Tropical milk production systems and milk quality: a review

We reviewed information on dairy cattle production systems in the tropics, the factors involved, and their influence on milk composition. Genetic factors had greater influence on milk production; specialized breeds produced more milk, and there was an inverse relation between the content of fat, protein, total solids, and the amount of milk produced. Season was related to the availability of forage, and the type of grazing system. Greater pasture area increased individual production, while a greater supply of feed concentrate did not increase milk production. The number of calvings positively affected milk production through the fifth calving, with subsequent declines in production. Milk production increased to a maximum and then declined as lactation progressed. Specialized systems had higher production and better hygienic milk quality; milking and container equipment are critical for maintaining milk sanitary quality. Factor interaction is highly complex, preventing the generation of specific recommendations and general principles applicable to the specific conditions for each system.

     

不同添加比例的两种纤维素酶对奶牛产奶量及乳品质的影响

试验选用100头胎次、产奶量、泌乳期相近的奶牛,随机分成5组(每组20头),在试验1组、试验2组、试验3组和试验4组饲料中分别添加纤维素酶A50g/t、纤维素酶A100g/t、纤维素酶B80g/t、纤维素酶B160g/t。测定5组奶牛产奶量及乳品质,研究其对奶牛产奶量的影响。结果表明,与试验前相比,不同纤维素酶组产奶量均呈上升趋势;与对照组相比,纤维素酶组在试验全期产奶量高于对照组(P>0.05);在本试验条件下,纤维素酶可有效提高奶牛产奶量,提高经济效益,对乳品质的影响效果不明显。     

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。     

Characterisation of smallholder dairy production systems using animal welfare and milk quality

The aim of the current study was to characterise and evaluate production system of smallholder dairy farmers using an index based on combined score of animal welfare and milk quality. Farms were grouped into three categories, tier 1, tier 2 and tier 3. To test the robustness of the characterisation, milk yield (MY), calving interval (CI) and body condition scores (BCS) were used. In the study area, the majority (66.3%) of smallholder dairy farmers practiced cut-and-carry as compared to 15.3% who grazed their cows. The rest combined cut-and-carry and grazing. Cows of farmers in tier 1 had the lowest mean MY (5.4?kg/day, SE?=?0.4), lowest mean BCS (2.1?kg/day, SE?=?0.09) and longest mean CI (603?days, SE?=?27) than farmers in tier 3, mean MY (10.8?kg/day, SE?=?0.6), mean BCS (2.6, SE?=?0.06) and mean CI (404?days, SE?=?17). The study demonstrated that a simple and yet novel method based on farm level indicators can be developed and could assist to timely identify specific problems on the farm.     

不同降雨年份和放牧方式对荒漠草原初级生产力及营养动态的影响

牧草品质直接体现了草地资源的质量和可利用性。本研究采用野外调查法对不同降雨年份和放牧方式下荒漠草原植物群落的地上净初级生产力(ANPP)、粗蛋白、粗纤维、粗灰分、粗脂肪、钙、磷和无氮浸出物进行了测定和分析。结果表明,1)在干旱的2011年,自由放牧显著降低了群落的ANPP,而在降雨量充足的2012年,休牧60 d的ANPP值最高;2)相比于欠雨年份,降雨量充足的年份生长高峰期ANPP、粗蛋白、粗灰分、钙和磷的含量分别是其的2.67,1.08,1.27,1.26和3.75倍;3)相比其他处理,粗蛋白、磷的含量在休牧60 d含量最高;4)在不同降雨量的两个放牧季节内,随着放牧的进行,粗蛋白、粗脂肪、粗灰分、钙和磷的含量呈现先增加后降低的趋势,均是在7或8月份达到一个峰值,而在植物枯黄期(10月份)值最低,而粗纤维和无氮浸出物的含量在7月份最低,而在植物枯黄期最高。降雨量与荒漠草原植物群落ANPP及植物群落营养季节动态之间存在着密切的关系;休牧60 d为合理的草原利用方式;不同年际间放牧和季节气候变化共同制约了群落营养成分的变化。     

Leather quality of beefalo‐Nellore cattle in different production systems

The aim was to compare the effects of two production systems on performance, carcass traits and physical‐mechanical characteristics of leather from Beefalo‐Nellore steers and heifers and to determine if the response to the production system was similar for both genders. A total of 40 Beefalo‐Nellore cattle, 20 steers and 20 heifers, were evaluated. Animals were divided into two production systems: slaughtered at 15 (intensive system) or 26 (extensive system) months of age. In the intensive system, all animals received a ration containing 600 g/kg corn silage and 400 g/kg concentrate. In the extensive system, animals were kept on a pasture predominantly based on Brachiaria sp. and supplemented with 2 kg/day concentrate. In the intensive system, there was no difference in slaughter weight (470 kg body weight) between steers and heifers but steers in the extensive system had greater slaughter weight than heifers (463 and 428 kg body weight, respectively). Leather weight was higher for animals in the intensive than extensive system but there was no difference in leather weight once excess fat was removed. Leather quality from Beefalo‐Nellore cattle slaughtered at 15 or 26 months of age is similar although carcass yield is higher for cattle slaughtered at a younger age.     

