published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

A aloamamentação parece desafiar o princípio geral de que o cuidado materno deve restringir-se à própria prole. Embora a aloamamentação em cobaias domésticas Cavia porcellus - espécie em que um macho dominante pode reproduzir-se com várias fêmeas em um sistema de harém e em que os filhotes são precoces e capazes de ingerir alimentos sólidos logo depois do nascimento - já tenha sido observada, não foi submetida até o momento a um estudo sistemático. Na presente pesquisa, realizada com cobaias comuns (Etapa 1) e cobaias albinas (Etapa 2), buscamos descrever os aspectos básicos da interação fêmea-filhote ao longo das primeiras quatro semanas de vida dos filhotes, comparando a freqüência e a duração da amamentação de fêmeas mantidas sozinhas com a sua ninhada (Condição FS, 20 fêmeas) à de fêmeas pareadas quando as ninhadas tinham no máximo 3 dias de diferença (Condição FP, 19 pares de fêmeas), uma condição em que pode surgir aloamamentação. Verificou-se que, apesar da existência de apego em relação à mãe (os filhotes na condição FP permaneciam próximos à mãe e mamaram mais dela do que da fêmea alheia), aproximadamente 60 % dos filhotes alomamaram. A aloamamentação, que se concentrou na primeira semana de vida com um decréscimo marcado em seguida e que não era sempre recíproca, decorreu basicamente da iniciativa dos filhotes. Os resultados não apóiam a hipótese funcional da aloamamentação enquanto competição entre os filhotes por um superávit de alimentação, mas indicam que constitui uma estratégia oportunista dos filhotes, propiciada pelas características da organização social das cobaias. / Allosuckling seems to challenge the general principle according to which maternal care should be retricted to offspring. While already reported, allosuckling in domestic guinea pigs Cavia porcellus - a species in which males may breed with several females, in a harem system, and in which pups are precocious and able to ingest solid food shortly after birth - has not been, to now, systematically described. The aim of the present research, performed with common guinea pigs (Phase 1) and albino guinea pigs (Phase 2) was to describe female-pups interactions throughout development, and to compare such interactions in isolated females with their litter (FS condition, 20 females) and in paired females with their litter (FP condition, 19 pairs), a condition in which allosuckling performance is likely to happen. In spite of pups\' attachment to their mothers (in condition FS, pups remained nearer to their mother than to the other lactating female and had longer and more frequent nursing episodes with her), allosuckling was relatively frequent (approximately 60% of pups were allonursed). Allosuckling peak occurred during the first week of life and markedly decreased thereafter, being mainly under the control of pups. Results do not favor a functional explanation of allosuckling as a competitive strategy of pups for a surplus of food, but suggest it is an opportunistic strategy which is made possible by the specific nature of guinea pigs social organization.

A aloamamentação parece desafiar o princípio geral de que o cuidado materno deve restringir-se à própria prole. Embora a aloamamentação em cobaias domésticas Cavia porcellus - espécie em que um macho dominante pode reproduzir-se com várias fêmeas em um sistema de harém e em que os filhotes são precoces e capazes de ingerir alimentos sólidos logo depois do nascimento - já tenha sido observada, não foi submetida até o momento a um estudo sistemático. Na presente pesquisa, realizada com cobaias comuns (Etapa 1) e cobaias albinas (Etapa 2), buscamos descrever os aspectos básicos da interação fêmea-filhote ao longo das primeiras quatro semanas de vida dos filhotes, comparando a freqüência e a duração da amamentação de fêmeas mantidas sozinhas com a sua ninhada (Condição FS, 20 fêmeas) à de fêmeas pareadas quando as ninhadas tinham no máximo 3 dias de diferença (Condição FP, 19 pares de fêmeas), uma condição em que pode surgir aloamamentação. Verificou-se que, apesar da existência de apego em relação à mãe (os filhotes na condição FP permaneciam próximos à mãe e mamaram mais dela do que da fêmea alheia), aproximadamente 60 % dos filhotes alomamaram. A aloamamentação, que se concentrou na primeira semana de vida com um decréscimo marcado em seguida e que não era sempre recíproca, decorreu basicamente da iniciativa dos filhotes. Os resultados não apóiam a hipótese funcional da aloamamentação enquanto competição entre os filhotes por um superávit de alimentação, mas indicam que constitui uma estratégia oportunista dos filhotes, propiciada pelas características da organização social das cobaias. / Allosuckling seems to challenge the general principle according to which maternal care should be retricted to offspring. While already reported, allosuckling in domestic guinea pigs Cavia porcellus - a species in which males may breed with several females, in a harem system, and in which pups are precocious and able to ingest solid food shortly after birth - has not been, to now, systematically described. The aim of the present research, performed with common guinea pigs (Phase 1) and albino guinea pigs (Phase 2) was to describe female-pups interactions throughout development, and to compare such interactions in isolated females with their litter (FS condition, 20 females) and in paired females with their litter (FP condition, 19 pairs), a condition in which allosuckling performance is likely to happen. In spite of pups\' attachment to their mothers (in condition FS, pups remained nearer to their mother than to the other lactating female and had longer and more frequent nursing episodes with her), allosuckling was relatively frequent (approximately 60% of pups were allonursed). Allosuckling peak occurred during the first week of life and markedly decreased thereafter, being mainly under the control of pups. Results do not favor a functional explanation of allosuckling as a competitive strategy of pups for a surplus of food, but suggest it is an opportunistic strategy which is made possible by the specific nature of guinea pigs social organization.

