| 1. |
- Clemensson Lindell, Ida, et al.
(författare)
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Adenosine triphosphate bioluminescence for hygiene testing of rubber liners and tubes on dairy farms
- 2018
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 101, s. 2438-2447
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Tidskriftsartikel (refereegranskat)abstract
- Prevention of biofilm formation in milking equipment is important to ensure good hygiene quality of raw milk. Key factors to achieving good results are a successful cleaning procedure and a method to check the cleanliness of milking equipment surfaces. Adenosine triphosphate bioluminescence is a fast and easy method for investigating bacterial contamination of surfaces. However, previous studies on the potential of ATP bioluminescence to assess the hygiene status of milking equipment have been hampered by lack of a validated test procedure. The aim of this work was therefore to establish a test procedure for assessing the cleanliness of milking equipment using ATP bioluminescence, and apply the method on-farm to study the hygiene status of aging rubber material in milking equipment. In developing the test procedure, the effects of sampling location in tubes and liners, sampling of dry versus wet barrels, milking point in the parlor, and acid or alkali detergent on ATP values were investigated. The results showed that, to obtain reproducible results, replicate sampling from the same milking points in the parlor is important. For milk tubes, samples should preferably be taken from the milk meter side, for liners on the inside of the barrel. For best results, sampling should be performed after use of alkali detergent. No beneficial effect was observed of sampling dry liner barrels, so sampling in the standardized test procedure is performed directly after cleaning. The standardized test procedure was used on 3 different commercial farms and sampling was initiated after replacement of old rubber parts. On one of the farms, additional sampling was performed to evaluate total bacteria count and determine the association with ATP level. The results suggest that, provided an efficient cleaning procedure is used, the hygiene quality of milking equipment can be maintained during the recommended lifetime of the rubberware. However, due to occasional variation in cleaning efficiency between milking points and liner barrels, random sampling on single occasions can lead to incorrect conclusions. Replicate sampling over time is therefore important for correct interpretation of ATP bioluminescence data. If ATP levels are very high, complementary sampling for total bacteria count should be used to verify that the level is due to bacterial contamination, and not other organic ATP-contributing material (e.g., milk residues).
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| 2. |
- Ferneborg, Sabine, et al.
(författare)
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Effects of automatic cluster removal and feeding during milking on milking efficiency, milk yield and milk fat quality
- 2016
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Ingår i: Journal of Dairy Research. - 0022-0299 .- 1469-7629. ; 83, s. 180-187
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Tidskriftsartikel (refereegranskat)abstract
- In order to increase milking efficiency, the effects of two different cluster take-off levels (200 and 800 g/min) and feeding vs. not feeding during milking were tested in a Latin square design study including 32 cows. Milk yield, milking time, milk flow and milking interval were measured and milk samples were analysed for gross composition, sodium and potassium concentration, free fatty acid (FFA) content, milk fat globule (MFG) size, MFG membrane (MFGM) material and fatty acid composition. Residual milk was harvested to evaluate udder emptying. Increasing the take-off level from 200 to 800 g/min at the whole udder level decreased milking time and increased harvest flow. Udder emptying decreased slightly, but there were no effects on milk yield, FFA content or MFGM. There were interactive effects of take-off level and feeding during milking on content of fatty acids C4:0, C6:0, C16:0, C18:3(n-3) and C20:0. Feeding during milking increased milk yield per day and decreased milking interval. Sodium and potassium concentrations in milk were unaffected by treatments, indicating no loss of tight junction integrity. From these results, it is clear that feeding during milking should be used to increase milk yield and improve milking efficiency, regardless of take-off level used, and that the effect of feeding is more pronounced when a low take-off level is used. Feeding seemed to counteract the effects of the low take-off level on milking time and milking interval. Low take-off levels can therefore be used in combination with feeding.
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| 3. |
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| 4. |
- Ferneborg, Sabine, et al.