Egg production and quality under three housing systems in the tropics

The aim of this study was to evaluate egg production and quality of Rhode Island Red (RIR) laying hens in an outdoor system in the subhumid tropic. Eighty RIR laying hens were measured in two periods and housed randomly under three treatments: outdoor (O), indoor (I) and in conventional cages (C). Egg weight (55.88, 53.76 and 57.16 g, for O, I and C, respectively), food intake/hen/day (138.94, 129.74 and 162.90 g, for O, I and C, respectively) and food efficiency (3.13, 3.22 and 3.96 for O, I and C, respectively) were significantly (P < 0.05) influenced by housing system; however, both egg production and final body weight were not different (P > 0.05). Yolk colour (10.76, 9.94 and 10.08 colour scale, for O, I and C, respectively), albumen weight (92.63, 92.28 and 90.08 g, for O, I and C, respectively) and yolk weight (15.19, 14.61, 15.48 g for O, I and C, respectively) were significantly (P < 0.05) influenced by housing system, but albumen height, Haugh units and egg shell weight remained similar (P > 0.05). Under the conditions of this study, outdoor egg production seems to be a sustainable system comparable to the commercial type based on wired cages.     

Consequences of genetic selection for increased milk production in European seasonal pasture based systems of milk production

The data presented in this review show that past selection for increased milk production in Ireland over a 14-year period (1990 to 2003) resulted in increases in milk production per cow but has been accompanied by undesirable side effects in reproduction and survival. Economic analysis in a EU milk quota scenario over this period showed that only 41% of the potential improvement in farm profit was achieved because of impaired reproductive performance. Strain comparison studies show that genetic selection for increased phenotypic milk production, which is generally accompanied with increased proportion of North American Holstein Friesian genes, was associated with increased milk production per cow, lower body condition score, greater milk production response to concentrate supplementation at pasture and reduced fertility and survival. The lower reproductive performance observed with cows selected solely for high milk production was associated with lower energy balance in early lactation, greater partitioning of additional nutrients towards milk production, inability to achieve desired grass intake from pasture and decreased plasma glucose and insulin like growth factor-1 concentrations. The existence of genotype by environment interactions suggests that germplasm selected in the future should be from within the management system in which it is to be used, and based on a selection index that combines production and other traits of economic importance.     

不同耕作措施旱地小麦生产应对气候变化的效应分析

为探索气候变化对小麦产量影响的机制和规律,在田间试验的基础上通过调试APSIM模型参数,并对模型进行检验,然后用APSIM模型模拟温度和CO₂浓度两因素七水平小麦产量,分析了3种耕作措施下小麦产量对温度和CO₂浓度的响应及敏感性强度。结果表明,不同耕作措施条件下,小麦产量随CO₂浓度升高呈二次抛物线上升型变化,但会出现报酬递减,且免耕覆盖的增产效应大于传统耕作和免耕2种耕作措施;小麦产量随温度升高呈二次抛物线型变化,其中传统耕作和免耕呈二次抛物线递减型变化,并呈叠加递减效应,而免耕覆盖呈二次抛物线拐点型变化,拐点值为0.94℃时,小麦产量可达到2 818.3 kg/hm²。温度和CO₂浓度互作对小麦产量的敏感性分不敏感、正敏感和负敏感区域,且免耕覆盖的敏感性变化较小。在3种耕作措施中,免耕覆盖CO₂浓度升高小麦的增产效应可以补偿高温所导致的减产,并且温度和CO₂浓度具有更好的协同促进作用。免耕覆盖小麦生产具有较好应对温度和CO₂浓度变化的能力,可以缓减气候变化带来的负效应。     

Optimal selection responses under varying milk prices and margins for milk production