Thesis (MSc. (Agriculture Pasture Science)) -- University of Limpopo, 2018 / This study was conducted at the University of Limpopo’s Experimental Farm (Syferkuil), in the Limpopo Province, South Africa. The objective was to determine the effect of foliar fertilizers on the dry matter production over a period of two growing seasons. The experiment was laid out in a 3 x 3 factorial arrangement, fitted in a randomized complete block design (RCBD), with 4 replications. The experiment was planted on 28th March 2014 for season 1 (2014) and 31st March 2015 for season 2 (2015). Three sources of fertilizer (Nitrospray Plus, Potaspray and a combination of the two) were applied to stooling rye at three different fertilizer application rates (0 kg or ℓ/ha, 2.5 kg or ℓ/ha and 5.0 kg or ℓ/ha). The Nitrospray Plus and Potaspray fertilizers were applied on the 09th May, 02nd July, 27th August and 30th October 2014 for Season 1 (2014). During the Season 2 (2015), they were applied on 11th May, 04th July, 29th August and 02nd November 2015. The application was done using a knapsack sprayer. Above-ground biomass was harvested four times during each season when the plants reached a height of 25–30 cm. During 2014, harvesting was done on the 27th May, 24th July, 12th September and the 17th November 2014. During 2015, harvesting was done on the 29th May, 26th July, 14th September and the 19th November 2015. The dry matter production was determined by harvesting 1 m2 quadrates at 3 cm height. After weighing fresh material, it was oven–dried at 55oC until a constant mass was reached. Samples were then weighed again and the DM production (kg/ha) was calculated. Results were compared, using analysis of variance and the Fisher’s LSD test at P≤ 0.05 within each season. Based on the Least Significance Difference test, treatments were grouped in different production classes. During both seasons, fertilizer application rates had a significant (P≤0.001) influence on dry matter production. In 2014, the highest total dry matter production obtained was 5323 kg/ha in the high potassium fertilizer treatment and the lowest total dry matter was 4049 kg/ha in the control or zero application treatment. xiii In 2015, the highest total dry matter production obtained was 5595 kg/ha in the high potassium fertilizer treatment and the lowest 3678 kg/ha in the control treatment. Potassium fertilizers produced significantly (P≤0.001) higher than nitrogen fertilizers in both seasons. The main conclusions from this study were that high foliar fertilizer application rates (5.0 kg/ha) led to high, low foliar application rates (2.5 kg/ha) to lower and no fertilizer to low dry matter production. High levels of potassium produced the best, followed by combinations of intermediate potassium and nitrogen, and high nitrogen application rates. Yields of above 5000 kg/ha were obtained under high potassium rates. Lower rates led to total productions of more than 4000 kg/ha, while no foliar application produced between 3700 and 4000 kg/ha. It was also concluded that stooling rye is a suitable winter fodder crop for the Pietersburg Plateau Bushveld, but that the application of fertilizers is necessary for increased dry matter production. Both and Nitrospray and Potaspray Plus, as individual foliar fertilizers or in combination, can be applied to increase the dry matter production of stooling rye. However, it is essential to investigate the adaptability of stooling rye in other areas of the Limpopo bushveld, to determine its suitability as a fodder crop in other areas in the province. Keywords: Dry matter production, cutting dates, foliar fertilizers, Nitrospray Plus, Potaspray.

