A study on the growth and reproductive performance of two rabbit breeds was undertaken. Data on 588 kits and 97 does of California White and 574 kits and 90 does of New Zealand White rabbits reared under hot and humid environment in Ghana were taken. The reproductive performance of the two breeds, in terms of litter size at birth and weaning, litter weight at birth and weaning, kindling interval, age at sexual maturity, and gestation length as influenced by breed, season of kindling (rainy and dry), year of kindling (2005–2012), and parity (first to sixth and over) were determined. The performance of California White in terms of litter size at birth, at weaning, kit weight at birth, and age at first kindling was 5.9?±?0.2, 4.6?±?0.1, 54.7?±?0.4 g, and 159.8?±?0.2 days, respectively. That of New Zealand White was 5.9?±?0.1, 5.1?±?0.1, 55.2?±?1.0 g, and 159.9?±?0.2 days, respectively. The results obtained also showed a significant breed effects on kit weight at birth, litter weight at weaning, and mortality; whereas no significant differences (p?>?0.05) were observed between the two breeds regarding the other traits measured. Parity had significant effects (p?<?0.05) on all the growth and reproductive parameters measured with the exception of age at first kindling. Year of kindling also had significant effect on litter weight at birth, kit weight at birth, and at weaning (p?<?0.05) but did not have any significant effect on the age at sexual maturity and mortality. Season also had significant (p?<?0.05) effects on kit weight at birth, gestation length, kindling interval, and mortality with better performance experienced during the rainy season.
Soil texture is an important factor governing a range of physical properties and processes in soil. The clay and fine fractions of soil are particularly important in controlling soil water retention, hydraulic properties, water flow and transport. Modern soil texture analysis techniques (x‐ray attenuation, laser diffraction and particle counting) are very laborious with expensive instrumentation. Chilled‐mirror dewpoint potentiameters allows for the rapid measurement of the permanent wilting point (PWP) of soil. As the PWP is strongly dictated by soil texture, we tested the applicability of PWP measured by a dewpoint potentiameter in predicting the clay, silt and sand content of humid tropical soils. The clay, silt, and sand content, organic matter and PWP were determined for 21 soils. Three regression models were developed to estimate the fine fractions and validated using independent soil data. While the first model showed reasonable accuracy (RMSE 16.4%; MAE 13.5%) in estimating the clay, incorporating the organic matter into the equation improved the predictions of the second model (RMSE 17.3%; MAE 10.9%). When used on all soil data, the accuracy of the third model in predicting the fine fraction was poor (RMSE 31.9%; MAE 24.5%). However, for soils with silt content greater than 30%, the model prediction was quite accurate (RMSE 7–12%; MAE 7–9%). The models were used to estimate the sand content and soil textures of soils, which proved relatively accurate. The dewpoint potentiometer can serve a dual purpose of rapidly estimating the PWP and the clay, fine fraction, and soil texture of soils in a cost efficient way. 相似文献
Our understanding of the processes influencing the storage and dynamics of carbon (C) in soils under semi-arid agroforestry systems in Sub-Saharan Africa (SSA) is limited. This study evaluated soil C pools in woodlot species of Albizia lebbeck (L.) Benth., Leucaena leucocephala (Lam.) de Wit, Melia azedarach (L.), and Gmelina arborea Roxb.; and in farmland and Ngitili, a traditional silvopastoral system in northwestern Tanzania. Soil organic carbon (SOC) was analyzed in the whole soil to 1 m depth and to 0.4 m in macroaggregates (2000–250 μm), microaggregates (250–53 μm), and silt and clay-sized aggregates (<53 μm) to provide information of C dynamics and stabilization in various land uses. Synchrotron-based C K-edge x-ray absorption near-edge structure (XANES) spectroscopy was also used to study the influence of these land use systems on the soil organic matter (SOM) chemistry to understand the mechanisms of soil C changes. Whole soil C stocks in woodlots (43–67 Mg C ha?1) were similar to those in the reserved Ngitili systems (50–59 Mg C ha?1), indicating the ability of the planted woodlots on degraded lands to restore SOC levels similar to the natural woodlands. SOC in the woodlots were found to be associated more with the micro and silt-and clay-sized aggregates than with macroaggregates, reflecting higher stability of SOC in the woodlot systems. The continuous addition of litter in the woodlots preserved recalcitrant aromatic C compounds in the silt and clay-sized aggregates as revealed by the XANES C K-edge spectra. Therefore establishment of woodlots in semi-arid regions in Tanzania appear to make significant contributions to the long-term SOC stabilization in soil fractions. 相似文献
Journal of Plant Diseases and Protection - Coconut is recognized for its popularity in contributing to food and nutritional security. It generates income and helps to improve rural livelihood.... 相似文献
1. Four hundred and eighty 1‐d‐old broiler chicks were fed on diets of equal protein content (210 g protein/kg) in which white maize had been partially replaced by fermented cassava peel meal (FCPM) at concentrations of 0, 50, 100 and 150 g/kg. The trial lasted 49 d.
