Development and validation of the African Women Awareness of CANcer (AWACAN) tool for breast and cervical cancer.

BACKGROUND: Measuring factors influencing time to presentation is important in developing and evaluating interventions to promote timely cancer diagnosis, yet there is a lack of validated, culturally relevant measurement tools. This study aimed to develop and validate the African Women Awareness of CANcer (AWACAN) tool to measure awareness of breast and cervical cancer in Sub-Saharan Africa (SSA). METHODS: Development of the AWACAN tool followed 4 steps: 1) Item generation based on existing measures and relevant literature. 2) Refinement of items via assessment of content and face validity using cancer experts' ratings and think aloud interviews with community participants in Uganda and South Africa. 3) Administration of the tool to community participants, university staff and cancer experts for assessment of validity using test-retest reliability (using Intra-Class Correlation (ICC) and adjusted Kappa coefficients), construct validity (comparing expert and community participant responses using t-tests) and internal reliability (using the Kuder-Richarson (KR-20) coefficient). 4) Translation of the final AWACAN tool into isiXhosa and Acholi. RESULTS: ICC scores indicated good test-retest reliability (≥ 0.7) for all breast cancer knowledge domains and cervical cancer risk factor and lay belief domains. Experts had higher knowledge of breast cancer risk factors (p < 0.001), and cervical cancer risk factors (p = 0.003) and symptoms (p = 0.001) than community participants, but similar knowledge of breast cancer symptoms (p = 0.066). Internal reliability for breast cancer risk factors, lay beliefs and symptom and cervical cancer symptom subscales was good with KR-20 values > 0.7, and lower (0.6) for the cervical cancer risk subscale. CONCLUSION: The final AWACAN tool includes items on socio-demographic details; breast and cervical cancer symptom awareness, risk factor awareness, lay beliefs, anticipated help-seeking behaviour; and barriers to seeking care. The tools showed evidence of content, face, construct and internal validity and test-retrest reliability and are available for use in SSA in three languages.

Genotype by environment interaction for production traits while accounting for heteroscedasticity.

Grazing (G) provides an alternative management system for dairy production. Heteroscedasticity (HV) of the data may bias estimates of genetic correlations of yield traits between environments, an indicator of genotype-by-environment interaction (GxE). The objective of this study was to investigate the effect of HV on estimates of heritabilities and genetic correlations for mature-equivalent milk, protein, and fat yield, and lactation-average somatic cell scores of daughters, and to determine if HV affects the ability of sire's predicted transmitting ability (PTA) to predict daughter production in G and confinement (C) herds. Data consisted of 72,489 records from 35,674 cows in 366 G herds from 11 states, and 117,629 records from 50,963 cows in 373 C herds from the same 11 states plus 1 geographically contiguous state. Herds were divided into variance quartiles (Q(V)1-Q(V)4) based on milk yield. A transformation was used to reduce HV by standardizing the within-herd standard deviation to the average across-herd standard deviation of a base year for each parity, and was similar to the method used in current USDA-DHIA genetic evaluations. Regression of daughter yield on sire PTA showed that PTA overestimated production of all traits in Q(V)1-Q(V)3 and of milk in Q(V)4 of G herds. For C herds, yields of milk in Q(V)1 and Q(V)2, and of protein and fat in Q(V)1 were overestimated, and protein was underestimated in Q(V)4. Reducing HV had little effect on G herds, but for C herds, regression did not differ from unity for milk and protein in Q(V)1 and Q(V)2. For milk, protein, and fat in G, heritabilities were approximately 0.17, 0.17, and 0.19, respectively. The heritabilities for milk, protein, and fat in C herds were approximately 0.16, 0.17, and 0.21, respectively. Genetic correlations between C and G did not suggest a GxE in 3 upper quartiles, but a possible GxE (correlation = 0.21, estimated standard error = 0.22) for the lowest quartile. Reducing HV did not affect estimates of heritabilities or genetic correlations. Results indicated that modest evidence for existence of GxE did not arise solely from HV.

