Calf management Lifetime productivity starts when the calf is born

Transcription

1 Calf management Lifetime productivity starts when the calf is born

2 High lifetime productivity of cows: the well deserved result of first class calf management When a cow is culled dairy farmers the world over would ideally aim to introduce a more profitable, newly calved primiparous cow raised on the farm to replace her. As first lactation cows often make up a substantial proportion of the herd (up to 40%) and as it may take one to two lactations before the cow repays the cost of rearing her, whatever helps the first calving cow remain healthy, fertile and productive from the start of her first lactation is a good investment. Ideally, heifers calve at 24 months, weigh something over 600 kg (1,320 lbs)*, can live a healthy, fertile life and provide a high lifetime milk yield. Generally, heavier, well developed heifers become pregnant earlier, produce more milk during their first lactation, and live a longer life and perform better. Not only is this what calf rearing is all about, it is also an important factor in determining the success of the dairy farm. However, as anyone working with dairy cows also knows, this is easier said than done. All decisions and actions taken on a farm rely for their success on farmer and staff skills and continuous training for their success. This booklet is aimed at providing the current, well documented knowledge and information to help dairy farmers achieve the best possible calf rearing in the herd. It includes information on dairy calf needs and recommends best management practices at different age periods in terms of feeding, housing and health management. We hope this booklet will be useful to you. Enjoy your reading and learning, and good luck with your calves! Following each important step of the calf s life Information is provided on management aspects for each of the critical development periods of the calf up to six months of age, when the calf turns into a heifer. *400 kg (880 lbs) for smaller breeds Conversion table The following units and conversions are used throughout the booklet 1 kg = 2.2 lbs 1 litre = 1 quart 1 m = 3.28 feet 1 m² = ft²

3 Contents and short summaries Before birth At birth First day Detailed attention to the nutrition and management of the dry cow and close-up period for both heifer and cow is needed if the goal is to provide healthy, strong calves at birth and an efficient start to early lactation. Good management at calving is the essential first step to successful calf rearing. Adopting a Standard Procedure (SOP) for calving supervision and intervention will reduce calving mortality and incidents of oxygen deprivation and bruising. Calving pen design and monitoring growth rate should also be included. The first day of life is critical for the new-born calf s survival. A good assessment routine and caretaking procedures are as important as having dry and clean bedding, which should be maintained throughout the first 6 months of life Colostrum First weeks First month Colostrum is key to calf survival. Strict colostrum management, based on the five golden rules of colostrum feeding, will ensure timely intake of a sufficient quantity of high quality colostrum to maximize the vitality and reduce disease risk and a poor start to life. The primary objectives of this period are to encourage the calf to drink milk or milk replacer to its full potential, the introduction of concentrate and water to the diet, and early identification of disease or other problems to ensure a strong start to rapid growth. A clean soil-free environment is critical to avoiding diarrhoea, and good ventilation and generous bedding are necessary to reduce pneumonia. As older animals are often the source of infection younger calves should be handled prior to older animals. With a focus on high growth rates different feeding systems and technologies are described according to best practice. Other areas addressed are the pros and cons of housing systems and the effects of low and high temperature on calves Second month The big challenge during this period is to maintain good growth and health during weaning. To do this it is important to ensure that the calf consumes a consistent amount of concentrate and that the milk intake is reduced gradually. Automatic calf feeders are excellent tools for smooth weaning. It is important to avoid movement and regrouping of calves during this period as this stress might increase the risk of pneumonia. Third to sixth month In order to achieve growth close to its maximum potential it is important to provide a well-balanced post-weaning ration with the correct protein to energy ratio. To prevent dips in growth rate regrouping calves, which often promotes respiratory disease should be minimized, and grazing without correct supplementary feeding avoided.

4 4 DeLaval calf management Lifetime productivity starts when the calf is born Performance indicators in calf rearing Three important targets to raise the desired number of healthy, fertile, productive heifers: 1 Keeping calf mortality to a low level 2 Maintaining good calf growth 3 Maintaining good calf health It is highly recommended that performance indicators are used to monitor how well your farm is meeting its targets in order to improve performance. These indicators are called key performance indicators (KPIs). KPIs serve as excellent tools for benchmarking, decision making and following up on the effect of changed practices. Different but overlapping KPIs are used for the three target areas. Keeping calf mortality to a low level The proportion of heifer calves lost during rearing often reaches 20%. If calf deaths during calving and the first 24 hours are included this figure is even higher. After a difficult birth the most common causes of death are diarrhoea in the first month of life and pneumonia at a later stage. Disparities between herds in terms of reproductive losses are very large, but the good news is that some producers have losses well below 10%. The urgency of increasing cow longevity in dairy production is often addressed but calf mortality is rarely considered, however, it would be more correct to include these losses in our calculations. Cow longevity begins at birth! In particular, poor reproductive performance combined with poor calf survival could result in a shortage of new heifers entering the milking herd. Only in herds with very good health do we recommend raising fewer than 35 heifers calving per 100 cows on a yearly basis. Using KPIs to keep track of calf losses and calculate availability of heifers Number of calvings per year or month Number of pregnant heifers Stillbirth frequency (deaths within 24 hrs) Mortality: week 1 Mortality: month 1 Mortality: months 2 3 Mortality: months 4 6 Culling/Mortality: 6 months to calving Keeping a record of causes of death/reasons for culling Maintaining a good growth rate throughout the rearing period Growth rate and nutrient intake prior to weaning have been shown to have a significant effect on milk yield, superior to genetic selection for production. Genetic selection yields around kg milk per lactation. Pre-weaning calf nutrition and management can yield at least 4 times more milk than genetic selection for the first and second lactation. In reality, there is wide variation in growth rates between herds and individual animals and there is virtually no advantage in restricting weight gain in any calf or heifer. The scientific evidence of the benefits of maintaining high growth rates for calves with good nutrition is overwhelming.

