Download or read book Puberty Development and Reproductive Performance in Beef Heifers Fed Rations Supplemented with Oregon By product Feeds written by Keely E. Oswald and published by . This book was released on 2011 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the majority of management scenarios, it is imperative that beef replacement heifers calve at two years of age. In order to achieve this goal, yearling heifers should reach 60 to 65% of their mature body weight by 13 months of age. Feed costs represent 75 to 80% of the total costs incurred by a beef producer in the development of replacement heifers. At current beef prices, it takes at least three live calves before the heifer development period is paid. Feed costs have become more problematic and volatile in recent years. Increasing pressure for the use of grains in brewing and for ethanol production has inflated feed prices. Demand for grain has also resulted in more ground being taken out of forage production which has resulted in much higher hay prices. However, the increased use of feedstuffs by fermentation industries results in by-product feeds that can be utilized best by beef cattle. Utilization of these by-product feedstuffs by cattle not only results in cheaper feed, and therefore production costs, but also enhances the sustainability of the fermentation industry. The objective of this research was to evaluate puberty onset and subsequent reproductive performance in heifers fed a traditional ration with grass hay to rations in which grass hay was substituted with either grass-seed straw or a grass seed straw-brewer's grain silage. Eighteen heifers (initial body weight = 561±11.4 lbs and age = 278±2.4 d) were randomly assigned to one of three treatment groups: grass hay (HAY), grass seed straw (STRAW), or grass seed straw-brewer's grain silage (SILAGE). Heifers were individually fed twice daily using Calan gates for 22 weeks. Heifers were weighed and 10-ml blood samples were recovered weekly. Plasma was recovered by centrifugation and stored at -20° C until analyzed for progesterone and Anti-Mullerian Hormone (AMH) concentrations. Puberty onset was defined as plasma progesterone exceeding 1 ng/ml. At week 21, heifers were estrous-synchronized using a CIDR-Select Synch protocol. Heifers displaying estrus were inseminated 12 h after onset with one straw of frozen semen. Heifers not displaying estrus were injected with PGF2[subscript alpha] 10 d after the initial PGF2[subscript alpha] injection in the CIDR-Select Synch protocol and subsequently observed for estrus and inseminated as described. Mean ages and weights of heifers were similar (P>0.10) across all treatments at the start of the feeding period. Heifer ages at puberty did not differ (P>0.10) due to treatment. Average daily gain of heifers during the feeding trial fed SILAGE were lower (P0.0005) than heifers fed either HAY or STRAW, However, no differences (p0.10) were found in body weight at puberty onset. However, body weights of heifers fed SILAGE were lower (P0.05) than heifers fed either HAY or STRAW at the starts of the breeding and calving seasons. No differences (P0.10) in services per conception, calving ease scores, calf vigor scores, or calf birth weights were observed between treatments. These results suggest that heifers fed the less expensive, by-product STRAW ration have weight gain and reproductive performance similar to heifers fed a traditional HAY ration. Although heifers fed the SILAGE diet had lighter body weights, a negative impact on reproductive measurements was not observed, suggesting the ration was adequate to support reproductive performance similar to a traditional HAY ration.
Download or read book Influence of Total Feed and Protein Intake on Reproductive Performance in the Beef Female Through Second Calving written by J. N. Wiltbank and published by . This book was released on 1965 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Increased Nutruent Intake on Growth Reporduction and Productivity of Beef Heifers written by Shelby Lynn Rosasco and published by . This book was released on 2016 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two experiments were conducted to determine the influence of increased nutrient intake on beef heifer performance and reproductive efficiency. Experiment 1 evaluated the effect of heifer development supplementation regimen on heifer performance and reproduction during the pre- and post-breeding period. Heifers were developed grazing native range and supplemented to achieve 1) a constant rate of gain (CG) or 2) low rate of gain for the first half of development period followed by a high rate of gain for the remaining half of the development period (LoHi). Heifer performance was similar over the development period, with supplementation regimen having no effect on reproductive performance between treatments. Feed costs and costs to develop 1 pregnant heifer was decreased for LoHi heifer compared to CG heifers due to supplementation strategy. Following breeding heifers were stratified and randomly assigned to graze native pasture and supplemented at a low (CON) or high (High) rate for 30 d. CON heifer had a trend for increased AI pregnancy rate compared to High heifers, indicating a potential influence of nutrition on reproductive success. Accurately predicting forage nutrient composition during Exp. 1 impacted performance, altering predicted gains. In Exp. 2 heifers were individually fed a silage based diet to imitate treatments and predicted gains from Exp. 1. Heifer BW was similar among treatments over the development period. Although total ADG was similar among both treatment, ADG and intake was increased for CG heifers during the first 45 d, while LoHi heifer ADG and intake was increased over the last 45 d of the development period. Feed efficiency increased for LoHi heifers and decreased for CG heifers over the treatment period, indicating a potential compensatory gain effect. Reproductive traits measured were not impacted by development strategy; however, additional research is warranted to fully understand the impact of increased nutrient intake and compensatory gain on metabolic hormones, oocyte competence, and follicular microenvironment. In summary, these experiments provided further evidence of the impact of nutrition on reproductive performance, with future research warranted specifically investigating follicular fluid metabolic hormone concentrations and gene expression in oocytes and granulosa cells, and their impact on reproductive success.
