梅花鹿生茸期能量代谢的初步研究

通过呼吸测热试验,结合不同能量进食水平和不同蛋白质水平条件下的消化、代谢试验,对成年梅花鹿生茸期的能量代谢规律进行了研究。结果表明：（１）梅花鹿的产热量（ＨＰ）和体能沉积量（ＲＥ）均随总能食入量（ＧＥＩ）的增加而增加;代谢能转化为体蛋白能和体脂肪能沉积的效率（Ｋｇｐ和Ｋｇｆ）分别为０．５９和０．６１;产热量（ＨＰ）与总能食入量（ＧＥＩ）的回归方程为：ＨＰ（ｋＪ／Ｗ０．７５ｄ）＝２６５．１２＋０．３３２ＧＥＩ（ｋＪ／Ｗ０．７５ｄ）。（２）产热量占总能食入量的百分比（ＨＰ／ＧＥＩ）,无论是在生茸期前期还是在生茸期后期,低蛋白组（ＣＰ为２２．０％）均明显高于高蛋白组（ＣＰ为２９．０％）（Ｐ＜０．０５）,在同一蛋白水平下生茸期前期与后期各组之间无显著差异（Ｐ＞０．０５）;体能沉积量占总能食入量的百分比（ＲＥ／ＧＥＩ）各组之间差异均不显著（Ｐ＞０．０５）;无论在生茸期前期还是在生茸期后期,体蛋白能沉积量占体能沉积量的百分比（ＲＰＥ／ＲＥ）,高蛋白组均高于低蛋白组（Ｐ＜０．０５）,而体脂肪能沉积量占体能沉积量的百分比（ＲＦＥ／ＲＥ）则与其相反（Ｐ＜０．０５）。     

高寒草甸放牧生态系统夏秋草场轮牧制度的模拟研究

利用ＧＭＡＭＥ１模拟高寒草甸放牧生态系统夏秋草场在临界放牧压力下的２７０种轮牧制度,并对其累积采食量进行比较分析。结果指出：在高寒草甸放牧生态系统中,最佳的轮牧小区数目为３或４个。证明了Ｍｏｒｌｅｙ规则：最佳轮牧小区数目应该小于１０。推荐２个高寒草甸地区最佳的轮牧模式供野外实验和放牧规划参考：（１）３个轮牧小区,每小区每次持续放牧２９ｄ,放牧压力为３０．１４ｋＪ／ｍ２·ｄ,累积牧草采食量最高为４２５０．４４３ｋＪ／ｍ２。（２）为保持牧草结构的稳定和各轮牧小区牧草生物量的均匀性,可以采用３个轮收小区,放牧持续时间７ｄ,放牧压力Ｉ（１４５）＝２８．８９１４ｋＪ／ｍ２·ｄ,累积采食量为４０７３．３４ｋＪ／ｍ２。     

[^3H]Cortisol及[^3H]Dexamethasone在大鼠肝细胞膜上的特异结合位点

本研究应用［３Ｈ］ｃｏｒｔｉｓｏｌ和［３Ｈ］ｄｅｘａｍｅｔｈａｓｏｎｅ（ＤＥＸ）两种配基,观察到大鼠肝细胞膜上存在一类糖皮质激素（ＧＣ）特异结合位点。这些位点与ＧＣ的结合具有饱和性、高亲和力及低容量。其平衡解离常数（Ｋｄ）分别为１２．８４±６．５８ｎｍｏｌ／Ｌ和４０．２７±２３．４４ｎｍｏｌ／Ｌ;最大结合容量（Ｂｍａｘ）分别为２．５７±１．８４ｐｍｏｌ／ｍｇ蛋白质与０．６４±０．１８ｐｍｏｌ／ｍｇ蛋白质（ｃｏｒｔｉｓｏｌ,ｎ＝４;ＤＥＸ,ｎ＝３;±ＳＥ）。动力学实验数据所得的Ｋｄ值与Ｓｃａｔｃｈａｒｄ分析所得的Ｋｄ值结果基本一致。［３Ｈ］ｃｏｒｔｉｓｏｌ和［３Ｈ］ＤＥＸ饱和结合实验数据用Ｓｃａｔｃｈａｒｄ作图分析,均显示为直线。Ｈｉｌｌ系数则分别为０．９８８０和０．９９９０．竞争抑制实验结果表明,ｃｏｒｔｉｓｏｌ对［３Ｈ］ｃｏｒｔｉｓｏｌ的结合位点有高度特异性竞争,比其它几种类固醇（强的松、黄体酮、ＲＵ４８６、ＤＥＸ）的竞争力至少强４０倍以上．用放射自显影技术进行研究,也提供了［３Ｈ］ｃｏｒｔｉｓｏｌ特异结合银粒位于大鼠肝细胞膜上的依据。     

