Moderate lameness leads to marked behavioral changes in dairy cows

Lameness is one of the most prevalent diseases affecting the welfare of cows in modern dairy production. Lameness leads to behavioral changes in severely lame cows, which have been investigated in much detail. For early detection of lameness, knowledge of the effects of moderate lameness on cow behavior is crucial. Therefore, the behavior of nonlame and moderately lame cows was compared on 17 Swiss dairy farms. On each farm, 5 to 11 nonlame (locomotion score 1 of 5) and 2 to 7 moderately lame (locomotion score 3 of 5) cows were selected for data collection in two 48-h periods (A, B) separated by an interval of 6 to 10 wk. Based on visual locomotion scoring, 142 nonlame and 66 moderately lame cows were examined in period A and 128 nonlame and 53 moderately lame cows in period B. Between these 2 periods, the cows underwent corrective hoof trimming. Lying behavior, locomotor activity, and neck activity were recorded by accelerometers (MSR145 data logger, MSR Electronics GmbH, Seuzach, Switzerland), and feeding and rumination behaviors by noseband sensors (RumiWatch halter, ITIN + HOCH GmbH, Liestal, Switzerland). Furthermore, visits to the brush and the concentrate feeder, and the milking order position were recorded. In comparison with nonlame cows, moderately lame cows had a longer lying duration, a longer average lying bout duration, and a greater lateral asymmetry in lying duration. Average locomotor activity, locomotor activity during 1 h after feed delivery or push-ups, and average neck activity were lower in moderately lame cows. Eating time and the number of eating chews (jaw movements) were reduced in moderately lame compared with nonlame cows, whereas no effect of moderate lameness was evident for ruminating time, number of ruminating chews and boluses, and average number of ruminating chews per bolus. Moderately lame cows visited the concentrate feeder and the brush less frequently, and they were further back in the milking order compared with nonlame cows. In conclusion, nonlame and moderately lame cows differed in a biologically relevant way in many of the behavioral variables investigated in this study. Therefore, the use of these behavioral changes seems to be promising to develop a tool for early lameness detection.     

Effect of temperature and retention period on biogas production from lignocellulosic material

The extensive utilization of biogas for energy needs of rural dwellers would reduce their dependence on fossil fuels and fuelwoods and henoe camplement Government afforestation programes. In this investigation, effect of temperature and retention period on biogas production from lignooellulosic material, hereafter referred to as cow dung were studied. Maximum gas production was dotained at thermophilic temperature. The results of the effect of retention period shows that gas production was qotimum at 4th and 7th weeks of production.     

我国奶牛场收入政策及发展

叙述了我国目前乳业概况，就经济体制转变以来，我国的奶生产情况，牧场收入，政府所起的作用及乳业今后面临的挑战等问题进行了分析和论述。     

Exosomal Cargo May Hold the Key to Improving Reproductive Outcomes in Dairy Cows

The reproductive status of dairy cows remains a challenge for dairy farmers worldwide, with impaired fertility linked to a significant reduction in herd profitability, due in part to impaired immunity, increased metabolic pressure, and longer postpartum anestrous interval (PPAI). Exosomes are nanovesicles released from a variety of cell types and end up in circulation, and carry proteins, bioactive peptides, lipids, and nucleic acids specific to the place of origin. As such, their role in health and disease has been investigated in humans and animals. This review discusses research into exosomes in the context of reproduction in dairy herds and introduces recent advances in mass-spectrometry (MS) based proteomics that have a potential to advance quantitative profiling of exosomal protein cargo in a search for early biomarkers of cattle fertility.     

