square errors of .21 kg and 2.6%, respectively.

Response of pigs to space allocation and diets varying in nutrient density

Three experiments were conducted to determine the main and interacting effects on growth performance of floor space allowance and dietary lysine and energy concentrations for growing-finishing pigs. In each experiment, space allocations of .56 or .78 m2/pig were achieved with 14 or 10 pigs per pen, respectively. In Exp. 1, diets investigated were National Research Council (NRC) recommended nutrient densities, NRC plus 5% added fat (F), NRC plus .15% added L-lysine. HCl (L), and NRC plus fat plus lysine (FL) in a 4 x 2 x 2 factorial arrangement of diets with space and season (winter vs summer). In Exp. 2 and 3, a 2 x 3 factorial treatment arrangement was used to investigate space and diet effects. Diets investigated contained 0, 2.5, or 5% added fat (choice white grease [Exp. 2]; tallow [Exp. 3]) with L-lysine.HCl added to maintain a constant lysine:ME ratio. In Exp.1, pigs given .56 m2/pig vs .78 m2/pig ate less feed (P < .001) and grew slower (P < .001) with no difference in gain:feed ratio or carcass lean percentage. Feed intake was decreased (P < .005) and gain:feed ratio increased (P < .001) for the FL vs L diet. In Exp. 2, pigs given .56 m2/pig vs .78 m2/pig grew slower (P < .001) with a poorer gain:feed ratio (P < .05) and a slower rate of lean gain (P < .05). In Exp. 3, pigs given .56 m2/pig vs .78 m2/pig grew slower (P < .05) with no difference in gain:feed ratio and a slower rate of lean gain (P < .005). There was a linear improvement in ADG (P < .01, Exp. 2; P = .011, Exp. 3) and gain:feed ratio (P < .001, Exp. 2 and 3) with increasing amounts of fat in the diet. The lack of space x diet interactions in these experiments suggests that the reduction in ADG associated with the reduction in ADFI for pigs given less space is independent of dietary lysine and energy concentrations.

Interactions of cytosine derivatives with T.A interruptions in pyrimidine.purine.pyrimidine DNA triplexes

The ability of triplex-forming oligopyrimidines to interact with duplex targets which contain a single pyr.pur interruption in their homopurine triplex binding site was studied. These oligonucleotides contain either N4-(3-carboxypropyl)deoxycytidine (3) or N4-(5-carboxytriazolyl)deoxycytidine (4) to target the pyr.pur interruption. The 3-carboxypropyl and the 5-carboxytriazolyl groups of these cytosine derivatives are designed to span the major groove of the duplex target. Molecular models suggest that the carboxyl group of 3 or 4 can serve as a hydrogen bond acceptor for the N6-amino hydrogen of A in a T.A base pair. Additional contacts are possible between the N4-amino hydrogen of 3 or 4 and the O4-carbonyl oxygen of T. UV melting experiments showed that a 15-mer, I(3), containing nucleoside 3 formed a stable triplex with duplex targets containing a single T.A interruption. The melting temperature of this triplex was 7 degrees C higher than that of a similar triplex containing a single G.T.A triad when a Tris buffer was employed. Oligomer I(3) also formed a triplex of lower stability with a target containing a G.C base pair but not with targets containing C.G, U.A, or A.T base pairs. A similar 15-mer, II, containing nucleoside 4 was found to be less selective than I(3) in its interaction with duplex targets. Thus, gel mobility shift experiments showed that in addition to interacting with T.A, oligomer II also formed triplexes with duplex targets containing U.A and C.G interruptions. These studies suggest that nucleoside derivatives which can potentially contact both bases of a pyr.pur interruption might provide a means to extend the range of sequences which can be recognized by triplex-forming oligonucleotides.

