复合益生菌制剂对奶牛泌乳性能及乳品质的影响

为研究复合益生菌制剂对奶牛泌乳性能及乳品质的影响,试验选取45头泌乳期相近的荷斯坦奶牛,随机分为3组,对照组、试验1组、试验2组,每组3个重复,每个重复5头。对照组饲喂基础日粮,试验1、2组分别在基础日粮中添加1%、2%的复合益生菌制剂,试验期为60d。结果表明:试验2组在第10、30、60天奶牛产奶量较对照组分别提高2.28%、0.62%、9.08%(P<0.05),试验1组在第10、60天较对照组分别提高4.6%、8.9%(P<0.05);第30天时,试验1、2组乳中总固形物含量较对照组均显著性提高(P<0.05),乳糖率、乳蛋白率、乳脂率之间差异不显著(P>0.05);第60天时,与对照组相比,试验1、2组乳中乳糖率分别提高了4.41%、7.02%(P<0.05),乳蛋白率提高了4.16%、9.97%(P<0.05),总固形物含量提高了2.44%、3.02%(P<0.05),乳脂率含量之间差异不显著(P>0.05)。综上,日粮中添加复合益生菌制剂可有效提高奶牛产奶量及乳品质,且添加2%复方益生菌制剂效果更优。     

不同营养水平代乳料对奶公犊生长性能及血液生化指标的影响

选用40头健康、体质量及出生日期相近的荷斯坦奶公犊,按体质量随机分为4组(每组10头),进行为期120d的生长育肥试验。不同处理组代乳料的营养水平为:Ⅰ组(22.00%CP,16.00 MJ/kg DE),Ⅱ组(20.00%CP,16.00 MJ/kg DE),Ⅲ组(22.00%CP,15.00 MJ/kg DE),Ⅳ组(20.00%CP,15.00 MJ/kg DE)。结果表明,Ⅰ组犊牛的日增重显著高于其他3组,比Ⅱ组、Ⅲ组和Ⅳ组分别提高了11.63%(P0.01),6.67%(P0.01)和5.49%(P0.01)。代乳料的蛋白水平对犊牛试验末体质量和日增重影响显著,蛋白质水平为22.00%的代乳料组试验牛的试验末体质量和日增重比20.00%代乳料组分别提高了3.29%(P0.05)和5.62%(P0.01)。代乳料的消化能(DE)水平显著影响犊牛的干物质采食量(DMI),随DE水平的提高而显著降低,与15 MJ/kg DE水平代乳料组相比,16 MJ/kg DE水平代乳料组犊牛的DMI降低了2.90%(P0.01);代乳料的蛋白水平对奶公犊60d和120d粗蛋白质和粗脂肪的消化率影响显著(P0.05),蛋白质水平为22.00%的代乳料组犊牛60d和120d粗蛋白质的消化率比20.00%代乳料组分别提高了3.49%(P0.05)和4.57%(P0.05),粗脂肪的消化率分别提高了6.67%(P0.05)和3.80%(P0.05);蛋白质水平为22.00%的代乳料组试验牛120d血清中BUN、TP和T3的含量比20.00%代乳料组分别提高了21.61%(P0.05),4.36%(P0.05)和5.79%(P0.05)。综上所述,在本试验条件下,Ⅰ组犊牛的日增重、试验末体质量和营养物质消化率最高,建议0~4月龄奶公犊日粮适宜的DE为16.00 MJ/kg,CP为22.00%。     

Growth,nutrient utilization,and body composition of dairy calves fed milk replacers containing different amounts of protein

