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Department of Animal Science: Faculty Publications

Series

1995

Articles 1 - 19 of 19

Full-Text Articles in Life Sciences

Growth Of Testes And Testicular Morphology After Eight Generations Of Selection For Increased Predicted Weight Of Testes At 150 Days Of Age In Boars, R. R. Harder, D. D. Lunstra, R. K. Johnson, Roman L. Hruska Oct 1995

Growth Of Testes And Testicular Morphology After Eight Generations Of Selection For Increased Predicted Weight Of Testes At 150 Days Of Age In Boars, R. R. Harder, D. D. Lunstra, R. K. Johnson, Roman L. Hruska

Department of Animal Science: Faculty Publications

Weights of testes and epididymides, body weight, and morphometric measurements of testicular tissue of 75 boars of a line selected for eight generations for predicted weight of testes at 150 d of age and 75 boars of a randomly selected control line were used to evaluate the effects of selection on testicular development at 70, 100, 130, 160, and 450 d of age (n = 15 boars per line per age). Body weights for boars of the select and control line did not differ (P <.05) and the shape of the body growth curve was similar for both lines. Boars of the select line had larger testes than control boars at each age (P < .05), but there was a significant line x age interaction. The percentage increase of the select line mean over the control mean for weight of testes was 37% at 70 d, a maximum of 120% at 100 d, and 25% at 450 d. The percentage of the testes made up of seminiferous tubules differed between lines (P <.01). Lines had similar means of approximately 28% at 70 d and 71% at 450 d, but the mean for the select line was larger between 100 and 160 d of age; the greatest difference was 11.6% (control = 43.7, select = 55.3%) at 100 d. After 70 d of age, select-line boars had a greater percentage of seminiferous tubules with lumens that contained elongated spermatids (P <.lo). The proportion of the testes occupied by Leydig cells was greatest at 70 d, declined sharply between 70 and 130 d with a sharper decline in select-line boars, and then declined more gradually from 130 to 450 d of age. We conclude that selection for weight of testes at 150 d resulted in lower age at puberty for boars of the select line.

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Growth Of Testes And Testicular Morphology After Eight Generations Of Selection For Increased Predicted Weight Of Testes At 150 Days Of Age In Boars, R. R. Harder, D. D. Lunstra, R. K. Johnson, Roman L. Hruska Oct 1995

Growth Of Testes And Testicular Morphology After Eight Generations Of Selection For Increased Predicted Weight Of Testes At 150 Days Of Age In Boars, R. R. Harder, D. D. Lunstra, R. K. Johnson, Roman L. Hruska

Department of Animal Science: Faculty Publications

Weights of testes and epididymides, body weight, and morphometric measurements of testicular tissue of 75 boars of a line selected for eight generations for predicted weight of testes at 150 d of age and 75 boars of a randomly selected control line were used to evaluate the effects of selection on testicular development at 70, 100, 130, 160, and 450 d of age (n = 15 boars per line per age). Body weights for boars of the select and control line did not differ (P <.05) and the shape of the body growth curve was similar for both lines. Boars of the select line had larger testes than control boars at each age (P < .05), but there was a significant line x age interaction. The percentage increase of the select line mean over the control mean for weight of testes was 37% at 70 d, a maximum of 120% at 100 d, and 25% at 450 d. The percentage of the testes made up of seminiferous tubules differed between lines (P <.01). Lines had similar means of approximately 28% at 70 d and 71% at 450 d, but the mean for the select line was larger between 100 and 160 d of age; the greatest difference was 11.6% (control = 43.7, select = 55.3%) at 100 d. After 70 d of age, select-line boars had a greater percentage of seminiferous tubules with lumens that contained elongated spermatids (P <.l0). The proportion of the testes occupied by Leydig cells was greatest at 70 d, declined sharply between 70 and 130 d with a sharper decline in select-line boars, and then declined more gradually from 130 to 450 d of age. We conclude that selection for weight of testes at 150 d resulted in lower age at puberty for boars of the select line.

