Dietary nano chromium picolinate can ameliorate some of the impacts of heat stress in cross-bred sheep

Two studies were conducted to evaluate the effect of nano chromium picolinate (nCrPic) during heat stress (HS) in sheep. In the initial study, 36 Merino × Poll cross-bred sheep were individually penned and allocated to 3 dietary treatments (0, 400 and 800 μg/kg nCrPic) for 8 wk. Body composition was determined at the beginning and end of the experiment using dual energy X-ray absorptiometry. The sheep remained in their dietary groups but were then placed in metabolic cages and randomly allocated within the dietary group to differing ambient temperature regimes, i.e., thermo-neutral (TN) (n = 18) and HS (n = 18), for 3 wk. Dietary nCrPic had no effect on growth performance and body composition during the initial study conducted under TN conditions. Heat stress decreased average daily feed intake (ADFI) (P = 0.002) whereas sheep under HS had reduced average daily gain (ADG) and indeed lost weight (P < 0.001). Dietary nCrPic increased both ADFI (P = 0.041) and ADG (P = 0.049) under both TH and HS conditions such that the performance of sheep receiving supplemental nCrPic and exposed to HS was similar to that of control sheep maintained under TN conditions. Heat stress increased rectal temperature (P < 0.001) and respiration rate (P < 0.001), particularly during the hottest parts of the day as indicated by interactions (P < 0.001) between time of day and thermal treatment. Rectal temperature was lower in sheep fed nCrPic (P = 0.050), particularly under peak HS conditions during the afternoon as indicated by the interactions between dietary nCrPic and time of day (P < 0.001) and dietary nCrPic, thermal treatment and time of day (P = 0.010). Similarly, respiration rate was lower in sheep fed nCrPic under peak HS conditions during the afternoon as indicated by the interactions between dietary nCrPic and thermal treatment (P < 0.001) and dietary nCrPic and time of day (P = 0.030). In conclusion, dietary nCrPic can partially ameliorate the negative effects of HS as indicated by the maintenance of ADFI and decreased physiological responses, such as elevations in rectal temperature and respiration rate.     

Feed efficiency and body composition are related to cortisol response to adrenocorticotropin hormone and insulin-induced hypoglycemia in rams

Metabolic rate and energy consumption increase through the activation of the hypothalamic-pituitary-adrenal axis when an animal is exposed to a stressor. Residual feed intake (RFI) as a measure of efficiency has been shown to be related to exogenous adrenocorticotropin hormone (ACTH)-stimulated cortisol concentrations, which is indicative of the relationship between an animal's response to stress and the efficiency with which the energy is used for growth and production. In this study, we tested the hypothesis that sheep with low post-ACTH serum cortisol concentration relative to the other sheep in the flock have lower RFI values and lower cortisol concentrations following insulin-induced hypoglycemia. Adrenocorticotropin hormone (2.0 μg/kg body weight)-stimulated cortisol concentrations were measured in 100 sheep. The extreme responders were selected (n = 12 high cortisol, n = 12 low cortisol), and feed efficiency and body composition parameters were measured. A second ACTH challenge and an insulin challenge were administered. More efficient sheep (more negative RFI value) were found to have lower (P < 0.05) cortisol concentrations following both an ACTH challenge and an insulin challenge. Low-cortisol sheep (low response to ACTH or insulin) were found to have a lower (P < 0.05) proportion of fat tissue in comparison to the high-cortisol animals. These data clearly indicate that an animal's response to exogenous ACTH or insulin-induced hypoglycemia as a stressor is related (P < 0.05) to efficiency of energy use when measured as RFI. These data have important implications in enabling identification of animals that are superior in terms of feed efficiency and for understanding the physiological mechanisms underlying efficiency of energy use.     