(författare)
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Milking time and risk of over-milking can be decreased with early teat cup removal based on udder quarter milk flow without loss in milk yield
- 2017
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 100, s. 6640-6647
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Tidskriftsartikel (refereegranskat)abstract
- Increasing the milk flow rate at which milking is terminated can shorten milking time and increase milking efficiency. The effects on milk yield and composition have not been fully investigated when the take-off is set at the udder quarter level and independent of feeding during milking. The objective of this study was to investigate the effect of 3 take-off levels at the udder quarter level (0.06, 0.3, and 0.48 kg/min) applied with or without feeding during milking on milking time, milk yield, the degree of udder emptying, milk composition, and free fatty acids. In this study, 30 cows were allocated into 6 groups, balanced by lactation number, lactation stage, and milk yield, and subjected to a 3 x 2 factorial arrangement of treatments using a Latin square design. Treatments were applied for 1 wk each. This study demonstrated milking time could be reduced by applying up to a take-off level of 0.48 kg/min on udder quarter level without losing milk yield or compromising milk composition or udder health.
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| 5. |
- Ferneborg, Sabine, et al.
(författare)
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The effect of pulsation ratio on teat condition, milk somatic cell count and productivity in dairy cows in automatic milking
- 2015
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Ingår i: Journal of Dairy Research. - 0022-0299 .- 1469-7629. ; 82, s. 453-459
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Tidskriftsartikel (refereegranskat)abstract
- The pulsation ratio of a milking machine affects milk flow and milking time, and has also been reported to influence teat condition and milk somatic cell count (SCC). However, most studies comparing pulsation ratios have been performed on conventional cluster milking (whole-udder level), where effects such as deteriorated teat end condition and increased milk SCC are likely to be caused by over-milking on teats that are emptied faster than the other teats. When the teat cups are detached from each udder quarter separately which can be done in automatic milking systems (AMS), the risk of over-milking, especially in front teats, may be significantly reduced. This study investigated the effects of pulsation ratio on teat end condition, milk SCC, milk yield, milking time and milk flow in an automatic milking system where each udder quarter is milked separately. In total, 356 cows on five commercial farms were included in a split-udder design experiment comparing three pulsation ratios (60:40, 70:30 and 75:25) with the standard pulsation ratio (65:35) during 6 weeks. Pulsation rate was 60 cycles/min and vacuum level 46 kPa. The 70:30 and 75:25 ratios increased peak and average milk flow and the machine-on time was shorter with 75:25, while both peak and average milk flows were lower and machine-on time was longer with the 60:40 ratio. No negative effects on teat condition or milk SCC were observed with any of the pulsation ratios applied during the study. Thus it is possible that increased pulsation ratio can be used to increase milking efficiency in AMS where quarter milking is applied.
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| 6. |
- Hang, Bui Phan Thu, et al.
(författare)
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High level of multidrug-resistant Escherichia coli in young dairy calves in southern Vietnam
- 2019
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Ingår i: Tropical Animal Health and Production. - : Springer. - 0049-4747 .- 1573-7438. ; 51, s. 1405-1411
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the occurrence of antimicrobial-resistant Escherichia coli in dairy calves in southern Vietnam. Fecal samples were taken directly from the rectum of 84 calves from 41 smallholder dairy farms, when newborn and at 14 days of age for isolation of E. coli. Escherichia coli strains were isolated from 144 of the 168 fecal samples tested. Of the 144 E. coli isolates, 40% were found to be susceptible to all 12 antimicrobial drugs tested and 53% of the E. coli isolates were resistant to at least three antimicrobials. Calves were colonized with antimicrobial-resistant E. coli already on the day of birth. Resistance to tetracycline was most common, followed by resistance to sulfamethoxazole, ampicillin, trimethoprim, and ciprofloxacin. Four isolates carried a gene encoding for extended-spectrum cephalosporinases (ESC), and these genes belonged to blaCTX-M group 1 (2 isolates), blaCTX-M group 9 (1 isolate), and blaCMY-2 (1 isolate). Thirty-three isolates had a plasmid-mediated quinolone resistance (PMQR) phenotype, and 30 of these carried the qnrS gene. These results are of importance for management routines of dairy cattle to prevent the spread of antimicrobial resistance.
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| 7. |
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| 8. |
- Hernandez, Carlos, et al.