Male Holstein calves < 1 wk of age were allowed a 2-wk adaptation period after purchase, and then were blocked by BW and assigned randomly within block to either a baseline slaughter group or one of four experimental groups (n = 8 to 9 per group). Treatments were isocaloric milk replacers (12.5% solids) fed at 12% of BW that contained 16.1, 18.5, 22.9, or 25.8% CP (DM basis) from whey protein sources. After a 6-wk feeding period, all calves were slaughtered and the weights and chemical composition of the viscera-free carcasses (VFC; including head, hide, feet, and tail) were determined. Gain of BW (0.38, 0.45, 0.56, and 0.62 kg/d) and gain:feed ratio (0.51, 0.59, 0.71, and 0.78) increased linearly (P < 0.001) as dietary CP increased; rate of change in body length, wither height, and heart girth also increased linearly (P < or = 0.05). Balance measurements conducted during wk 3 and 4 of the experimental period showed that both absorbed N (16.9, 20.0, 25.8, and 30.6 g/d) and retained N (7.6, 9.0, 13.2, and 15.6 g/d) increased linearly (P < 0.001) as dietary CP increased. Retained N as a percentage of absorbed N increased linearly (P < 0.01) as dietary CP increased (44.3, 44.7, 50.7, and 50.9%), whereas biological value was unaffected (71.1, 68.7, 69.5, and 67.3%; P = 0.26). Digestible energy and ME represented 94.5 and 89.7% of intake energy, respectively, and were not affected by dietary CP content. Plasma urea N concentration increased linearly (2.9, 3.3, 4.6, and 6.0 mg/dL) as dietary CP increased. Contents of water (68.2, 69.1, 70.2, and 70.5%; P < 0.001) and protein (19.6, 20.0, 20.0, and 20.2%; P < 0.10) in VFC increased linearly, whereas contents of fat (7.2, 6.2, 5.5, and 5.2%; P < 0.001) and ash (5.1, 5.2, 4.8, and 4.7%; P < 0.02) decreased linearly as dietary CP increased. Trends in visceral tissue composition were similar to those for VFC. The content of water in VFC tissue gain increased, whereas contents of fat and energy decreased, as dietary CP increased. Final VFC energy and gain of energy in VFC were not affected by dietary CP. At similar initial ME intakes, increasing dietary CP (i.e., increasing protein: energy) linearly increased ADG, gain:feed, N retention, and deposition of lean tissue in VFC, demonstrating that diet composition can markedly affect components of body growth in preruminant dairy calves.     

Growth and body composition of dairy calves fed milk replacers containing different amounts of protein at two feeding rates

Previous research has demonstrated that increasing the CP concentration from 16 to 26% in milk replacers fed to male preruminant dairy calves at 1.5% of BW (DM basis) daily resulted in increased ADG, G:F, and deposition of lean tissue. However, the effects of dietary CP would be expected to vary depending on ME intake. Here, male Holstein calves < 1 wk old were used to determine the effects of feeding rate and CP concentration of isocaloric, whey protein-based milk replacers on growth and body composition. After a 2-wk standardization period, calves were assigned randomly to an initial baseline group or to treatments in a 2 x 4 factorial arrangement of feeding rate (1.25 or 1.75% of BW daily, DM basis) and milk replacer CP concentration (14, 18, 22, or 26% of DM). No starter was offered, but calves had free access to water. After a 5-wk feeding period, calves were slaughtered and body composition was determined. Increasing the feeding rate increased (P < 0.05) ADG, G:F, empty-body gains of chemical components and energy, the percentage of fat in empty BW gain and in the final empty body, and concentrations of IGF-I and insulin in plasma. Increasing the feeding rate decreased (P < 0.01) percentages of water and protein in the empty body and decreased urea N in plasma. Increasing dietary CP concentration linearly increased (P < 0.05) ADG, body length, heart girth, and gains of water and protein but linearly decreased (P < 0.05) fat gain. As dietary CP increased, fat content in empty body gain decreased, and water and protein increased. Increasing CP concentration increased (quadratic, P < 0.02) G:F, with greatest efficiencies for calves fed 22% CP. Gross energetic efficiency (retained energy:intake energy) was greater (P < 0.05) for calves fed at 1.75% of BW daily. Efficiency of dietary protein use for protein gain was greater for calves fed at 1.75% of BW daily but was not affected by dietary CP. The ratio of protein gain to apparently digestible protein intake above maintenance decreased as dietary CP increased. Interactions (P < 0.05) of feeding rate and CP concentration for gains of water and protein indicated that when dietary CP was 26% the ME supply limited protein use by calves fed at 1.25% of BW daily. Body composition of preruminant calves can be markedly altered by manipulating the protein to energy ratio in milk replacers. These dietary effects on body composition and growth are not predicted by current NRC standards.     

