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The Effect Of Nocturnal Sampling On Semen Quality And The Efficiency Of Collection In Bovine Species, Jennifer H. Yates Jan 2002

The Effect Of Nocturnal Sampling On Semen Quality And The Efficiency Of Collection In Bovine Species, Jennifer H. Yates

LSU Master's Theses

The objective of this study was to evaluate two semen collection schedules utilizing the assumed behavioral differences between bovine species. The efficiency was measured by bull behavior and semen quality parameters. Four Holstein and four Brahman bulls were collected each during a morning and a night collection time weekly. Ejaculates (n=64) were obtained via artificial vagina over four-weeks. To avoid masking benefits of night collection, the first collection of the week was alternated between night and day. Two collection teams were employed to reduce the time needed for collection, and the variability in collection method. Sampling order and collection team …


The Effects Of Growth Hormone Or Melatonin On The Reproductive Axis Of Stallions, William Andrew Storer Jan 2002

The Effects Of Growth Hormone Or Melatonin On The Reproductive Axis Of Stallions, William Andrew Storer

LSU Master's Theses

Two experiments were conducted to determine the effects of growth hormone (GH) or melatonin on the reproductive axis of the stallion. In Experiment 1, nine stallions were treated with GH (20 µg/kg BW) or saline for 21 d starting in January. During the last week of treatment, stallions were subjected to low and high dose injections of luteinizing hormone (LH), as well as low and high dose combined injections of gonadotropin releasing hormone (GnRH) and thyrotropin releasing hormone (TRH). Two months after the onset of GH treatment, semen was collected from all stallions every other day for 2 weeks. Treatment …


Follicular Growth And Development And Gonadotropin Response Of Mares Treated With Dihydrotestosterone And Estradiol Benzoate, Scarlett Lynn Mcmeen Jan 2002

Follicular Growth And Development And Gonadotropin Response Of Mares Treated With Dihydrotestosterone And Estradiol Benzoate, Scarlett Lynn Mcmeen

LSU Master's Theses

An experiment was conducted to determine the effects of dihydrotestosterone (DHT) and estradiol benzoate (EB) given simultaneously on concentrations of FSH and LH and the associated follicular activity, and to monitor the subsequent recovery of the gonadotropes and follicular growth following treatment with either DHT or EB. Twelve mares were assigned to daily treatments of DHT (150 Fg/kg BW) plus EB (22 Fg/kg BW) from d 0 through 30 (Phase I). Beginning on d 31, mares were randomly assigned to one of three treatment groups: 1) oil, 2) DHT (150 Fg/kg BW), or 3) EB (22 Fg/kg BW). On d …


The Effects Of Phytase In Nutritionally Adequate Diets, Diets Deficient In Calcium And Phosphorus, And The Interactive Effects Of Phytase And Eimeria Acervulina Infection In Broiler Chicks, Brandy Centrell Watson Jan 2002

The Effects Of Phytase In Nutritionally Adequate Diets, Diets Deficient In Calcium And Phosphorus, And The Interactive Effects Of Phytase And Eimeria Acervulina Infection In Broiler Chicks, Brandy Centrell Watson

LSU Master's Theses

Six experiments were conducted to determine the interactive effects of Eimeria acervulina (E. acervulina) infection and phytase, and the effects of phytase in nutritionally adequate diets and in diets deficient in Ca and available P (aP). Corn-soybean meal (C-SBM) diets were used. In Exp 1, treatments were: 1) C-SBM, 1.0% Ca and 0.45% aP; 2) C-SBM, 0.80% Ca and 0.25% aP; 3) Diet 1 + 600 FTU phytase/kg; 4) Diet 2 + 600 FTU phytase/kg; 5 to 8) Diets 1 to 4 but infected with coccidiosis. Weight gain (ADG), feed intake (ADFI), and gain:feed were reduced (P < 0.01) by the coccidial infection and the reduction in Ca and aP. Phytase increased (P < 0.02) ADG and ADFI, regardless of the Ca and aP content of the diet or the presence of coccidiosis. Gain:feed was increased by phytase but only in uninfected chicks (phytase x coccidiosis interaction, P < 0.02). Phytase increased (P < 0.02) bone ash percentage but only in diets deficient in Ca and aP (P < 0.01). Experiments 2 and 3 included only treatments 1 to 4 of Exp 1. The reduction in Ca and aP reduced (P < 0.01) ADG, ADFI, and gain:feed. Phytase addition increased (P < 0.02) ADG and ADFI in diets deficient in Ca and aP and in the nutritionally adequate diets. Experiments 4, 5, and 6 were conducted to determine the effects of phytase on intestinal transit time in broilers. Diets were: 1) C-SBM, 0.9% Ca and 0.35% aP; 2) C-SBM, 0.80% Ca and 0.25% aP + 600 FTU phytase/kg. Transit time on Day 1, but not on Day 7, was faster (P < 0.03) in chicks fed phytase. These data indicate that phytase is effective in the presence of a coccidial infection, but it may not be as effective as in uninfected chicks. Futhermore, phytase increases growth in diets deficient in Ca and aP and in diets formulated to be adequate in all nutrients. This increase in growth may be due to a faster transit time of feed through the digestive tract, resulting in a greater feed intake and gain.