Effects of supplementation of Farta sheep fed hay with sole or mixtures of noug seed meal and wheat bran on feed intake,digestibility and body weight change

Digestibility and feeding trials for 10 and 90 days were conducted using 25 yearling Farta rams with a mean body weight (BW) of 16.8 ± 0.17 kg (mean ± SD) to study the effects of supplementation with sole or mixtures of noug seed meal (NSM) and wheat bran (WB) on feed intake, digestibility and BW change in Farta sheep fed hay. The experimental design was a randomized complete block design. The sheep were arranged in five blocks based on initial BW, and the five treatments were assigned randomly to each animal in a block. The five treatments comprised of ad libitum hay (control, T1) and ad libitum hay plus daily supplementation of 300 g dry matter (DM) sole WB (T2), 2WB:1NSM (T3), 1WB:2NSM (T4) and sole NSM (T5). Supplementation increased total DM (P < 0.01) and crude protein (CP) (P < 0.001) intake and promoted daily BW gain (P < 0.001). Non- supplemented sheep consumed more (P < 0.01) hay DM compared to the supplemented treatments, except T2. Among supplemented sheep, T5 had higher (P < 0.001) CP intake than the other treatments. Supplementation improved (P < 0.001) the digestibility of CP. Lack of statistical differences in daily BW gain between the different supplements used in this study suggests that sheep producers can use the different feed supplements considered in this study depending on their availability in the order of T4, T5, T3 and T2, respectively.     

Performance and effects of small ruminal boluses for the electronic identification of fattening lambs

Two types of electronic boluses were evaluated in two experiments using intensively reared lambs. In Experiment 1, 148 lambs were assigned to three treatments defined by bolus type and lamb's age: mini (M, 5.2 g) applied as early as possible; small (S, 20.0 g) applied after weaning; and control (C), without bolus. Application of the M and S boluses required lambs older than 8 and 46 days, respectively. No differences in total mortality (6.8%), milk and concentrate intakes, and final live weight (LW) were observed between bolus types at the end of fattening (11 weeks). Total retention rates of boluses were 59.0% and 100% for the M and S boluses, respectively. Abattoir retrieval was 100%. Conventional ear tag loss rate in the same period was 2.1%. In Experiment 2, we used 94 lambs in three treatments, 2 of them applied with M boluses at: M1, 1 week before weaning; M2, 1 week after weaning; and C, without bolus. Bolus retention rate (43.5%) of M boluses was not affected by weaning. Ear tag loss rate was 3.2%. In conclusion, application age of M boluses was earlier than 8 days of age but their retention rates need to be improved. The S boluses are feasible to use as a permanent identification system in lambs older than 7 weeks. For earlier tagging, boluses as small as M but with greater weight and specific gravity should be developed.     

Supplementation of cottonseed meal on feed intake, digestibility, live weight and carcass parameters of Sidama goats

The experiment was conducted at Dilla Agricultural Technical Vocational Education and Training (ATVET) College in Ethiopia using twenty-four yearling intact male Sidama goats with a mean body weight (BW) of 16.8 ± 1.14 kg (mean ± SD). The objective of the experiment was to examine the effect of different levels of cottonseed meal (CSM) supplementation on the feed intake, digestibility, BW gain, and carcass parameters of Sidama goats. The experiment consisted of 90 days of feeding trial and 10 days of digestibility trial followed by evaluation of carcass parameters at the end of the experiment. The treatments included ad libitum feeding of hay (T1, control) and daily supplementation of CSM at 200 g (T2), 300 g (T3) and 400 g (T4) per head on dry matter (DM) basis. The experimental design was a completely randomized block design. The experimental goats were blocked on initial BW and six goats were randomly assigned to each treatment. Hay DM, crude protein (CP) and neutral detergent fiber (NDF) intake were higher (P < 0.001) in the non-supplemented than in the supplemented goats, however, the contrary was true for total CP intake. Total DM intake was higher (P < 0.001) for goats supplemented with the high level of CSM than those on the control treatment. Among CSM supplemented goats, the intake of CSM DM, CP, NDF (P < 0.001) and total CP (P < 0.01) were higher in the order of T4 > T3 > T2. The high level of supplementation with CSM resulted in better (P < 0.05) apparent digestibility coefficient (DC) of DM and organic matter (OM) compared to the non-supplemented goats. The apparent DC of CP was higher (P < 0.01) for supplemented than non-supplemented goats. The non-supplemented goats had lower daily BW gain, empty BW, dressing percentage on slaughter weight base, rib-eye muscle area (P < 0.01), BW change (P < 0.001), final BW (P < 0.05) and higher feed conversion ratio (P < 0.01) than the supplemented ones. The medium level of supplementation resulted in higher daily BW gain (P < 0.01), BW change (P < 0.001), final BW (P < 0.05) and lower feed conversion ratio (P < 0.01) than the lower level of supplementation, but with no differences (P > 0.05) in these parameters with the high level of supplementation. Therefore, it is concluded that supplementation of CSM at 300 g DM per head per day resulted in better animal performance parameters in Sidama goats.     