Disturbances in the soil: finding buried bodies and other evidence using ground penetrating radar

Ground penetrating radar (GPR) is an efficient and effective means to search for buried evidence, whether it be a clandestine grave, formal burial, or certain missing articles from a crime scene. The procedures for GPR used by the U.S. Army Central Identification Laboratory, Hawaii (CILHI), are the result of several years of experimentation on a variety of ground surfaces in Hawaii, Southeast Asia and the mainland U.S. This remote sensing method does not usually provide direct information that there is a body or other specific object beneath the ground. Most of the time the GPR has been used to determine where a target object is not located. The key feature of GPR is that it can detect recent changes in shallow soil conditions caused by the disturbance of soil and the intrusion of different material. Using the methods described here, the investigator should be able to determine the precise metric grid coordinates for a subsurface disturbance, as well as the approximate size, the general shape, and the depth of the buried material. Success will vary with soil conditions. The conditions suitable or not practical for using GPR are summarized. This remote sensing technology can have wider use in crime scene investigations due to the recent introduction of more user-friendly software and more portable hardware.

Triplex formation by oligonucleotides containing novel deoxycytidine derivatives

Homopurine sequences of duplex DNA are binding sites for triplex-forming oligodeoxyribopyrimidines. The interactions of synthetic duplex DNA targets with an oligodeoxyribopyrimidine containing N4-(6-amino-2-pyridinyl)deoxycytidine (1), a nucleoside designed to interact with a single C-G base pair interruption of the purine target tract, was studied by UV melting, circular dichroism spectroscopy and dimethylsulfate alkylation experiments. Nucleoside 1 supports stable triplex formation at pH 7.0 with formation of a 1-Y-Z triad, where Y-Z is a base pair in the homopurine tract of the target. Selective interaction was observed when Y-Z was C-G, although A-T and, to a lesser extent, T-A and G-C base pairs were also recognized. The circular dichroism spectra of the triplex having a 1-C-G triad were similar to those of a triplex having a C(+)-G-C triad, suggesting that the overall structures of the two triplexes are quite similar. Removal of the 6-amino group from 1 essentially eliminated triplex formation. Reaction of a triplex having the 1-C-G triad with dimethylsulfate resulted in a 50% reduction of methylation of the G residue of this triad. In contrast, the G of a similar triplex containing a U-C-G triad was not protected from methylation by dimethylsulfate. These results are consistent with a binding mode in which the 6-amino-2-pyridinyl group of 1 spans the major groove of the target duplex at the 1-C-G binding site and forms a hydrogen bond with the O6 of G. An additional stabilizing hydrogen bond could form between the N4 of the imino tautomer of 1 and the N4 amino group of C.

Triplex formation by a psoralen-conjugated oligodeoxyribonucleotide containing the base analog 8-oxo-adenine

Oligodeoxyribonucleotides containing thymidine and 8-oxo-2'-deoxyadenosine can form pyr.pur.pyr type triplexes with double-stranded DNA. Unlike triplexes whose third strands contain thymidine and deoxycytidine, the stability of these triplexes is independent of pH. We have prepared d-ps-TAAATAAATTTTTAT-L [I(A)], where A is 8-oxo-2'-deoxyadenosine, ps is 4'-hydroxymethyl-4,5',8- trimethylpsoralen and L is a 6-amino-2-(hydroxymethyl)hexyl linker. The oligomer is designed to interact with a homopurine sequence in the promoter region of the human gene coding for the 92 kDa form of collagenase type IV. Oligomer I(A) and oligomer I(C), which contains 2'-deoxycytidine in place of 8-oxo-2'-deoxycytidine, both form stable triplexes at pH 6.2, but only I(A) forms a stable triplex with a model duplex DNA target at pH 7.5, as determined by UV melting experiments. Triplex formation is stabilized by the presence of the psoralen group. Upon irradiation both I(A) and I(C) form photoadducts with the DNA target at pH 6.2, but only I(A) forms a photoadduct at pH 7.5. In these photoreactions oligomer I(A) appears to selectively form a photoadduct with a C in the purine-rich strand of the duplex target. Although a T residue is present in the pyrimidine-rich strand of the target at the duplex/triplex junction, essentially no adduct formation takes place with this strand, nor is interstrand cross-linking observed. The extent of photoadduct formation decreases with increasing temperature, behavior which is consistent with the UV melting curve of the triplex. A tetramethylrhodamine derivative of I(A) was prepared and found to cross-link less extensively than I(A) itself. Oligomer I(A) is completely resistant to hydrolysis when incubated for 24h in the presence of 10% fetal bovine serum at 37 degree C, although it is hydrolyzed by S1 nuclease. The properties of oligomer I(A) suggest that 8-oxo- containing oligomers may find utility as antigene oligonucleotide reagents.