Molecular cloning and characterization of the Plasmodium falciparum cytidine triphosphate synthetase gene.

Using degenerate oligonucleotides derived from conserved amino acid regions of cytidine triphosphate synthetase, a fragment of the gene from the malarial parasite, Plasmodium falciparum, was isolated by polymerase chain reaction (PCR). This fragment was used as a probe in the isolation of genomic clones containing the entire pfCTP synthetase coding region (2580 bp). The gene encodes the largest CTP synthetase found in any organism to date due to the presence of two additional sequences which are part of the continuous open reading frame and are not introns as their presence in the mRNA was confirmed by reverse transcriptase-PCR. These features distinguish the parasite enzyme from that of the host making it an attractive target for structure based drug design.

An ATP-dependent inhibition of protein synthesis in ascites cell extracts by wheat germ protein.

A high speed supernatant fraction from wheat germ was shown to be a very effective inhibitor of protein synthesis in a cell-free protein synthesizing system from Ehrlich ascites cells. Low concentrations of the extract were equally effective in inhibiting the translation of EMC viral RNA, ascites cell mRNA (exogenous) and endogenous mRNA. The kinetics of inhibition in the presence and absence of pactamycin, as well as the observed inhibition of polyphenylalanine synthesis, indicate that the wheat germ inhibitor acts at the level of elongation. Preincubation of the ascites system with the wheat germ inhibitor in the presence and absence of ATP showed that ATP was required for the development of the inhibition. The inhibitor was partially purified and appears to be a basic protein with a molecular weight of 30 000--40 000. These results are discussed with respect to the hypothesis that this may be another example of a protein kinase-induced inhibition of protein synthesis.

Isolation, characterization and expression of the gene encoding cytidine triphosphate synthetase from Giardia intestinalis.

The cytidine triphosphate synthetase gene from Giardia intestinalis was cloned using a PCR-based strategy. A 519 bp PCR product was obtained from the amplification of genomic DNA using two oligonucleotides derived from the CTP synthetase amino acid consensus sequences DPYINVDPG and KTKPTQ. This product was used to probe restriction endonuclease digested genomic DNA and the respective plasmid mini-libraries. Two genomic clones were obtained one with a 3.6 kb HindIII DNA fragment, containing approximately three-quarters of the 5'-end of the synthetase gene and subsequently, a 5.8 kb PstI DNA fragment which contained the whole gene. The intronless gene has a 1863 bp open reading frame encoding 620 amino acids (M(r) of 68.3 kDa). A well conserved catalytic glutamine aminotransferase (GAT) domain was identified. In addition, three insert sequences were found which are not present in CTP synthetase from other species. Alignment and comparison of the deduced amino acid sequence relative to CTP synthetases from other species revealed a high degree of identity (34%) with a greater resemblance to prokaryotes than eukaryotes. The gene is located on chromosome 6 and the messenger RNA encoding it is estimated to be 1.9 kb. The coding region of G. intestinalis CTP synthetase was generated by PCR and subsequently cloned into the pQE30 vector for expression in E. coli. This construct yielded a soluble and enzymatically active recombinant protein which was purified by a Ni-NTA affinity column. The purified recombinant protein had a subunit molecular weight of 69.5 kDa and a native molecular weight of approximately 274 kDa. Kinetic studies of the partially purified recombinant G. intestinalis CTP synthetase gave apparent K(m) values of 0.1 mM and approximately 0.5 mM for the substrates UTP and L-glutamine respectively in accord with previously reported values for the native enzyme.

A cytidine triphosphate synthetase gene in Plasmodium falciparum.

The malarial parasite Plasmodium falciparum is dependent on de novo synthesis for its pyrimidine nucleotide requirements. However, the activity of the key enzyme in cytidine nucleotide synthesis, CTP synthetase (EC 6.3.4.2), has not been reported. We present evidence for a CTP synthetase gene in P. falciparum, having isolated a PCR product obtained using 2 primers derived from the CTP synthetase amino acid consensus sequences DPYINVDPG and GICLGMQ. The amplified DNA segment encodes an amino acid sequence with considerable homology to CTP synthetases from several other species including human and yeast.