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Estimation Of Variances Due To Direct And Maternal Effects For Growth Traits Of Nelore Cattle, J. P. Eler, L. Dale Van Vleck, J. B. S. Ferraz, R. B. Lobo May 1995

Estimation Of Variances Due To Direct And Maternal Effects For Growth Traits Of Nelore Cattle, J. P. Eler, L. Dale Van Vleck, J. B. S. Ferraz, R. B. Lobo

Department of Animal Science: Faculty Publications

Estimates of (co)variance components and genetic parameters were obtained for birth, 205-d, and 365-d weight for Nelore cattle in Brazil, using single and multiple-trait animal models. Data were from the Brazilian Zebu Breeders Association (ABCZ). Records of 27,549 calves sired by 587 bulls and raised on pasture in 57 herds were analyzed by restricted maximum likelihood fitting an animal model including direct and maternal genetic and permanent environmental effects. Single and multiple- trait analyses were carried out. Heritability estimates for direct effects were lower than previous values reported for the Nelore breed. The estimates for maternal genetic effects showed that …

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Effect Of Accounting For Different Phenotypic Variances By Sire Breed And Sex On Selection Of Sires Based On Expected Progeny Differences For 200- And 365-Day Weights, F. A. Rodriguez-Almeida, L. Dale Van Vleck, Larry V. Cundiff Apr 1995

Effect Of Accounting For Different Phenotypic Variances By Sire Breed And Sex On Selection Of Sires Based On Expected Progeny Differences For 200- And 365-Day Weights, F. A. Rodriguez-Almeida, L. Dale Van Vleck, Larry V. Cundiff

Department of Animal Science: Faculty Publications

The effects of accounting for different phenotypic variances according to sire breed and sex subclasses on estimation of sire breed effects and prediction of expected progeny differences of sires mated to Hereford and Angus cows were investigated. Data consisted of 6,977 and 6,530 records of 200-d (weaning) and 365-d (yearling) weights, respectively, of F1 calves sired by bulls (662 and 661, respectively) of 23 breeds that have been evaluated in the Germ Plasm Evaluation Program at the U.S. Meat Animal Research Center, Clay Center, NE. Models compared included fixed effects of genetic group of sire (samples of sires evaluated …

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Heterogeneity Of Variance By Sire Breed, Sex, And Dam Breed In 200- And 365-Day Weights Of Beef Cattle From A Top Cross Experiment, F. A. Rodriguez-Almeida, L. Dale Van Vleck, Larry V. Cundiff, Stephen D. Kachman Apr 1995

Heterogeneity Of Variance By Sire Breed, Sex, And Dam Breed In 200- And 365-Day Weights Of Beef Cattle From A Top Cross Experiment, F. A. Rodriguez-Almeida, L. Dale Van Vleck, Larry V. Cundiff, Stephen D. Kachman

Department of Animal Science: Faculty Publications

The nature of the heterogeneity of variance for 200- and 365-d weights by sex, sire breed, and dam breed subclasses was studied. Data consisted of records for weaning f n = 7,829) and yearling (n = 7,367) weights of progeny from 673 and 672 sires, respectively, from 22 breeds that have been evaluated in the Germ Plasm Evaluation Program at the U.S. Meat Animal Research Center, Clay Center, NE. Sires were mated to Hereford and Angus cows. Each trait was analyzed separately. Three studies were undertaken separately to investigate heterogeneity due to the different factors (i.e, sire breed, sex, or …

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Prediction Of Genetic Values Of Sires For Growth Traits Of Crossbred Cattle Using A Multivariate Animal Model With Heterogeneous Variances, R. Nunez-Dominguez, L. Dale Van Vleck, Larry V. Cundiff Apr 1995

Prediction Of Genetic Values Of Sires For Growth Traits Of Crossbred Cattle Using A Multivariate Animal Model With Heterogeneous Variances, R. Nunez-Dominguez, L. Dale Van Vleck, Larry V. Cundiff