5 DeLaval calf management Lifetime productivity starts when the calf is born 5 Benefits of high growth rates Higher early (pre-weaning) growth rates have been associated with reduced mortality Higher early growth rates have been associated with increased milk yields during first and second lactation Higher growth rates (> 600 g/day) have been shown to increase fertility both in the heifer and in first-lactating animals Higher growth rates enabling heifers to calve for the first time at a young age (24 25 months) result in greater lifetime yields Higher growth rates and earlier first calving reduces feed and labour during rearing The recommendation for larger breeds is to reach a weight gain of at least 750 g per day or higher over the rearing period. The recommended weight gain for smaller breeds like Jersey is 500 g or higher KPIs for tracking growth rate It is recommended to measure weight gain during the following periods: Birth to weaning Weaning to six months Weaning to breeding Breeding to calving Maintaining good health throughout the rearing period Health issues have a detrimental effect on calf growth and later performance of the milking cow. For example, calves treated with antibiotics have been shown to produce around 500 Kg less milk in first lactation compared to non-treated calves. Here again, health status varies among herds, with the proportion of calves treated with antibiotics ranging from 0 to 100%. In addition, KPIs for calf mortality are also useful for monitoring calf health. Calf mortality not only causes shortages in the availability of new heifers but is also a strong indication of a calf health problem. KPIs for tracking calf health Antibiotic treatment of calves Mortality: month 1 Mortality: months 2 3 Mortality: months 4 6 Growth rate from birth to weaning Growth rate from weaning to 6 months Examples of key performance indicators for calf rearing Stillborn calves %, dead within 24 hours included Excellent Acceptable Action level Calf mortality 1 60 days % Calf mortality 2 months puberty >2 Daily weight gain g/day for the full rearing period: - Large breeds 750 g < Small breeds 500 g <400

6 6 DeLaval calf management Lifetime productivity starts when the calf is born Measuring weight gain and growth knowing and monitoring After mortality rates, weight gain and growth during the rearing period are the most important KPIs to follow up when it comes to calf-rearing performance. Body weight alone does not reflect the complete nutritional status of a heifer. Heifer development is more accurately evaluated when weight measurements are accompanied by measurements of skeletal growth such as withers height. The height of a heifer reflects skeletal growth while body weight reflects the growth of organs, muscles and fat tissue. There are several reasons to monitor growth rate: To prevent delays in reaching sexual maturity and first calving To determine whether calves are underfed To determine whether heifers are overfed or underfed To establish correct body weight at first calving To minimise calving problems Above all, to be sure you re exploiting the full potential of the heifer calf by achieving excellent growth rates. Calves can be weighed using four different methods: Using electronic scales: though time and labour consuming, this method provides accurate information on live weight and daily gains. Measuring withers height (the height measured at the shoulder or hip the highest part of the heifer's back measured from the should or hip; "a" in picture). This measure is correlated with calf size and weight. Using girth tapes to measure the size/ circumference of the chest to estimate weight. The accuracy of this method is highly dependent on correct use*. Measuring rump height ( b in picture). Rump height for a Holstein heifer should be about 103 cm at four months, 105 cm at five months and 109 cm at 6 months. Regularly monitoring of heifer size provides an indication of when heifers have reached their target weight and whether there are seasonal differences. It yields information about feed quality and whether any supplements are required. Growth rate assessment can be done over the entire rearing period (birth calving) or during specific phases or rearing periods (birth weaning, weaning breeding, breeding calving, grazing period, etc.) a b Correct use of a girth tape Small intestine Note: The calf should be standing as shown. For reliable Abomasum results, ensure correct posture, tape position and tape tension. Where to measure Withers height (line a) and rump height (b) 3 2 Target live weight 1 and withers height for Holstein-Friesian and Jersey calves Age (months) Holstein-Friesian Jersey Rumen Live weight kg/lb Withers height cm/inch Live weight kg/lb Withers height cm/inch 0 40/88 77/16 27/60 66/26 Throat 2 85/187 86/34 60/132 76/ /287 94/37 88/194 86/ / /41 118/260 99/39 Small intestine Abomasum