A simple method for the purification of mitochondrial DNA from Plasmodium falciparum.

Mitochondrial DNA (mtDNA) from Plasmodium falciparum was isolated by conventional differential centrifugation in an SS34 rotor, a simpler method than CsC1 centrifugation of total DNA as employed by other workers. The nature of the sample was verified by sequencing a polymerase chain reaction (PCR) product obtained using oligonucleotide primers derived from known malarial mtDNA sequence.

Efficacy of alternative multivariate best linear unbiased prediction models for genetic evaluation of swine.

A comparison of the accuracy of alternative BLUP evaluations of swine performance data is reported. A simulated data set of performance for days to market, backfat, number born alive, number weaned, and litter weight in six herds was used for the evaluation. The data structure was derived by using the performance records of six herds sampled from the American Yorkshire Club's STAGES (Swine Testing and Genetic Evaluation System) database. For growth traits, 10,360 pig records from 129 sires and 897 dams were recorded. For maternal traits, records on 2,598 litters of 1,209 sows from 147 sires and 585 dams were included. The actual observed performance of each record was removed and replaced with simulated performance. These simulated data were analyzed by within- and across-herd BLUP models using STAGES and Animal Model (AM) procedures. Results indicate that the alternative BLUP procedures produced similar estimates. Correlations between STAGES and AM EPD ranged from .84 to .95. Correlations between STAGES EPD and true genetic value (G) ranged from .41 to .74, and correlations between AM EPD and G ranged from .40 to .74. On average, AM EPD had a .04 larger correlation with G than did STAGES EPD, although the difference in the correlations was not significant (P greater than .05). Trends in EPD for sires, dams, and pigs or sows were the same. Likewise, standard errors of prediction for AM EPD averaged 4% smaller than those for STAGES EPD. Computationally, the AM procedures used 15 to 20 times as much processing time as did STAGES procedures.

Optimal contemporary group structure to maximize genetic progress through genetic evaluation of swine.

Accuracies of sire EPD were calculated for a typical growth trait and a typical maternal trait for alternative contemporary group structures. For a given family size (number of progeny tested for a sire in a contemporary group), accuracy increased as the number of sires increased and as the number of contemporary groups increased. An exponential equation was found to best predict accuracy from the number of sires and groups. Partial derivatives can be used to determine the optimal number of sires and groups for a given economic situation (fixed number of animals tested per group). It is recommended that progeny of at least two sires be represented in each contemporary group, but having more than five sires does not effectively increase accuracy further. Accuracy increases with a larger herd size, as more sires and more groups of pigs are tested. When the number of litters that can be tested is at its limit, accuracy is maximized with a small number of sires, and progeny divided among several contemporary groups. However, accuracy is only part of the herd's genetic improvement. Selection decisions must be made to avoid inbreeding, which can be a problem, particularly in small herds.

Effect of birth and fraternal litter size and cross-fostering on growth and reproduction in swine.

Twelve hundred fifty-one pigs from six farrowings (FGRP) were classified within a FGRP by their birth litter size (BL- = below average and BL+ = above average), randomly allotted to nursing litter sizes of 6 or 12+ pigs/sow (NL- vs NL+) and reared by their own or foster dams (XF- vs XF+). Pigs were weighed at birth, 21 d and when near 105 kg. A random sample of 40 gilts per FGRP was retained for observation of pubertal age and primipara conception. Twenty-four gilts per FGRP were farrowed and rebred for a second parity. Pigs born in large litters were younger at 105 kg than those born in small litters (189 vs 196 d +/- 1.4); no other differences (P greater than .05) were observed for BL. Pigs reared in larger litters had lower survival rate from birth to weaning (79 vs 86% +/- 1), had slower weight gains to 21 d of age (5.3 vs 6.6 kg +/- .17) and were older at 105 kg (195 vs 190 d +/- 1.4) than those reared in small litters (P less than .04). Cross-fostered pigs were slower gaining to 21 d (5.9 vs 6.1 kg +/- .14) and were older at 105 kg (195 vs 191 d +/- 1.4) than pigs not cross-fostered pigs (P less than .02). Growth beyond 105 kg and pubertal age were unaffected by any factor studied (P greater than .05). Although size of birth litter did not affect (P greater than .05) any reproductive trait, an interaction between litter size and farrowing group was detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Maternal performance of Duroc, Hampshire and Landrace backcross gilts fed normal and high fiber diets during postweaning growth.