Department of Animal Science: Faculty Publications

The purpose of this study was to evaluate the effect of adjusting for heterogeneous variances across breed groups on prediction of breeding values (PBV) of selected sires and on breed of sire effects. Data on weights at birth (BWT), 200 d (WW), and 365 d (YW) of purebred and crossbred calves from matings of Angus (A), Hereford (H), Polled Hereford, Charolais, Shorthorn, Simmental, Limousin, Maine-Anjou, Chianina, Gelbvieh, Tarentaise, and Salers bulls to A and H cows were used. Calf performance in H and A dams was treated as a different trait. Models compared included fixed birth year, cow age, and …

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Role Of Specific Response Elements Of The C-Fos Promoter And Involvement Of Intermediate Transcription Factor(S) In The Induction Of Sertoli Cell Differentiation (Transferrin Promoter Activation) By The Testicular Paracrine Factor Pmods*, Patricia D. Whaley, Jaideep Chaudhary, Andrea S. Cupp, Michael K. Skinner Apr 1995

Role Of Specific Response Elements Of The C-Fos Promoter And Involvement Of Intermediate Transcription Factor(S) In The Induction Of Sertoli Cell Differentiation (Transferrin Promoter Activation) By The Testicular Paracrine Factor Pmods*, Patricia D. Whaley, Jaideep Chaudhary, Andrea S. Cupp, Michael K. Skinner

Department of Animal Science: Faculty Publications

A mesenchymal-epithelial cell interaction exists in the testis between the Sertoli cells that form the seminiferous tubule and the mesenchymal-derived peritubular myoid cells that surround the tubule. Analysis of the mesenchymal-epithelial interactions between these cells revealed the local production of a mesenchymal factor, PModS. PModS modulates the differentiated functions of Sertoli cells in uitro, including stimulation of the iron-binding protein transferrin (Tf). Previous results have indicated that PModS-induced Tf gene expression involves the activation of immediate early genes. One of the immediate early genes was identified as c-fos. The importance of c-fos was demonstrated in the current study when a …

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Estimates Using An Animal Model Of (Co)Variances For Yields Of Milk, Fat, And Protein For The First Lactation Of Holstein Cows In California And New York, L. G. Albuquerque, G. Dimov, Jeffrey F. Keown, L. Dale Van Vleck Mar 1995

Estimates Using An Animal Model Of (Co)Variances For Yields Of Milk, Fat, And Protein For The First Lactation Of Holstein Cows In California And New York, L. G. Albuquerque, G. Dimov, Jeffrey F. Keown, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

First lactation yields of milk, fat, and protein from Holstein cows in New York and California were used to obtain REML estimates of (co)variances for yield traits using a multitrait animal model. Data from each state were split randomly into 10 samples, averaging 5504 cows per sample from California and 5078 from New York. Mean heritability estimates for milk, fat, and protein yields were .30 ± .02, .31 ± .01, and .29 ± .01 for California data and .33 ± .01, .35 ± .01, and .30 ± .01 for New York data. Averages of genetic correlation estimates for California and …

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Sperm Production In Boars After Nine Generations Of Selection For Increased Weight Of Testis, Thomas A. Rathje, R. K. Johnson, D. D. Lunstra Mar 1995

Sperm Production In Boars After Nine Generations Of Selection For Increased Weight Of Testis, Thomas A. Rathje, R. K. Johnson, D. D. Lunstra

Department of Animal Science: Faculty Publications

Body, testis, and epididymis weights were recorded and homogenization-resistant sperm nuclei were counted to determine daily sperm production and the number of sperm stored within the cauda epididymis (CAUDASP) in 145 boars of a control line (C) and 128 boars of a line selected for increased predicted weight of testis (TS) at 150 d of age. Random samples of boars were evaluated at five ages between 70 and 450 d in Generation 8 and 15 ages between 70 and 296 d in Generation 9. Data were analyzed using an animal model that included the fixed effect of line and the …

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Hormone Concentrations In The Caudal Vena Cava During The First Ovarian Follicular Wave Of The Oestrous Cycle In Heifers, F. M. Rhodes, L. A. Fitzpatrick, K. W. Entwistle, J. E. Kinder Jan 1995