Download or read book Hay Quality Breed and Ovarian Development Effects on Onset of Puberty and Reproductive Performance of Beef Heifers written by Randy Charles Perry and published by . This book was released on 1989 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Post weaning Development Regimen on Reproductive Performance of Beef Heifers from First to Second Pregnancy written by Jay D. Olsen and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Feeding Perennial Peanut Hay on Growth Development Attainment of Puberty and Fertility in Beef Replacement Heifers written by Kalyn Marie Bischoff and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: The objective of this study was to determine the influence of supplemental feeding of perennial peanut hay (Arachis glabrata Benth.) on growth performance and age at puberty in growing beef cattle heifers. Over a two year period, 120 heifers were randomly allocated into pens and assigned to one of three supplement treatments: 80% corn and 20% soybean meal supplement (CSBM), perennial peanut hay supplementation (PPH), and a control which received no supplement (CON). All heifers received ad libitum access to bermudagrass hay (Cynodon dactylon (L.) Pers.) during the 140-developmental phase. Following the developmental phase, heifers were comingled for a 77 d breeding season during the breeding phase. Period influenced ADG (P = 0.002) and treatment effected ADG, with the CON tending (P = 0.06) to be have lesser ADG than the CSBM and PPH heifers. There was a treatment \U+00d7\ day interaction (P = 0.06) on mean body weight (BW) with heifers in the CON treatment being lighter at the conclusion of the development phase (P = 0.02). Total DMI during the 140-d development phase was greater (P
Download or read book Ovarian and Endocrine Dynamics Associated with Sexual Maturation in Beef Heifers and the Influence of Diet Weaning Age and Other Factors During Early Reproductive Development written by Chad Lamar Gasser and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: A series of experiments was designed to test the ability to induce precocious puberty in heifers and to determine the underlying mechanisms responsible for the precocious attainment of puberty. A model consisting of early weaning (3-4 months of age) and feeding a high-concentrate diet was used for each experiment. This method resulted in increased body weight gain. Additionally, precocious puberty was induced in a vast majority of heifers; and consequently, mean age at puberty was substantially reduced. Heifers that achieved precocious puberty did so at lesser body weights. In addition, subsequent estrous cycles continued after precocious attainment of puberty. In the first experiment, heifers that were weaned early and fed the high-concentrate diet exhibited a greater frequency of LH pulses leading to precocious attainment of puberty. In the second experiment, ovarian maturation was accelerated during the same period leading up to puberty. This was evidenced by increased maximum diameter of dominant ovarian follicles, increased duration of waves of ovarian follicular development, and increased peak estradiol concentrations during follicle waves. In the third experiment, estradiol-implanted, ovariectomized heifers that were weaned early and fed the high-concentrate diet escaped from estradiol negative feedback on LH secretion at a younger age, which was similar to the age at which ovary-intact heifers on the same diet attained puberty. It was concluded from these results that advancement of the decline in estradiol negative feedback on secretion of LH is the mechanism by which early weaning and feeding a high-concentrate diet induces precocious puberty in heifers. Essentially, the peripubertal period of development in heifers was shifted to a younger age with this model. A fourth experiment was conducted to determine the relative effects of timing of feeding the high-concentrate diet on age at puberty in early-weaned heifers. It was discovered that feeding the high-concentrate diet only for a period of 10 weeks after early weaning successfully advanced puberty to an extent similar to that of continuous feeding of the high-concentrate diet after early weaning. These experiments provide evidence that nutritional control during the early maturational period in heifers exerts substantial influence on timing of puberty.
Download or read book Nutritional and Management Strategies to Enhance the Reproductive Performance of the Cowherd written by Reinaldo Fernandes Cooke and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Four experiments were conducted to evaluate nutritional and management strategies to enhance the reproductive performance of forage-fed Brahman-crossbred females. Experiment 1 compared performance and physiological responses of replacement heifers consuming an energy-based supplement daily or 3 times per week at similar weekly amounts. Daily supplementation resulted in a normalized mRNA expression pattern of genes associated with nutritional metabolism and growth, reduced daily variation in plasma concentrations of urea nitrogen, glucose, and insulin, and increased hepatic mRNA expression and plasma concentrations of IGF-I. These beneficial physiological effects of daily supplementation were translated into the greater BW gain and hastened attainment of puberty and pregnancy detected in daily-fed heifers compared to heifers supplemented thrice weekly. Experiment 2 evaluated physiological responses of brood cows offered supplements similar to those of Experiment 1. Daily supplementation resulted in a normalized pattern of gluconeogenic enzyme mRNA expression, reduced variation in plasma concentrations of glucose and insulin, and improved cow nutritional status as observed by increasing plasma IGF-I concentrations.
