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Full-Text Articles in Animal Sciences

Amino Acid Additions To A Low Protein Corn-Soy Diet For Egg Production, Ali Baghaye Kashani Jan 1975

Amino Acid Additions To A Low Protein Corn-Soy Diet For Egg Production, Ali Baghaye Kashani

Electronic Theses and Dissertations

The present study was conducted to determine if the protein level of layer diets could be lowered from the: commonly used 16 percent to 12 percent by supplementation of some of the essential amino acids without reducing the performance of hens. The amino acids used were methionine, lysine, tryptophan and isoleucine. Egg production, egg shell thickness, interior egg quality, body weight, feed efficiency and free amino acid content of the albumen of eggs produced were criteria used to measure the (--) to treatment.


Initiation Of Parturition In Dairy Cows With Dexamethasone And Dexamethasone Plus Estradiol Benzoate, Gary Lee Beardsley Jan 1974

Initiation Of Parturition In Dairy Cows With Dexamethasone And Dexamethasone Plus Estradiol Benzoate, Gary Lee Beardsley

Electronic Theses and Dissertations

Parturition was initiated in 25 of 29 (Trial 1) and 26 of 26 (Trial 2) Holstein cows given dexamethasone (Trial 1), 4.4 mg/100 kg body weight, or dexamethasone plus .25 mg estradiol benzoate (Trial 2) at day 273 of gestation. Parturition occurred at 45.l z +/-11.1 h (Trial 1) and 40.8 ± 9.6 h (Trial 2) after injection. Twenty-nine control cows (Trial 1) and 26 control cows (Trial 2) had average gestation lengths of 280 and 281 days, respectively. In Trial 1, calving difficulty was greater (P <.05) while birth weight of calves was 3.0 kg less (P<.05) for the induced cows compared to controls. In Trial 2, no differences in calving difficulty were found, while calf birth weight was 2.5 kg less (P <.10) for the induced cows compared to controls. Average birth weights of calves were 42.4 and 45.4 kg, Trial 1; and L~o.8 and 43.3 kg for Trial 2, for induced and control groups. Severity of udder edema did not differ for either trial. Average daily milk production for the first 9 wk of lactation was 2l~.8 kg and 27.8 kg (Trial 1) and 24.2 kg and 27.7 kg (Trial 2), for induced and control groups. In both trials, differences in milk fat or fat corrected milk were nil. Total milk production (305 day-2X-mature equivalent) was not significantly different for either trial. Changes in body weight were similar for control and induced cows in both trials. The incidence of retained placental membranes was 76 and 10'/4 (Trial 1) and 50 and 4% (Trial 2) for induced and control cows. Average days to first heat, days to firs+, service, days to conception, and services per conception for induced cows were: 58 .4, 79-9, 117.8, 2.0 (Trial l); 80.7, 81.4, 102.2, 1.64 (Trial 2); and for control cows were: 58.6, 82.3, 105.5, 1.8 (Trial l); 89.0, 91.4, 128~6, 1.94 (Trial 2). In Trial 1, the incidence of milk fever in cows with no previous history was 24 and 10'/4 for induced a"'1.d control cows. There were no differences in the incidence of metabolic disorders in Trial 2. Results of California Mastitis Tests were similar for control and induced cows in both trials. In both Trial 1 and Trial 2, fat, protein, total solids, and gamma globulin content of the colostrum did not differ between control an treatment groups;· Casein values were lower (P <.05) for the treatment group in both trials. Average daily gains from 0 to 10 weeks were .63 and .60 kg, for Trial 1; and .51 and .46 kg, for Trial 2, for induced and control calves. No differences were found in calf death loss or health disorders between groups. Similar levels of serum gamma globulin were found for both groups at 0 (before sucking) and 3 days of age in both trials. No meaningful differences were found in total serum protein, albumin, and alpha and beta globulin levels in both trials. No differences were found at birth, in chest depth, shoulder width, head circumference, hip width, and wither height of calves.