(författare)
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Colostrum feeding routines - Passive immunity and welfare in dairy calves
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Calves are born with insufficient immunity to fight disease and rely on the passive transfer of immunity via ingestion of maternal immunoglobulins (IG) present in the colostrum. To ensure adequate transfer of immunity, dairy farmers utilize different methods to feed colostrum to their calves. Feeding methods include bottle or bucket feeding, oesophageal tube (OT) feeding, or suckling the dam. However, inherent differences between the feeding methods are known to result in different levels of transfer of passive immunity to the calves. These differences are related to the ability to control 1) the timing of first colostrum feeding, 2) the quality of the colostrum (mainly IgG content) and 3) the volume of colostrum consumed by the calves. With OT feeding it is easy to control the timing, quality and volume. With bottle or bucket feeding it is easy to control the timing and quality but more difficult to control the volume of colostrum consumed by the calves. In suckled calves, it is more difficult to control all, the timing, quality and volume of the colostrum consumed. Because OT feeding makes it possible to control the three main factors affecting transfer of passive immunity, farms that feed colostrum via OT have less failure of passive transfer (FPT) of immunity (often defined as serum IgG1 concentrations of <10 mg/ml at 24 h of age) than farms that bottle feed or allow the calves to suckle their dams. While the presence of the dam and suckling has been shown to increase absorption of immunoglobulins in dairy calves, several studies have found that dairy farms that allow the calves to obtain their first colostrum by suckling their mothers are at increased risk of FPT of immunity. Similarly, a study of Swedish dairy farms found an increased risk of severe diarrhoea in farms where calves were allowed to suckle compared to farms where the farmer fed their calves their first meal. The discrepancy between increased rate of absorption in suckled calves and increased FPT of immunity is likely due to the low volume of colostrum that the calves voluntarily consume during the first 24 h and a delayed ingestion of their first colostrum that outweighs any improvement in the rate of absorption. For these reasons, some dairy farms in North America feed first colostrum via OT as a way to ensure a good transfer of passive immunity in dairy calves, and now this practice is also being promoted in Sweden. While the OT feeding method seems ideal from the transfer of passive immunity point of view, it is not without risks and could compromise the welfare of the new born calf. Oesophageal tube feeding is an invasive procedure that requires trained personnel in order to prevent injury and prevent colostrum entering the respiratory tract, which could lead to pneumonia and in extreme cases death. In addition, force feeding strong and healthy calves with an OT, as opposed to intubating only weak, anorexic/dehydrated calves, could result in calves that resist and struggle excessively in response to the intubation procedure increasing the risk of injury, discomfort and distress. Furthermore, due to the large variation in colostrum quality (IgG content), it is often recommended to feed 3-4 L of colostrum or 10 % of the calf's body weight in the first meal to ensure adequate passive transfer of immunity. These large amounts of colostrum far exceed the abomasum capacity of the average new born calf (approx. 2 L for a 35 kg calf) and exceeds the amount of colostrum that calves voluntarily consume in the first 24 h after birth (2.4 ± 1.5 L). In addition, oesophageal tube feeding does not stimulate the oesophageal groove reflex, which directs the colostrum from the oesophagus to the abomasum where the necessary enzymes for digestion are found. Force feeding large volumes of colostrum in a short period of time to new born calves, such as during OT feeding, could lead to unnecessary discomfort and stress, but this has not been studied yet. While most studies have focused on the effects of OT feeding on transfer of passive immunity, health outcomes and mortality rates, there is no scientific evidence about the consequences of OT colostrum feeding for the behaviour and welfare of dairy calves. For this reason, a large multidisciplinary project is currently being carried out at the Department of Animal Nutrition and Management at SLU. ) aimed at addressing some of the issues concerning the routine use of OT feeding. The project aims to investigate the effects of OT vs suckling vs bottle colostrum feeding at birth, on the transfer of passive immunity, physiological, endocrine and behavioural response to the three feeding methods, growth, health, development of gut microbiota and welfare in dairy calves. In addition, the public's perception of oesophageal tube feeding as a routine management for colostrum feeding in dairy calves will be investigated. Further research on calves and colostrum management at our department include a study by PhD student Lisa Andree O´Hara comparing the use of refractometer (% Brix) and colostrometer as estimators of IgG content in milk (supervisor: Kjell Holtenius) and the PhD project of Bui Phan Thu Hang aimed at improving calf performance in small-scale dairy production in Southern Vietnam (supervisors: Kerstin Svennersten, Ewa Wredle, Johan Dicksved and Duong Nguyen Khang).
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| 9. |
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| 10. |
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| 11. |
- Johansson, Monika, et al.
