In order to solve this problem, first bovine colostrum is extremely rich in IG (especially immunoglobulin type G) and other components, to be ingested by the newborn as soon as possible. The absorption of colostrum immunoglobulins is made through the intestine, which has a maximum absorption capacity in the first 2 hours of life and from here is decreasing the absorption capacity which cease completely even 24 hours after birth. This mother's immunity transfer process for the newborn through colostrum is named passive immunity transfer.
There are some critical points to achieve adequate passive immunity in all newborns:
1 - Colostrum Quality – It´s important to ensure that there is sufficient immunoglobulins in colostrum to be absorbed by calf.
2 - Colostrum quantity – Administration of an adequate volume of colostrum for a sufficient amount of IgG intake.
3 - Timing of first colostrum intake – administer colostrum as soon as possible after birth (ideally within 2 to 4 hours) to ensure greater intestinal absorption of IgG.
In medium or large-sized farms (> 200 cows milking) colostrum management and the administration to the newborn, takes main highlight once there are animals constantly giving birth, sometimes with several deliveries a day. Although it requires a greater effort by workers, these conditions allow to improve colostrum management protocol in order to ensure a healthier rearing that will certainly bring major economic returns.
Nowadays there are several auxiliary tools to proper management of colostrum in dairy farms. The colostrometer (hydrometer) is a device for assessing the density of colostrum and assigning a green to red color scale depending on whether colostrum is more or less dense, once the density of colostrum is directly related to the amount of immunoglobulins. More recently, manual or digital spectrofotometer are being used with a greater sensitivity for the same purpose. With these meters we can evaluate the colostrum of different recently calved cows and select the best to freeze and to feed calves in the early hours, with the remainder stored colostrum for the following doses. Because deliveries occur at any time and is not always possible to milk the cow immediately, it should be created frozen stock of good quality colostrum. This allows that on day to day operation, there is always colostrum available to be administered within 6 hours of life to the newborn, even when for practical reasons the cow only can be milked several hours after delivery. This colostrum should be kept in containers of 2 to 4 L (appropriate bags, plastic bottles) properly sanitized. The containers of 2 L, because they have smaller volumes, allow a faster freezing and thawing. The thawing of colostrum should be in hot water bath, which can never exceed 50 ° C at the risk of denaturing the present immunoglobulins. Each feed with this colostrum should be approximately 4 L at 39º C also as soon as possible within the first 6 hours of life.
Regarding to the feed volume colostrum, this can vary with several factors, however when we are establishing a protocol on the farm, it should be as uniform as possible and equal for all animals. Once the concentration of immunoglobulins can be highly variable between different colostrum, is known that a volume of 3 to 4 L with a medium amount of colostrum immunoglobulin (50 mg / L), administered to the calves within the first 6 hours is extremely effective in passive immunity transfer from mother to calve. However, knowing that by the conventional method (bottle, bucket) is very difficult to achieve the required amount of colostrum ingestion of 4 L, it is advisable whenever necessary that the first intake of colostrum should be accomplished by intubation probe which will allow the placement of colostrum in the desired quantities directly in the rumen / abomasum. With practice, intubation of calves by employees is very easy and practical to apply successfully in dairy farms.
Several studies demonstrated the great advantages in the implementation of this kind of techniques in dairy farms. Comparisons have been made on the differences between financial benefits from calves that achieved an adequate passive immunity transfer (> 10 mg / ml Ig in the blood) and calves which had failed passive immunity transfer (Ig blood <10mg / ml). These studies evaluated differences in weight gain, feed conversion difference, difference in the incidence of disease and treatment costs, and difference in mortality rate. All of these criteria taken together showed a difference of about 25 € from calves with good passive immunity and calves that failed passive immunity.
In an attempt to create and establish a colostrum management protocol in dairy farms, the following aspects should be clearly included:
• Use only the first milking colostrum.
• Evaluation of the quality (density) of colostrum with the aid of a colostrometer.
• If the colostrum is of good quality keep an identification to be administered properly to the calf of that cow.
• Storage and freezing of higher quality colostrum for stock maintenance (freezing in 2 liter volumes).
• 4 L beverage for larger/medium calves and 3L for small calves in the first 6 hours of life.
• If you must use frozen colostrum, the thawing temperature can`t exceed 50 ° C (always use 4 L of frozen colostrum).
• When appropriate, use intubation probe to manage all of the 4L.
• Use colostrum from other milkings for the following doses.
• With the help of your vet, monitor if your calves are acquiring good passive immunity transfer or if additional/ corrective measures are required.
The colostrum pasteurization is a tool that is beginning to be seen more frequently and clearly has great advantages in terms of bio-security. When raw colostrum is given, transmission of agents such as S. aureus, Mycobacterium paratuberculosis and Mycoplasma to the newborn is a possibility that must be taken into account, especially in farms where the prevalence of some of these agents is high. When colostrum is pasteurized at 61-62ºC, some immunoglobulins are lost by denaturation. However, some studies indicate that a pasteurizer of colostrum can be included in a protocol without compromising the success of passive immunity transfer. Likewise one pasteurizer for recovery of the milk/colostrum of following milkings for use as an alternative to milk replacer is a measure that has shown good results. It is expected, in the near future, the availability of programmable pasteurizers capable of pasteurizing both colostrum and milk (since the cycles for colostrum and milk require different temperatures), which will be a tool with a more satisfactory quality/ utility/ price relationship.