β-乳球蛋白IgG抗原决定簇的识别

以β-乳球蛋白氨基酸序列为模板,错位合成β-乳球蛋白多肽,以收集到的牛乳过敏患者血清为抗体,鉴定β-乳球蛋白IgG抗原决定簇,探讨牛乳过敏机理．结果表明,β-乳球蛋白IgG抗原决定簇有2条,它们在β-乳球蛋白中的氨基酸序列定位分别为aa22—36和aa127—141．结果表明通过特异性水解抗原决定簇实现牛奶脱敏的方法是可行的．     

共轭亚油酸强化型乳制品的稳定性研究

通过牛乳液中添加共轭亚油酸（CLA）,分析杀菌温度、均质压力、乳化剂类型、CLA添加量对牛乳稳定性的影响.实验结果表明：脱脂乳中添加0.17%的CLA稳定性较好,口感纯正;当灭菌温度超过100℃时,CLA含量明显降低;以单苷酯、三聚苷酯和蔗糖酯的混合乳化剂,按1∶1∶2混合的乳液稳定性好;35MPa以上的均质压力下,乳液中的脂肪球细小,分布均匀,口感细腻。     

The effect of fertilizer nitrogen input to grass-clover swards and calving date on the productivity of pasture-based dairy production

The objective of this systems-scale study was to investigate grazing season timeframes on pasture and milk production and on milk processability of dairy systems with compact spring-calving dairy cows grazing white clover (Trifolium repens L.) based grassland. Fifty-four primiparous and multiparous Holstein-Friesian dairy cows were used in a one-factor study with 3 systems (n = 18) and repeated over 2 yr (2008/09 and 2009/10). The 3 systems were: early spring calving with annual fertilizer N input of 100 kg·ha^?1 applied in spring (ES100N; 2.1 cows·ha^?1; grazing February to November), early spring calving without fertilizer N (ES0N; 1.6 cows·ha^?1; grazing February to November) and late spring calving without fertilizer N (LS0N; 1.53 cows·ha^?1; grazing April to January). Annual pasture production was affected by an interaction between grazing system and year: Mean annual pasture yields for 2008 and 2009 were ES100N; 10.35 and 9.88, ES0N; 8.88 and 8.63, LS0N; 9.18 and 10.31 t of dry matter (DM)·ha^?1 (SEM 0.39). LS0N had higher pasture DM yield in 2009 due to higher clover DM production and biological N fixation compared with the other systems. Clover stolon and root mass in the following February was correlated with stolon and root mass in the previous November with 64% of stolon mass present on LS0N in February (R² = 0.84). There were no detectable differences in per-lactation milk yield (6,335 kg·cow^?1), fat, protein and lactose yields (271, 226, 297 kg·cow^?1, respectively), cow liveweight (585 kg) or body condition score (3.02). Although winter grazing favored subsequent clover DM production, biological N fixation and pasture DM production, delaying calving date in spring and extending lactation into the following winter led to inefficient use of this pasture by the grazing herd and lowered the quality of late-lactation milk for processing purposes. Hence, a mean calving date in mid- to late-February is recommended for zero-fertilizer N input clover-based grassland.     

Effects of monensin on glucose metabolism in transition dairy cows

Eight multiparous periparturient Holstein cows fitted with ruminal cannula were used in a split plot design to evaluate the effects of monensin on plasma glucose metabolism. Diets were top-dressed daily with 0 mg/cow of monensin (control) or 300 mg/cow of monensin (MON) both pre- and postpartum. Plasma glucose kinetic parameters on d ?13 ± 2.0 and 19 ± 1.6 relative to parturition were determined by using stable isotopes. Na-1-¹³C₃-Propionate (labeled propionate) was infused into the rumen to measure glucose synthesis originating from ruminal propionate, and U-¹³C-glucose (labeled glucose) was injected into the jugular vein to determine total glucose kinetics. A sampling period of 480 min following labeled glucose injection was implemented. A compartmental analysis was employed to determine steady state glucose kinetic parameters. To develop a steady state glucose model, the Windows version of SAAM software (WinSAAM) was used. A 4-compartment model was adequate to comprehensively describe plasma glucose metabolism. The main model compartments consisted of propionate and plasma glucose. The time frame of the 480-min sampling period post-tracer glucose infusion allowed accurate quantification of glucose metabolism. The model estimated that glucose input from sources other than ruminal propionate decreased with MON, from 2.26 to 1.09 g/min postpartum. Gluconeogenesis, expressed as the propionate contribution to the plasma glucose pool, increased in cows fed MON (22 vs. 31%), whereas glucose oxidation, expressed as the glucose disposal rate, significantly decreased (1.67 vs. 0.92 g/min). In conclusion, MON may improve the energy status of transition cows by (1) improving the efficiency of propionate to produce glucose and (2) decreasing glucose oxidation in body tissues.     