Parasites Of Salmonid Fishes From Southcentral Alaska, James Carl Riis Jan 1974

Parasites Of Salmonid Fishes From Southcentral Alaska, James Carl Riis

Electronic Theses and Dissertations

The importance of fish parasites is directly related to the value of the fish they affect. Alaskan salmonids are extremely important and are constantly increasing in value to the United States. Other countries, such as Japan and Russia, are also finding Alaskan salmonids important as a foodstuff. If human populations continue growing at present rates, in only a few years there could be twice as many people eating fish. As a recreational asset in Alaska, salmonids rank at or near the top, both for sportfishing and as a natural attraction. It is thus important from an economic point of view …


In Vitro And In Vivo Evaluation Of Protecting Whey Protein Concentrate For Ruminants, David Rodriguez Maltos Jan 1974

In Vitro And In Vivo Evaluation Of Protecting Whey Protein Concentrate For Ruminants, David Rodriguez Maltos

Electronic Theses and Dissertations

In experiment I a series of in vitro buffer and rumen fermentation studies were conducted to evaluate protein solubility at pH 6.8 and pH 2.5 (with pepsin) and ammonia production from whey protein concentrates (WPC, 55% protein) treated with 0, .25, .5, 1.0, and 3% formaldehyde; 1, .5, 1.0, 2.0, 3.0, and 6% tannic acid; and 0, 1, 2, and 3 hr of heat treatment at 104 C. Protein solubility and ammonia production from casein treated with 0, .5, 1.0, and 3% formaldehyde and 0, .5, 1.0, and 3% tannic acid were also studied. All levels of formaldehyde treatment of …


Gonadal Hormone Levels Prior To And Following Puberty In Straightbred And Crossbred Beef Heifers, Walter Ronald Parker Jan 1974

Gonadal Hormone Levels Prior To And Following Puberty In Straightbred And Crossbred Beef Heifers, Walter Ronald Parker

Electronic Theses and Dissertations

Five heifers from each of four breed groups (Angus x Angus, Charolais x Charolais and the two reciprocal crosses) were used in a study of gonadal hormone levels during the interval from 16 weeks before puberty to puberty (trial I). Puberty was defined as the first standing estrus. Two heifer calves from dams from each of the above breed groups and sired by a single Polled Hereford bull were used in a study of gonadal hormone levels from birth to weaning (trial II). Blood samples were collected at weekly intervals from trial I heifers before puberty and three times weekly …


Effects Of Fungus-Fermented Soybeans On Broiler Growth And Life Cycle Performance Of Coturnix Quail, Cheong Choo Chah Jan 1974

Effects Of Fungus-Fermented Soybeans On Broiler Growth And Life Cycle Performance Of Coturnix Quail, Cheong Choo Chah

Electronic Theses and Dissertations

Despite the extensive data that have accumulated on the detrimental effect of molds on the growth of farm animals, very little is known as to the beneficial role of fungi in animal feed. Recent studies at South Dakota State University research laboratories revealed, however, that only 164 of 392 strains of Aspergilli were found to be toxic. When the cultures were grown on sterile soybeans or wheat, some of the tested cultures exerted positive effects on growth of chicks and mice. Hence, the investigations reported herein were initiated to obtain further information on those cultures beneficial to chick performance and …


The Effects Of Gestation Metabolizable Energy Levels On Sow Productivity And Hematology, George W. Libal Jan 1974

The Effects Of Gestation Metabolizable Energy Levels On Sow Productivity And Hematology, George W. Libal

Electronic Theses and Dissertations

It has been estimated that of the potential ova shed by the sow on1y about 55% result in live pigs born. Reproductive inefficiency can occur as a result of oversupplying or undersupplying energy. Since 1959, the National Research Council has reduced its listed energy requirements for the gravid sow considerably. The studies reported herein were conducted to evaluate metabolizable energy (ME) levels for gestating sows at and below the recommended levels and measure their effect on sow productivity as well as sow hematology at various stages of reproduction. Two experiments, each consisting of three trials, were conducted. Experiment 1, two …


Dried Whey As An Additive For Alfalfa Haylage And As A Grain Supplement For Dairy Cows, Sitakantha Dash Jan 1973

Dried Whey As An Additive For Alfalfa Haylage And As A Grain Supplement For Dairy Cows, Sitakantha Dash

Electronic Theses and Dissertations

This research was conducted to explore the possibility of utilizing surplus whey in dairy cattle rations. Four experiments determined the influence of whey on preservation, digestibility and feeding value of alfalfa haylage. The last experiment was initiated to evaluate dried whey as a grain supplement. When dried whole whey was added at O, 1, and 10% levels to reconstituted alfalfa haylage (chopped baled hay plus 50% water) and preserved in sealed metal containers, it reduced pH, decreased acetic acid, and increased lactic acid. The general pattern of fermentation was better in whey-treated haylages than in corresponding untreated haylages. An in …