Hormone Concentrations In The Caudal Vena Cava During The First Ovarian Follicular Wave Of The Oestrous Cycle In Heifers, F. M. Rhodes, L. A. Fitzpatrick, K. W. Entwistle, J. E. Kinder

Department of Animal Science: Faculty Publications

Changes in pulsatile secretion of LH, FSH, oestradiol and progesterone were related to the growth phase, early plateau phase and regression phase of the first ovarian dominant follicle of the oestrous cycle in Bos indicus heifers. Relationships between these hormones during the three phases were also investigated. Accurate measurements of episodic ovarian steroid secretion were obtained by catheterizing the caudal vena cava via the lateral saphenous vein; the tip of the catheter was positioned just cranial to the ovarian vein using transrectal ultrasonography. Pulsatile secretion of oestradiol was increased only during the growth phase of the dominant follicle and was …

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Uterine Mass And Uterine Blood Volume In Mice Selected 21 Generations For Alternative Criteria To Increase Litter Size, Merlyn K. Nielsen, R. J. Kittok, Y. L. Kochera Kirby Jan 1995

Uterine Mass And Uterine Blood Volume In Mice Selected 21 Generations For Alternative Criteria To Increase Litter Size, Merlyn K. Nielsen, R. J. Kittok, Y. L. Kochera Kirby

Department of Animal Science: Faculty Publications

Lines of mice, selected for 21 generations using alternative criteria to increase litter size, were evaluated for uterine mass and uterine blood volume to help explain differences in uterine capacity. For this study, mice were sampled from Generation 27, the sixth generation after relaxation of selection. Mice came from all four criteria of selection (LS = selection on number born to unaltered females; M = selection on an index of ovulation rate and ova success; UT = selection on uterine capacity; and LC = unselected control) in each of three replicates (a total of 12 lines). Measurement was at one …

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Differences In Pup Birth Weight, Pup Variability Within Litters, And Dam Weight Of Mice Selected For Alternative Criteria To Increase Litter Size, M. A. J/ Van Engelen, Merlyn K. Nielsen, E. L. De A. Ribeiro Jan 1995

Differences In Pup Birth Weight, Pup Variability Within Litters, And Dam Weight Of Mice Selected For Alternative Criteria To Increase Litter Size, M. A. J/ Van Engelen, Merlyn K. Nielsen, E. L. De A. Ribeiro

Department of Animal Science: Faculty Publications

Selection for litter size had been practiced for 21 generations and relaxed selection for 13 generations in mice. Three replicates were used with four selection criteria: index of components (ovulation rate and ova success), uterine capacity, litter size, and an unselected control. Especially with selection for litter size and the index relative to the control, number of pups born had increased, and differences also occurred in mating weight. Dams of the three replicates and their litters were used to evaluate the effects of accumulated selection on pup birth weight, variability in weight of littermates, and dam's weight at mating and …

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Variance Of Interaction Effects Of Sire And Herd For Yield Traits Of Holsteins In California, New York, And Pennsylvania With An Animal Model, G. Dimov, L. G. Albuquerque, Jeffrey F. Keown, L. Dale Van Vleck, H. D. Norman Jan 1995

Variance Of Interaction Effects Of Sire And Herd For Yield Traits Of Holsteins In California, New York, And Pennsylvania With An Animal Model, G. Dimov, L. G. Albuquerque, Jeffrey F. Keown, L. Dale Van Vleck, H. D. Norman

Department of Animal Science: Faculty Publications

An animal model with a REML algorithm was used to estimate variances of additive genetic effects and interaction effects of sire and herd. Milk and fat yields were analyzed for fmt, second, and thrd lactations of Holsteins from California, New York, and Pennsylvania. Twenty samples of data were used in the study: 10 from California, 4 from New York, and 6 from Pennsylvania. Mean number of lactations per sample was 36,820 from 18,189 cows in 156 herds. Mean fractions of phenotypic variance of interaction effects of sire and herd for milk and fat yields were .015 and .019 for first …