Ca^2＋敏感性微电极在心肌胞浆Ca^2＋活度检测中的应用

改进的中性载体Ｃａ２＋敏感性微电极（Ｃａ－ＩＳＥ）在尖端直径为０．４—０．８μｍ时仍具有良好特性,可用于心肌胞浆Ｃａ２＋活度（αＣａｉ）的检测。测得豚鼠右心乳头肌、狗心室肌和浦肯野纤维静息时分别为０．１９±０．０１（ｎ＝２２）,０．２０±０．０２（ｎ＝１１）和０．４６±０．０７（ｎ＝１３）μｍｏｌ·Ｌ－１。毒毛旋花苷Ｇ３μｍｏｌ·Ｌ－１使静态及动态心肌分别增高０．１８±０．０２和６．６９±２．０９μｍｏｌ·Ｌ－１（ｎ＝２２）,并出现触发活动（ＴＡ）。１００μｍｏｌ·Ｌ－１蝙蝠葛碱可抑制毒毛旋花苷Ｇ引起的增高,同时使其ＴＡ消失。表明Ｃａ－ＩＳＥ技术可用于心肌组织ＴＡ与的同步检测。     

红树植物秋茄落叶分解碎屑的有效能研究

测定了福建红树植物秋茄各季节落叶分解碎屑中水解有效能（ＨＡＣ）、无丹宁水解有效能（ＴＦＨＡＣ）和化学有效能（ＣＡＣ）的绝对含量和相对含量。测定结果表明：落叶中有效能的绝对含量和它占总能量的百分含量的季均值是：ＨＡＣ４．０６ｋＪ／ｇＤＷ,２０．８５％;ＴＦＨＡＣ３．３２ｋＪ／ｇＤＷ,１６．６８％。在半分解（失重率为５０％）的碎屑中它们降为ＨＡＣ１．７５ｋＪ／ｇＤＷ,９．２５％ ;ＴＦＨＡＣ１．６４ｋ     

黑曲霉产木聚糖酶发酵条件的研究

正交设计试验结果表明,黑曲霉（Ａｓｐｅｒｇｉｌｌｕｓ ｎｉｇｅｒ ｍ１２）产木聚糖酶活力达７６．６０ｕ／ｍｌ,合适的产酶发酵条件如下,培养基（ｇ／Ｌ）：麸皮４０,尿素６．６７,ＫＨ２ＰＯ４ １．０,ＭｇＳＯ４．７Ｈ２Ｏ０．５,ＮａＣｌ０．３,Ｔｗｅｅｎ－８０ ３．０,ＣａＣＯ３ ２．０,２８℃,１２０ｒ／ｍｉｎ水浴振荡培养５．５ｄ。     