Download or read book Effect of Supplemental Nutrient Source on Heifer Growth and Reproductive Performance and on Utilization of Corn Silage based Diets by Beef Steers written by Chad Michael Howlett and published by . This book was released on 2002 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Pre and Postweaning Nutrition on Fertility and Feed Efficiency in Beef Heifers written by Maggie K. Bloomsburg and published by . This book was released on 2018 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cattle in the Pacific Northwest graze a variety of forages which vary in quality. The effects of forage quality on heifer reproductive development and fertility is still under investigation. Therefore, the first objective was to investigate the effects of grazing different quality forages preweaning and postweaning on reproductive traits and feed efficiency in heifers. Although nutritional differences were present, pre- and postweaning treatments did not affect reproduction. This indicates different qualities of forage present in Idaho may be utilized for heifers. Feed costs represent a large portion of cattle producers' expenses. Selecting for feed efficiency allows producers to capitalize on these expenses. However, the effects of selecting for efficiency on reproduction is still undetermined. The second objective was to study the relationship between feed efficiency and reproductive development and fertility. No differences in reproductive traits were detected among heifers ranked as efficient, average or inefficient at utilizing feed for growth.
Download or read book Effects of Post weaning Development Regimen on Reproduction Performance of Beef Heifers from First to Second Pregnancy written by Jay D. Olsen and published by . This book was released on 1992 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Nutrition on Reproductive Physiology and Growth in Beef Heifers written by James Edward Blakely and published by . This book was released on 1964 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forty-eight Hereford heifers averaging 690 pounds were randomly assigned to three groups or 16 heifers each and wintered at three planes of nutrition from October 15, 1962 to May 27, 1963 (224 days). Daily rations were adequate in protein and high (12.65 1b. TDN), medium (9.66 1b. TDN) or low (4.24 1b. TDN) in energy. Slaughter data was obtained and a bioassay of the pituitary conduced. Heifers were exposed to bulls March 7, 1963 and pregnancy examinations were by rectal palpations. Fifteen of 16 heifers bred in lots fed a high energy ration were examined pregnant as compared to 14 of 15 heifers bred in lots fed a medium ration. Two heifers in the low energy lot bred and only one conceived. All were showing signs of estrus at the start of the trial but no visual signs could be detected in the low energy group at the time of breeding. Thyroid secretion rates were estimated in November, February and May. A significant decrease (P
Download or read book Effect of Level of Winter Feed Supplementation on Puberty and Subsequent Reproduction in Brahman Heifers written by Helton Mattana Saturnino and published by . This book was released on 1981 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agrindex written by and published by . This book was released on 1986 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of the Use of Hormones and Levels of Feeding on the Reproductive Performance and Blood Constituents of Beef Heifers written by James W. Menzies and published by . This book was released on 1962 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Use of Ultrasound Body Composition Measurements to Track Puberty in Heifers and to Predict the Reproductive Ability of Mature Beef Cows written by Mercedes Marambio and published by . This book was released on 2005 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Two experiments were conducted in an attempt to predict age at puberty in heifers and reproductive performance in cows with real-time ultrasound as one of the principal tools. We measured backfat, ribeye area, intramuscular fat and rump fat. Other measurements used in the heifers were body weight and hip height combined with metabolic and hormonal profiles (glucose, insulin, and progesterone). Weight was a significant variable to predict onset of puberty. We did not find statistical evidence that adding the ultrasound measurements as explanatory variables to the logistical regression model will improve the fitness of the model. However that does not mean there is no relationship between ultrasound measurements and age at puberty. Rump fat (RF) at least had a tendency (r 0.167 and P = 0.128) to be a valuable tool in the model for predicting puberty. The lack of statistical evidence may be caused by the limited data set. The initial analysis conducted with the cows identified a high correlation among several of the primary predictor variables (ultrasound measurements). That analysis demonstrated the possibility of a statistically significant relationship between the probability of a successful pregnancy and the lower quip measurement. Upper Quip (UQ) could be another Intramuscular fat (IMF) measurement of value and merits further investigation. The log likelihood test value for UQ was close (P = 0.06) to being significant.
Download or read book Effects of Feeding a High Fat Diet on Reproductive Performance in Pre and Postpartum Beef Heifers written by Gail M. Oss and published by . This book was released on 1993 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