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Increasing Concentrations Of 17Β-Estradiol Has Differential Effects On Secretion Of Luteinizing Hormone And Follicle-Stimulating Hormone And Amounts Of Mrna For Gonadotropin Subunits During The Follicular Phase Of The Bovine Estrous Cycle, Andrea S. Cupp, F. N. Kojima, M. S. Roberson, T. T. Stumpf, M. F. Wolfe, L. A. Werth, Roger J. Kittok, H. E. Grotjan, J. E. Kinder Jan 1995

Increasing Concentrations Of 17Β-Estradiol Has Differential Effects On Secretion Of Luteinizing Hormone And Follicle-Stimulating Hormone And Amounts Of Mrna For Gonadotropin Subunits During The Follicular Phase Of The Bovine Estrous Cycle, Andrea S. Cupp, F. N. Kojima, M. S. Roberson, T. T. Stumpf, M. F. Wolfe, L. A. Werth, Roger J. Kittok, H. E. Grotjan, J. E. Kinder

Department of Animal Science: Faculty Publications

The hypothesis tested was that 17β-estradiol (E2) would increase amounts of mRNA for α, LHβ, and FSHβ subunits during the follicular phase of the estrous cycle prior to the preovulatory surge of gonadotropins in cows. On Day 16 (Day 0 = estrus) of the estrous cycle, all cows were treated with prostaglandin F2α (PGF2α). Cows served as intact controls (CONT, n = 4) were ovariectomized (OVX, n = 5), or were ovariectomized and administered E2 (OVXE, n = 6) in increasing doses starting at the time of treatment with PGF2α. Cows were …

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Relationship Of Restriction Fragment Length Polymorphisms (Rflp) At The Bovine Calpastatin Locus To Calpastatin Activity And Meat Tenderness, S. M. Lonergan, C. W. Ernst, M. D. Bishop, Chris R. Calkins, Mohammad Koohmaraie Jan 1995

Relationship Of Restriction Fragment Length Polymorphisms (Rflp) At The Bovine Calpastatin Locus To Calpastatin Activity And Meat Tenderness, S. M. Lonergan, C. W. Ernst, M. D. Bishop, Chris R. Calkins, Mohammad Koohmaraie

Department of Animal Science: Faculty Publications

Restriction fragment length polymorphisms (RFLP) have been identified at the bovine calpastatin locus. The objective of the present study was to determine whether these polymorphisms are related to variations in calpastatin activity or beef tenderness in unrelated animals of mixed breeding. A sample of 83 crossbred steers from sires representing eight different breeds was examined to determine this relationship. A 2.2-kb cDNA coding for domains 2 through 4 plus a 3&#;&#;untranslated region of bovine skeletal muscle calpastatin was used as a probe for calpastatin RFLP. Polymorphisms were found using the restriction enzymes BamHI and EcoRI. Polymorphic restriction fragments for BamHI …

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The Effects Of Orientation And Storage Time On The Prediction Of Beef Rib Composition Using Electromagnetic Scanning, B. L. Gwartney, N. L. Meseck, Chris R. Calkins Jan 1995

The Effects Of Orientation And Storage Time On The Prediction Of Beef Rib Composition Using Electromagnetic Scanning, B. L. Gwartney, N. L. Meseck, Chris R. Calkins

Department of Animal Science: Faculty Publications

To investigate the effects of orientation of beef ribs in an electromagnetic field and storage time on the prediction of rib composition, 64 ribs (IMPS 103) were scanned (2.5 MHz) in three different orientations: posterior end first (POS), dorsal end first (DOR), and fat side first, blade end down (BLD). Scans were obtained after 1 and 5 d of storage. Scan peak, rib weight, 3/4 fat depth, length, and temperature were used to predict percentage and weight of dissectable and fat-free lean. The mean peak for the BLD scans was four to six times higher than the POS or DOR …