Inhibition of human collagenase activity by antisense oligonucleoside methylphosphonates

Oligodeoxyribonucleoside methylphosphonates (d-OMP) were synthesized whose sequences are complementary to sequences found in the mRNA coding for the 72-kDa (MMP-2) or 92-kDA (MMP-9) forms of human collagenase i.v., matrix metalloproteinases (MMP) whose excessive secretion correlates with the metastatic potential of tumor cells. The effects of these oligomers on MMP-2 and MMP-9 activities secreted by HT1080 cells, a human fibrosarcoma cell line, were studied using a gelatin zymography assay. A d-OMP, M2.3, complementary to nucleotides 14 to 28 of the initiation codon region of MMP-2 mRNA selectively inhibited MMP-2 activity, whereas a d-OMP, M9.1, which was targeted to nucleotides -19 to -5 of the 5'-untranslated region of MMP-9 mRNA selectively inhibited MMP-9 activity over the concentration range 5-50 microM. At 100 microM concentration, both M2.3 and M9.1 inhibited the activities of both MMP-2 and MMP-9. These oligomers were completely stable under cell culture conditions and did not appear to adversely affect cell growth after 48 hours at concentrations up to 100 microM, although 100 microM M9.1 did reduce cell growth 30% after prolonged, 120-hours exposure. Other d-OMP tested either had no effect on collagenase activity or inhibited both MMP-2 and MMP-9 activities. The latter oligomer was complementary to MMP-2 mRNA and partially complementary to MMP-9 mRNA. Oligomer M2.3 was also tested for its effects on the morphology of malignant human lung cells, BZR-T33, growing on the surface of reconstituted base membrane, Matrigel, in culture. In absence of oligomer, the BZR-T33 cells formed extensive networks indicative of the ability of the cells to invade the Matrigel substrate. In the presence of 100 microM M2.3, BZR-T33 formed colonies of rounded cells, a morphology typical of noninvasive cells. Other non-complementary d-OMP had no effect on the morphology of BZR-T33 under these conditions. These results suggest that antisense d-OMP may be useful for inhibiting expression of collagenase in human tumor cells and for studying the role of collagenase expression in tumor cell metastasis.

Pork characteristics as affected by two populations of swine and six crude protein levels

Previous research has investigated the effect of genetic line and dietary CP on gilt growth and carcass composition. The aim of this research was to characterize lean tissue composition, color, tenderness, and water-holding capacity as affected by protein level and genetic lines. Thirty-six Gene Pool pigs, a population with low lean growth potential, and 36 Hampshire pigs, a population with a high lean growth potential, had ad libitum access to diets consisting of 10, 13, 16, 19, 22, or 25% CP. Longissimus muscles of Hampshire pigs were lighter, more red, and more yellow than those from Gene Pool pigs (P< .01). Redness and yellowness of longissimus muscles decreased linearly (P < .01) as protein level increased. Chops from Hampshire pigs required less force and less total energy to shear but had lower cooking yields and water-holding capacity than chops from Gene Pool pigs (P < .01). Chops from pigs fed 19 and 22% protein required greater force (quadratic, P < .01) and more total energy (quadratic, P < .05) to shear. Objective color differences revealed that restructured, cured hams from Hampshire pigs were lighter, less red, and had less intense cured color (P < .01). The Hampshire line of gilts produced pork muscle that was leaner, more pale in color, more tender, and lower in water-holding capacity than the Gene Pool line. Level of dietary CP caused alterations in tenderness and lean composition, especially when diets contained less protein.

Inhibition of herpes simplex virus replication by antisense oligo-2'-O-methylribonucleoside methylphosphonates