In The Netherlands the price a farmer receives for milk is formed by the price per kg for fat and protein and a negative base price for milk. The price ratio between fat and protein is about 1:1, and the base price about — Dfl 0.12 kg⁻¹ milk. Feed costs for producing fat are Dfl 3.34 kg⁻¹, for protein Dfl 1.70 kg⁻¹ and for carrier (milk-fat-protein) Dfl 0.0622 kg⁻¹.The net economic returns (sales-feed costs) are Dfl 0.1822 kg⁻¹ for carrier, Dfl 6.28 kg⁻¹ for fat and Dfl 7.92 kg⁻¹ for protein. These values are used for the breeding goal. An index (INET) was constructed for combination of breeding values for kg milk, % fat and % protein. Weighting factors were 0.316, 260 and 500, respectively.Correlations of the optimal indices to be used in the different circumstances with INET and the responses for the milk characteristics were calculated to study the sensitivity of INET. Correlations were almost one when the base price per kg milk was varied from Dfl 0.00 to − Dfl 0.20, the margin from Dfl 0.30 to Dfl 0.40 kg⁻¹ milk and the fat/protein price ratio varied from 2:1 to 1:2.When production level increased to 6000 kg milk with 3.6% fat and 3.2% protein, the correlation with INET declined to 0.96 and to 0.93 when the production level was decreased to 4000 kg milk with 6% fat and 4% protein. It was concluded that INET is an efficient selection criterion for a broad scale of aggregate genotypes, which may be valid in the future in The Netherlands.     

Growth performance and rumen development in Malabari kids reared under different production systems

Tropical Animal Health and Production - In order to investigate the effect of rearing systems on growth and rumen development in Malabari male kids, 14 pre-weaned Malabari male kids of uniform...     

不同类型炔诺酮阴道海绵栓对奶山羊同期发情效果比较研究

为了比较十八甲基炔诺酮(NG)和左旋十八甲基炔诺酮(LNG)对奶山羊同期发情效果,为奶山羊养殖场选择合适的孕激素阴道海绵栓进行奶山羊的同期发情处理提供基础研究资料。将108只健康奶山羊随机分为三组,每组3个重复,每重复12只羊;3个试验组羊分别采用氯前列烯醇(PG,0.1 mg/只)+不同类型和剂量十八甲基炔诺酮阴道海绵栓+50单位促卵泡素(FSH)进行同期发情处理,其中试验1组采用NG 60 mg/枚的阴道海绵栓,试验2组采用LNG30 mg/枚的阴道海绵栓,试验3组采用LNG 40 mg/枚的阴道海绵栓。结果表明,三组羊96 h发情同期率分别为86.11%、94.44%和88.89%,各组间差异不显著(P0.05);72 h的发情同期率分别为80.53%、94.44%和88.89%,第2组显著高于第1组(P0.05),但与第3组差异不显著(P0.05);从处理结束到发情开始的平均间隔时间分别为45.29 h±18.99、48.35 h±13.02和42.38 h±12.19;发情持续时间分别为30.19 h±11.95、30.71 h±8.11和29.63 h±8.41,均无显著差异。综合分析表明,LNG对奶山羊发情同期效果优于NG,且30 mg LNG的效果比40 mg LNG效果好,建议在制作羊用阴道海绵栓时选择LNG,并采用30 mg LNG/枚的剂量。     

不同播量对宝兴鸭茅种子生产性能的影响

在四川宝兴县鸭茅Dactlis glomerata原种基地进行了不同播期处理对鸭茅种子生产性能的研究并对收获的种子进行了质量检验和评价。结果表明:宝兴鸭茅种子生产的最佳播量为2 g/m2,其种子产量最高,为293 kg/hm2,发芽势、发芽指数及发芽率较高。     

Growth performance of fast-growing broilers reared under different types of production systems with outdoor access: Implications for organic and alternative production systems

Outdoor access is an important part of organic and free-range poultry production, yet limited information exists on the effect of various housing and production systems on growth performance and colonization of food-borne pathogens. Therefore, the primary purpose of the current study was to evaluate the influence of different housing systems, particularly fixed versus small, portable houses, with and without outdoor access to pasture, on seasonal growth performance, leg quality, and presence of bacterial food-borne pathogens. In the current study, we used fast-growing broilers, as many small producers use commercial broilers due to their carcass conformation and high breast yield compared with slow-growing hybrids or standard heritage breeds. Although interest in alternative genetics exists because they may be more adapted to outdoor production, they require longer growing periods, with accompanying labor and cost. A pasture containing a mixture of forages was used to simulate the conditions common for small farms in the local region. The experiment had 4 treatment groups: (1) small, portable hoop houses with access to pasture, (2) small, portable hoop houses without access to pasture, (3) a fixed house with access to the outdoors, and (4) a fixed house without access to the outdoors. The present study was repeated at different times of the year to determine if a seasonal effect on the consumption of pasture and carcass quality was present. Overall, raising birds in hoop houses resulted in a reduced growth rate compared with birds raised in the fixed house. None of the production systems altered bone strength or feed conversion. Food-borne pathogens commonly associated with poultry were not found in any of the environments tested. Seasonal production was an issue in the small hoop house birds, as extreme heat in the summer resulted in early termination of that trial. Expanding on forage choice in pastures and customizing hoop houses to deal with weather fluctuations, especially in regions where extreme heat may affect production, are important considerations for these systems.     