Hemato-biochemical changes, disease incidence and live weight gain in individual versus group reared calves fed on different levels of milk and skim milk

A 2 × 3 factorial design was used to study the impact of rearing systems, individual (I) versus group (G) and different levels of milk/skim milk feeding (F1, F2 and F3) on hemato‐biochemical profile, disease incidence and average daily gain of crossbred (Bos indicus × Bos taurus) calves. Six calves were taken in each group on the basis of their birth weight and housed in individual (2.20 × 1.16 m²/calf) or in group pens (2.20 × 1.03 m²/calf). After 3 days of colostrum feeding, calves were allocated to one of three different milk feeding schedules: milk fed up to 8 weeks of age (F1), milk up to 4 weeks followed by 50% replacement by skim milk up to 6 weeks and 100% thereafter (F2) and 100% replacement of milk with skim milk after 4 weeks (F3). Calf starter and cereal green fodders were fed ad libitum from the second week of age and continued for 14 weeks. Parameters on health and disease profiles of calves (disease incidence, duration of illness, response to treatment and recovery) and weekly live weight change were recorded. Calf scour predominated (52.8%), followed by joint ill (25.0%) and respiratory infections (19.4%). The disease incidence was greater (P < 0.01) in individually housed calves (94.4 vs. 55.9%). The management of navel ill required longer recovery (7.01 days) followed by joint ill (4.87 days) and respiratory infection (4.86 days). The average daily gain during 0–14 weeks of age was higher (P < 0.01) in group‐housed calves (433 ± 22 vs. 355 ± 31 g), while the effect of feeding was not significant. Blood samples collected at 4, 8 and 14 weeks of age showed some periodic higher concentrations (but within normal range) of plasma urea and total protein in group housed calves on F2 and F3 feeding schedules in response to high protein intake. Other parameters remained non‐significantly different. Thus, group‐housed calves can be reared successfully with comparatively better performance and less illness than individually housed ones under the present health care and housing management system. However, the system should not be used as a substitute for good management, and frequent observations of calves should be an integral part of any successful rearing program.     

The health status and metabolic indicators in calves fed colostrum and first milk preserved with potassium sorbate and milk replacements

The aim of the experiments was to investigate the effects of the preservation of colostrum and unripe milk with potassium sorbate at a concentration of 0.5% and of its storage for three to five days at normal environmental temperatures on the calf health condition. A set of 30 calves divided into two groups was included in the trial. Calves belonging to the experimental group were fed preserved colostrum and unripe milk from day 9 to day 30 of their life (the first experimental period), and from day 31 to day 50 (the second experimental period) milk replacer. Calves belonging to the control group were fed milk replacer from day 9 to day 50 of their life. One calf from the experimental group died from a respiratory disease. In the control group, one calf died and another had to be slaughtered; in both cases digestive tract diseases were diagnosed. The number of calves which had to be treated medically was also lower in the experimental group--in the calves fed preserved colostrum--one case of periodic tympany was recorded in comparison with four cases in the control group. When haematological and biochemical characteristics were examined, significantly lower haemoglobin levels were found in experimental calves at the end of the first experimental period (105.4 g.l-1 when compared with 112 g.l-1 in the control group) and significantly higher values of proteinaemia were found in the blood plasma of these calves at the same period (59.6 g.l-1 and 53.8 g.l-1, respectively). Similar differences were also found during a single haematological and biochemical examination.     

