No description available.

No description available.

Considerable changes have occurred in environmental regulations in recent years, only one of which is the requirement of stand alone heifer operations and feedlots to carry environmental permits. While growth of heifers is a widely researched topic, publications concerning nutrient utilization, partitioning, and excretion are scarce and are becoming necessary. That combined with the fact that feeding programs for heifers are highly variable from region to region and even from farm to farm indicated the need to examine the effects of diet on nutrient utilization. Therefore, the objective of this work was to evaluate how differences in levels of dietary protein and energy will affect growth and nutrient utilization in heifers from birth to calving. Two projects were conducted, one in 20 month old bred heifers where forage level in the diet was altered to provide the required nutrients in less feed and one in young calves where energy and protein content of the milk replacer was altered. Three diets were fed to 18 (n=6), 20 month old heifers who were in late gestation; the first was the high forage (HF) ration which was 90.7% forage and 9.3% concentrate, the second was a by-product (BP) ration which was designed to have the same level of fiber as the HF ration, however soybean hulls and cottonseed hulls were added at the sacrifice of the grain mix which increased the fiber content; the last ration was the low forage (LF) which was 54.7% concentrate and 45.3% forage and was fed at ~89% of the ad libitum intake of heifers fed the HF ration. Heifers fed the HF ration had greater fecal excretion compared to those fed LF, however heifers fed the LF ration exceeded the heifers fed HF and BP by 4.5 and 2.5 times, respectively, in urine volume excretion (40.2 vs. 8.9 and 16.9 kg/d, respectively). Although total N excretion (kg/d) was not different, heifers fed the LF ration tended to partition more N to urine than to feces. Phosphorus excretion in the feces was not different, however heifers fed HF and BP tended to have greater fecal P (P < 0.06). Urinary P excretion was less in heifers fed HF and BP compared to LF, however these heifers were excreting as much urinary P as a lactating cow. Calves were purchased from a commercial dairy at 3 d old (&#177; 1d) and transported to the VT Dairy Center. They remained on study until 63 d when they were harvested for body composition. Four treatment diets were fed; a control milk replacer (24/17; 24% CP, 17% Fat), a high protein, low fat (32/17; 32% CP, 17% Fat), a high protein, high fat (31/24, 31% CP, 24% fat), and that same 31/24 milk replacer fed at 1460 g/d powder (31/24+). Calves were offered a 20% cottonseed hull starter at 1 d after arrival to the VT Dairy Center. Calves fed 24/17 consumed more starter than those fed the other milk replacers and therefore had a lower apparent digestibility and greater fecal excretion. Fecal N excretion was not different, although calves fed 24/17 tended to have greater fecal N excretion. Urinary N excretion was higher in calves fed 31/24+ compared to those fed 31/24. Total N excretion and N retention were not different. Empty body weight (EBW) gain was greater in calves fed 31/24+ compared to 31/24, however those same calves also had a higher percent of EBW as fat. Calves fed 32/17 had the most lean gain (in the form of N gain) compared to those fed extra energy (31/24) and also had a higher N as a percent of EBW. Limit feeding Holstein heifers late in gestation did not reduce nutrient excretion, however, more digestible nutrients were available to the heifer and fetus. Heifers in late gestation are likely over fed P and therefore excrete nearly everything they consume which has negative implications for nutrient management planning. Calves fed a low protein, low fat milk replacer did not grow as well as calves fed higher protein. Nitrogen retention and CP gain were higher when protein was at least 31% and fat was at least 17%. Feeding fat over 17% only increased fat gain and not CP gain. Overall, paying for extra nutrients in bred heifer diets seemed to be beneficial, however, feeding above 31% CP and 17% fat increased nutrient loss to the environment. / Ph. D.

Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2016-03-15T15:04:04Z No. of bitstreams: 2 arquivototal.pdf: 509626 bytes, checksum: 30e4f0c026fa899a21a33f324f18a271 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-03-15T15:04:04Z (GMT). No. of bitstreams: 2 arquivototal.pdf: 509626 bytes, checksum: 30e4f0c026fa899a21a33f324f18a271 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2010-12-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The aim of this study was to evaluate the behavior of peanut (Arachis hypogaea L.) variety BR-1 under different periods of application of organic sources. The experiment was conducted in a greenhouse without temperature control, at the headquarters of EMBRAPA /CNPA, Campina Grande, from October 2009 to March 2010. The treatments were distributed in 4 x 3 factorial arrangement, consisting of four periods of manure application (0, 15, 30 and 45 days before sowing) and three organic sources (manure cattle, goat and poultry) with four replications in completely randomized design. Peanuts have a significant effect on age assessment in main stem length, leaf area and number of branches, was also significant in interaction between age assessment with organic sources applied to the last variable. Regarding of the peg not reach the ground, number of pods produced and root dry matter were influenced significantly by the organic sources applied, while the number of normal pods and shoot dry matter showed a significant effect for treatments, both in times of application and organic sources. The use of poultry manure as organic source provided higher biomass of peanut. The peanut has benefited from fertilization with poultry manure to produce more normal pods and, consequently, increased production of pods. The peanut production was negatively influenced by the use of poultry manure, goat manure and cattle manure before sowing. / O objetivo do presente estudo foi avaliar o comportamento do amendoim (Arachis hypogaea L.) var. BR-1 quando submetida a diferentes épocas de aplicação de fontes orgânicas. O experimento foi conduzido em casa de vegetação, sem controle de temperatura, nas dependências da EMBRAPA/CNPA, em Campina Grande, no período de outubro 2009 a março de 2010. Os tratamentos foram distribuídos em arranjo fatorial 4 x 3, constituídos de quatro épocas de aplicação de esterco ( 0, 15, 30 e 45 dias antes da semeadura) e três fontes orgânicas (estercos bovino, caprino e de galinha) com quatro repetições, em delineamento inteiramento casualizado. O amendoim mostrou efeito significativo sob idade de avaliação em comprimento da haste principal, a área foliar e número de ramos, também foi significativo na interação entre idade de avaliação com fontes orgânicas aplicadas para o ultimo variável. No que tange ginóforos que não atingiram o solo, número de vagens produzidas e a matéria seca de raiz, foram influenciadas significativamente pelas fontes orgânicas aplicadas, enquanto o número de vagens normais e matéria seca da parte aérea mostraram efeito significativo aos tratamentos, tanto nas épocas de aplicação como fontes orgânicas. A utilização de esterco de galinha como fonte orgânica proporcionou plantas de amendoim com maior acúmulo de biomassa. A cultura do amendoim beneficiou-se da adubação com esterco de galinha para produzir mais vagens normais e, consequentemente, maior produção de vagens. A produção do amendoim foi influenciada negativamente pela utilização dos estercos de galinha, caprino e bovino, antes da semeadura.

No description available.

