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Data collected from 1993 to 2006 at the Animal Research Institute of Ghana was used to compare the performance of Sanga and Friesian-Sanga crossbred calves on natural pasture. Performance traits analyzed were birth weight (BWT), weaning weight adjusted to 210 days (WW7), preweaning average daily gain to 210 days (ADG 1), weight at 12 months adjusted to 365 days (W12), weight at 18 months adjusted to 540 days (W18) and postweaning average daily gain (ADG 2, from weaning to 540 days). Effects in the model describing these traits were breed, season, sex and first-order interactions between these effects. With the exception of heavier birth weight of Friesian-Sanga crossbred calves (19.98 kg vs. 19.18 kg), body weights of Sangas at weaning, 12 months and 18 months exceeded those of the Friesian-Sanga crossbred calves by 3.76 kg, 35.06 kg and 46.24 kg respectively. The Sangas were also superior in preweaning average daily gain (0.35 kg/day vs. 0.26 kg/day) and postweaning average daily gain (0.28 kg/day vs. 0.21 kg/day). There was a tendency of increasing weight difference between the two breeds with advancing age. It was suggested that improved nutrition such as supplementary feeding would be necessary for crossbreds to express their potential for growth.  相似文献   
2.
A cross-sectional survey investigating the contribution of free-range village chickens to household economies was carried out in four administrative districts within 60km of Accra. Answers were provided by 101 men and 99 women. Nearly all respondents claimed to keep chickens for meat, with a far smaller percentage claiming to keep them for egg production. Over 80% of respondents kept chickens to supplement their incomes. The proportion of the flock eaten varied between administrative areas (p=0.009 and p=0.027), although this was possibly a consequence of differences in consumption patterns between occupation of the respondent, land area cultivated and flock size. The proportion of chickens sold varied as a result of differences in flock size (p=0.013), the proportion sold increasing with number of birds in the flock. Respondents generally agreed that chickens could be sold without difficulty. A majority of chicken sales were from the farm gate, directly to consumers or traders. Sales were on demand or when the owner needed money. Money from the sale was kept by the owner of the chicken and the money was spent on personal needs. The proportion of the flock sold varied between administrative areas (p=0.025) and occupation of the respondent (p=0.040). Respondents describing animal production as their main occupation tended to have greater reliance on chicken sales for their income. Consideration is given to estimating the offtake from the flock and the financial contribution to the household.  相似文献   
3.
The reproductive performance of 76 Sanga cows was studied from February 1995 to July 1996 in smallholder peri-urban dairy systems in the coastal savanna zone of the Accra plains of Ghana. The interval from calving to resumption of cyclic ovarian activity was 101±7 days; that from calving to conception was 152±4 days; gestation length was 292±16 days; and the calving interval was 444±16 days. The effects of location, season of calving, parity, body condition score and sex of calf were studied. Calving to cycling interval was significantly shorter in the dry season than in the wet season, and decreased significantly with increasing body condition score. Calving to conception interval was affected only by location. Gestation length was not affected by any of the variables studied. Calving interval was affected by location, season of calving, parity and body condition score. It is concluded that long post-partum anoestrus leads to prolonged calving intervals and poor reproductive performance. Feed supplementation to improve the nutritional status and body condition score of cows and early weaning of calves could be introduced to enhance reproductive performance.  相似文献   
4.
Milk yield traits and lactation length of two breeds of cattle raised on natural pasture with little or no supplementation were assessed. A total of 42 573 daily milk records on 98 Friesian-Sanga cows collected over a period of 10 years and 17 790 daily milk records on 72 Sanga cows spanning a 6-year period were used in the study. Traits examined for each breed were daily milk yield, total milk yield, 305-day milk yield, 305-day milk yield/day and lactation length. Friesian-Sanga cows outperformed their Sanga counterparts in all traits studied. Friesian-Sanga cows had an average daily milk yield of 1.35?±?0.00 kg; average total milk yield of 266?±?12 kg; average 305-day milk yield of 339?±?10 kg; average 305-day milk yield/ day of 1.11?±?0.03 kg and mean lactation length of 201.1?±?6.9 days. Average values for Sanga cows were 1.01?±?0.00 kg as daily milk yield; 162?±?12 kg as total milk yield; 244?±?10 kg as 305-day milk yield; 0.80?±?0.03 kg as 305-day milk yield/day. Mean lactation length for Sanga cows was 164.1?±?9.4 days. Season of calving significantly (P?<?0.05) influenced daily milk yield of Friesian-Sanga cows and all traits of Sanga cows with animals calving in the major rainy season surpassing those that calved in the minor and dry seasons. Daily milk yield for both Friesian-Sanga and Sanga cows was significantly (P?<?0.05) influenced by season of lactation. Daily milk yield gradually declined from second parity towards the sixth parity for Friesian-Sanga cows. A gradual increase in daily milk yield from first to third parity was observed in Sanga cows. Year of calving significantly influenced all traits for both breeds. Genetic improvement in milk yield traits and lactation length is achievable for both breeds of cattle as co-efficient of variation of traits were moderate to high.  相似文献   
5.
A cross-sectional[4pc] survey investigating husbandry and productivity of free-range village chickens was carried out in four administrative districts within 60km of Accra. Responses were provided by 101 men and 99 women. The mean (SD) household flock size was 28.7 (25.97) and the median was 20. The factors included in the final model investigating variance in flock size were sex of the respondent (p=0.011), administrative area (p=0.004), the numbers of members in the household (p=0.017) and the number of cattle, sheep and goats owned by the household (p=0.031). Chickens were owned by individual members of the household, but women and children were the predominant providers of care for chickens. All respondents described their chickens as scavengers that were provided with supplementary feed, and over 80% of respondents named maize as a supplementary food source. Approximately 50% of respondents claimed difficulty in providing supplementary feed, with the degree of difficulty varying between administrative areas (p<0.001). A majority of respondents (approximately 65%) claimed that their chickens laid 3–4 clutches of eggs per year. Over 70% of respondents estimated that each clutch contained 10–20 eggs, and approximately 70% of respondents estimated that 75% of the eggs hatched. Opinions on mortality varied, but 60% of men and 70% of women estimated that between 50% and 75% of both chicks and adult birds died each year. Approximately 80% of respondents named Newcastle disease as the most important health issue. The opportunities for and consequences of controlling Newcastle disease are discussed.  相似文献   
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