Duroc (DDDY), Hampshire (HHHY) and Landrace (LLLY) backcross gilts produced from matings of purebred sires and sixth or seventh parity F1 Duroc-Yorkshire, Hampshire-Yorkshire or Landrace-Yorkshire sows were fed and libitum either a high fiber (8.8% crude fiber, 2,910 kcal metabolizable energy (ME/kg) or normal fiber (3.9% crude fiber, 3,428 kcal ME/kg) diet during the postweaning growth period (70 to 170 d of age). A sample of 176 gilts was assigned randomly to one of three groups and exposed to purebred Yorkshire boars. All pregnant gilts were retained and exposed to boars for three additional production cycles. Sows failing to farrow were retained and returned to breeding with their contemporaries. Maternal performance, litter sizes at birth and weaning, pig weights, total litter weights and sow productivity index through four farrowings were not affected by postweaning dietary treatment of gilts. Interactions of nutritional regimen with either backcross type or exposure number were nonsignificant. Performances of the backcross types did differ. The DDDY had larger litter sizes at birth and weaning than HHHY or LLLY (12.0 vs 10.9 and 10.3 at birth and 9.6 vs 8.6 and 8.6 at weaning, respectively). Individual pig weights were similar at weaning among sow backcrosses. Therefore, DDDY females weaned heavier litters due to more pigs per litter and had higher sow productivity indices. Additionally, HHHY had a higher lactational weight loss and greater breeding and gestation weight gains than DDDY or LLLY. Sow feed consumption during lactation did not differ among backcrosses. Backcross type did interact statistically with sow group and exposure for several variables. Most significant interactions were due to differences in relative performance rather than absolute rank.

Mature weight, maturation rate, maternal performance and their interrelationships in purebred and crossbred cows of angus and milking shorthorn parentage.

Mature weight, maturation rate and lifetime maternal performance, through a maximum of seven calving seasons, were analyzed for 182 cows of Angus (A) and Milking Shorthorn (S) breeds and the two reciprocal crossbred groups. Mature weight and rate of maturation were estimated for the three-parameter growth curve described by Brody. Estimates derived for mature weight (kilograms), both unadjusted and adjusted for cow condition, were, respectively: Angus, 421, 407; Shorthorn, 409, 459; A x S, 448, 455 and S x A, 440, 441 (approximate standard error, 8 kg). Estimates for the maturation rate parameter were, respectively: Angus, 5.8, 6.3; Shorthorn, 6.6, 5.4, A x S, 6.2, 6.1 and S x A, 5.9, 6.1%/month (approximate SE, .3%/month). Heterosis for mature weight was 3 to 7% (28 +/- 8 and 15 +/- 6 kg, respectively). No heterosis was observed for the maturation rate parameter. Birth weight (.048 +/- .025 kg/kg) and weaning weight (.142 +/- .044 kg/kg) of the first calves were positively related with mature size of the dam. Weaning weights of first calves increased with increasing rate of maturation of the dams (3.6 +/- 1.5 kg/percentage/month) while birth weights remained unchanged. Under the culling criteria used in this study, the number of calves produced by a cow in her lifetime decreased (-.007 +/- .003 calves/kg) with increasing mature weight, while average weaning weight of the calves increased (.132 +/- .03 kg/kg). Total weight weaned, years in the herd and weight weaned per year tended to decrease (P greater than .05) with increasing mature weight of dam, but not significantly. Positive heterosis was expressed for all lifetime cow productivity characters, with crossbred cows weaning 22% (230 +/- 57 kg) more calf weight in their lifetime.

