Life Sciences Commons^™

Reproductive Efficiency Of Purebred And Crossbred Dairy Cattle, R. E. Mcdowell, J. A. Velasco, L. Dale Van Vleck, J. C. Johnson, G. W. Brandt, B. F. Hollow, B. T. Mcdaniel

Department of Animal Science: Faculty Publications

Nine measures related to breeding efficiency were used for comparisons among purebred Ayrshires, Brown Swiss, Holsteins, and Jerseys and between purebreds and 32 crossbred groups representing 2-breed, 3-breed, 5/8, and backcrosses by purebred sires and progeny of crossbred sires. There were four herds with Holsteins common to all, Brown Swiss and Jerseys in three herds and Ayrshires in one herd. Four 2-breed, two 3-breed, and two backcross groups were common to two or more herds. Among purebreds, breed effects were significant in 16 of 72 tests, but there was no consistent trend favoring one breed. Generally, Jerseys were better than …

Evaluation Of Purebreds And Two-Breed Crosses In Swine: Reproductive Performance, R. K. Johnson, I. T. Omtvedt

Department of Animal Science: Faculty Publications

The data included records on 440 purebred sows and gilts of Duroc, Hampshire and Yorkshire breeding mated in all combinations to produce purebred and two-breed cross litters. A total of 119 purebred gilts (39 with purebred litters and 80 with crossbred litters) were slaughtered 30-days postbreeding and their reproductive tracts evaluated for number of corpora lutea and early embryo development. Farrowing records included 89 purebred and 161 two-breed cross litters produced at the Ft. Reno Experiment Station during the spring and fall of 1971 and the summer of 1972.

Reproductive failures (females not exhibiting estrus or open at slaughter or …

Genetic Aspects Of Beef Production Among Holstein-Friesians Pedigree Selected For Milk Production, L. L. Calo, R. E. Mcdowell, L. Dale Van Vleck, P. D. Miller

Department of Animal Science: Faculty Publications

To explore the potential of cattle to produce both milk and beef, the genetic aspects of beef production among Holstein-Friesian bulls pedigree selected for milk were studied. The data included growth records of 504 bulls (DPT) by 120 sires (SPT) pedigree selected for progeny testing by American Breeders Service, 1964 to 1971. DPT bulls with proofs had an average predicted difference for milk (PMD) of +180 kilograms. The daughter average was 7,273 kg per lactation under varying herd conditions. Sires accounted for 10% of the variation in average daily gain (ADG), 10% in daily gain per 100 kg body weight …

Reproductive Efficiency And Viability In Two Bos Indicus And Two Bos Taurus Breeds In The Tropics Of India And Colombia, L. (Lemka) Hamed, R. E. Mcdowell, L. Dale Van Vleck, H. Guha, J. J. Salazar

Department of Animal Science: Faculty Publications

Records from two herds in India and two in Columbia representing respectively two breeds of Bos indicus (Hariana and Deshi) and two Bos taurus breeds—Blanco Orejinegro (BON) and Costeño Con Cuernos (CCC) were evaluated for breeding efficiency and viability. Average age at first calving was 52.1, 46.3, 39.5 and 40.7 months for Hariana, Deshi, CCC and BON. Season of birth did not influence age at calving. Ranking for calving interval was similar, average 479, 418, 396 and 382 days with season effects significant (P<.05) for only Deshi. BON and CCC had fewer days open but much shorter lactation periods, average 73 and 157, thus days carried calf in lactation were similar for all breeds. Percent of time dry per calving interval was high for all breeds, 44.2, 36.7, 64.1 and 81.0 for Hariana, Deshi, BON and CCC. Average annual mortality of females by 12 months of age was 23.6% for Hariana, 17.0% Deshi and 27.0% BON. In the same herds 46.4%, 51.1% and 49.0% of females born alive lived to first calving and annual losses among cows were 18.0%, 17.0%, and 21.0%; therefore, affording little opportunity for selection among females. Temperament, as determined by response to the milking process with and without the calf present, showed all the breeds were similar in this respect. Environmental effects were most important for all traits but genetic differences were indicated for age at first calving and milk yield. On a theoretical basis little gain could be expected in net dairy merit from crosses between the Columbian and Indian breeds.

Factors For Extending In-Progress Lactation Records To A 305-Day Equivalent, Jeffrey F. Keown, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Paper for Presentation at the 64th Annual Meeting of the American Society of Animal Science. The data consisted of 204,558 complete Holstein lactations in 2,100 herds compiled by the New York Dairy Records Processing Laboratory from 1959 to 1969. All lactation records had to have a 9th or 10th test day present to be regarded as complete. The generalized least squares analysis used a model including effects due to the mean, herd-year and season-age-stage of freshening which were assumed to be fixed. The error term included the random effects due to the cow and residual. Generalized least squares estimates for …

Evaluation Of Purebreds And Two-Breed Crosses In Swine: Feedlot Performance And Carcass Merit , R. K. Johnson, I. T. Omtvedt, L. E. Walters

Department of Animal Science: Faculty Publications

Feedlot performance of 941 barrows and gilts and carcass traits of 190 barrows of purebreds and crossbreds of the Duroc, Hampshire and Yorkshire breeds were evaluated for differences between purebreds and reciprocal crosses and for heterosis. Purebred and crossbred litters were farrowed contemporaneously at the Ft. Reno Experiment Station in the 1971 spring and fall farrowing seasons.