Although colostrum management is a key point for a quality rearing in dairy farms, its implementation does not require a lot of work increase. It requires rather a good routine and consistency from people responsible for the tasks which must be properly instructed and assisted by both the assistant veterinary team and the remaining employees from the farm.
By Bruno Carneiro
Pregnancy rate: [(No. of pregnant cows) / (No.of available cows)];
Service rate: [(No.of cows imseminated) / (No.of available cows)]; and
Conception: (P/AI) [(No.of pregnant cows) / (No.of cows inseminated)].
Increasing the proportion of pregnant cows at each insemination (conception or P/AI) will have a direct positive effect on pregnancy rate and in the herd fertility. A limiting factor to fertility in cows inseminated after being synchronized with an Ovsynch protocol (day 0, GnRH; day 7, PGF; day 9.5, GnRH; 16 h TAI) is incomplete regression of the corpus luteum (CL) at the time of the last GnRH.
To better understand how incomplete CL regression affects fertility two studies were performed: 1) a retrospective analysis of data from previous studies, and 2) a field study with the objective to increase the percentage of cows with complete CL regression.
In the first stage, fertility data of cows synchronized with an Ovsynch protocol (n=3148) and whose circulating progesterone (P4) concentration at the time of the last GnRH was known were analyzed. Cows were divided in 8 P4 concentration groups from 0 to ≥ 0.7 ng/mL, using increments of 0.1 ng/mL. At 32 d after TAI, P/AI differed (P < 0.01) among groups, and was less for cows with P4 concentration ≥ 0.4 ng/mL compared to cows with P4 concentrations < 0.4 ng/mL [14% (61/435) vs. 41% (1125/2713), respectively].
In the second stage, 898 cows were synchronized with an Ovsynch protocol. Cows were divided in two groups (Figure 1): 1) control group (7D1PGF, n = 463), which received an Ovsynch protocol as described previously (day 0, GnRH; day 7, PGF; 56 h, GnRH; 16 h, TAI); and 2) treatment group (7D2PGF, n = 435), which received an extra prostaglandin-F2α injection (PGF) 24 hours after the first (day 0, GnRH; day 7, PGF; 24 h, PGF; 32 h, GnRH; 16 h TAI).
Overall, at the time of the last GnRH injection, cows with P4 concentration less than 0.4 ng/mL had greater (P < 0.01) P/AI compared with cows with P4 concentration greater or equal than 0.4 ng/mL [39.1% (279/713) vs. 11.8% (10/85), respectively]. The administration of the second PGF injection increased (P < 0.01) the proportion of cows with complete CL regression [95.5% (283/401) vs. 83.8% (356/425)]. Cows treated with a second PGF injection had more P/AI (+6.6 % points) compared with the control cows [37.7% (164/435) vs. 31.1% (144/463), respectively].
In conclusion, administration of a second PGF injection 24 hours after the first, increased the proportion of cows with complete CL regression and increased P/AI in lactating dairy cows.
By Vanda Santos
There are a lot of molecules in the market that should be chosen accordingly with the problems identified in each particular farm.
The common question for every farmer is… can we afford a little bit in the post-dip?
At the farm Caldeirinhas, Gijs has created an interesting option to reduce the unintentional waste that sometimes happens during milking.
Wooden block's glue was added to the bottom of the post-dip cup in order to reduce its depth. This allows to deep two thirds of the teat, without excess of fluid.
The companies responsible for the execution of the milk collections are properly certified and authorized.
It consists in the register and evaluation of the milk produced by each individual cow, in the successive months of lactation, with evaluation of the quantity of milk produced, content of fat and protein, and somatic cell count, etc.
Milk records should be interpreted associated with other sources of information like the team of veterinary assistants, management and infrastructure of the farm, nutritionist team, and the farmer.
Some problems in the herd may be suspected through the analysis of some parameters:
• Fat content:
A high percentage of fat in the first milk testing post-partum, in individual animals, may be an indicator of metabolic problems including fatty liver and ketosis.
Since this value can be determined, approximately, from 7 days to 35 days post-partum, the prevalence of animals that have fat >5.5% and less than 60 days of lactation can be calculated. A prevalence >10% may be indicative of a herd with problems of fatty liver or ketosis.
In contrast, if there are animals with fat <2.5%, and if the percentage of animals with this characteristic is 10% of the herd, one can suspect of sub-acute ruminal acidosis.
• Protein content:
The content of protein by itself does not give much information. Therefore, the ratio between fat and protein (fat/protein) should be calculated. If this value is >1.4 one can suspect of negative energy balance.
• Performance of first lactation cows:
The peak of lactation is well correlated with the total production during the 305 days post-partum. We can compare the value of primiparous cows with the mean of multiparous cows. It is expected that the ratio would be 75% for a farm with good performance. If the ratio is 80% for primiparous cows it can represent a good farm performance or that multiparous cows may not be performing well. If the percentage is below 70% it means that there might be a problem with primiparous cows.
• Data analysis:
Through the download of the data into an excel file we can make a differential treatment of the data in order to obtain more information. Some examples of the parameters that should be analyzed monthly are listed below.
We can calculate:
New infection rate
Chronic infection rate
Rate of non-infected cows
The Milk quality programs analyze all the data from the milk testing, allowing the farmer to have a better knowledge of the problems in his farm, and also understand which major risk factors harm its milk production and quality. Therefore, the main objective of these programs is to make the dairy farm as efficient as possible through the monthly evaluation of the farm.
By Ema Roque