Antisense oligonucleoside methylphosphonates complementary to the 12 nucleotides found at the intron/exon junction of the splice acceptor site of herpes simplex virus type 1 (HSV-1) immediate early mRNAs 4 and 5 were synthesized. The methylphosphonate oligomers contained either 2'-deoxyribose nucleosides, d-OMPs, or 2'O-methylribose nucleosides, mr-OMPs. At 37 degrees C, the affinity of the mr-OMP for a complementary 12-mer RNA target was approximately four times higher than that of the corresponding d-OMP as measured by a constant activity gel electrophoresis mobility shift assay. An mr-OMP whose sequence contained two mismatched bases did not bind to the RNA target under these conditions. The mr-OMP also showed improved ability to inhibit HSV-1 replication in HSV-1 infected Vero cells in culture. Thus the IC50 of the mr-OMP was five times less than that of the d-OMP. No inhibition was observed by the mismatched mr-OMP, and no inhibition of herpes simplex virus type 2 (HSV-2) replication was observed with any of the oligomers. These results demonstrate a direct correlation between oligomer binding affinity and antisense activity in cell culture and suggest that oligo-2'-O-methylribonucleoside methylphosphonates are promising candidates for development of effective antisense reagents.

The effects of dietary protein concentration on compensatory growth in barrows and gilts

An experiment using 120 crossbred pigs (60 barrows and 60 gilts) was conducted to determine the effect of dietary protein concentration on the compensatory response in growth after a period of feed restriction. Thirty pigs were allowed ad libitum (AL) access to one of five corn-soybean meal diets (13.1 to 18.4% CP) from approximately 42 to 102 kg BW. Thirty additional pigs were restricted (R) to a maintenance amount of a 14.4% CP diet for 21 d, after which they were allotted to one of the five diets and allowed ad libitum access to feed until they reached 102 kg. Restricted pigs had lower ADFI, ADG, and ADG/ADFI (P < .05) than did AL pigs. During the postrestriction period, R pigs had higher ADFI and ADG (P < .001) and tended to be more efficient (P < .08) than AL pigs. Average backfat thickness was not different (P > .8) between AL and R pigs. Lean percentage (5% fat) was not affected (P > .5) by feeding regimen but increased linearly (P < .1) as protein level increased. Organ weights (expressed as a percentage of empty BW.75) were similar in AL and R pigs. However, kidney and stomach weights differed among protein levels (P < .01), as did liver weight (P < .06), with a linear increase (P < .02) in both kidney and liver weights to dietary protein level. Barrows had higher ADFI and ADG and greater average backfat thickness (P < .02) than gilts. Barrows had smaller LMA, a lower percentage of lean (P < .001), and higher average backfat (P < .005) than gilts. Liver weight was heavier (P < .02) and small intestine weight tended to be heavier (P < .07) for barrows than for gilts. Kidney, spleen, and lungs were heavier (P < .05) in gilts than in barrows. Livers from barrows tended to contain more protein (P < .06) and less fat (P < .05) than livers from gilts. These results indicate that a compensatory growth response occurred during relimentation, and that the effects of dietary protein concentration on growth rate and carcass measurements were similar in both AL and R pigs.

Changes in plasma urea concentration can be used to determine protein requirements of two populations of pigs with different protein accretion rates

The experiment had two objectives: 1) to determine the protein requirements of two strains of growing-finishing pigs based on growth performance, carcass characteristics, tissue accretion rates, and organ weights and 2) to evaluate whether protein requirements can be determined from changes in plasma urea concentration. Forty-six Gene Pool (GP) and 46 Hampshire (H) gilts with an initial BW of 28.5 kg were used. Pigs were allotted to two trials of a randomized complete block experiment with a 2 x 6 factorial arrangement of treatments. Five pigs from each strain were randomly selected and slaughtered at the beginning of each of the two trials. The remaining 72 pigs were individually penned and allotted to one of six dietary treatments (10, 13, 16, 19, 22, or 25% CP). Pigs remained on the experiment until the mean weight of a treatment group within each strain reached 115 kg (16 wk for GP and 14 wk for H), at which time all pigs of that strain were slaughtered. The only strain x protein level interactions that were detected were for carcass protein and water accretion rates. Gene Pool pigs grew less rapidly and utilized feed less efficiently than H pigs (P < .001). Average daily gain (quadratic, P < .05) and ADG/ADFI (quadratic, P < .05) were increased as protein level increased until a plateau was reached. Backfat depths were decreased (linear, P < .001) and longissimus muscle areas were increased (linear, P < .001) as protein level increased. Protein accretion rate was lower (P < .01) and fat accretion was higher (P < .01) in GP pigs than in H pigs. Protein accretion increased (quadratic, P < .001) and fat accretion decreased (linear, P < .001) with increasing dietary protein level. Examination of the response of plasma urea concentration over time suggested that GP pigs required 13% CP from 30 to 80 kg and 10% CP thereafter, whereas H pigs required 19% CP from 30 to 45 kg, 16% CP from 45 to 100 kg, and 13% CP thereafter.