(författare)
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Composition and enzymatic activity in bulk milk from dairy farms with conventional or robotic milking systems
- 2017
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Ingår i: Journal of Dairy Research. - 0022-0299 .- 1469-7629. ; 84, s. 154-158
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the studies reported in this research communication was to investigate differences in composition and enzymatic activities in bulk milk samples provided from Swedish dairy farms with different management systems, i.e. automated (AMS) and conventional milking systems (CMS). A bulk milk sample was collected from each of 104 dairy farms, 51 using AMS and 53 using CMS, located in the same geographical region. Sampling took place within two consecutive days during the indoor period (October). Milk samples were analysed for contents of total fat and protein, free fatty acids (FFA), caseins and whey proteins, somatic cell count (SCC), pH, plasmin and plasminogen derived activities, and total proteolysis. Our results showed a lower protein content and higher SCC in bulk milk from AMS herds compared with milk from CMS herds. Plasmin, plasminogen and total plasmin/plasminogen derived activities were lower in milk from AMS herds but despite this, total casein and the beta-casein fraction as % of total protein were lower in milk from AMS herds than in milk from herds using CMS. Total proteolysis was higher in milk from AMS herds, suggesting that other proteases than plasmin, e.g. cellular and bacterial proteases, contributed to the degradation of casein. This was supported by a positive correlation between SCC and total proteolysis (P < 0.01), as well as a negative correlation between total proteolysis and beta-casein fraction (P < 0.05). In conclusion, comparing the quality of bulk milk from commercial dairy herds using AMS and CMS, respectively, several differences were observed, suggesting a significant effect from management system.
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| 12. |
- Phan Thu Hang, Bui, et al.
(författare)
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Colostrum quality, IgG absorption and daily weight gain of calves in small-scale dairy production systems in Southern Vietnam
- 2017
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Ingår i: Tropical Animal Health and Production. - : Springer Science and Business Media LLC. - 0049-4747 .- 1573-7438. ; 49, s. 1143-1147
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Tidskriftsartikel (refereegranskat)abstract
- Dairy production is expanding rapidly in Vietnam, but still, the smallholder farms are most common. The aim of this study was therefore to get improved knowledge about colostrum quality in dairy cows, immunoglobulin G (IgG) absorption, daily weight gain in dairy calves and calf management in small-scale dairy production systems in Southern Vietnam. A field survey was conducted on 40 farms, with two calves on each farm being intensively studied. It was observed that newborn calves were separated from their dams immediately after birth and offered 2-4 L first colostrum within 4 h by bucket feeding. The first colostrum IgG level, fat and protein content were on average 35.6, 4.8 and 21.4%, respectively, and 91% of the cows produced colostrum of good quality (Brix value > 22%). The IgG level in serum of calves, measured as Brix value, was on average 9.3%. Colostrum in the samples studied was of quite high quality and on-farm observations showed that colostrum was offered on the first day of calf life, so passive transfer of immunity to the calves was high. In total, 10% of the calves had a Brix value for IgG in serum lower than 8.3%, indicating that those calves had suffered from failure of passive immune transfer (FPT). The daily weight gain of female and male calves was 0.75 and 0.54 kg, respectively. Serum IgG was positively correlated with colostrum protein (P = 0.002). Daily weight gain and diarrhoea was negatively correlated (P = 0.001).
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| 13. |
- Thulin, Måns, et al.
(författare)
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Increased take-off level in automatic milking systems - effects on milk flow, milk yield and milking efficiency at the quarter level
- 2019
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Ingår i: Journal of Dairy Research. - 0022-0299 .- 1469-7629. ; 86, s. 85-87
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Tidskriftsartikel (refereegranskat)abstract
- This research communication describes how different detachment levels (0.48, 0.3 and 0.06 kg milk/min) at the quarter-level affect milk flow profiles and overall milking efficiency in automatic milking systems. We hypothesized a higher detachment level would result in greater mean flow rates without affecting the volume of harvested milk per cow during 24 h compared to lower detachment levels. The data suggest milk flow decreased to a rate below the overmilking limit within the 6-s delay time required for termination in all treatments, but the duration of overmilking was shorter for the greatest detachment level compared to the other treatments. We conclude that setting a detachment level at a greater milk flow rate reduces the duration of overmilking without affecting the amount of milk harvested when applied to cows in mid-lactation during quarter-level milking. We also suggest that the steepness of the decline phase of the milk flow curve might have a larger effect than the actual detachment level on the duration of overmilking.
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