Feed intake,digestibility and body weight change in Farta sheep fed hay supplemented with rice bran and/or noug seed (<Emphasis Type="Italic">Guizotia abyssinica</Emphasis>) meal

The study was conducted to determine the effect of supplementation with rice bran (RB) and /or noug seed (Guizotia abyssinica) meal (NSM) on feed intake, digestibility, and body weight (BW) change in hay based feeding of Farta sheep. Twenty five yearling Farta rams with a mean initial BW of 19.23 ± 0.28 kg were used in randomized complete block design arranged into five blocks of five animals. The five dietary treatments that consisted of hay alone (T₁), hay + RB (T₂), hay + mixture of RB and NSM at a ratio of 1:2 (T₃), hay + mixture of RB and NSM at a ratio of 2:1 (T₄) and hay + NSM (T₅) were randomly assigned to each sheep within a block. The supplements were daily offered at 300 g dry matter (DM) head⁻¹ in two equal parts at 800 and 1600 h. Supplementation improved the total DM and acid detergent fiber (ADF) intake (P < 0.05), organic matter (OM) intake (P < 0.01), crude protein (CP) intake (P < 0.001). The apparent digestibility of DM in T₅ was higher (P < 0.05) than in T₁ and T₂ and that of T₄ was also higher (P < 0.05) than in T₁. The apparent digestibility of CP in T₅ and T₄ were higher (P < 0.001) than in T₁ and T₂ and that of T₃ and T₂ were also higher (P < 0.001) than for T₁. The BW gain of experimental sheep was improved (P < 0.01) by supplementation with NSC (T₅) and/or its mixtures with RB (T₃ and T₄). The results of the study showed that supplementation with either of both mixtures of NSM and RB at 43% of total DM intake promoted better feed intake, digestibility and BW gain in Farta sheep.     

玉米秸处理方法与替换干草水平对绵羊瘤胃发酵与采食量的影响

选用12只安装有永久性瘤胃瘘管、十二指肠近端瘘管的内蒙古半细毛羯羊。在1 1M饲喂水平下,研究不同处理的玉米秸对生长肥育羊瘤胃发酵和采食量的影响,试验结果表明:不同处理的玉米秸替换干草的水平,对瘤胃pH值无显著影响(P>0 05)。与未处理组(C组)比较,兴牧宝处理组(XT)组NH3 N浓度较低,而氨化处理组(AT组)的较高(P<0 05)。XT组和AT组的微生物蛋白(MCP)产量均明显高于C组(P<0 05),分别提高了33 67%和25 68%。随着玉米秸替换干草水平的增加,NH3 N浓度、MCP的合成及乙酸、丙酸和丁酸的浓度均显著降低(P<0 05)。XT组的丙酸浓度高于C组和AT组(P<0 05)。XT组、AT组采食量分别提高了4 90%和3 75%。玉米秸替换干草的适宜比例为30%～60%(占日粮干物质比例的21%～42%)。     