烷基聚氧乙烯醚硫酸钠对肌酸激酶的变性及复性

系统的研究了十二烷基聚氧乙烯醚硫酸钠Ｃ１２Ｈ２５（ＯＣ２Ｈ４）ｎＳＯ４Ｎａ（ｎ＝０,１,３,５,７;记为Ｃ１２ＥｎＳ）对肌酸激酶的活力和构象的影响。结果表明：随着氧乙烯基个数（ｎ）的增加,Ｃ１２ＥｎＳ对Ｃ．Ｋ．的活力破坏逐步减小;Ｃ１２ＥｎＳ引起Ｃ．Ｋ活力的丧失明显早于可测构象的变化。ＣＫ经Ｃ１２ＥｎＳ变性后,稀释时即可完全复性。Ｃ１２Ｅ７Ｓ不仅对Ｃ．Ｋ的变性能力强（１０ｍＭ就使Ｃ．Ｋ完全失活）;而且在１０－９５℃的温度范围内,能阻止Ｃ．Ｋ聚集沉淀。Ｃ１２ＥｎＳ是Ｃ．Ｋ的高效可逆变性剂。     

THINOPYRUM BESSARABICUM和THINOPYRUM ELONGATUM的基 …

对２个八倍体Ｃ．Ｓ－Ｔｈｉｎｏｐｙｒｕｍ ｂｅｓｓａｒａｂｉｃｕｍ（ＡＡＢＢＤＤＪＪ,２ｎ＝８ｘ＝５６）和Ｇｏｓｈａｗｋ（ＧＨＫ）－Ｔｈｉｎｏｐｙｒｕｍ ｅｌｏｎｇａｔｕｍ（ＡＡＢＢＤＤＥＥ,２ｎ＝８ｘ＝５６）的根尖细胞染色体进行Ｃ－分带,从中分检出Ｔｈ．ｂｅｓｓａｒａｂｉｃｕｍ和Ｔｈ．ｅｌｏｎｇａｔｕｍ的各自染色体进行核型分析,结果表明：Ｔｈ．ｂｅｓｓａｒａｂｉｃｕｍ和Ｔｈ．ｅｌｏｎｇａｔｕｍ的     

α受体激动对绵羊心肌瞬时性内向离子流的影响

用乙酰毒毛旋花子甙元（ＡＳ）０．０５μｍｏｌ／Ｌ诱发绵羊心浦肯野纤维产生稳定的瞬时性内向离子流（Ｉｔｉ）,用普萘洛尔０．５μｍｏｌ／Ｌ阻断β受体,观察α受体激动剂苯肾上腺素（ＰＥ）０．３,１．０μｍｏｌ／Ｌ对Ｉｔｉ幅值与时程的影响。ＰＥ１．０μｍｏｌ／Ｌ灌流２０,５０ｍｉｎ时Ｉｔｉ幅值分别由对照值１２．８±１．９ｎＡ减小至１０．７±１．２ｎＡ（ｎ＝５,Ｐ＜０．０５）与９．６±１．９ｎＡ（ｎ＝５,Ｐ＜０．０１）;ＩｔｉＤ５０时程分别由对照值１４５±２４．４ｍｓ延长至１８３．３±２８．１ｍｓ（ｎ＝５,Ｐ＜０．０５）与２０７．５±３４．２ｍｓ（ｎ＝５,Ｐ＜０．０１）,ＰＥ对Ｉｔｉ的抑制作用呈剂量依赖性与时间依赖性。Ｉｔｉ到达峰值的时间和回复到基线的时间都延长,提示ＰＥ作用下Ｉｔｉ通道动力学发生了变化。如果在β受体激动剂异丙肾上腺素（ＩＳＯ）１．０μｍｏｌ／Ｌ增强Ｉｔｉ的基础上,ＰＥ１．０μｍｏｌ／Ｌ灌流１０ｍｉｎ,对Ｉｔｉ幅值的抑制及时程的延长作用更显著,Ｉｔｉ幅值由对照值１５．６±３．２ｎＡ减小到１０．３±２．２ｎＡ;ＩｔｉＤ５０由９２．５±１４．３ｍｓ延长到１３２．５±３６．０ｍｓ（ｎ＝５,Ｐ＜０．０１）。     

