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61.
本研究以毛木耳为发酵对象,以青稞为发酵原料,研制出毛木耳青稞生物技术乳。通过对影响毛木耳发酵过程的发酵时间、发酵温度、接种量、装液量四个因素进行单因素试验和正交试验,最终确定毛木耳青稞生物技术乳的最佳发酵工艺为发酵时间6d、接种量4%、发酵温度24%、装液量300mL三角瓶装80mL。 相似文献
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64.
本试验旨在研究菜用大豆荚壳混合青贮饲料对奶牛产奶量、乳品质和血液生化指标的影响。试验选取12头体况、产奶量、泌乳天数相近的奶牛,随机分为3组。对照组奶牛按牛场原有日粮和饲喂方式饲喂;试验Ⅰ组用6kg豆荚混合青贮饲料替代1.5kg苜蓿干草,试验Ⅱ组用9kg豆荚混合青贮饲料替代2.5kg苜蓿干草,其他均不作变动。结果表明:混合豆荚青贮饲料代替部分苜蓿干草对奶牛产奶量无显著影响,对乳蛋白、乳脂率、乳糖、非脂固形物和血液生化指标无显著影响。以产1kg标准乳计,试验Ⅰ组和Ⅱ组可分别节约饲料成本0.08元和0.14元,可见利用混合豆荚青贮饲料替代部分苜蓿干草饲喂奶牛经济、可行。 相似文献
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66.
Christian Swensson Gösta Gustafsson 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(2):49-56
The effects of manure handling system and feeding of dairy cows were studied using a simple method to analyse the level of ammonia release in cow stables. Two ratios based on the balances of ammonia and sensible heat, and ammonia and carbon dioxide, respectively, in animal houses were determined and considered to give characteristic levels of the release of ammonia in relation to the animal density independently of the ventilation rate. This required measurements of ammonia, carbon dioxide and temperature with hand-held instruments in the buildings and in outside air. In total, 34 dairy herds were investigated in the south of Sweden. The results clearly demonstrated higher release of ammonia from free stall barn with liquid manure than from conventional tie stall barn with solid manure. There was a clear effect of the content of crude protein, gram per kg dry matter, in the total feed ration on ammonia release in tie stall barn with liquid manure. 相似文献
67.
Anki Roxström Erling Strandberg Britt Berglund Ulf Emanuelson Jan Philipsson 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(1):7-14
The main objective of this study was to estimate genetic correlations between fertility and production traits in first, second and third lactations as well as between fertility traits measured in the same way at different ages. The fertility traits studied were: number of inseminations per service period, number of treatments for reproductive disturbances, interval between first and last inseminations, interval between calving and first insemination, and interval between calving and last insemination. Early milk production was measured as the average of the energy-corrected milk yield at the second and third monthly testdays in a lactation. The number of records was approximately 450 000, 350 000, 180 000 and 75 000 in the heifer period, first, second, and third lactations, respectively. A linear, trivariate model that included the effects of herd-year, year, month, age and sire of the cow was applied. To reduce the effect of ongoing selection, 305-days kg protein production in first lactation was included as a variate in all of the analyses. Correlations between the herd-year effects indicated that factors of herd-year level conducive to increased production had a tendency to increase the number of inseminations as well as the number of reproductive treatments, although there was an earlier start and termination of the insemination period. Genetic correlations between fertility traits and production were in the range of 0.2-0.4, all of them unfavourable and higher at later parities. The genetic correlations between fertility traits in the heifer period and the same traits in first lactation were 0.7. Genetic correlations between the first and second lactation varied between 0.7 and 0.9, and between the second and third lactation they were all 0.9 or higher. In conclusion, fertility and production traits need to be selected for simultaneously if fertility is going to be maintained along further genetic improvement on production, and such selection should include fertility results from lactating cows. 相似文献
68.
Peter Kappel Theil Thomas Thymann Nielsen Niels Bastian Kristensen Rodrigo Labouriau Viggo Danielsen Charlotte Lauridsen 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(4):221-232
The milk intake in piglets from four lactating sows was measured in three 48 h periods, starting on days 3, 10 and 17 of lactation, using the deuterium oxide (D 2 O) dilution technique. The milk intake was estimated from the water turnover in the piglets corrected for the production of metabolic water. The water turnover was estimated from the water dilution space and the fractional turnover of body water, determined by the rate of D 2 O dilution. To determine the magnitude of isotopic recycling, a randomly selected piglet in each litter was not enriched with D 2 O. Milk production of the four lactating sows was also measured by the weigh-suckle-weigh (WSW) method on days 4, 11 and 18 of lactation. The average daily milk production determined by the D 2 O dilution technique (9.91 - 0.69 kg) was higher ( P <0.05) than that determined by the uncorrected WSW method (8.65 - 0.81 kg). Different procedures for selecting piglets were evaluated to obtain the best possible estimation of total milk production from three piglets in each litter. The total milk production of a sow based on three piglets in the litter was obtained from a quadratic model of the relationship between milk intake and daily gain. When the daily gain of all piglets were known the Pearson correlation between milk production determined for the whole litter ( n -1) and only three median piglets was 0.98. 相似文献
69.
Abstract Thirty-two Chinese Holstein lactating cows were used to investigate the relationship of milk urea nitrogen (MUN) and nitrogen excretion loading to the environment. Cows were fed a similar amount of forage, and concentrates according to milk production. Total collection of urine and faeces were conducted continuously for three days. The milk urea nitrogen was significantly correlated to total nitrogen excretion (R 2=0.70), urinary nitrogen excretion (R 2=0.85), and nitrogen excretion from faeces (R 2=0.22). The following equation was proposed to predict total nitrogen excretion (TNE) (g/d) based on milk urea nitrogen (MUN) (mg/dl): TNE?=?15.46(±1.83)×MUN?+?193.40(±28.79). The results obtained in this study suggested that MUN might be used to predict TNE from lactating cows. 相似文献
70.
Kazumasa HONDA Ayako SUDO Kentaro IKEDA 《The Journal of reproduction and development》2013,59(6):569-574
The present experiments were undertaken to examine whether oxytocin cells in the
supraoptic nucleus receive synaptic inputs from the contralateral supraoptic nucleus
or paraventricular nucleus. Using urethane-anesthetized lactating rats, extracellular
action potentials were recorded from single oxytocin or vasopressin cells in the
supraoptic nucleus. Electrical stimulation was applied to the contralateral
supraoptic nucleus or paraventricular nucleus, and responses of oxytocin or
vasopressin cells were analyzed by peri-stimulus time histogram or by change in
firing rate of oxytocin or vasopressin cells. Electrical stimulation of the
contralateral supraoptic nucleus or paraventricular nucleus did not cause antidromic
excitation in oxytocin or vasopressin cells but caused orthodromic responses.
Although analysis by peri-stimulus time histogram showed that electrical stimulation
of the contralateral supraoptic nucleus or paraventricular nucleus caused orthodromic
excitation in both oxytocin and vasopressin cells, the proportion of excited oxytocin
cells was greater than that of vasopressin cells. Train stimulation applied to the
contralateral supraoptic nucleus or paraventricular nucleus at 10 Hz increased firing
rates of oxytocin cells and decreased those of vasopressin cells. The results of the
present experiments suggest that oxytocin cells in the supraoptic nucleus receive
mainly excitatory synaptic inputs from the contralateral supraoptic nucleus and
paraventricular nucleus. Receipt these synaptic inputs to oxytocin cells may
contribute to the synchronized activation of oxytocin cells during the milk ejection
reflex. 相似文献