Interactions of oligonucleotide analogs containing methylphosphonate internucleotide linkages and 2'-O-methylribonucleosides

The interactions of oligonucleotide analogs, 12-mers, which contain deoxyribo- or 2'-O-methylribose sugars and methylphosphonate internucleotide linkages with complementary 12-mer DNA and RNA targets and the effect of chirality of the methylphosphonate linkage on oligomer-target interactions was studied. Oligomers containing a single Rp or Sp methylphosphonate linkage (type 1) or oligomers containing a single phosphodiester linkage at the 5'-end followed by 10 contiguous methylphosphonate linkages of random chirality (type 2) were prepared. The deoxyribo- and 2'-O-methylribo- type 1 12-mers formed stable duplexes with both the RNA and DNA as determined by UV melting experiments. The melting temperatures, Tms, of the 2'-O-methylribo-12-mer/RNA duplexes (49-53 degrees C) were higher than those of the deoxyribo-12mer/RNA duplexes (31-36 degrees C). The Tms of the duplexes formed by the Rp isomers of these oligomers were approximately 3-5 degrees C higher than those formed by the corresponding Sp isomers. The deoxyribo type 2 12-mer formed a stable duplex, Tm 34 degrees C, with the DNA target and a much less stable duplex with the RNA target, Tm < 5 degrees C. In contrast, the 2'-O-methylribo type 2 12-mer formed a stable duplex with the RNA target, Tm 20 degrees C, and a duplex of lower stability with the DNA target, Tm < 5 degrees C. These results show that the previously observed greater stability of oligo-2'-O-methylribonucleotide/RNA duplexes versus oligodeoxyribonucleotide/RNA duplexes extends to oligomers containing methylphosphonate linkages and that the configuration of the methylphosphonate linkage strongly influences the stability of the duplexes.

Bioavailability of zinc from inorganic and organic sources for pigs fed corn-soybean meal diets

Two experiments were conducted with pigs 1) to determine the effect of supplemental Zn on growth performance, bone Zn, and plasma Zn in pigs fed Zn-unsupplemented, corn-soybean meal diets and 2) to assess bioavailability of Zn from inorganic and organic Zn sources. In both experiments, weanling pigs were fed a diet with no supplemental Zn for 5 wk to deplete their Zn stores. In Exp. 1, 192 pigs were fed a corn-soybean meal diet (growing diet, 32 mg/kg of Zn; finishing diet, 27 mg/kg of Zn) supplemented with feed-grade ZnSO4.H2O to provide 0, 5, 10, 20, 40, and 80 mg/kg of supplemental Zn. Supplemental Zn did not affect weight gain, feed intake, or gain/feed during either the growing or the finishing period (P > .05). However, bone and plasma Zn concentrations increased linearly (P < .01) in response to supplemental Zn at dietary Zn levels between 27 mg/kg (basal) and 47 mg/kg (breakpoint). In Exp. 2, three levels of supplemental Zn from ZnSO4.H2O (0, 7.5, and 15 mg/kg of supplemental Zn) were used to construct a standard curve (metacarpal, coccygeal vertebrae, and plasma Zn concentrations regressed on supplemental Zn intake; R2 = .93, .89, and .82, respectively). From the standard curve, the bone and plasma Zn concentrations obtained from pigs fed 15 mg/kg of supplemental Zn from ZnO and 7.5 mg/kg of supplemental Zn from Zn-methionine (ZnMET) and Zn-lysine (ZnLYS) were used to calculate bioavailable Zn via multiple linear regression, slope-ratio analysis. The estimates of Zn bioavailability differed depending on which variable was used. Overall trends indicated the following rankings: ZnSO4.H2O > ZnMet > ZnO > ZnLys.