白鱀豚能量需求模型

分析了１头雄性白豚（Ｌｉｐｏｔｅｓｖｅｘｉｌｉｆｅｒ）１５ａ的饲养记录,建立了该豚日能需求模型,即ＤＥＲ（Ｃ）＝９．８６０ｌｎ（Ａ）＋１０．４３３（Ｒ２＝０．９４７２）。参考其他海洋哺乳动物能量学资料,估算出白豚身体能量密度、基础代谢率、运动耗能和体温调节耗能。建立了野生白豚雌、雄个体日能量需求模型,即ＤＥＲ（Ｆ）＝１０．８４８ｌｎ（Ａ）＋８．１２６（Ｒ２＝０．９８３４）;ＤＥＲ（Ｍ）＝７．０８３ｌｎ（Ａ）＋１２．５８６（Ｒ２＝０．９９３２）。雄性豢养个体早期的日能需求与野生个体相近,但随着豢养时间的延长,豢养个体的日能需求呈下降趋势,年下降率约为０．４０１２ＭＪ／ｄ。     

Prediction of methane emission from beef cattle using data measured in indirect open-circuit respiration calorimeters

The objectives of the present study were to examine relationships between methane (CH4) output and animal and dietary factors, and to use these relationships to develop prediction equations for CH4 emission from beef cattle. The dataset was obtained from 108 growing-to-finishing beef steers in five studies and CH4 production and energy metabolism data were measured in indirect respiration calorimeter chambers. Dietary forage proportion ranged from 29.5% to 100% (dry matter (DM) basis) and forages included grass silage, fresh grass, dried grass and fodder beet. Linear and multiple regression techniques were used to examine relationships between CH4 emission and animal and dietary variables, with the effects of experiment or forage type removed. Total CH4 emission was positively related to live weight (LW), feeding level and intake of feed (DM and organic matter) and energy (gross energy (GE), digestible energy (DE) and metabolisable energy (ME)) (P < 0.001), while CH4/DM intake (DMI) was negatively related to energy digestibility and ME/GE (P < 0.05 or less). Using LW alone to predict CH4 emission produced a poor relationship when compared to DMI and GE intake (GEI) (R2 = 0.26 v. 0.68 and 0.70 respectively). Adding feeding level, dietary NDF concentration and CP/ME or feeding level, energy digestibility and ME/GE to support LW resulted in a R2 of 0.66 or 0.84. The high R2 (0.84) was similar to that obtained using DMI or GEI together with energy digestibility and ME/GE as predictors. Further inclusion of dietary forage proportion and ADF and NDF concentration to the multiple relationships using GEI as the primary predictor resulted in a R2 of 0.87. These equations were evaluated through internal validation, by developing a range of similar new equations from two-thirds of the present data and then validating these new equations with the remaining one-third of data. The validation indicated that addition of energy digestibility and ME/GE to support LW with feeding level, DMI and GEI considerably increased the prediction accuracy. It is concluded that CH4 emission of beef steers can be accurately predicted from LW plus feeding level, DMI or GEI together with energy digestibility and ME/GE. The dataset was also used to validate a range of prediction equations for CH4 production of cattle published elsewhere.     

Constraints on energy intake in fish: the link between diet composition, energy metabolism, and energy intake in rainbow trout