Tributyrin administration improves intestinal development and health in pre-weaned dairy calves fed milk replacer

Butyrate and its derivatives possess various nutritional and biological benefits for mammals,whereas its effects on dairy calves have not been well characterized.This study evaluated the effects of tributyrin administration on blood immune,intestinal immune and barrier functions,and microbial composition of pre-weaned dairy calves.Twenty newborn Holstein bull calves were randomly assigned into a control group (no tributyrin supplementation,CON;n=10) or a treatment group (supplemented with tribut...     

Effect of level of milk replacer fed to Holstein calves on performance during the preweaning period and starter digestibility at weaning

Calves following an enhanced-growth feeding program usually show lower starter intakes during the preweaning period compared with conventionally-fed calves. To assess whether this low intake in calves following an enhanced-growth feeding program affects calf capacity to digest starter after weaning, 19 Holstein male calves were used to measure apparent nutrient digestibility at weaning. Calves were divided in two groups: calves on a conventional feeding program (CF) and calves on an enhanced-growth feeding program (EF). After one week of adaptation to milk replacer (25% CP and 19% fat), the CF calves were fed 4 l/d of milk replacer (MR) at 12.5% DM dilution rate from d 1–28, and 2 l/d from d 29 to weaning day at d 35, and the EF calves were offered MR at 18% DM dilution rate: 4 l/d from d 1–6, 6 l/d from d 7–13, 7 l/d from d 14–20, 6 l/d from d 21–28, and 3 l/d from d 29 to 35. Calf starter (20% CP) was offered ad libitum from the beginning to the end of study at d 42, and its consumption was recorded daily. Calves were weighed at d 3, 17, 24, 31, 38 and 42. Daily total faeces collection was conducted for the last 5 d of study. Final BW was numerically greater in EF than in CF calves (88.6 vs 81.2 ± 3.36 kg, respectively). Starter DMI was greater (P < 0.05) in CF compared with EF calves during the preweaning (0.68 vs 0.36 ± 0.078 kg/d, respectively) and postweaning (2.52 vs 1.90 ± 0.102 kg/d, respectively) periods, but there were no differences in total DMI (1.12 and 1.26 ± 0.078 kg/d, in CF and EF calves, respectively) during the preweaning period. However, apparent DM, OM, NDF, CP, and GE digestibility coefficients were greater (P < 0.05) in CF compared with EF calves (77.4 vs 71.8 ± 1.23%, 78.7 vs 73.2 ± 1.18%, 34.7 vs 20.3 ± 3.79%, 77.1 vs 71.6 ± 1.29%, and 75.6 vs 69.8 ± 1.25%, respectively) the week after weaning. It is concluded that calves in the EF treatment presented lower nutrient digestibility coefficients compared with CF calves the week after weaning.     

复合微生态制剂对奶牛泌乳性能和乳品质的影响

本研究旨在探讨复合微生态制剂对奶牛泌乳性能和乳品质的影响,为微生态制剂在奶牛养殖中的推广应用提供参考依据。将90头荷斯坦奶牛随机分成3组(对照组、试验Ⅰ组、试验Ⅱ组),对照组饲喂基础日粮,试验Ⅰ组、Ⅱ组分别在基础日粮中添加0.5 g·kg~(-1)、1.0 g·kg~(-1)的复合微生态制剂。通过测定各处理组的产奶量、采食量、料奶比等泌乳性能指标和乳脂率、乳蛋白率、乳糖率、乳干物质率、体细胞数等乳品质指标,比较分析复合微生态制剂不同添加水平对奶牛泌乳性能和乳品质的影响。结果显示,试验Ⅱ组与对照组相比,日产奶量显著提高(P0.05),料奶比显著降低(P0.05),乳脂率、乳蛋白率均显著提高(P0.05),体细胞数显著降低(P0.05)。该结果表明奶牛基础日粮中添加1.0 g·kg~(-1)的复合微生态制剂能显著改善奶牛的泌乳性能和乳品质。     