Effect of genetic merit for energy balance on luteal activity and subsequent reproductive performance in primiparous Holstein-Friesian cows

Postpartum energy status is critically important to fertility. However, studies dealing with the relationship between both traits are rare and most refer only to the phenotypic level. In this study, random regression models were used to generate cow-specific lactation curves for daily breeding values (BV) of energy balance (EB) to assess the effect of genetic merit for energy status on different traits derived from progesterone profiles and on subsequent reproductive performance of high-producing dairy cows. Individual feed intake, milk yield, and live weight were recorded for lactation d 11 to 180, and EB was estimated on a daily basis. The results provided the basis for the estimation of BV for 824 primiparous Holstein-Friesian cows. For a subset of these cows (n = 334), progesterone profiles for the resumption of ovarian activity were available. Four different traits describing the genetic merit for EB were defined to evaluate their relationship with fertility. Two EB traits referred to the period in which the average daily EB across all cows was negative (d 11 to 55 postpartum), and 2 parameters were designed considering only daily BV for d 11 to 180 in lactation that were negative. We found that cows with a high genetic merit for EB had a significantly earlier resumption of ovarian activity postpartum. Thus, an EB (indicator) trait should be included in future breeding programs to reduce the currently prolonged anovulatory intervals after parturition.     

Treatment with a nonsteroidal antiinflammatory drug after calving did not improve milk production,health, or reproduction parameters in pasture-grazed dairy cows

Previous research results have indicated an increase in pregnancy rate in pasture-grazed cows treated with a nonsteroidal antiinflammatory drug (NSAID) 3 to 4 wk postcalving, when a high proportion of nucleated cells from within the uterus were polymorphonucleated; however, no effect on milk production was detected. It was hypothesized that this lack of effect on milk production was because the administration of the NSAID was too late after calving. The aims of the current study were to evaluate the timing of administering a propionic acid-derived NSAID (i.e., carprofen) on milk production, metabolic status, uterine health, and reproductive performance. Six-hundred and thirty-nine cows (134 primiparous and 505 multiparous) calving between July 4 and September 5, 2012, in 2 herds (herd 1: n = 228; herd 2: n = 411) were enrolled. Using a randomized block design, cows were allocated to 1 of 3 treatment groups as they calved: (1) no treatment (control; n = 221), (2) NSAID administered on d 1, 3, and 5 postcalving (early; n = 214), and (3) NSAID administered on d 19, 21, and 23 postcalving (late; n = 204). Milk production and composition, and body condition were determined weekly. Blood was sampled at 4 time points (1 precalving and 3 postcalving) to determine the effects of treatment on indicators of metabolic health and energy status. Uterine health was determined by measuring the proportion of nucleated cells that were polymorphonucleated following cytobrush sampling of the uterus between d 13 to 24 and d 30 to 49 postcalving. Irrespective of timing of application, NSAID did not affect milk production, body weight, or body condition during early lactation. Treatment with an NSAID 19 to 23 d postcalving increased the proportion of cows submitted for breeding during the first 3 wk of the seasonal breeding program (control: 85%, early: 83%, and late: 92%), but did not affect conception or pregnancy rates. No detectable effect of treatment on uterine health or circulating metabolites and minerals existed, although cows in the early NSAID treatment group had marginally lower serum β-hydroxybutyrate concentrations (0.1 mmol/L) than the other groups between 2 and 26 d in milk. In conclusion, administration of this particular NSAID at either 1 or 3 wk after calving did not improve milk production, indicators of health, or reproductive performance.