The hypothesis was tested that fish fed to satiation with iso-energetic diets differing in macronutrient composition will have different digestible energy intakes (DEI) but similar total heat production. Four iso-energetic diets (2 × 2 factorial design) were formulated having a contrast in i) the ratio of protein to energy (P/E): high (H(P/E)) vs. low (L(P/E)) and ii) the type of non-protein energy (NPE) source: fat vs. carbohydrate which were iso-energetically exchanged. Triplicate groups (35 fish/tank) of rainbow trout were hand-fed each diet twice daily to satiation for 6 weeks under non-limiting water oxygen conditions. Feed intake (FI), DEI (kJ kg(-0.8) d(-1)) and growth (g kg(-0.8) d(-1)) of trout were affected by the interaction between P/E ratio and NPE source of the diet (P<0.05). Regardless of dietary P/E ratio, the inclusion of carbohydrate compared to fat as main NPE source reduced DEI and growth of trout by ~20%. The diet-induced differences in FI and DEI show that trout did not compensate for the dietary differences in digestible energy or digestible protein contents. Further, changes in body fat store and plasma glucose did not seem to exert a homeostatic feedback control on DEI. Independent of the diet composition, heat production of trout did not differ (P>0.05). Our data suggest that the control of DEI in trout might be a function of heat production, which in turn might reflect a physiological limit related with oxidative metabolism.     

DIGESTIBILITY OF CRUSTACEANS and CAPELIN IN HARP SEALS (PHOCA GROENLANDICA)

Gross energy intake (GEI), apparent digestible efficiency (%DE), and body-mass change were studied both in recently weaned and in subadult harp seals fed capelin ( Mallotus villosus ) and crustaceans ( Parathemisto libellula and Thysanoessa sp.) ad lib. The median %DE of Parathemisto libellula (with a wet-weight energy density (ED) of 3.9 kJ/g) and Thysanoessa sp. (ED: 2.3 kJ/g) was 81% and 83%, respectively, while the median %DE of capelin (ED: 8.6 kJ/g) was 94% and 93% for subadult harp seals and one harp seal pup, respectively. No correlation between age and %DE was obtained (P > 0.05). Despite ad lib. access to the food, the harp seal pups were unable to maintain body mass while on a crustacean diet, and it is therefore suggested that harp seal pups most likely must supplement their crustacean diets with fish to maintain growth.     

温度与光周期对白头鹎体质量、能量收支和消化道形态的影响

温度与光周期是环境季节性变化的最直接表现因子及时间变化指示标志,对动物的形态、生理及行为产生重要的影响.本文以白头鹎为研究对象,探讨了不同温度与光周期对其体质量、能量收支和消化道形态的影响,分析了能量收支与消化道形态特征的关系.将28只白头鹎(12雄16雌)分为4组:暖温长光组(30℃,16 L8 D;3雄4雌)、暖温短光组(30 ℃,8 L16 D;3雄4雌)、低温长光组(10 ℃,16 L8 D;3雄4雌)和低温短光组(10 ℃,8 L16 D;3雄4雌).结果表明: 低温与短光照可促进白头鹎的体质量、摄入能及同化能明显增加,同时温度与光周期的交互作用对白头鹎的摄入能及同化能影响显著.低温条件下,胃、小肠、直肠及总消化道的湿质量及干质量明显增加.残差分析表明,小肠与总消化道的长度及干质量与摄入能和同化能显著相关.表明低温与短光照下白头鹎通过增加体质量、能量摄入和改变消化道形态来应对严酷的环境条件.     

Effects of temperature acclimation on body mass and energy budget in the Chinese bulbul Pycnonotus sinensis

Chinese bulbuls(Pycnonotus sinensis) are small passerine birds that inhabit areas of central, southern and eastern China. Previous observations suggest that free–living individuals of this species may change their food intake in response to seasonal changes in ambient temperature. In the present study, we randomly assigned Chinese bulbuls to either a 30 °C or 10 °C group, and measured their body mass(BM), body temperature, gross energy intake(GEI), digestible energy intake(DEI), and the length and mass of their digestive tracts over 28 days of acclimation at these temperatures. As predicted, birds in the 30 °C group had lower body mass, GEI and DEI relative to those in the 10 °C group. The length and mass of the digestive tract was also lower in the 30 °C group and trends in these parameters were positively correlated with BM, GEI and DEI. These results suggest that Chinese bulbuls reduced their absolute energy demands at relatively high temperatures by decreasing their body mass, GEI and DEI, and digestive tract size.     