Partial Characterization Of Animal Growth Inhibitors From Soybeans, Joseph Richard Uckert Jan 1973

Partial Characterization Of Animal Growth Inhibitors From Soybeans, Joseph Richard Uckert

Electronic Theses and Dissertations

The pH 4. 4 supernatant from raw (unheated) soybean meal was separated into 5 fractions on a Sephadex G-25 column in efforts to isolate the animal growth inhibitors present soybeans. Each fraction was added to the diet of growing mice and growth inhibition (GI) activity was determined by comparing their_ growth rates to g1"'owth rates achieved on an autoclaved soybean meal diet. Fractions I and II each contained about 50% of the GI activity, with a trace in fraction III and none in fractions IV and V. Only fraction I contained trypsin inhibitor and caused pancreatic enlargement. Fraction I was …


The Vitamin E Status Of Lactating Dairy Cows After Receiving Stored Feeds For 15 Months, Marc Dellhime Eckhart Jan 1973

The Vitamin E Status Of Lactating Dairy Cows After Receiving Stored Feeds For 15 Months, Marc Dellhime Eckhart

Electronic Theses and Dissertations

The trend in dairying in recent years has been towards more confinement housing and higher producing animals. Such confinement housing often leads to year-around feeding of stored feeds, such as silage, haylage, and hay with no pasture grazing or feeding of freshly cut forages. Since stored feeds contain substantially less vitamin E than those same forage when freshly cut or grazed, it may be important to re-evaluate the vitamin E status of cows fed stored feeds continuously. The requirement of cattle for vitamin E are largely unknown. The one study involving adult cattle, conducted 25 years ago, found that 1.82 …


Processing Methods For Corn Grain Fed With Various Types, Sources And Levels Of Roughage To Cattle, Jerry Burkhardt Jan 1973

Processing Methods For Corn Grain Fed With Various Types, Sources And Levels Of Roughage To Cattle, Jerry Burkhardt

Electronic Theses and Dissertations

The research reported in this thesis involved experiments to determine the value of grain processed by various methods when fed various kinds and ratios of concentrate to roughage to feedlot beef animals of various ages and degree of fatness.


The Eriophyoidea Of South Dakota, Magdalena Lopez Briones Jan 1973

The Eriophyoidea Of South Dakota, Magdalena Lopez Briones

Electronic Theses and Dissertations

This paper presents the results of the taxonomic investigation of the Eriophyoidea in South Dakota. Information is given on the morphology, discussion of variation within a population, distribution, damage in host plants, economic importance and techniques of collecting and preparing specimens. There are 42 previously described species included in this study. Of the 48 species studied, six are new. Species described are: Aculops maximilianae, Diptacus pengsonae, Eriophyes arceosae, Eriophyes taylori, Tegonotus lindenus, and Tetra mcdanieli.


The Effects Of Chlorpropamide In Diets Of Gravid Gilts On Embryo Survival, Fetal Weight And Fetal And Dam Blood Sugar Levels, Duane E. Wachholz Jan 1972

The Effects Of Chlorpropamide In Diets Of Gravid Gilts On Embryo Survival, Fetal Weight And Fetal And Dam Blood Sugar Levels, Duane E. Wachholz

Electronic Theses and Dissertations

Seventy-six primiparous, crossbred gilts averaging approximately 125 to 135 kg were used in a series of two experiments to determine the effects of chlorpropamide upon reproductive and blood criteria. The drug, fed at the rate of 1000 ppm (1816 mg per day) and 3000 ppm (5448 mg per day), was included in a 14% protein basal diet from the day following breeding until gilts were sacrificed after 60 or 95 days of gestation. The 515 fetuses collected from these gilts were used to obtain information about the effects of chlorpropamide on individual weights and blood glucose and fructose levels. Data …


Amino Acid Supplementation Of Low Protein Layer Diets, Harlal Choudhury Jan 1972

Amino Acid Supplementation Of Low Protein Layer Diets, Harlal Choudhury

Electronic Theses and Dissertations

Experiments were conducted at the South Dakota State University Poultry Research Center to study the effects of amino acid supplementation of low protein diets on performance of laying type hens. Hans, housed in 8-inch cages, were fed at 24 weeks of age typical 16% protein corn-soy diets diluted with glucose to 10.8% protein and supplemented with 0.15% DL-methionine, 0.19% L-lysine and 0.04% DL-tryptophan. After about 20 weeks of depletion, supplements of 0.05 and 0.1% DL-threonine and DL-valine and 0.1% DL-isoleucine alone and in all combinations were fed for a further period of 16 weeks using a factorial design. Individual supplements …