Beef X beef and dairy X beef females mated to Angus and Charolais sires II. Calf growth, weaning rate and cow productivity.

Preweaning growth of 814 progeny was studied, and weaning rate and kilograms of calf weaned/cow exposed were determined for 310, 2- to 7-yr-old angus x Hereford (AH), Charolais X Hereford (CH), straight bred Hereford (HH) and Brown Swiss X Hereford (SH) cows mated to Angus and Charolais bulls. Charolais-sired calves grew more rapidly (P less than .01) then Angussired calves were heavier (P less than .01) at 130 and 210 d of age. Progeny of SH females grew faster (P less than .05) and were the heaviest at 130 (164 kg) and 210 (231 kg) d, whereas calves from HH dams grew the slowest and weighed the least (P less than 0.5) at 130 (125 kg) and 210 (180 kg) d of age. Progeny from AH and CH dams had similar 130-d weights (CW130) and made similar daily gains from birth to 130 of age (ADGI). Calves from CH females gained faster (P less than .05) from 130 to 210 d (ADG2) and had higher (P less than .05) 210-d weights (CW210) than did calves from AH dams. ADG1 and ADG2 of male calves were .043 and .072 kg/d greater, respectively (P less than .01) than those of heifer calves. Age of dam influenced (P less than .01) calf preweaning gains and weights. Calves from 4- to 7-yr old cows had greater (P less than .05) ADG1 and ADG2 and higher (P less than .05) CW130 and CW210 than progeny of younger dams. Progeny of 2-yr-old cows grew more slowly (P less than .05), and were last (P less than .05) in all traits (ADG1, ADG2, CW130 and CW210), whereas progeny of 3-yr-old cows were intermediate to those of 2 and 4- to 7-yr-old females. Cow breed type influenced (P less than .01) weaning rate (WR) and kilograms of calf weaned/cow exposed. SH females has the highest WR (83.4%), AH and CH were intermediate at 76 .8 and 77.7%, respectively, and HH dams had the lowest (P less than .05) WR, 66.4 calves/100 cows exposed. SH cows weaned 34.6 kg more (P less than .05) calf/cow exposed than AH and CH dams. HH dams were least productive (P less than .05), weaning 122.3 kg calf/cow exposed. Dairy X beef dams (SH) weaned 47.6 kg more (P less than .01) calf/cow exposed than the average of beef X beef dams (AH, CH, HH). Dairy X beef females had the highest WR and weaned the heaviest calves.

Characterization of cattle of a five-breed diallel. III. Puberty in bulls and heifers.

Pubertal characters of bulls and heifers produced in a diallel mating of Angus, Brahman, Hereford, Holstein and Jersey cattle were analyzed. Ninety-one heifers and 138 bulls in individual pens adn 286 bulls in drylots were fed a 72% TDN diet ad libitum; another 384 heifers were placed on pasture with supplemental feed. Puberty in heifers was defined as time of first ovulatory estrus; in bulls, as first detection of sperm cells in an electroejaculate. Breed type least-squares means, adjusted for birth month, were estimated within sex-nutrition-management groups and then decomposed into breed effects, average heterosis (h), general combining ability (GCA) and specific combining ability (SCA) by diallel analysis techniques. Breed effects were a significant source of variation for all characters studied. Heterosis (h, GCA, SCA) was not significant for pubertal age of bulls or heifers receiving complete diets in pens, a rather high nutritional plane. However, on pasture, crossbred heifers reached puberty at a younger age (P less than .05) than straightbreds. Average heterosis was significant (P less than .05) for increased weight and hip height at puberty and ratios involving these characters for both sexes. Specific combining abilities were not statistically significant for the majority of the pubertal characters, yet large differences among estimates of combining abilities were expressed. Ad libitum feeding of the penned heifers tended to decrease pubertal age and increase pubertal size as compared to pubertal age and size of pastured heifers. The breed type x management interactions within both sexes indicated a different ranking of the breed types for each management regimen.