2. Birds fed on diets containing FCPM consumed more food than those fed on the diet with no peel meal, but the difference was not statistically significant. In addition, improvements in growth rate and efficiency of food utilisation by FCPM‐fed birds were also not significantly different from values registered by their counterparts receiving no peel meal. 相似文献
This paper examines the extent of cost inefficiency at 120 small-scale broiler farms in the Ashanti Region of Ghana by the use of stochastic frontier cost function, which incorporates cost inefficiency effects. Furthermore, farm-specific determinants that help explain why cost inefficiencies are different across broiler farms are identified. The findings confirm the presence of cost inefficiencies in small-scale broiler production in the area studied. Specifically, the results suggest that the broiler farms in question have the potential to reduce their production costs by 13.6% by being more efficient in cost management. The findings further indicate that experience in broiler production, an increase in farm size, veterinary contacts, use of self-prepared quality broiler feed, and membership in the Poultry Farmers’ Association (PFA) all help minimize cost inefficiency. On the other hand, the findings show that cost inefficiency appears to worsen with an increase in the market age of a farm’s broiler birds.
OBJECTIVE: To evaluate the analgesic effects of medetomidine (MED) and butorphanol (BTO) in cats after ovariohysterectomy. STUDY DESIGN: A placebo-controlled, blinded monocenter clinical study. ANIMALS: Healthy adult female client-owned cats. METHODS: Sixty-four cats weighing 3.15 +/- 0.6 kg, presented to the University of Helsinki's Small Animal Teaching Hospital for routine elective ovariohysterectomy, received MED at 15 microg/kg (n = 18), BTO at 0.1 mg/kg (n = 23), or saline (PL) (n = 23) intramuscularly immediately after ovariohysterectomy. Level of pain perception, degree of restlessness, and extent of sedation were scored subjectively before and at 30, 60, 90, and 120 minutes after test-drug administration. RESULTS: BTO provided the best pain relief, followed by MED. Saline provided the least pain relief. Both MED and BTO effectively and identically prevented postoperative restlessness. MED and BTO produced an identical degree of sedation that was better than the PL. CONCLUSIONS: Both MED (at 15 microg/kg) and BTO (at 0.1 mg/kg) prevent postoperative pain in cats after ovariohysterectomy. Clinical Relevance-MED and BTO are useful for preventing postoperative pain in cats. 相似文献
Recent studies have found evidence of a local employment multiplier’s effect. For the most part, these studies provide an average estimate for all labor markets. In this paper, we examine how the average local employment multiplier, the effect of an exogenous increase in employment in the tradable sector on total employment, depends on the characteristics of the local labor market. Specifically, we estimate the average multipliers for coastal, noncoastal, large, and small metropolitan statistical areas (MSAs) across different time periods using the data of 333 US MSAs. Overall, we find a reduced form of local employment multiplier ranging from 1.38 to 2.24, which is within the range of typically estimated local employment multipliers. In addition, the characteristics of the local labor market matter. The local multipliers appear larger in noncoastal and large MSAs. For small and coastal metros, the multiplier is closer to 1.5 than to 2.0 while in the case of large and noncoastal metros, it is closer to 2.0 than to 1.5. The local multipliers are also sensitive to the time period considered. 相似文献