Swine production represents approximately 40% of the world's meat production, and swine wastes contain high concentrations of organic matter, nitrogen (N) and phosphorus (P). Swine production is intensifying as meat demand increases and concentrated animal feeding operations (CAFOs) are becoming increasingly common, making it difficult to treat the waste generated. A system for holistic treatment of swine waste produced in CAFOs was investigated in this study that sustainably generates energy and recovers N and P as saleable fertilizers. The system uses anaerobic digestion (AD) for methane production and solids stabilization, followed by precipitation of struvite (MgNH4PO4*6H2O) and recovery of N by ion exchange onto natural zeolites. This process is expected to mitigate both eutrophication of receiving waters and greenhouse-gas emissions while generating products that meet agronomic nutrient demands; however, the economic and environmental sustainability remains unknown. The objectives of this study were to: (1) evaluate water quality and the fate of nutrients and ions in each step in the proposed system through pilot and bench scale experiments, (2) evaluate content/quality of struvite precipitates formed in wastewater treatment processes, (3) assess basic composition of zeolite materials that are being considered for use as IX materials, (4) quantify the environmental impact of the proposed system, and (5) estimate the economic benefits and costs of the proposed system. The results of a bench scale evaluation of the system show that although water quality greatly improves throughout the treatment process, the effluent water quality has high concentrations of COD (2,803 mg O2/L) and E. coli (106.3 CFU/100ml). This limits reuse options for the reclaimed water, however a variety of on-farm applications may be suitable. During struvite precipitation, the recovery efficiency of SRP was 87% (60 mg/L recovered); however, although measurements that take into account P in suspended solids show a lower recovery efficiency, they also show higher mass recovery (77% efficiency, 66 mg/L recovered). N recovery during struvite precipitation showed a similar trend, with 49% of TN and 7% of NH4-N being recovered. Struvite recovery can only occur from NH4-N and soluble reactive P. The additional recovery observed is likely due to adsorption of the nutrients onto the precipitate. Therefore, to accurately measure and report recovery, measurements of N and P that take into account suspended solids should be used. In most wastes, magnesium is the limiting constituent for struvite formation, but for swine AD effluents, P is the limiting constituent. Therefore, a higher soluble P concentration would increase recovery potential. The majority of the remaining N and P as well as a significant amount of potassium (K) were recovered during IX. Six struvites from commercial processes as well as our bench-scale experiments were assessed and compared by X-ray diffraction, SEM imaging, and SEM-EDX scans. All samples were confirmed as struvite by XRD, however they varied widely in crystal size and shape. The elemental composition of the samples was similar; however, struvite formed from phosphate mining waste had higher amounts Mg and P, indicating more pure struvite formation. The presence of impurities in some samples was likely due to the reactor design and solids separation methods. XRD was also used to confirm the identity of zeolites. Three clinoptilolites had similar crystal size and elemental composition except for Zeosand [reg] which showed a surface roughness, which likely contributes to higher cation exchange capacity. Chabazite has smaller crystal size and larger pores than clinoptilolite, which also likely contributes to its higher capacity. Life cycle assessment (LCA) was used to evaluate the environmental sustainability of the system and the results suggested that environmental benefits were provided across almost all impact categories. Two alternatives for raising the pH in struvite precipitation (NaOH addition vs. aeration) and two alternatives for zeolite IX materials (chabazite vs. clinoptilolite) were assessed, but there were negligible differences between alternatives. The system was also assessed at a medium and large scale, and the large scale was more environmentally friendly across all categories. Operational impacts were significantly greater than construction impacts; therefore, the environmental impact of the system can be accurately assessed by only including operation. A life cycle cost assessment (LCCA) was also performed on the system and showed a payback period of 39 years for a medium sized system and 15 years for a large size. This, however, is when compared to a "business-as-usual" scenario and does not consider renewable energy credits or government grants. Furthermore, although a larger system is more economically beneficial, this must be balanced with quality of animal care. From a cost standpoint, IX recovery using chabazite is not recommended and struvite precipitation using aeration is more economically beneficial than NaOH addition.

Giant pandas in captivity are typically fed discrete amounts of highly concentrated food on a fixed time schedule, in addition to limited amounts of fresh bamboo throughout the day. In response to informal observations that these animals engage in a number of undesirable behaviors just prior to the predictable feeding of concentrated meals, we examined the existing feeding regime at the Research Base of Giant Panda Breeding in Chengdu, Peoples Republic of China. We sought to determine whether undesirable behaviors were occurring more frequently before the delivery of meals than at other times of day and whether modified feeding regimes would result in a more species-appropriate activity budget overall. As predicted, female giant pandas spent significantly more time engaged in door-directed/human-oriented behavior, stereotypic behavior, and non-stereotypic locomotion in the 30-minute periods prior to the feeding of concentrated meals. When placed on a modified feeding schedule in which frequency of bamboo provisioning was increased (total amount was held constant), significant differences were not found between study phases for the above-mentioned behaviors of interest, though a visual trend towards a decline in stereotypic behavior during the experimental phase was noted. Male pandas, when placed on a less predictable feeding schedule, did not exhibit significant behavioral differences in behaviors of interest between experimental phases or observation periods. These findings may be attributable in part to the low power inherent in the small sample size. However, visual trends that may be indicative of feeding anticipatory activity (FAA) were apparent. It appears that giant pandas, like many other animal species cited in the literature, are sensitive to periodic feeding regimes, though it is less clear as to which regime modifications will prove most beneficial.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2002. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.