Loss of nitrogen (N) from dairy manure during storage is an issue of economic, environmental, and social concern for farming communities. The lost N 1) decreases the value of manure as a fertilizer and is an economic loss because supplemental inorganic N fertilizer is purchased to meet N needs on farms; 2) produces the potential pollution for water and air systems, thereby damaging the associated ecosystems; 3) causes challenges to human health. Thus, it is vital to manage and use N in an efficient and eco-friendly manner. N mineralization is a pathway in the N cycle, which converts organic N to inorganic N that is more susceptible to loss. The objective of this study was to conduct lab-scale experiments to assess the effects of temperature, manure solids content, using manure seed and autoclave sterilization operation at the start of storage, and storage time on the N mineralization and the associated microbial community during the storage of liquid dairy manure. Manure scrapped from the barn floor of a commercial dairy farm and diluted to make experimental stocks with high (46 to 78 g/L) and low (19 to 36 g/L) total solids (TS), to simulate what is typically transported to the manure storage pit was used. The manure was incubated in the laboratory at three temperatures (10, 20, and 30°C) for two storage periods (60 and 180 days). Manure samples were taken at different storage time for analyses. The results showed that temperature and using sterilization operation at the start of storage had significant effects on N mineralization for both storage periods (p < 0.05). The highest N mineralization rate occurred at 30℃, which rate constant (k) was 0.096 week-1. While, the lowest N mineralization occurred at 10℃, and its corresponding k was 0.013 week-1. The concentrations of mineralized N (Nm) with non-sterilized (R) manure were significantly higher than that with sterilized (R0) manure (p < 0.05). Compared to that with high TS (H) manure, the concentrations of Nm were significantly higher with low TS (L) manure after 180-d storage (p < 0.05). Raw manure augmented with manure seed (MS) had significantly higher Nm than the manure seed only (SO) (p < 0.05). In order to investigate the changes of microbial community in manure, samples were collected on days 0, 30, 90, and 180 for the 180-d storage experiment, and days 0, 30, and 60 for the 60-d storage experiment, and then manure DNA under different condition was successfully extracted from collected samples and used for 16S rRNA sequencing. This study provided a more comprehensive understanding of the impact factors for manure storage, and was expected to clarify the relationship between N mineralization and the associated microbial community. / Master of Science / Loss of nitrogen (N) from dairy manure during storage is rooted in the process of degradation via microbial activities. During storage of dairy manure, up to 60% of N can be lost to the environment (the air, rivers, groundwater, etc.), causing damages such as global warming and water pollution. However, it is challenging to manage and reduce the N lost during manure storage because of lack of comprehensive knowledge of the complex microbial activities in manure storage structures. Thus, the long-term goal of this study is to discern the interactions of the physical, chemical, and microbial processes that affect the N transformation. The generated information will help to mitigate/minimize the loss of nitrogenous gases during storage of dairy manure. The specific objectives included: 1) to evaluate the effects of selected factors (including storage time, temperature, manure solids content, using manure seed and sterilization operation at the beginning of storage) on N mineralization during storage of liquid dairy manure and determine the associated N mineralization rate; 2) to reveal the microbial communities in stored liquid dairy manure under different conditions (listed above). The outcome of this study could be used to refine N mineralization input parameter of manure storage submodules of the process-based models such as Manure DeNitrification-DeComposition model (Manure-DNDC) and Integrated Farm System Model (IFSM) with the goal to improve their accuracy of estimating or accounting for the fate or cycling of N in dairy manure during storage.

Enhanced biological phosphorus removal (EBPR) has been widely used in municipal wastewater treatment, but no previous studies have examined the application of EBPR to treat dairy manure. This study was conducted to evaluate the (i) performance of pilot-scale EBPR systems treating liquid dairy manure, to balance the ratio of nitrogen to phosphorus in manure to meet crop nutrient requirements, (ii) effects of dissolved oxygen and solids retention time on the efficiency of EBPR, and (iii) effectiveness of gravity thickening for reducing the volume of harvested EBPR aerated mixed liquor. Two pilot-scale EBPR systems were used in this study. The ratio of the manure chemical oxygen demand expressed as volatile fatty acids to phosphorus used ranged from 18:1 to 45:1. The phosphorus removal efficiencies of the EBPR system were investigated at three solids retention times (4, 6 and 10 d), and three dissolved oxygen levels (3, 4 and 6 mg O₂/L). The total phosphorus removal was highest (84%) at 10 d solids retention time and lowest (63%) at 4 d solids retention time. The sludge from the 6 d solids retention time tests had better sludge settling characteristics with a sludge volume index of 62 mL/g compared to 80 mL/g for the 4 d solids retention time. The EBPR system achieved 90% dissolved reactive phosphorus removal when the system was operated at 4 mg O₂/L, and the ratio of nitrogen to phosphorus in effluent increased to about 5:1, which was higher than the normal ratio in dairy manure. On the other hand, phosphorus removal performance deteriorated when dissolved oxygen level was 3 mg O₂/L. In the gravity thickening tests, 93-95 % total suspended solids (TSS) was removed from the settled supernatant, with 1.2 to 1.54 % total solids (TS) in the settled solids after 90 min gravity-induced thickening. The extent of phosphorus release during gravity thickening process needs to be further investigated. / Master of Science

No description available.

No description available.

No description available.