Sephadex G-25 And Charcoal Separation Of Mouse Growth Inhibitors In Soybeans From Trypsin Inhibitors, Larry James Tidemann Jan 1972

Sephadex G-25 And Charcoal Separation Of Mouse Growth Inhibitors In Soybeans From Trypsin Inhibitors, Larry James Tidemann

Electronic Theses and Dissertations

Rising costs have changes man’s ideals and eating habits. Plant ingredients, because of their relatively low costs, have been increasingly used as a substitute for animal proteins. If these plant ingredients could be directly utilized by man, this would be a more efficient use of energy and nutrients. One plant source currently used in such a manner is soybeans, which is a prime source of protein for human and livestock nutrition. However, soybeans contain several factors that are detrimental to man and livestock. Heating of soybeans counteracts these factors, since the undesirable factors are heat labile. However, heat alters the …


Carboxymethylcellulose As A Carrier For Follicle Stimulating Hormone In The Female Rat And Bovine, C. Leroy Johnson Jan 1972

Carboxymethylcellulose As A Carrier For Follicle Stimulating Hormone In The Female Rat And Bovine, C. Leroy Johnson

Electronic Theses and Dissertations

A series of biological assays were conducted to compare physiological saline (PSS) and carboxymethylcellulose (CMC) as carriers for follicle stimulating hormone (FSH) and to determine the optimum ratio of FSH to CMC. Constant individual dosages of 0.5 mg FSH were injected into a total of 384 immature female rats in four experiments. Treatments included single injections of FSH in PSS, FSH in 1 percent CMC at ratios (mg FSH: ml CMC) OF 1:3, 1:2, 1:1, 2:1, 3:1, 5:1 and FSH in 2 percent CMC at a ratio of 1:1. Parameters of primary and secondary response were ovarian and uterine weight, …


The Effect Of Level Of Dietary Protein On The Growth And Carcass Characteristics Of Growing-Finishing Swine Fed To A Heavy Weight, Keith E. Gilster Jan 1972

The Effect Of Level Of Dietary Protein On The Growth And Carcass Characteristics Of Growing-Finishing Swine Fed To A Heavy Weight, Keith E. Gilster

Electronic Theses and Dissertations

Two hundred sixteen crossbred barrows and 96 crossbred gilts were used in a series of three experiments to determine the effect of dietary protein level during three different growth periods on growth am quantitative and qualitative carcass traits of the growing-finishing pig. Pigs were fed from approximately 20 to 113 kilograms. Corn-soybean meal diets fortified with recommended levels of vitamins, minerals and an antibiotic were fed. Pigs fed 20, 18 or 16% protein diets from weights of 20 to 45 kg gained both significantly faster and more efficiently than pigs fed diets of 12% protein. Feeding a low (12%) protein …


Effects Of Manganese Chloride On Gravid Gilts And Newborn Pigs, Dale A. Wade Jan 1972

Effects Of Manganese Chloride On Gravid Gilts And Newborn Pigs, Dale A. Wade

Electronic Theses and Dissertations

Excessive dietary manganese in young mammals has depressed hemoglobin levels, red blood cell synthesis and growth in some investigations, while in other research these were increased. Toxic levels, mode of action and specific physiological effects are unknown although manganese, cobalt and iron appear to compete for absorption mechanisms. Manganese functions in enzyme systems and in carbohydrate and lipid metabolism, is present in red cells and plasma and may be incorporated into the hemoglobin molecule. Gravid gilts were utilized in these investigations since piglet anemia is an economic problem and manganese effects in swine have not been fully defined. Gilt rations …


The Lipid Composition Of Milk As Affected By High Grain-Limited Roughage Rations Containing Whey Products, Roger Charles Peper Jan 1971

The Lipid Composition Of Milk As Affected By High Grain-Limited Roughage Rations Containing Whey Products, Roger Charles Peper

Electronic Theses and Dissertations

Certain rations fed to lactating dairy cows appear to have a dramatic influence on the lipid composition of milk fat produced. A high grain ration fed with a limited amount of roughage tends to cause a depression in milk fat production while at the same time changing the milk fat composition. There have been various attempts to alleviate the depression in milk fat. Minerals used in the ration seem to slightly relieve the milk fat depression caused by high grain rations. One drawback has been lower milk production due to a decline in concentrate consumption. Whey products added to a …