补铬对断奶仔猪代谢、免疫功能和生产性能的影响

选择(32±2)日龄、平均体重为(8.24±0.85)kg的三元杂交(杜×长×大)仔猪108头,随机分为3个处理,分别饲喂基础日粮、基础日粮添加甲基吡啶铬(C r3+含量200μg/kg)和基础日粮添加酵母铬(C r3+含量200μg/kg)3种日粮。试验持续4周,猪只自由采食和饮水。结果表明,日粮补铬对仔猪血浆铬、尿素氮、葡萄糖、甘油三酯、总蛋白、球蛋白、白蛋白等含量无显著影响(P>0.05);对卵清蛋白抗体效价、猪瘟(SFV)抗体效价以及经植物凝集素(PHA)刺激后皮褶厚度(DST)的变化无显著影响(P>0.05);对仔猪平均日增重(ADG)、平均日采食量(ADFI)和饲料转化效率(FCR)也均无显著影响(P>0.05)。结果提示,尚不能确定在生产实践中添加铬对仔猪免疫和生产性能的促进作用。     

不同季节收获的星星草对绵羊采食量和养分消化率的影响

旨在研究不同季节收获的星星草(Puccinellia tenuiflora)对绵羊采食量及养分消化率的影响。选用平均体重为30.37±2.15kg的乌珠穆沁公羊12只,随机分为4个处理,每个处理3个重复,分别饲喂四季收获的星星草。试验绵羊采取单笼饲养,预饲期15d,正式试验期7d,自由采食和饮水,采用全收粪法进行消化代谢试验。结果表明:绵羊四季采食星星草干物质含量分别为412.42、639.23、741.49和321.30g/d,秋季显著高于春季和冬季的干物质采食量(P<0.05);秋季星星草有机物消化率显著低于其他季节(P<0.05);不同季节的星星草对绵羊的碳、氮采食量均有显著影响(P<0.05),饲喂不同季节星星草的绵羊均处于氮的负平衡状态,分别为-1.12、-0.78、-0.13和-3.16。总之,星星草低的含氮量和采食量是限制星星草饲喂价值的重要因素。     

Dietary supplementation with curcumin-loaded nanocapsules in lambs:Nanotechnology as a new tool for nutrition

Curcumin-containing nanocapsule powder formulations have not been used in ruminant feed to date, despite the fact that curcumin is known to be a functional food additive. The objective of this study was to determine whether ethyl polymethacrylate (Eudragit L-100) nanocapsules loaded with curcumin (N-CU) would improve health and growth of lambs. Thirty-two male Lacaune lambs (body weight [BW] = 16 ± 0.99 kg; 45 d of age) were randomly assigned to 1 of 4 treatments: T0, T1, T2 and T4, representing supplementation of curcumin at 0, 1, 2, and 4 mg/kg concentrate, respectively. The animals in each treatment were allocated in 4 pens of 2 lambs each (8 lambs per treatment). The experiment lasted 17 d, with samples and measurements collected on d 0, 7, 12, and 17. The T2 lambs had greater average daily gain than T0 lambs. Regression analysis showed that the ideal dose of N-CU to enhance weight gain was 1.89 mg/kg concentrate. There were significant interactions (P < 0.05) between treatments × time for hematological variables, particularly for increases in erythrocytes (T2) and reductions in counts of leukocytes, neutrophils, and lymphocytes in T1 and T2. There were significant interactions between treatment × time for total protein, globulin, urea, and triglyceride levels. Stimulation of the antioxidant system was also observed. There were increased levels of non-protein thiols (NPSH), as well as increased activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) in the supplemented animals. Levels of reactive oxygen species (ROS) were lower in the serum of supplemented lambs. In general, the 4 mg/kg dose had no positive effects on growth or health. This was an unexpected result, given the known properties of curcumin. Taken together, these findings suggest that addition of low concentrations of nanoencapsulated curcumin (T1 and T2) in lamb feed improves health, minimizing oxidative stress and generates anti-inflammatory effects that may have contributed indirectly to greater weight gain. Nanocapsules potentiate the effects of curcumin and may emerge as a new tool in animal nutrition.     