Effect of paratuberculosis on culling, milk production, and milk quality in dairy herds

OBJECTIVE: To determine the effect of paratuberculosis on culling, milk production, and milk quality in infected dairy herds. DESIGN: Cross-sectional study. ANIMALS: 689 lactating dairy cows in 9 herds. PROCEDURE: Milk, blood, and fecal samples were obtained from all cows. Fecal samples were evaluated via mycobacterial culture. Serum samples were tested with a commercially available ELISA for antibodies against Mycobacterium avium subsp paratuberculosis, and preserved milk samples were tested with an ELISA for antibodies against M paratuberculosis. Mixed effect and proportional hazards models were used to determine the effect of paratuberculosis on 305-day milk, fat, and protein production; somatic cell count linear score; and the risk of culling. RESULTS: Cows with positive results of bacteriologic culture of feces and milk ELISA produced less milk, fat, and protein, compared with herdmates with negative results. No difference in 305-day milk or fat production was detected in cows with positive results of serum ELISA, compared with seronegative cows. The 3 survival analyses revealed that cows with positive results of each test were at higher risk of being culled than cows with negative results. Paratuberculosis status, as determined by use of all 3 diagnostic tests, was not associated with milk somatic cell count linear score. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that for the 9 herds in this study, paratuberculosis significantly decreased milk production and cow longevity.     

Microbiological evaluation of milk feed mixtures for calves

Hundred-and-two samples of four kinds of mild replacers for calves, produced in Czechoslovakia, were examined and evaluated. None of the studied pathogenic germs was detected in the samples. More than a half of the samples contained 1000 and 10000 mesophilous germs per 1 g. More than a third contained 1 to 1000 coliform germs per 1 g. On the basis of the results it is recommended--within microbiological requirements for the product--to propose that the maximum total number of microorganisms should be 100000 per 1 g of product.     

Egg production and efficiency of food conversion of khaki campbell ducks under different management systems

1. Thirty‐two Khaki Campbell laying ducks were divided into two equal groups and housed either in floor pens or in cages in an environmentally controlled building. The food for two replicate groups of four birds each in each management system was rationed by weight and two other replicate groups were fed ad libitum. Housing and feeding treatment effects were assessed by measuring efficiency of food conversion into eggs and egg production.

2. Housing ducks in cages did not reduce egg production or efficiency of food conversion compared with the more conventional floor‐pen housing system. Egg production and egg size were adversely affected by the restricted feeding programme.

3. Caging in a controlled environment with unrestricted food appears to be a potentially feasible management system for laying ducks, comparable with such systems for laying fowls.     

不同水平复合益生菌制剂添加对奶牛生产性能、乳品质及体细胞数量的影响

为分析不同水平复合益生菌制剂添加对奶牛生产性能、乳品质及体细胞数量的影响,试验选择胎次、产奶量、泌乳天数相近的荷斯坦奶牛160头随机分成4个组,每个组4个重复,每个重复10头,1组饲喂基础日粮为对照组,试验2、3、4组每头奶牛分别在基础日粮中添加20、40、60 g/d复合益生菌制剂,预试验7 d,试验期为60 d。结果表明:(1)试验后的30、60 d,试验3、4组的平均产奶量较1相比分别提高16.0%、14.9%、25.6%、24.1%(P<0.05);(2)试验2、3、4组的4%乳脂校正、乳蛋白率、总固形物均高于1组(P>0.05);试验2、3、4组的尿素氮均低于1组(P>0.05);试验3、4组的乳糖率、乳脂率较1组分别提高14.6%、13.4%、5.0%、4.2%(P<0.05);(3)试验后的60 d,试验3、4组乳中体细胞数量较1组相比降低9.3%、7.1%(P<0.05)。综上,每头牛每天添加40 g复合益生菌制剂可以提高奶牛的生产性能、乳品质,减少体细胞数量。