Evaluation Of Orally Administered Sodium D-Thyroxine As A Teratogen In New Zealand White Rabbits, Gary A. Thibodeau Jan 1971

Evaluation Of Orally Administered Sodium D-Thyroxine As A Teratogen In New Zealand White Rabbits, Gary A. Thibodeau

Electronic Theses and Dissertations

Sodium D-thyroxine was evaluated for possible embryotoxic and/or teratogenic effects following oral administration in New Zealand White rabbits. All animals utilized were alert, active and apparently disease-free virgin does weighing three and one-half to four kilograms. Rabbits were individually housed in stainless steel batteries and maintained on a commercially available palletized diet and mineral supplement. Feed and water were provided ad libitum in animal quarters air conditioned to minimize environmental temperature fluctuations. Following a 14-day post-delivery observation period does were bred to New Zealand White bucks and randomly allocated to one of two experimental groups or the control group each …


Effects Of Various Factors On The Rachitogenic Activity Of Isolated Soy Protein, Donald James Arshem Jan 1971

Effects Of Various Factors On The Rachitogenic Activity Of Isolated Soy Protein, Donald James Arshem

Electronic Theses and Dissertations

The nature of the rachitogenic activity of isolated soy protein was investigated in fifteen studies. A RP-100-glucose purified diet was fed to day-old turkey poults housed in stainless steel batteries. Feed and water were provided ad libitum. Corn, oat hulls, solvent-extracted soybean meal, full-fat extruded soybeans, C-1 protein, casein and texturized forms of soy protein were added to the basal diet at various levels. All feedstuffs were added at two particle sizes: natural form of the feedstuff (>250 u); and ground in a ball mill (<250 >u). The effects of autoclaving for 60 minutes at 120°C were also investigated. …


Effects Of Various Levels Of Dietary Selenium And Arsenic On Chickens, Richard L. Arnold Jan 1971

Effects Of Various Levels Of Dietary Selenium And Arsenic On Chickens, Richard L. Arnold

Electronic Theses and Dissertations

Various levels of selenium and arsenic additions were made to several types of chicken diets to study their effects on growth and reproduction criteria. Three experiments were conducted. The first study involved day-old chicks and terminated at 64 weeks of age. These yearling hens were then used for the second experiments which terminated when the hens were 104 weeks old. The third study was initiated with 20 week old pullets and terminated when they were 52 weeks old. Feeding purified diets resulted in slower chick growth and lower mature body weights of hens. Selenium additions of 2.0 ppm resulted in …


Effects Of Feeding Leptaden To Dairy Cows, Sitakantha Dash Jan 1971

Effects Of Feeding Leptaden To Dairy Cows, Sitakantha Dash

Electronic Theses and Dissertations

Leptaden is a herbal drug which was recently introduced to the market by Alarsin Pharmaceuticals, Bombay, India. It consists of the extracts of two indigenous medical plants, namely Leotadenia reticulata (Jeevanti) and Breynia patens (Kamboji) in equal proportions. In 1947, Patel first drew the attention of gynaecologists to the usefulness of Leptaden in habitual abortions and allied conditions in women and later on pointed out its lactogenic and galactagogue properties. His original observations are supported by growing clinical experience over a twenty year period of medical practice. Published clinical experience shows that in most cases Leptaden stimulates, lactation within twelve …


Temperature Computer Measurements, Production And Carcass Traits Of Individually Fed Weight Constant Steers, Lowell M. Anderson Jan 1971

Temperature Computer Measurements, Production And Carcass Traits Of Individually Fed Weight Constant Steers, Lowell M. Anderson

Electronic Theses and Dissertations

During 1968, 29 Hereford steers were individually fed and marketed at one of seven constant weight classes from approximately 386 to 522 kg at intervals of 22.7 kg. During 1970, 21 Angus and Hereford crossbred steers were individually fed and marketed at one of four constant weight classes from approximately 386 to 522 kg at intervals of approximately 45.0 kg. The amounts of edible portion, trimmed fat, removed bone and the summation of the kidney, pelvic, and cod fat were determined on the steers of both years. In 1970 two experiments examined the usefulness of an analog computer for calculation …


Responses Of Rumen Microflora To Whey Products Added To High-Grain Low-Roughage Rations, Virgil L. Metzger Jan 1971