Multiple regression and principal components analysis of puberty and growth in cattle.

Multiple regression and principal components analyses were employed to examine relationships among pubertal and growth characters. Records used were from 424 bulls and 475 heifers produced by a diallel mating of Angus, Brahman, Hereford, Holstein and Jersey breeds. Characters studied were age, weight and height at puberty and measurements of weight and hip height from 9 to 21 mo of age; pelvic measurements of heifers also were included. Measurements of weight and height near 1 yr of age were related most highly to pubertal age, weight adn height. Larger size near 1 yr of age was associated with younger, larger animals at puberty. Growth rate was associated with pubertal characters before, but not after, adjustment for effects of breed-type. Principal components of the variation of pubertal and growth characters among animals were strongly related to both weight and height. The majority of the variation among breed-types was due to height. Characteristic vectors of principal components describing the variation of bulls and heifers were strikingly similar. The variance-covariance structure of pubertal characters was essentially the same for both sexes even though the mean values of the characters differed.

Effects of body composition, pre- and postpartum energy intake and stage of production of energy utilization by beef cows.

Mature Charolais x Angus cows (n = 128) were adjusted to a body condition score (BCS) of 3 (1 = very thin, 3 = moderate, 5 = very fat) between 130 and 190 d of gestation. When cows averaged 190 d of gestation, they were assigned randomly to a maintenance energy diet (ME) or to a diet very low in energy (LE). Cows were allotted within these prepartum (PRP) diets to a high-energy (HE) or LE diet at parturition. At 30 d postpartum (PP), cows were allotted to four treatments: a) slaughter at 0 (n = 32) or b) 48 h after calf removal (n = 32), c) cows whose calves were early weaned at 30 d PP (n = 32) or d) normally weaned at 205 d PP (n = 32). Low energy PRP intake reduced (P less than .01) BCS, cow weight, total empty body lipid (TEBL), body energy (BE) and daily predicted maintenance energy (PME)/W.75 by parturition. Pre- and postpartum energy intake combined to affect (P less than .10) these same factors in a similar manner at 30 d PP. From 30 to 60 d PP, early weaning reduced (P less than .05) PME/W.75. Cow BCS at 190 d of gestation had little effect (P greater than .10) on PME/W.75 or PME/Mcal of BE. Body condition score at parturition, however, affected (P less than .05) delta BCS, delta BE and PME/Mcal of BE by 30 and 60 d PP, with thinner cows losing less condition and requiring more PME/Mcal of BE. Cow BCS had a similar effect from 30 to 60 d PP. Total daily PME was greater for the fat cows during both the PRP and PP periods. Body composition, PRP and PP energy intake and early weaning affect energy requirements and energetic efficiency of beef cows.

Adapting best linear unbiased prediction (BLUP) for timely genetic evaluation: I. Progeny traits in a single contemporary group for each sex.

The first step of a procedure to partially circumvent the voluminous calculations with extremely large matrices for the usual algorithms for a BLUP (best linear unbiased prediction) approach is presented. This procedure, specific for a hierarchical portion of a model relevant to many animal breeding populations, is pertinent especially for polytocous species such as swine and poultry. For these, the occurrence of full-sib families makes the inclusion of dam effects in the model more necessary than in dairy or beef cattle models, where dam effects often are omitted. The formulas are derived for the hierarchical model for sires, dams within sires, individuals within full-sib family, and records within individuals, showing a relatively simple structure for such predictors. These formulas provide the basis for an alternative computing algorithm for obtaining evaluations having the statistical properties of best linear unbiased prediction. Formulas also are developed to approximate the prediction error variances for such models. Following this, the methodology for combining separate BLUP predictors, both error-independent and correlated, is developed.