Performance and ruminal changes of early-weaned calves fed lasalocid

Twenty-two neonatal calves were assigned to a control or lasalocid-fed group and weaned at 3 wk of age. They were fed a prestarter diet from 3 d of age until they consumed 227 g/d and then a mixture of 227 g prestarter daily and starter diet in ad libitum amounts. The lasalocid-fed group received lasalocid in milk at 1 mg/kg body weight daily from 4 to 7 d and at .5 mg/kg body weight daily in milk and medicated prestarter diet (88 mg lasalocid/kg) during the 2nd wk. After 2 wk, lasalocid-fed calves were given medicated prestarter and starter (44 mg lasalocid/kg) diets. Four calves in each group were ruminally cannulated at 3 to 5 d of age, and ruminal contents were obtained at weekly intervals to monitor microbial activity. Rectal fecal samples were collected from all calves and examined for coccidial oocysts. Lasalocid-fed calves had a greater weekly feed intake and weight gain than control calves after 6 wk of age. Total ruminal volatile fatty acid concentrations were higher, but the acetate:propionate ratio was lower in lasalocid-fed calves than in control calves. Total viable anaerobic and amylolytic bacterial counts were higher in lasalocid-fed calves than in control calves. No significant treatment effect was found for ruminal NH3-N concentration or ruminal lasalocid-resistant, lactobacilli, lactate-utilizing, cellulolytic or methanogenic bacterial numbers. No evidence of coccidiosis was detected in either group. In general, lasalocid-fed calves had greater feed intake, weight gain and ruminal microbial activity than the calves fed no lasalocid in the diet.     

Total tract nutrient digestion and milk fatty acid profile of dairy cows fed diets containing different levels of whole raw soya beans

Whole oilseeds such as soya beans have been utilized in dairy rations to supply additional fat and protein. However, antinutritional components contained in soya beans, such as trypsin inhibitors and haemagglutinins (lectins) may alter digestibility of nutrients and consequently affect animal performance. The objective of the present experiment was to quantify the effect of different levels of whole raw soya beans in diets of dairy cows on nutrient intake, total tract digestion, nutrient balances and milk yield and composition. Sixteen mid to late‐lactation cows (228 ± 20 days in milk; mean ± SD) were used in four replicated 4 × 4 Latin square design experiment with 21‐d periods. Cows were assigned to each square according to milk yield and DIM. The animals were randomly allocated to treatments: control (without soya beans addition; CO), WS9, WS18 and WS27, with addition of 9%, 18% and 27% of whole raw soya bean in diet on a dry matter (DM) basis respectively. All diets contained identical forage and concentrate components and consisted of maize silage and concentrate based on ground corn and soya beans at a ratio of 60:40. There were no differences in OM, CP, NDF and NE_L intakes (kg/day and MJ/day) among the treatments (p > 0.05). However, DM and NFC intakes were negatively affected (p = 0.04 and p < 0.01, respectively) and ether extract (EE) intake was positively affected (p < 0.01). Total tract digestion increased linearly with whole raw soya beans for EE (p < 0.01) and NDF (p = 0.01). The excretion (kg/day) of digested soya beans grains increased linearly according to addition of whole raw soya beans. However, the nutritive characteristics of excreted grains were not altered. Milk (kg), milk lactose (kg) and protein (kg) yield decreased linearly (p < 0.01, p < 0.01 and p = 0.04, respectively) milk fat content (%) increased linearly (p < 0.01) with whole raw soya beans inclusion. Increasing addition of whole raw soya beans affected milk fatty acid profile with a linear decrease of cis‐9‐trans 11CLA and total saturated FA; and linear increase of total unsaturated and C_18:3 FA. Energy balance was positively affected (p = 0.03) by whole raw soya beans as well as efficiency of NEL milk/DE intake (p = 0.02). Nitrogen balance and microbial protein synthesis were not affected by whole raw soya beans. Increasing doses of whole raw soya beans decreased dry matter intake and milk yield, however, led to an increase of unsaturated acids in milk and higher milk fat concentration.     