Responses Of Rumen Microflora To Whey Products Added To High-Grain Low-Roughage Rations, Virgil L. Metzger

Electronic Theses and Dissertations

Many factors present in livestock feeds affect the numbers and types of protozoa and bacteria in the rumen. A small particle size of feed and a fast rate of passage of the feed through the ruminant decreases protozoal numbers. Full feeding of a concentrate ration and an acid pH in the rumen also tend to reduce protozoa numbers. Bacteria numbers tend to increase as the protozoa numbers decrease. Knowledge of rumen microflora population changes on different rations is lacking. It is known that restricted-roughage rations will generally cause lower protozoal numbers. Since whey is an available source of lactose and …


Flavor Preference And Stability Of A Low-Fat Dairy Spread, James Robert Miller Jan 1970

Flavor Preference And Stability Of A Low-Fat Dairy Spread, James Robert Miller

Electronic Theses and Dissertations

Low-fat dairy spread has been defined as a product which contains only dairy ingredients and has a lower fat content than the commonly used spreads, butter and margarine (5). Although some low-fat spreads have contained very little fat, most of those which have been developed during the past 30 years have contained about one-third to two-thirds as much fat as the commonly used spreads and have had a higher protein content. ·The low-fat dairy spread studied in this project contained about ten times more protein and only one-half as much fat as butter and margarine. The present day justification of …


Effect Of Days Open On Lactation Production, Roger L. Ripley Jan 1970

Effect Of Days Open On Lactation Production, Roger L. Ripley

Electronic Theses and Dissertations

Accurate evaluation of dairy production records is essential if dairymen are to establish and maintain profitable dairy herds and efficient culling programs. Improper record evaluation may result in. saving breeding stock that otherwise might be eliminated. Many factors may influence the validity of individual production records. Adjustment factors, currently in use by the United States Department of Agriculture (USDA) for sire and cow evaluations, are generally accepted as removing the majority of these influences. Consequently, these factors are invaluable to practical dairymen. The adjustment factors, suggested by McDaniel, et al. (24) in 1967, take into account the geographical location, season …


Abnormal Milk Evaluations In Eastern South Dakota Milk Plants And Dairy Herds, Edwin J. Kleen Jan 1970

Abnormal Milk Evaluations In Eastern South Dakota Milk Plants And Dairy Herds, Edwin J. Kleen

Electronic Theses and Dissertations

For many years bovine mastitis has been a major problem for dairy producers, the seriousness of which can be measured by the volumes of literature which have been written about it as well as the economic losses incurred by the dairy industry because of it. The fact that mastitis is still a virulent disease in spite of the vast amount of research conducted on it would suggest either that the underlying causes of mastitis still are not completely understood or that the knowledge gained through research has not been presented effectively to those who need it most—namely the dairy farmer. …


The Effect Of Harvesting And Storage Methods On Chemical Composition And In Vitro Digestibility Of First Cutting Alfalfa Hay, Perry A. Fales Jan 1970

The Effect Of Harvesting And Storage Methods On Chemical Composition And In Vitro Digestibility Of First Cutting Alfalfa Hay, Perry A. Fales

Electronic Theses and Dissertations

The importance of alfalfa hay in dairy cattle feeding is generally acknowledged. The reasons why alfalfa is used so extensively in dairy cattle rations are due to its high protein content, high acceptability by cattle, its wide ·area of adaptation, and high yields. A popular way of handling the forage is to put it up as hay. South Dakota produced 3,261,000 tons of alfalfa hay in 1968. There were 73 million tons of alfalfa hay produced in the United States during 1968 (10) making it a crop of major importance. Farming practices have changed considerably the last ten years. Among …


Indoor Versus Outdoor Calf Rearing At Three Weaning Ages, Larry J. Jorgenson Jan 1969

Indoor Versus Outdoor Calf Rearing At Three Weaning Ages, Larry J. Jorgenson

Electronic Theses and Dissertations

In order to be profitable, a dairy herb must have good heifers to meet replacement needs. According to USDA (51), these needs are substantial because 25% of the cows in an average herd must be replaced each year as they no longer return a profit. Meeting these herd replacement needs has long been a serious problem of the dairyman. Nation-wide calf loss estimates ranged between 8 and 25% with an estimated annual loss to the industry of $50 million (10). South Dakota dairymen are not immune to these mortality losses and some studies (28, 52) indicate that their losses may …