Rams with poor feed efficiency are highly responsive to an exogenous adrenocorticotropin hormone (ACTH) challenge

An animal's response to a stressor is to increase metabolic rate, and thus energy consumption through the activation of the hypothalamic-pituitary-adrenal axis. Changes to energy use by an animal are likely to influence the efficiency with which it is utilised. In this study, we tested the hypothesis that less efficient sheep are more responsive to exogenous administration of adrenocorticotropin hormone. This was done by firstly determining the appropriate dose (0.4, 1.6 or 6.4microg/kg LW) and peak serum cortisol response time (45min) to exogenous administration of adrenocorticotropin hormone in a pilot study (n=3 sheep). Following this, adrenocorticotropin hormone (2.0microg/kg LW) stimulated cortisol levels were measured in a larger group of sheep (n=50) of known feed efficiency (feed conversion ratio and residual feed intake values). Less efficient sheep (more positive residual feed intake values) were found to have a greater (P<0.001) increase in cortisol concentration in comparison to more efficient animals. Those sheep which had higher levels of cortisol also had a greater proportion (P<0.001) of fat tissue. These data clearly demonstrated that efficiency of energy use, when measured as residual feed intake, is significantly related to an animal's stress response. These findings have important implications for understanding the physiological mechanisms underpinning efficiency of energy use, and may be useful in successfully identifying animals which are superior in terms of feed efficiency.     

Feed intake,digestibility, body weight and carcass parameters of Afar rams fed tef (Eragrostis tef) straw supplemented with graded levels of concentrate mix

The experiment was conducted at Alamata Agricultural Research Center, Ethiopia using 20 Afar rams with an initial body weight (BW) of 18.2 ± 1.76 (mean ± SD) kg. The objectives were to study the effect of supplementation with concentrate mix consisting of wheat bran (WB), noug seed cake (NSC) and sesame seed cake (SSC) at the ratio of 2:1:1 on dry matter (DM) basis, respectively on feed intake, digestibility, BW gain and carcass parameters of Afar rams fed tef (Eragrostis tef) straw basal diet. The experiment was arranged with four treatments and five replications in a randomized complete block design. The treatments included feeding sole tef straw (T1, control), and daily supplementation with the concentrate mix offered at 150 (T2, low), 250 (T3, medium) and 350 (T4, high) g DM per head. Total DM intake, crude protein (CP) digestibility, daily BW gain (P < 0.001), DM and organic matter (OM) digestibility, and carcass parameters (P < 0.05) were higher in the supplemented than in the control treatment. Intake of tef straw reduced as the level of supplementation increased, whereas the contrary was true for CP intake. Performance in carcass parameters was better for the medium compared to the low level of concentrate mix supplementation. Moreover, the medium level of supplementation did not substitute tef straw intake. Therefore, it is concluded that the medium level of concentrate mix supplement maintained the utilization of the roughage feed and resulted in better carcass parameters.     

日粮中添加调味剂对围产期奶牛采食量、产后体重和体况评分的影响

选用32头干奶后期荷斯坦牛,按照年龄、体重、胎次和上个周期产奶量相同或相近的原则,随机分成4个处理组,研究在日粮中添加草香味调味剂、焦糖味调味剂和果香味调味剂（添加比例100g/t TMR日粮）,对奶牛采食量、产后体重恢复和体况评分的影响。结果表明,在日粮中添加调味剂对围产期奶牛产前和产后的干物质采食量有提高的趋势,其中产前日粮添加调味剂A（草香味）和调味剂B（焦糖味）可以显著提高奶牛的干物质采食量（P〈0.05）;在日粮中添加调味剂对围产期奶牛产后体重的恢复有促进作用,其中添加调味剂B（焦糖味）组奶牛在产后28天和42天的测定值显示,可以显著影响围产期奶牛产后的体重恢复（P〈0.05）;在日粮中添加调味剂对围产期奶牛产后体况的恢复有促进作用,其中在奶牛产后14天的测定值显示,添加调味剂B（焦糖味）可以显著改善奶牛的体况（P〈0.05）;在产后28天,添加调味剂B（焦糖味）和调味剂C（果香味）可以显著改善奶牛的体况（P〈0.05）;在产后42天,添加调味剂A（草香味）、调味剂B（焦糖味）和调味剂C（果香味）都可以显著改善奶牛的体况（P〈0.05）。即在围产期奶牛日粮中添加不同风味的调味剂,都可以提高奶牛的干物质采食量,促进奶牛产后体重和体况的恢复,其中焦糖味调味剂的效果最为明显。     

