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Full-Text Articles in Life Sciences
Sire Comparisons For Holsteins In Mexico Versus The United States And Canada, R. E. Mcdowell, G. R. Wiggans, J. K. Camoens, L. Dale Van Vleck, D. G. St. Louis
Sire Comparisons For Holsteins In Mexico Versus The United States And Canada, R. E. Mcdowell, G. R. Wiggans, J. K. Camoens, L. Dale Van Vleck, D. G. St. Louis
Department of Animal Science: Faculty Publications
Henderson's mixed model procedure was used to determine sire comparisons for Holstein sires from the United States, Canada, or local bred in 48 Mexican herds. For sires with five or more daughters, 74% of the sires in artificial insemination from the United States had plus values compared to 34% from Canada, 44% from the local stud, and 40% for local bred sires. Genetic correlations with Mexican sire comparisons were Northeast Artificial Insemination Sire Comparison with >20 daughters in Mexico .86, with 10 to 20 daughters .71, United States Department of Agriculture (USDA) proof >10 daughters .81, and Canada Northeast Artificial …
Factors Affecting Performance Of Holsteins In Subtropical Regions Of Mexico, R. E. Mcdowell, J. K. Camoens, L. Dale Van Vleck, E. Christensen, E. Cabello Frias
Factors Affecting Performance Of Holsteins In Subtropical Regions Of Mexico, R. E. Mcdowell, J. K. Camoens, L. Dale Van Vleck, E. Christensen, E. Cabello Frias
Department of Animal Science: Faculty Publications
Effects of herd, year, age, season, and their interactions on milk yield, lactation length, and reproductive efficiency for purebred and high grade Holsteins were determined by analysis of variance of 17,255 lactation records from 48 herds in Mexico. Herds differed in all traits. Herd average milk yield ranged from 2620 to 7670 kg. Years, ages, and seasons were important to milk yield, but these variables had little influence on lactation length, days open, days dry, and calving interval. Most two-, three-, and four-way interactions for milk yield and days in milk were of importance. Main effects and interactions accounted for …
Genetic Value Of Sexed Semen To Produce Dairy Heifers, L. Dale Van Vleck, R. W. Everett
Genetic Value Of Sexed Semen To Produce Dairy Heifers, L. Dale Van Vleck, R. W. Everett
Department of Animal Science: Faculty Publications
Economic value of sexed semen due to increased intensity of selection on cows to produce replacements can be determined from a slight modification of a procedure used to predict net worth of semen of different costs from sires of different transmitting abilities. Table values corresponding to precision of sexing (selection intensity allowed for cows), discount rate, investment period, and conception rate are used in simple equations to determine the economic value of sexed or regular semen. The additional price that can be paid for sexed semen as compared to regular semen also can be determined. For example, sexed semen resulting …
Reproductive Efficiency Of Jerseys, Red Sindhis, And Crossbreds, R. E. Mcdowell, B. F. Hollow, J. K. Camoens, L. Dale Van Vleck
Reproductive Efficiency Of Jerseys, Red Sindhis, And Crossbreds, R. E. Mcdowell, B. F. Hollow, J. K. Camoens, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Ten measures related to breeding efficiency were used for comparisons among pure Jerseys and Red Sindhis and crossbreds with ¾, ½, or ¼ European dairy inheritance (Brown Swiss, Holstein, or Jersey) at two locations. Jerseys and crossbreds were common to both herds with Sindhis only at Jeanerette. Means for age at puberty (first estrus after 12 mo) were 425 ± 4.2, 434 ± 6.9, 459 ± 6.9, 504 ± 14.1, and 717 ± 40.4 days for Jerseys, crosses of ¾, ½, or ¼ and Sindhi. The increase in age of puberty was additive but not entirely. The ¾and ½ tended …
Oestrus, Lh, Ovulation And Fertility In Beef Heifers, R. K. Christenson, S. E. Echternkamp, D. B. Laster
Oestrus, Lh, Ovulation And Fertility In Beef Heifers, R. K. Christenson, S. E. Echternkamp, D. B. Laster
Department of Animal Science: Faculty Publications
The pregnancy rate resulting from matings at a single oestrus in beef cattle averages 70% for natural mating (Turman, Laster, Renbarger & Stephens, 1971) and 60% for artificial insemination (Laster, Glimp & Gregory, 1972). The sources and causes of low pregnancy rates have not been defined, but might include variation in time of ovulation relative to deposition of spermatozoa in the female reproductive tract, fertilization failure, ovum transport, abnormal ova and blastocyst development, and implantation failure. The interval from onset of oestrus to ovulation in dairy cattle has been reported to average 29±6hr with a range from 16 to 42 …
Maternal Heterosis In Swine: Reproductive Performance And Dam Productivity, R. K. Johnson, I. T. Omtvedt
Maternal Heterosis In Swine: Reproductive Performance And Dam Productivity, R. K. Johnson, I. T. Omtvedt
Department of Animal Science: Faculty Publications
The objectives of this study were to estimate the heterosis of crossbred gilts for ovulation rate and the maternal heterosis of crossbred gilts for dam productivity. A total of 470 gilts were saved for breeding of which 72 were considered reproductive failures. Estimates of heterosis were made from 193 pregnant gilts slaughtered 30 days postbreeding (106 crossbred and 87 purebred)and 192 litters farrowed (98 three-breed and 94 two-breed cross). The reproductive failure rate for all gilts was 15.3% with there being very little difference~ between purebred and crossbred gilts. Estimates of heterosis for ovulation rate were not significantly different from …
Effects Of Source On Copper Uptake By Swine, G. L. Zoubek, E. R. Peo, Jr., B. D. Moser, T. Stahly, P. J. Cunningham
Effects Of Source On Copper Uptake By Swine, G. L. Zoubek, E. R. Peo, Jr., B. D. Moser, T. Stahly, P. J. Cunningham
Department of Animal Science: Faculty Publications
Four catheterized crossbred (Y x H) barrows were used in a 4 x 4 latin square arrangement of treatments in a completely randomized block design, to determine the effect of source on copper uptake as determined by serum Cu concentration changes over a 7.5-hr sampling period.
Influence Of Exercise On Performance And Carcass Parameters Of Confinement Reared Swine, G. M. Weiss, E. R. Peo, Jr., R. W. Mandingo, B. D. Moser
Influence Of Exercise On Performance And Carcass Parameters Of Confinement Reared Swine, G. M. Weiss, E. R. Peo, Jr., R. W. Mandingo, B. D. Moser
Department of Animal Science: Faculty Publications
Fifty-six crossbred growing and finishing swine were used to determine the effect of treadmill exercise on several performance and carcass parameters When housed in confinement on 100% slatted floors. The exercised swine were subjected to walking 1.6 km/hr for 1 hr 5 days per week. The mean experimental duration was 71 days. Jugular vein blood samples and gracilus muscle biopsy samples were obtained prior and following completion of exercise. Exercise had no major influence on average daily gain, daily feed intake or gain/feed ratio. Bone breaking strength of the left fourth metatarsal was significantly (P <.01) greater for exercised pigs than non exercised. However, right third and fourth metatarsal and left third metatarsal bone breaking strengths were not influenced by exercise.