Adapting best linear unbiased prediction (BLUP) for timely genetic evaluation: II. Progeny traits in multiple contemporary groups within a herd.

The second step of a procedure to partially circumvent the voluminous calculations for some BLUP (Best Linear Unbiased Prediction) computing algorithms for genetic evaluation is presented. In addition, the procedure allows timely evaluations of each contemporary group. This procedure is pertinent especially for polytocous species such as swine and poultry, for which the occurrence of full-sib families makes the inclusion of dam effects in the model necessary and tests are completed throughout the year. Formulas are developed for a model including sires, dams, individuals within full-sib families and records within individuals. This model has a fundamentally hierarchical structure but includes some cross-classification. The formulas for predictors combine information across contemporary groups within a herd and incorporate relationships between sires and(or) dams in that herd. Formulas to approximate prediction error variances also are developed.

Genetic improvement programs in livestock: swine testing and genetic evaluation system (stages).

Genetic evaluations for the U.S. swine industry are conducted by the eight purebred associations of the National Association of Swine Records. Within-herd evaluations of the growth traits (days to 105 kg [market] and backfat depth) were first reported in 1986. Analyses of the maternal traits (litter size at birth and weaning, and litter 21-d weight) were inaugurated in 1987. Expected progeny differences (EPD) are reported for all traits and for general, paternal, and maternal bioeconomic indexes. A sow productivity index combining only maternal traits is available. All records are adjusted according to National Swine Improvement Federation (NSIF) guidelines for effects such as number of pigs transferred at crossfostering and age at recorded observation prior to the BLUP evaluation. Within-herd analyses of individual contemporary groups are conducted immediately on receipt of performance records at each breed association office. All parents in the herd and the young pigs in the current group are evaluated. A report is returned to the breeder for use in herd selection and the EPD are placed in the pedigree file. The genetic base of each herd is defined as the first n tested pigs or litters, where n is the number of pigs registered annually within the herd. Change in mean EPD between groups is indicative of genetic trend. Periodic across-herd analyses are used to update interim within-herd analyses and a national sire summary is published.

Variables associated with peripartum traits in dairy cows. IX. Relationship of season and other factors to blood plasma concentrations of progesterone and the estrogens.

Least-squares associations of month, average daily temperature, photoperiod (h daylight/24 h) and other factors with plasma concentrations of hormones during the prepartum period were examined in 172 Holstein cows and heifers. The data were summarized and expressed as values for prepartum d 7, 4 and 1, which represented the means for d 8 to 6, 5 to 3, and 2 to 0. respectively. All animals calved during a period of 19 consecutive months. Across days, least-squares means for plasma hormones were 4.0 ng/ml for progesterone (P4), 232 pg/ml for estradiol-17 beta (E beta), 478 pg/ml for estradiol-17 alpha (E alpha), 1,970 pg/ml for estrone (E1) and 2,680 pg/ml for total estrogen (TE; sum of E beta, E alpha and E1). Variations in plasma concentrations of certain steroids were associated (P less than .05 to P less than .01) with diet group (E beta), calf sex (TE), prepartum day (all hormones), month (E beta, E alpha) and linear covariates of cow weight (E beta, E alpha) calf birth weight (E beta, E alpha, E 1, TE), temperature (P4, E beta) and photoperiod (P4, E beta). The independent linear regressions for temperature and for photoperiod in prediction equations for each plasma hormone were always inversely related. The combined use of these regressions only partially accounted for fluctuations in the least-squares monthly means for hormones. Changes in least-squares monthly means for P4, E beta and E alpha tended to be only partially paralleled during the year. Nonparallel trends among hormones were most apparent during May to July (decreasing P4 but increasing E beta and E alpha), September to November (decreasing P4 and E beta but increasing E alpha) and January and February (only E alpha elevated). We hypothesize that seasonal differences in parturient traits reported for cows may be explained in part by the seasonally associated nonparallel changes in plasma concentrations of P4, E beta and E alpha.