复合益生菌对荷斯坦犊牛生长性能、腹泻率和血清指标的影响

为研究复合益生菌对荷斯坦犊牛生长性能、腹泻率和血清生化指标、抗氧化指标、免疫指标的影响,将40头荷斯坦公犊牛随机分成四组(对照组、低剂量组、中剂量组、高剂量组),分别在基础饲料中添加0、0.05％、0.1％、0.2％的复合益生菌,试验期为60 d.结果 表明:(1)中剂量组、高剂量组的末重较对照组分别提高2.79％、3...     

Nutrient supply of health and sick fluid fed calves]

In the department for calves being fed with fluid feed of a specialised enterprise for calf rearing the daily intake of fluid feed (skim milk improved with milk substitute), concentrated feed and hay of a total of 341 female animals and the daily intake of energy and protein was calculated thereof. The average consumption of nutrients of the 206 healthy calves was compared with some international and national norms for the demand of nutrients. The comparison with some international values of demand and the results of the partial correlation analysis between energy and protein intake and live weight increase showed that the applied nutrition regime (particularly the kind of fluid feed) has resulted in an excessive supply of the calves with proteins and an insufficient supply with energy. This could not be realised from the GDR nutrients norm for the raising of calves published in 1976. Based on theoretical considerations and some recent findings of the science of nutrition we derived values of the protein and energy demand of our own. Subsequently an attempt is made to assess the supply with nutrients for sick calves.     

不同微生态制剂对奶牛产奶性能和乳品质的影响

[目的]研究旨在探讨不同微生态制剂对奶牛产奶性能和乳品质的影响,[方法]将40头荷斯坦奶牛随机分成4个处理组,对照组饲喂基础日粮,微生态制剂1组、微生态制剂2组、微生态制剂3组分别在基础日粮中添加0.1%的三种微生态制剂产品。[结果]结果显示：与对照组相比,微生态制剂1组、微生态制剂2组、微生态制剂3组的平均日产奶量、乳蛋白率均显著增加（P＜0.05）,体细胞数均显著降低（P＜0.05）。与对照组相比,微生态制剂1组的平均日采食量、乳脂率均显著增加（P＜0.05）,料奶比显著降低（P＜0.05）。与微生态制剂2组相比,微生态制剂1组的平均日产奶量、乳蛋白率均显著增加（P＜0.05）。[结论]说明三种微生态制剂产品均能在一定程度上提高奶牛的产奶性能和乳品质,以微生态制剂产品1的作用效果最好。     

Melamine residues in eggs of quails fed on diets containing different levels of melamine

1. An experiment was conducted to determine residual melamine concentrations in eggs of quail given diets containing different concentrations of melamine, and to estimate the time at which withdrawing melamine from the diet would result in undetectable concentrations in eggs. A total of 600 Japanese quails (Coturnix coturnix japonica) were randomly divided into 5 treatments, and given melamine at concentrations of 0, 2, 10, 50, and 100?mg/kg diet respectively for 30?d. From d 31 to 41, all quails were given a diet without melamine. Each diet was offered to 4 replicates (cages) of 30 quails each. On d 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, and 41, eggs were collected for the determination of melamine and cyanuric acid levels.

2. Throughout the 41?d experimental period, inclusion levels of melamine in the diets of quails had no significant effect on daily feed intake, egg production percentage, and feed efficiency. No detectable amount of cyanuric acid was found in all eggs. When the diets contained melamine at 2?mg/kg, the amounts of melamine in eggs were below the detection limit. During the entire 30?d exposure, the maximum melamine concentrations in eggs were 0·162, 0·998 and 1·784?mg/kg for the 10, 50 and 100?mg/kg treatment groups, respectively, which demonstrated a linear dose-response relationship.

3. Upon feeding a diet without melamine, the melamine concentration in eggs decreased rapidly. The time taken for the amounts of melamine to decline below the detection limit were 1, 5, and 5?d for quails fed on the diets containing melamine at 10, 50, and 100?mg/kg respectively.

4. Melamine is not metabolised into cyanuric acid in quails, and a positive relationship exists between the concentrations in feed and in eggs.