Methane production in cattle calculated by the nutrient composition of the diet

In this study data originating from complete metabolic trials with cattle of both sexes, fed 337 rations at feed intake levels between one to three times maintenance energy requirement were used to regress the total CH4 emission to the level of DM intake and to the nutrient composition, respectively. A major component of the measured CH4 emission cannot be explained by DM intake but is rather due to differences in dietary nutrient composition. The amount of digestible nutrients especially of the carbohydrate fraction (starch, sugar, N-free residuals) are reliable to estimate CH4 release with high precision (r2 = 0.885). Its production rate increased to 1.9-fold higher levels (range 1.8-2.1) per g of N-free residuals compared to that induced per g of protein, starch or sugar, respectively. Furthermore, diets rich in fat reduced CH4 formation in the rumen. The regression equations fit a wide range of diets and diet compositions, and more importantly, they are applicable to various types of production systems.     

Methane emissions from two breeds of beef cows offered diets containing barley straw with either grass silage or brewers’ grains

Increasing the concentration of dietary lipid is a promising strategy for reducing methane (CH₄) emissions from ruminants. This study investigated the effect of replacing grass silage with brewers’ grains on CH₄ emissions of pregnant, non-lactating beef cows of two breeds. The experiment was a two×two factorial design comprising two breeds (LIMx, crossbred Limousin; and LUI, purebred Luing) and two diets consisting of (g/kg diet dry matter (DM)) barley straw (687) and grass silage (301, GS), or barley straw (763) and brewers’ grains (226, BG), which were offered ad libitum. Replacing GS with BG increased the acid-hydrolysed ether extract concentration from 21 to 37 g/kg diet DM. Cows (n=48) were group-housed in equal numbers of each breed across two pens and each diet was allocated to one pen. Before measurements of CH₄, individual dry matter intake (DMI), weekly BW and weekly body condition score were measured for a minimum of 3 weeks, following a 4-week period to acclimatise to the diets. CH₄ emissions were subsequently measured on one occasion from each cow using individual respiration chambers. Due to occasional equipment failures, CH₄ measurements were run over 9 weeks giving 10 observations for each breed×treatment combination (total n=40). There were no differences between diets for daily DMI measured in the chambers (9.92 v. 9.86 kg/day for BG and GS, respectively; P>0.05). Cows offered the BG diet produced less daily CH₄ than GS-fed cows (131 v. 156 g/day: P<0.01). When expressed either as g/kg DMI or kJ/MJ gross energy intake (GEI), BG-fed cows produced less CH₄ than GS-fed cows (13.5 v. 16.4 g/kg DMI, P<0.05; 39.2 v. 48.6 kJ/MJ GEI, P<0.01). Breed did not affect daily DMI or CH₄ expressed as g/day, g/kg DMI or kJ/MJ GEI (P>0.05). However, when expressed as a proportion of metabolic BW (BW^0.75), LUI cows had greater DMI than LIMx cows (84.5 v. 75.7 g DMI/kg BW^0.75, P<0.05) and produced more CH₄ per kg BW^0.75 than LIMx cows (1.30 v. 1.05 g CH₄/kg BW^0.75; P<0.01). Molar proportions of acetate were higher (P<0.001) and propionate and butyrate lower (P<0.01) in rumen fluid samples from BG-fed compared with GS-fed cows. This study demonstrated that replacing GS with BG in barley straw-based diets can effectively reduce CH₄ emissions from beef cows, with no suppression of DMI.     

