Browsing by Author "Jerry Spears, Committee Member"

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DFM/Probiotic effects on gastrointestinal tract development and immune function of broiler chicken
(2009-11-11) Qiu, Rongsheng; Jim Croom, Committee Co-Chair; Jerry Spears, Committee Member; Jack Odle, Committee Member; Matt Koci, Committee Chair
Effects of dietary fiber and other nutrients on swine manure odorants
(2007-08-16) Zhang, Weifang; Jerry Spears, Committee Member; Jack Odle, Committee Member; Eric van Heugten, Committee Chair; Theo van Kempen, Committee Member; Vivek Fellner, Committee Member
Effects Of Feeder Space and Feeding Programs During Rearing and Laying On Broiler Breeder Reproductive Performance and Livability.
(2010-10-29) Leksrisompong, Nirada; John Brake, Committee Chair; Edgar Oviedo-Rondon, Committee Chair; Jerry Spears, Committee Member; Charles Stark, Committee Member; Craig Sullivan, Committee Member
Effects of Protected Fat When Fed to Dairy Cattle and the Interaction Between Supplemental Fat and Antibiotics in Mixed Cultures.
(2003-09-22) Daves, Meredith Gail; Joe Cassady, Committee Member; Vivek Fellner, Committee Chair; Jerry Spears, Committee Member
Fat is added to diets of lactating dairy cattle as an affordable method of increasing the amount of energy available to the animals. Unsaturated fatty acids are desirable end-products of milk production. However, their presence in the rumen can be toxic to ruminal bacteria, which will then decrease digestion. Unsaturated fatty acids are biohydrogenated into saturated fatty acids by specific bacteria in the rumen, which will decrease positive benefits associated with their consumption. Our first study evaluates the efficiency of calcium salts VALFEED 100M and VALFEED 200 in protecting unsaturated fatty acids from biohydrogenation in the rumen and also observes the effects of these 'protected fats' on lactation performance. Twenty-eight Holstein cows in early lactation were divided equally into four different treatment groups: 1) Control (with no supplemental fat); 2) Prilled fat; 3) Calcium salt of VALFEED 100M; 4) Calcium salt of VALFEED 200. Fat supplements were added to diets in place of corn in the concentrate mix at 3.2% of total dry matter intake. Cows were housed in free stalls equipped with Calan gates. The cows were fed twice daily, at 0800 and 1500 in amounts to allow ad libitum consumption. Weekly feed samples were taken and dried in order to calculate daily dry matter intake. Milk production was measured daily, and milk fat and protein content were analyzed at days 30 and 90. Body weights were taken at the beginning (day 0) and the end (day 90) of the trial. Prilled and VALFEED 100M fat supplements decreased (P <0.05) dry matter intake. Body weights were higher (P <0.05) in cows fed the control diet than those fed the prilled and VALFEED 100M diets. VALFEED 200-treated cows had similar (P >0.10) body weights when compared to all treatment groups. Milk yield was highest in cows fed VALFEED 200 (37.1 kg/d), and cows fed prilled and VALFEED 100M diets had lower (P <0.05) milk yields than those fed the control diet (32.0 kg/d, 32.8 kg/d, and 35.1 kg/d, respectively). Feeding VALFEED 100M significantly decreased (P <0.05) milk fat percentage when compared to the control and prilled diets. VALFEED 200 feeding did not significantly alter milk fat percentage when compared to prilled and control diets. Both VALFEED 100 and VALFEED 200 decreased (P <0.05) milk protein percentage. Feeding VALFEED 100M and VALFEED 200 resulted in an increase (P <0.05) in the cis- and trans- isomers of oleic acid (C 18:1) content of milk when compared to the control and prilled treatments. Both VALFEED 100M and VALFEED 200 also increased (P <0.05) linoleic acid (C 18:2) content in milk fat. The addition of VALFEED 100 to dietary rations depresses milk fat percentage (P <0.05) and increases (P <0.05) the percentage of trans-fatty acids in the milk when compared to the addition of VALFEED 200, suggesting that VALFEED 100 is less inert in the rumen than VALFEED 200. As previously mentioned, fat can be used as a feed additive to provide additional energy for the diet, but it also affects ruminal fermentation by decreasing waste loss and increasing feed efficiency. Ionophores, such as monensin, are drugs that alter ion transport and concentration gradients in specific ruminal bacteria. In doing so, they are capable of altering rumen fermentation and improving feed efficiency. Bacitracin is a non-ionophore antibiotic that affects similar bacteria as monensin but has a different mode of action. It also increases feed efficiency in ways similar to monensin. But, when ionophores are added to diets supplemented with fat, ionophore efficiency decreases. This interaction stimulated interest in conducting our second study. The inclusion of fat and ionophore-antibiotics to experimental diets and the sequence of their addition were investigated. Rumen fluid collected from a dry, fistulated cow was incubated in 8 fermentors for a total of eight days. The first two days of the trial represent a stabilization period. On day three, two fermentors received monensin (50 ppm), two received bacitracin (50 ppm), and the other four received fat (4.4% of DMI). On day 6, one of the fermentors receiving monensin and one receiving bacitracin got fat. The other two continued receiving either only monensin or only bacitracin. Of the remaining four fermentors that were receiving fat, one received monensin, one received bacitracin and the other two continued to only receive fat. Methane and pH were recorded several times daily. Culture samples were taken on days 2, 5, and 8 for analysis of SCFA, LCFA, NH3, and PCR. There were no statistical differences (P >0.10) in acetate and propionate production (mM) among treatments. However, the concentration of butyrate was higher (P <0.01) in cultures treated with monensin when compared with cultures treated with bacitracin. The proportion of C 18:2 in rumen bacteria increased (P <0.05) when monensin was added prior to fat in comparison to when fat was added prior to monensin. Preliminary results indicate that the sequence of fat and antibiotic addition effects the growth of Gram- and Gram+ bacteria. The results from this study show that the sequence in which fat and ionophore-antibiotics are added to mixed rumen cultures can alter the response of bacteria to the additives.