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Melengestrol Acetate At Greater Doses Than Typically Used For Estrous Synchrony In Bovine Females Does Not Mimic Endogenous Progesterone In Regulation Of Secretion Of Luteinizing Hormone And 17Β-Estradiol, F. N. Kojima, J. R. Chenault, M. E. Wehrman, E. G. M. Bergfeld, Andrea S. Cupp, L. A. Werth, V. Mariscal, T. Sanchez, Roger J. Kittok, J. E. Kinder Jan 1995

Melengestrol Acetate At Greater Doses Than Typically Used For Estrous Synchrony In Bovine Females Does Not Mimic Endogenous Progesterone In Regulation Of Secretion Of Luteinizing Hormone And 17Β-Estradiol, F. N. Kojima, J. R. Chenault, M. E. Wehrman, E. G. M. Bergfeld, Andrea S. Cupp, L. A. Werth, V. Mariscal, T. Sanchez, Roger J. Kittok, J. E. Kinder

Department of Animal Science: Faculty Publications

Our working hypothesis was that doses of melengestrol acetate (MGA) greater than those typically administered in estrous synchrony regimens would regulate secretion of LH and 17β-estradiol (E2) as endogenous progesterone (P4) does during the midluteal phase of the estrous cycle. We also hypothesized that endogenous P4 from the CL would interact with MGA to further decrease the frequency of LH pulses and E2. Cows on Day 5 of their estrous cycle (Day 0 = estrus) were randomly assigned to an untreated control group (CONT, n = 5) or to one of six MGA …

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Estimation Of Non-Additive Genetic Variances In Three Synthetic Lines Of Beef Cattle Using An Animal Model, F. A. Rodriguez-Almeida, L. Dale Van Vleck, R. A. Willham, S. L. Northcutt Jan 1995

Estimation Of Non-Additive Genetic Variances In Three Synthetic Lines Of Beef Cattle Using An Animal Model, F. A. Rodriguez-Almeida, L. Dale Van Vleck, R. A. Willham, S. L. Northcutt

Department of Animal Science: Faculty Publications

Dominance and additive x additive genetic variances were estimated for birth and weaning traits of calves from thee synthetic lines of beef cattle differing in mature size. Data consisted of 3,992 and 2,877 records from lines of small-, medium-, and large-framed calves in each of two research herds located at Rhodes and McNay, IA, respectively. Variance components were estimated separately by herd and line for birth weight (BWT), birth hip height (BH), 205-d weight (WW), and 205-d hip height (WH) by derivative-free REML with an animal model. Model 1 included fixed effects of year, sex, and age of dam. Random …

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Dosage Of The Synthetic Progestin, Norgestomet, Influences Luteinizing Hormone Pulse Frequency And Endogenous Secretion Of 17Β-Estradiol In Heifers, T. Sanchez, M. E. Wehrman, F. N. Kojima, Andrea S. Cupp, E. G. M. Bergfeld, K. E. Peters, V. Mariscal, Roger J. Kittok, J. E. Kinder Jan 1995

Dosage Of The Synthetic Progestin, Norgestomet, Influences Luteinizing Hormone Pulse Frequency And Endogenous Secretion Of 17Β-Estradiol In Heifers, T. Sanchez, M. E. Wehrman, F. N. Kojima, Andrea S. Cupp, E. G. M. Bergfeld, K. E. Peters, V. Mariscal, Roger J. Kittok, J. E. Kinder

Department of Animal Science: Faculty Publications

The objective of this study was to determine whether there were doses at which the synthetic progestin, norgestomet, could mimic midluteal phase concentrations of progesterone in regulating the secretion of LH and 17β-estradiol in bovine females. Heifers were randomly assigned to one of five groups to receive: 1) one (Norg, n = 5), 2) two (2Norg, n = 5), 3) four (4Norg, n = 5), or 4) eight (8Norg, n = 5) norgestomet implants or to serve as untreated control heifers (control, n = 5). On Day 7 (Day 0 = behavioral estrus), implants containing norgestomet were inserted, and they …

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