Comparison of growth and nutritional status of juvenile Komodo monitors (Varanus komodoensis) maintained on rodent or poultry‐based diets

Nutrition and growth data were collected on six juvenile Komodo monitors (Varanus komodoensis) over 20 months. The animals were captive‐bred from two separate clutches, laid 6 months apart. Three animals were fed a rodent diet, and the other three were fed a poultry‐based diet. The animals were all weighed and measured weekly. Blood samples were collected monthly. Blood samples were analyzed for sodium (Na), potassium (K), calcium (Ca), phosphorus (P), magnesium (Mg), 25‐OH‐D, and cholesterol. Significant differences (P<0.05) were observed in dry matter intake (DMI) (1.12 vs. 0.90 %BW) and gross energy intake (GEI) (182.3 vs. 143.0 kcal GE/d), between rodent and poultry‐based diets, respectively. However, there were no differences in growth (average daily gain=6.13 vs. 6.33 g BW/d) between the two dietary treatments. Blood Na, K, Ca, P, Mg, and 25‐OH‐D concentrations were similar across treatments, while cholesterol levels were higher in the animals maintained on the rodent‐based diet. Zoo Biol 23:239–252, 2004. © 2004 Wiley‐Liss, Inc.     

Effects of nitrogen fertilisation rate and maturity of grass silage on methane emission by lactating dairy cows

Grass silage is typically fed to dairy cows in temperate regions. However, in vivo information on methane (CH₄) emission from grass silage of varying quality is limited. We evaluated the effect of two rates of nitrogen (N) fertilisation of grassland (low fertilisation (LF), 65 kg of N/ha; and high fertilisation (HF), 150 kg of N/ha) and of three stages of maturity of grass at cutting: early maturity (EM; 28 days of regrowth), mid maturity (MM; 41 days of regrowth) and late maturity (LM; 62 days of regrowth) on CH₄ production by lactating dairy cows. In a randomised block design, 54 lactating Holstein–Friesian dairy cows (168±11 days in milk; mean±standard error of mean) received grass silage (mainly ryegrass) and compound feed at 80 : 20 on dry matter basis. Cows were adapted to the diet for 12 days and CH₄ production was measured in climate respiration chambers for 5 days. Dry matter intake (DMI; 14.9±0.56 kg/day) decreased with increasing N fertilisation and grass maturity. Production of fat- and protein-corrected milk (FPCM; 24.0±1.57 kg/day) decreased with advancing grass maturity but was not affected by N fertilisation. Apparent total-tract feed digestibility decreased with advancing grass maturity but was unaffected by N fertilisation except for an increase and decrease in N and fat digestibility with increasing N fertilisation, respectively. Total CH₄ production per cow (347±13.6 g/day) decreased with increasing N fertilisation by 4% and grass maturity by 6%. The smaller CH₄ production with advancing grass maturity was offset by a smaller FPCM and lower feed digestibility. As a result, with advancing grass maturity CH₄ emission intensity increased per units of FPCM (15.0±1.00 g CH₄/kg) by 31% and digestible organic matter intake (33.1±0.78 g CH₄/kg) by 15%. In addition, emission intensity increased per units of DMI (23.5±0.43 g CH₄/kg) by 7% and gross energy intake (7.0±0.14% CH₄) by 9%, implying an increased loss of dietary energy with advancing grass maturity. Rate of N fertilisation had no effect on CH₄ emissions per units of FPCM, DMI and gross energy intake. These results suggest that despite a lower absolute daily CH₄ production with a higher N fertilisation rate, CH₄ emission intensity remains unchanged. A significant reduction of CH₄ emission intensity can be achieved by feeding dairy cows silage of grass harvested at an earlier stage of maturity.     

Food habits of sika deer and nutritional value of sika deer diets in eastern Hokkaido, Japan

Rumen content analysis and field observations were used to investigate the food habits and diet quality of sika deer (Cervus nippon yesoensis Heude) from 1991 to 1993 in eastern Hokkaido, Japan. Diets varied seasonally, with deer consuming graminoids and browse in winter, forbs and agricultural crops in spring and summer and all of these plant foods in autumn. Eighty-four plant species with sika deer bite marks were identified and their use also varied seasonally. The diversity of food resources available provided both critical protein and digestible energy, allowing for physiological maintenance and seasonal growth. With these high-quality diets, deer maintained good body condition in eastern Hokkaido, where the population density was relatively low.