Rather distinct differences between the pure breeds were evident for most traits. In general, Durocs gained weight more rapidly than Hampshires and Yorkshires while Yorkshires were the most efficient pure breed. Hampshire barrows had less backfat, more loin eye area and more total …

Gain, Feed Conversion And Carcass Traits Of Swine Fed Under Two Nutritional Regimes, P. J. Cunningham, T. E. Socha, E. R. Peo, Jr., R. W. Mandingo

Department of Animal Science: Faculty Publications

Data involving 505 Gene Pool boars, barrows and gilts and 126 Hampshire boars and gilts fed two nutritional diets were presented. One diet consisted of high lysine corn, minerals and vitamins (10% protein) while the other diet was a 14% protein corn-soy diet.

Effect Of A Combination Of Diethylstilbestrol And Methyltestosterone And Protein Level In The Diet On Performance And Carcass Traits In An Unselected Line Of Swine, L. E. Lucas, E. R. Peo, Jr., A. J. Svajgr

Department of Animal Science: Faculty Publications

Two experiments involving 372 barrows were conducted to evaluate the effects of orally administered diethylstilbestrol (DES) and methyltestosterone (MT) with varying levels of dietary protein.

Parameters Of Growth Of Holstein-Friesian Bulls, L. L. Calo, R. E. Mcdowell, L. Dale Van Vleck, P. D. Miller

Department of Animal Science: Faculty Publications

Growth records of 504 pedigree selected Holstein-Friesian bulls by 120 sires collected for progeny testing at the American Breeders Service, Inc., DeForest, Wisconsin from 1964 to 1971, were studied to determine the shape of the growth curve, relationships among body weights and growth rates at various ages and to estimate heritability of growth. Body weight and average/daily gain were consistently higher than the previous growth standards for Holstein-Friesian bulls. Bulls weighed about 480 kg at 15 months, which was 46% of average mature weight. Average daily gain ranged from 1.3 to 0.8 kg between 6 and 18 months of age. …

Effect Of Amino Acids On Non-Protein Nitrogen Utilization By G-F Swine, P. D. Platter, E. R. Peo, Jr., P. E. Vipperman, P. J. Cunningham

Department of Animal Science: Faculty Publications

Two metabolism and one feeding experiment were conducted with a total of 118 crossbred pigs to determine the effect of amino acids on non-protein nitrogen (NPN) utilization by G-F swine.

Reproductive Efficiency In Aged Female Rabbits Given Supplemental Progesterone And Oestradiol, Larry L. Larson, C. H. Spilman, H. O. Dunn, R. H. Foote

Department of Animal Science: Faculty Publications

The reproductive efficiency of twenty-eight aged does, 49 to 72 months old, was compared with that of eighteen young does, 6 to 13 months old. Fertilization rate and development in vitro of fertilized ova from rabbits induced to superovulate were not influenced by the doe's age. Ovulation rates following natural mating were only slightly reduced with age. However, the number of embryos per doe was much greater in young than in old does at 12 and 24 days post coitum. All young does had viable embryos, whereas the percentages of aged does with detectable implantation sites and viable embryos were …

Subjective Evaluation Of Teat Canal Anatomy, R. D. Appleman

Department of Animal Science: Faculty Publications

Since radiographic techniques have shown that streak canals with larger diameters tend to milk-out faster and are more susceptible to new intramammary infections, a practical visual test was sought to provide easier determination of cows with either extremely narrow (slow milking) or extra wide (susceptible to new infections) streak canals.

A subjective teat classification scheme was developed to describe five different teat-end shapes in 159 Holstein and Brown Swiss cows in the University of Nebraska dairy herd. Approximately one-fourth of the cattle had pointed or round teat ends, one-half had fiat or near flat, and one-fourth were either disk or …

Relationship Between Weight And 40K Count In Steers , R. K. Johnson, L. E. Walters, J. V. Whiteman

Department of Animal Science: Faculty Publications

Thirty-six Angus-Hereford steers were fed four diets of different potassium concentration for 2-week periods such that each steer received each diet for a 2-week period. The relationship between ⁴⁰K count loss and weight loss during a 24-hr. shrink period was evaluated by regression analysis. At the end of each of the four feeding periods the steers ,were weighed and ⁴⁰K counted unshrunk and again after 24-hr. shrink.

The mean weight loss during shrink was similar for all treatments (overall mean of 22.8 kg), however the mean ⁴⁰K count loss was larger for the high potassium diets than …