Effect of target structure on cross-linking by psoralen-derivatized oligonucleoside methylphosphonates

A series of psoralen-derivatized oligodeoxyribonucleoside methylphosphonates were examined for their abilities to cross-link to DNA and RNA oligonucleotide targets. These targets were designed to have either a random coil or a hairpin structure in solution. The methylphosphonate oligomers cross-linked with approximately the same rates to the random coil DNA and RNA targets, although the extent of cross-linking to the DNA target was higher than that to the RNA target. For a given methylphosphonate sequence, cross-linking decreased as the temperature increased, and this behavior paralleled the interaction of the oligomer with the target as determined by ultraviolet melting experiments. The oligomers also cross-linked efficiently with the DNA hairpin target, but little or no cross-linking was observed with the RNA hairpin. In the case of these hairpin targets, the extent of cross-linking was dependent upon the location of the oligomer binding site relative to the stem and loop regions of the hairpin. The lack of reactivity with the RNA hairpin may be due to the high stability of the stem of this target versus that in the DNA target and the relatively lower efficiency of binding of the methylphosphonates to RNA versus DNA targets. The sequences of the oligomers are complementary to vesicular stomatitis virus M-protein mRNA. One of the oligomers was tested, and was found to cross-link at 20 degrees C to VSV N-mRNA to approximately the same extent as observed for cross-linking with the random coil RNA target, suggesting that the mRNA binding site for the oligomer most likely is in a somewhat open conformation.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of protein intake on boar libido, semen characteristics, and plasma hormone concentrations

To determine the effect of low protein intake on boar libido, semen characteristics, and plasma hormone concentrations, 20 crossbred boars (1 yr of age) were divided into 10 littermate pairs, and boars from within pairs were fed 44 g/kg of BW.75 per day of either a low-protein diet (7% CP) or a control diet (16% CP) with the same energy content (3.41 Mcal of ME/kg). During the first 16 wk and from wk 19 to 23, semen was collected two times per week. During wk 17 and 18, boars were subdivided within dietary treatment and semen was collected either two or seven times per week. Blood samples were collected at 12-min intervals for 6 h before and 1 h after an intravenous injection of GnRH (375 ng/kg of BW) during wk 24. All plasma samples were analyzed for LH and pooled samples were analyzed for estradiol-17 beta and testosterone. Boars with low protein intakes required more time to start ejaculation (P = .11, wk 0 through 7; P < .04, after wk 7), had a shorter duration of ejaculation (P < .09, wk 19 through 23), and had reduced semen volumes (P < .01, after wk 7) compared with boars on the control treatment. There was no interaction between dietary treatment and semen collection frequency (P > .39) for any of the semen or libido measurements. Testosterone and LH concentrations were not affected by protein intake (P > .5). However, concentration of estradiol-17 beta was greater in boars fed the control diet than in boars fed the low-protein diet (582 vs 202 pg/mL, respectively; P < .08). Estrogen concentrations in boars were negatively correlated with the time required for the boar to start ejaculating (r2 = .72). Boars with low protein intakes had reduced libido and semen volume. This reduction in libido and semen volume may be a result of a decrease in estradiol-17 beta concentration in circulation.

The effect of energy and protein intakes on boar libido, semen characteristics, and plasma hormone concentrations

To determine the effect of energy and protein intakes on boar libido, semen characteristics, and plasma hormone concentrations, 24 crossbred boars (1 yr of age) were allotted to one of three dietary treatments. Two protein levels (7.7 and 18.1 g/d of lysine) and two energy levels (6.1 and 7.7 Mcal/d of ME) were combined to create 1) low-energy and low-protein (ep), 2) low-energy and high-protein (eP), and 3) high-energy and high-protein (EP) treatments. Semen was collected two times per week for 27 wk. During wk 28, blood samples were collected before and after a intravenous injection of GnRH (375 ng/kg of BW). The EP boars had higher (P < .01) ADG than the eP boars (373 vs 169 g), which had higher (P < .01) ADG than the ep boars (169 vs 92 g). Fewer EP and eP boars (zero of eight and two of eight, respectively) than ep boars (five of eight) consistently refused to mount the collection dummy (P < .05). During the final 20 wk of the semen-collection period, EP and eP boars had 33% longer durations of ejaculation (P < .04), had 60% greater semen and gelatinous fraction volumes (P < .03), but had 25% lower sperm concentration in their semen (P < or = .12) than ep boars. The EP boars produced 38% more sperm than the ep boars (P < .10). Baseline LH concentration, LH pulse frequency, LH pulse amplitude, testosterone concentration, and estradiol-17 beta concentrations were not affected by treatment (P > .10).(ABSTRACT TRUNCATED AT 250 WORDS)