季节和体重对肉用绵羊超数排卵的影响

本试验选择64只(次)健康经产的德国美利奴、无角道赛特、特克塞尔肉用绵羊,集中饲养,分别在秋季、冬季和春季,根据体重分组进行超数排卵,即41～50 kg组、51～60 kg组、61～70kg组和71～80kg组.结果表明,不同品种超数排卵的结果无显著差异(P＞0.05).不同季节对肉用绵羊超数排卵影响差异不显著(P＞0.05),但胚胎可用率秋季和冬季高于春季(P＜0.01).不同体重组对肉用绵羊超数排卵反应亦没有影响(P＞0.05),但41～50kg组和51～60kg组的可用胚数高于71～80kg组(P＜0.05),胚胎可用率41～50kg组高于其它组(P＜0.01),51～60 kg组的胚胎可用率高于71～80kg组(P＜0.01),61～70kg组的胚胎可用率高于71～80 kg组(P＜0.05).本试验结果说明肉用绵羊在秋冬春季超数排卵效果差异不明显,可在这些季节进行胚胎生产和移植.体重在41～70 kg的供体母羊进行超排效果较好.     

Lactation efficiency as a result of body composition dynamics and feed intake in sows

Through genetic selection and improvement of environment, litter size of sows increases. Increased energy requirement during lactation, increases the risk of excessive mobilization from body stores, with detrimental effects on reproductive performance. Feed intake capacity tends to decrease due to selection towards leaner pigs with a lower feed conversion ratio. However, to facilitate sows to wean large litters extra feed intake, or even better, a higher feed efficiency during lactation would be favourable. The objective of the present study was to describe the dynamics of body composition of sows and piglets during lactation, and to relate these traits to a newly introduced trait called “lactation efficiency”. Energy metabolism of lactating sows was described, based on on-farm observations of weight and backfat of sows before parturition and at weaning, weight of piglets at birth and at weaning and feed intake of sows during lactation. “Lactation efficiency” was defined as energy efficiency of sows, and calculated for individual sows at two different farms. The average lactation efficiency was 68% and 65% for both farms; meaning that 68 and 65% of the metabolisable energy through feed intake or mobilization from body stores, above maintenance of the sow (input), was used for piglet growth and piglet maintenance (output). The association between lactation efficiency and other reproductive traits was studied by estimating the correlations within farms. Sows with a higher lactation efficiency showed lower feed intake (r = − 0.27 and r = − 0.35 for both farms respectively) and smaller fat losses (r = − 0.34 and r = − 0.29, respectively). The energy output of efficient sows was slightly higher (r = 0.23 and r = 0.30). The more efficient sows were the better mothers, as mortality of their piglets was lower (r = − 0.12 and r = − 0.16), piglet growth rate was higher (r = 0.16 and r = 0.23), and at weaning their litters were less variable (r = − 0.08; only available at one farm). Results were remarkably similar for the two farms, despite different feeding strategies. Extra input, by means of feed intake or mobilization from body stores generated extra output by means of litter weight at weaning. This experiment demonstrated that an accurate recording of energy metabolism and relevant reproduction traits with little intervention is possible on commercial farms.     