An Evaluation of the Feeding Value of Prolina Soybean Meal in Male Broiler Chicken Diets by Altering Dietary Protein, Amino Acids, and Metabolizable Energy
(2005-03-31) Lenfestey, Bridget Ann; John Brake, Committee Chair; Sam L. Pardue, Committee Co-Chair; Jerry Spears, Committee Member; Richard F. Wilson, Committee Member
The purpose of this research was to evaluate Prolina, a soybean cultivar developed through traditional plant breeding, as a potential feedstuff in male broiler chicken diets. Prolina soybeans were selected to possess relatively higher oil and protein while maintaining agronomic yields to improve the potential profitability of the soybean grower. Since a large portion of the value of the soybean lies in the soybean meal used as a primary protein source in poultry and other livestock diets, six experiments were designed to investigate the effects of Prolina soybean meal when substituted for commercially available soybean meals in broiler diets. Two batches of Prolina soybeans and commercial variety soybeans were grown and processed into soybean meals. Several laboratory analyses were performed on the soybean meal samples to estimate available nutrient content such as percentage amino acids and metabolizable energy. Various strains and crosses of male broilers in both battery cages and floor pens were utilized. The response of the broilers to the dietary treatments containing the different soybean meals were generally measured by body weight, feed efficiency, and livability. Although the experiments were able to establish that broilers could respond to increased dietary crude protein and metabolizable energy with increased body weight and improved feed efficiency, it was difficult to differentiate this effect among the soybean meal sources. However, it was observed that when dietary metabolizable energy was limiting in a diet that was formulated to be deficient in crude protein, Prolina soybean meal fed broilers had higher body weight as compared to those fed the commercial variety soybean meals. In the final experiment, Prolina soybean meal fed broilers had the best overall performance (measured using the European Efficiency Factor) compared to birds fed commercial variety soybean meal under heat stress conditions. Supplementation of amino acids to the diet did not directly improve broiler performance, however, it was shown that birds fed diets supplemented with L-threonine had improved livability under heat stress conditions. The six experiments conducted established that Prolina soybean meal could be substituted for commercial variety soybean meals without any decrease in broiler performance. Positive results for Prolina soybean meal were found when dietary crude protein and metabolizable energy were limiting or during heat stress conditions. Therefore, Prolina soybean meal may have an increased value in areas where these circumstances may exist.
Increasing Dietary Phosphorus Retention and Decreasing Fecal Phosphate Excretion in Modern Commercial Broilers
(2004-02-08) Auman, Stephen K.; Peter Ferket, Committee Member; Frank Edens, Committee Member; Jim Garlich, Committee Chair; Jerry Spears, Committee Member
Phosphorus is a potential environmental pollutant. The objectives were to minimize fecal phosphorus (P) by optimizing the efficiency of utilization of dietary available phosphorus (aP) for carcass and skeletal growth. In two experiments, Arbor Acres X Arbor Acres male broiler chicks were fed from 0-3 weeks of age a diet adequate in vitamin D, calcium (Ca) and P (National Research Council (NRC) 1994). Experiment 1A assessed body weight gain and whole dry skeletal weight at 2,4,6,and 8 wks of age. Experiment 1B used a central composite, rotatable experimental design with dietary Ca from 0.55% to 0.85% and aP from 0.15% to 0.45% from 4 to 7 wks of age. Decreasing the dietary Ca:aP produced a statistically significant (P<.05) increase in %P retention and a decrease in % fecal total P. Experiment 2 used a dietary Ca:aP = 2.0. In 2A, aP varied from 0.25% to 0.4% for age 3-6 wks and 0.25% to 0.35% for age 6-7 wks. There were no effects on body weight or bone ash. Experiment 2B was a P retention, depletion/repletion study from 28 to 45days (d) of age. The 7 treatments varied in dietary aP from 0.25% to 0.40% for age 28-40 d and from 0.30 to 0.45% for age 40-45 d. Measurements were taken from 41 to 45 d of age. Retention of total P and phytate P were significantly increased and total fecal P and fecal phytate P were significantly reduced compared to the NRC-based control treatments when the broilers were fed a P-adequate diet from 40-45 d of age after having been fed a low P diet from 28-40 d of age. Body weight and bone ash were not affected. In conclusion, subsequent experimental designs should evaluate treatments in which dietary Ca and aP would bracket the following values: (1) dietary Ca:aP =2.22, aP=.45% for 1-20 d of age; Ca:aP=2.0, aP=.35% for 20-30 d of age; Ca:aP=1.7, aP=.35% for 30-40 d of age. Repletion would utilize Ca:aP=2.0, aP=.35 until market age.
Performance of Growing Beef Heifers Grazing Stockpiled Tall Fescue and being Fed Differing Amounts of Corn Gluten Feed and Soyhulls.
(2010-06-30) Scruggs, Jessica; Matt Poore, Committee Chair; Mark Alley, Committee Member; Jerry Spears, Committee Member