Diet preference and meal patterns of weanling pigs offered diets containing either spray-dried porcine plasma or dried skim milk

Preference tests and meal pattern analyses were conducted to examine the feed intake response of weanling pigs to spray-dried porcine plasma (SDPP). In Exp. 1, 36 weanling pigs (mean +/- SD; 6.2 +/- .8 kg and 26 d of age) were allowed to choose between a SDPP diet (8.5% SDPP, 20% dried whey, 10% lactose, and .13% DL-methionine) and a dried skim milk (DSM) diet (20% each of DSM and dried whey) throughout 21 d postweaning. Twenty-eight pigs preferred the SDPP diet and seven pigs preferred the DSM diet. Preference for SDPP became apparent by d 2 (60% of total feed consumption) and increased (P < .01) to d 21 (71% of total feed consumption). Average daily feed consumption was 371 and 172 g for the SDPP and DSM diets, respectively (P < .01). The meal patterns of 16 weanling pigs (mean +/- SD; 7.2 +/- .3 kg and 26 d of age) offered either the SDPP or the DSM diet were examined in Exp. 2. On d 3, 7, and 14 postweaning, feeding behavior was observed continuously for 18 h (0600 to 2400). Time spent consuming feed and time between periods of feeding were recorded. Although the difference was not significant, pigs fed the SDPP diet consumed 27 and 6% (P = .38) more feed than pigs fed the DSM diet during the first 7 d and during the entire 21-d period, respectively. This difference was reflected in increased (P < .05) rate of feed consumption on d 3 and 7. Diet had no effect (P > .10) on meal size, the number of meals, or the percentage of time spent consuming feed. Weanling pigs prefer diets containing SDPP to those containing DSM, and the increased consumption of diets containing SDPP may be due to greater palatability.

Synergistic antiviral activities of oligonucleoside methylphosphonates complementary to herpes simplex virus type 1 immediate-early mRNAs 4, 5, and 1

An oligonucleoside methylphosphonate (ONMP) complementary to the splice acceptor site of immediate-early (IE) pre-mRNAs 4 and 5 (IE4,5SA) inhibits herpes simplex virus type 1 (HSV-1) growth in vitro and in infected animals. The antiviral effect appears to be due to inhibition of IE pre-mRNA 4 and 5 splicing and/or IE4 gene expression (M. Kulka, M. Wachsman, S. Miura, R. Fishelevich, P. S. Miller, P. O. P. Ts'o, and L. Aurelian, Antiviral Res. 20:115-130, 1993). We describe the potentiation of antiviral activity when we targeted two IE genes with different ONMPs. A psoralen derivative of an ONMP complementary to the IE mRNA 1 (IE1) translation initiation site (IE1TI) covalently bound a 2.8-kb transcript that hybridized with a 20-base oligonucleotide complementary to the 5' leader sequence of IE1 but not a 20-base oligonucleotide complementary to the first intron of IE1. IE1TI inhibited IE1 gene expression and virus replication in cells infected with HSV-1 in vitro. Inhibition was specific because it was not observed with oligomers mutated in two (IE1TImu1) or four (IE1TImu2) central residues or in cells infected with an IE1 deletion mutant (HSV-1 dl1403). IE1TI potentiated the antiviral activity of IE4,5SA (synergistic effect), while potentiation was not observed when IE4,5SA was mixed with IE1TImu1. A similar synergistic effect was seen when IE1TI was mixed with an ONMP complementary to the translation initiation site of IE mRNA 4 but not with an ONMP complementary to the translation initiation site of IE mRNA 5. These findings suggest that synergistic antiviral activity is mediated by targeting at least two IE genes (IE1 and IE4).