Effect of supplementing urea-treated barley straw with lucerne or vetch hays on feed intake,digestibility and growth of Arsi Bale Sheep

The study was conducted at Sinana Agricultural Research Center, Ethiopia to assess the supplementation of graded levels of vetch (Vicia dasycarpa `lana’) and lucerne (Medicago sativa,’ Hunter river’) hay on feed intake, digestibility and body weight (BW) change of Arsi-Bale sheep fed urea treated barley straw (UTBS). A 7 day- digestibility and a 90 day- feed intake trials were conducted using 28 and 35 sheep, respectively. The experimental design was a randomized complete block design with seven dietary treatments that consisted of feeding UTBS (T1) as the control treatment, UTBS plus 150, 250 and 350 g dry matter (DM) per day of vetch for T2, T3, T4, respectively and UTBS plus 150, 250 and 350 g DM per day of lucerne for T5, T6 and T7, respectively. Intake of UTBS was not affected (P > 0.05) by inclusion of lucerne hay at 25–35% of daily DM intake. The supplements increased daily intake of total DM, organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF) and metabolizable energy (ME) (P < 0.001) as well as apparent digestibility of DM, OM (P < 0.001), NDF (P < 0.01), ADF, crude protein (CP) (P < 0.05) and daily BW gain (P < 0.001). Supplementation with lucerne than vetch hay promoted higher (P < 0.001) CP and ME intakes and daily BW gain. Feeding with the UTBS without supplementation was enough to meet the maintenance requirements of the sheep and allow small BW gain. The results of the study showed that urea treatment of barley straw in conjunction with supplementation of lucerne or vetch hay could serve as a useful strategy in improving smallholder sheep production in the tropics.     

Effect of supplementation of dietary protected lipids on intake and nutrient utilization in Deccani lambs

Four complete isonitrogenous (crude protein 13%) rations with 0 (T₁), 5 (T₂), 10 (T₃) and 15 (T₄) per cent calcium soap from red palm oil (protected fat) were formulated and evaluated using four Deccani lambs (19.32 ± 0.82 kg) in a completely randomized design at the end of a growth trial. The average daily dry matter intake (% body weight or g/kg W^0.75 per day) in lambs fed ration T₄ was significantly (p < 0.05) lower than in those fed rations T₁, T₂, and T₃. There was no significant difference in the digestibility of proximate principles and cell-wall constituents except for ether extract (EE) and cellulose. EE digestibility was significantly (p < 0.05) higher by 15.71, 14.65 and 11.56 percentage units, respectively in lambs fed rations T₂, T₃ and T₄ as compared to those fed ration T₁. Ration T₄ had significantly (p < 0.05) lower cellulose digestibility than rations T₁, T₂ and T₃. Nitrogen and phosphorous balances (g/day) were not significantly (p > 0.05) different among the four rations. Calcium balance (g/day) was higher by 0.65, 1.39 and 1.40, respectively, in lambs fed rations T₂ (p > 0.05) and T₃ and T₄ (p < 0.05) in comparison to those fed ration T₁. Digestible crude protein and total digestible nutrients content (g/kg DM) of rations were not significantly (p > 0.05) different among the four rations. It is concluded that calcium soap from red palm oil can be supplemented up to 10% level as a concentrated energy source in the rations of Deccani lambs without any adverse effect on dry matter intake and cellulose digestibility.     

Effects of dietary concentrate level and chromium-methionine supplementation on ruminal fermentation,and ruminal bacterial and fatty acid composition in Tan lambs北大核心CSCD