Postpartum hypophagia in primiparous sows: II. Effects of feeding level during gestation and exogenous insulin on lactation feed intake, glucose tolerance, and epinephrine-stimulated release of nonesterified fatty acids and glucose

The objectives of this experiment were 1) to determine whether allowing sows ad libitum access to feed from d 60 of gestation affects glucose tolerance and 2) to determine whether exogenous insulin increases feed intake by preventing mobilization of nonesterified fatty acids (NEFA). Sixty crossbred sows were assigned to one of two feeding regimens during gestation, either a standard level of feed (SL; 1.85 kg/d) or allowed ad libitum access to feed (AL). Sows also received an injection of either .75 IU of insulin/kg BW or saline daily during the first 7 d of lactation. Exogenous insulin increased ADFI at d 7 of lactation (P = .07) and increased total feed intake at d 7 and 14 of lactation (P = .09). Total feed intake during d 0 to 21 was not affected by insulin treatment. Compared with the SL sows, the AL sows were less tolerant of glucose infusion (1 g of glucose/kg BW, i.v.) on d 1 of lactation (P < .01). Baseline and peak concentrations of insulin were not affected by feeding level during gestation (P = .4). Baseline and peak concentrations of NEFA were greater in AL sows than in SL sows (P < .001) and were not affected by insulin treatment (P = .39). Release of NEFA after epinephrine stimulation was greater in AL sows than in SL sows (P < .05). The data indicate that the reduced feed intake during lactation exhibited by sows that are overfed during gestation may be caused by insulin resistance. Exogenous insulin seems to increase feed intake by reducing plasma glucose rather than be affecting plasma NEFA.

Postpartum hypophagia in primiparous sows: I. Effects of gestation feeding level on feed intake, feeding behavior, and plasma metabolite concentrations during lactation

To investigate the relationship between feeding level during gestation and voluntary feed intake, feeding behavior, and plasma metabolite levels during lactation, 18 crossbred, primiparous sows were assigned to two dietary treatments. From d 60 of gestation until farrowing, sows were fed either a standard level of feed (SL; 1.85 kg/d) or were allowed ad libitum (AL) access to feed. During a 28-d lactation all sows were allowed ad libitum access to feed. Eight SL and seven AL sows completed the experiment. Feed intake was measured daily during the final 40 d of gestation and throughout lactation. On d 105 of gestation and d 1, 7, 14, and 21 of lactation, feeding behavior was observed and blood samples were collected via indwelling catheters. Plasma was analyzed for nonesterified fatty acids (NEFA), insulin, glucose, and alpha-amino N. During gestation AL sows ate more feed than did SL sows. This increased intake was balanced by reduced feed intake during lactation, when AL sows ate less than SL sows (P < .001). The AL sows gained more weight during gestation (P < .001) and lost more weight during lactation (P < .005) than did the SL sows. Feed intake and weight change during gestation and lactation combined were not different between treatments (P = .85). During lactation, the AL sows ate fewer meals (P < .05) of a similar size than did the SL sows. During lactation, the area under the curve formed by plasma NEFA concentration was greater (P = .06) and that for insulin was less (P < .01) in AL than in SL sows.(ABSTRACT TRUNCATED AT 250 WORDS)

Interactions of psoralen-derivatized oligodeoxyribonucleoside methylphosphonates with vesicular stomatitis virus messenger RNA

The ability of oligonucleotides to interact selectively with their targets is an important consideration in the design of antisense oligonucleotides. This is especially important in the case of antisense oligomers, such as psoralen-derivatized oligomers, which can irreversibly bind to their targets. We have studied the interactions of a series of psoralen-derivatized antisense oligonucleoside methylphosphonates with the mRNAs of vesicular stomatitis virus (VSV), mRNAs that have a high degree of sequence homology. Cross-linking reactions were carried out under conditions of low ionic strength in order to reduce mRNA secondary structure. A 12-mer, whose sequence was complementary to VSV M-mRNA and partially complementary to sequences found in N, NS, and G mRNA cross-linked extensively to N-message. On the other hand, 16-mers whose sequences were uniquely complementary to binding sites on N- or M-mRNA specifically and efficiently cross-linked to their targeted mRNAs over the temperature range 0 degree to 37 degrees C. A reverse transcriptase-catalyzed primer extension assay was used to show that one of the N-specific oligomers cross-linked at the expected site on N-mRNA and to estimate the extent of cross-linking. The results demonstrate that psoralen-derivatized oligonucleoside methylphosphonates can cross-link in a sequence-specific manner if the sequences of these oligomers are chosen carefully so as to avoid extensive partial complementarity with other mRNA sequences.