This study evaluated the effects of dietary concentrate level and chromium methionine(Cr-Met)supplementation on ruminal fermentation and fatty acid composition, and ruminal bacteria abundance in Tan lambs. Forty male Tan lambs [(21.00±1.23) kg body weight, 5 months of age] were randomly assigned to four treatment groups with 10 lambs in each treatment. The treatments were: a low-concentrate (LC) diet (concentrate:forage, 35:65) without Cr-Met supplementation; a high-concentrate (HC) diet (concentrate:forage, 55:45) without Cr-Met supplementation; groups fed the HC diet with 0.75 or 1.50 g·d-1·lamb-1 Cr-Met (HCM and HCH, respectively). Ruminal fluid was collected on day 65 with an oral stomach tube about 3 h after the morning feed and samples used for fermentation analysis, fatty acid composition determination and bacterial DNA extraction. It was found that: 1) Ruminal pH, acetate proportion and acetate:propionate were greater (P<0.05) with the LC diet whereas microbial crude protein, propionate and valerate proportions were greater (P<0.05) with the HC diet. The acetate:propionate was greater (P<0.05) in the HCM group than in the HC group. 2) For the HC diet, the DNA abundances of Butyrivibrio fibrisolvens vaccenic acid subgroup (Butyrivibrio VA) and Ruminococcus flavefaciens were decreased (P<0.05), compared with the LC diet, whereas the DNA abundance of Anaerovibrio lipolytica was increased (P<0.05). For lambs fed the HC diet, DNA abundances of B. fibrisolvens stearic acid subgroup, Butyrivibrio VA, Butyrivibrio proteoclasticus, and A. lipolytica showed a linear decrease (P<0.05) with increasing Cr-Met supplementation level; However, the DNA abundance of R. flavefaciens showed a linear increase (P<0.05). 3) Compared with the LC group, the concentrations of t11 C18:1, trans C18:1, c9t11 CLA, t10c12 CLA, C18:2n6, and C18:3n3 were decreased by the HC diet without Cr-Met supplementation whereas the concentration of C18:0 was increased. There was a linear increase in t11 C18:1 and trans C18:1 with increasing Cr-Met supplementation level in lambs fed the HC diet. The results suggest that the HC diet inhibited the growth of ruminal bacteria involved in the ruminal biohydrogenation process, and the addition of Cr-Met had a potentially positive effect on conjugated linoleic acid (CLA) synthesis in body tissue. © 2022, Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

吡啶甲酸铬对生长猪生产性能和组织中铬残留的影响

选用96头体重(24.67±0.36)kg,公母各半达兰猪,随机分为4组,每组4个重复,每个重复6头。对照组饲喂基础日粮,3个试验组分别添加200、400μg/kg和800μg/kg吡啶甲酸铬(以铬计)。另外,选用8头体重(24.98±0.56)kg达兰猪,随机分为2组,添加1600μg/kg和3200μg/kg吡啶甲酸铬(以铬计),试验期28d。结果表明,添加200～800μg/kg吡啶甲酸铬对猪平均日增重和饲料转化效率无显著影响(P>0.05),但可提高饲料采食量,800μg/kg处理组的采食量显著高于其他3个处理组(P=0.01)。添加200～3200μg/kg吡啶甲酸铬猪组织中铬残留量为0.08～0.35mg/kg。     

瘤胃蛋白降解率和添加频率对饲喂低质饲料的羔羊的影响研究

4头初始体重为34.5±2.0kg、插有瘤胃瘘管的萨福克阉公羊羔被用来评估瘤胃蛋白降解率和添加频率对饲喂低质饲料的羔羊瘤胃特性的影响。羔羊以成熟皇冠干草（含4.2%CP）为基础日粮,各日粮组分为4组,分别是：1）RDP-D：每天饲喂高的瘤胃降解蛋白质（RDP）;2）RDP-A：每隔1d饲喂高的RDP;3）RUP-A：每隔1d饲喂非瘤胃降解蛋白质（RUP）;4）MIX-A：每隔1d按照RDP：RUP=1：1的比例来饲喂。结果显示,各处理组的羔羊粗饲料的有机质（OM）、氮（N）、中性洗涤纤维（NDF）或酸性洗涤纤维（ADF）的采食量没有显著差异;混合组（MIX-A）的羔羊瘤胃有机质的消化率比其他组的要高（P〈0.001）;RUP-A组羔羊的真瘤胃氮消化率较其他处理组的低（P〈0.01）;混合组MIX-A瘤胃NDF和ADF的代谢较其他处理组高（P≤0.01）。当在羔羊日粮中添加RUP相对添加RDP-D可以降低其瘤胃氨气浓度,且RUP-A组的羔羊的瘤胃氨气浓度最低。各处理组的瘤胃脲酶活性差异不显著,瘤胃微生物N流量差异不显著,不过RDP-D组的羔羊的瘤胃微生物N合成效率有增加趋势（P=0.004）。隔天饲喂羔羊混合组的日粮可以改善低质粗饲料的消化率,这可能是由于内源性氮循环利用增强导致瘤胃氨气浓度有所下降。