7 DeLaval calf management Lifetime productivity starts when the calf is born 7 There are a number of different types of growth charts. These can differ depending on recommendations for different breeds and countries. Examples of charts for withers heights by age and weight for growing Holstein Friesian and Jersey heifers are shown below: Withers heights by age Holstein Friesian and Jersey heifers 160 Withers height (cm) Insemination Holstein Friesian Jersey Age of calf (months) Weight by age Holstein Friesian and Jersey heifers Insemination Holstein Friesian Jersey Weight (kg) Age of calf (months)

8 8 DeLaval calf management Lifetime productivity starts when the calf is born Calf and heifer performance begins before birth Do Allow a minimum dry period of 45 days Adjust dry cow ration to avoid overconditioning at calving Ensure sufficient supplementation of fat-soluble vitamins Provide tasty forage of high hygienic quality, clean and fresh water Watch close-up cows carefully at least twice a day If needed vaccinate the dry cows to boost antibody level in colostrum Avoid Omitted or very short dry period High calcium and or potassium intake Moving cows in the period 10 3 days before calving Heat stress in late gestation Overstocking of close-up cows Sudden changes in ration ingredients Calving on slats or in the cubicles Calf performance starts with the dam Dry cows and pregnant heifers often receive far less attention than they deserve from a profitability point of view. Most farmers would agree that a hungry and healthy fresh cow is the best predictor of successful and healthy lactation. Such successful lactations are frequent in herds with a clear strategy for dry cow feeding and management. A cow s performance, as well as that of the calf and heifer, is to a large extent affected by dry cow feeding and management quality. Hence, it is fair to say that future calf and heifer performance begins before birth. Optimal management and proper dry cow and pregnant heifer nutrition ensure the birth of healthy, strong calves and optimal start of lactation for the cow. Dry cow management may affect calf performance Calving difficulties are associated with lower calf growth rates Over-conditioned cows have more calving difficulties Cows with health issues deliver weaker and more vulnerable calves Cows that are stressed show higher stillbirth frequencies; heat stress during late pregnancy leads to growth retardation and affects the calf before weaning An omitted or very short dry period has a negative effect on colostrum quantity and quality Inappropriate feeding of the dam can impair colostrum quality

9 DeLaval calf management Lifetime productivity starts when the calf is born 9 The dry period from the calf's perspective The dry period is divided into two stages: 1 Far dry-off period (dry off until 3 weeks before calving) 2 Close-up period (3 weeks before calving): this latter period is more important for both calving and calf performance and of course includes pregnant heifers with no preceding dry period Far dry-off period The far dry-off period ( > 3 weeks before due date) is the ideal time to attend to practical jobs such as regrouping animals, hoof trimming, clipping hair from the udder and vaccinating cows. Early vaccination will boost antibody content of colostrum against respiratory and gastro-intestinal pathogens. To avoid stress close to calving, it is important to do these tasks long before the predicted calving date. Close-up period Optimal management and proper nutrition for the dry cow and pregnant heifer during the closeup period (3 weeks before calving) is critical for the cow as well as the calf. Focus should be on encouraging a good feed intake for the cow to ensure a successful delivery. Providing a balanced, tasty diet with enough structure and avoiding sudden changes in diet increases the chances of this occurring. Vitamin E and Selenium additives, given to dry cows during this period can help improve disease resistance in the cow, the quality of colostrum and ultimately the calf's health. Cow comfort is also essential at this critical time. Providing a comfortable lying area as well as generous bunk space for loosely housed cows will minimise social stress and prevent lameness. Changes in diet or the cow's environment, whether a move to a new environment or introducing new pen mates, is to be avoided. Moving the cow to the calving pen during the 10 days before calving should be avoided. Also, heat stress can reduce placental development and, in turn, calf development, and should be prevented. Far dry off period Close-up period Requirements for good close-up housing Clean, dry, soft, spacious, non-slippery lying area or cubicle Feeding place with no or little competition for feed Avoid standing time on concrete Good ventilation with no draughts Enough light (also important during night-time) Easy supervision Easy entry and exit of close-up pen for the cows and people

10 10 DeLaval calf management Lifetime productivity starts when the calf is born Close-up pens When close-up cows are housed in traditional free stall or tie stall systems they can be moved to a calving pen a few hours before calving. A comfortable option is a straw-bedded yard provided the straw is kept dry and plentiful and ventilation ensures good air quality. Where possible, it is recommended to isolate heifers and weak cows in a smaller group to reduce stress and ensure closer supervision of the cows. There should be enough room for all the cows in the group to lie down and move freely. In the close-up pen 11.2 m 2 (120 sq ft) of bedded area per cow should be provided. A rule of thumb is to have space for 140% of average expected number of calvings in order to accommodate high calving periods. Space requirement for the close-up pens in bedded areas: at least 11.2 m 2 (120 sq ft.) per cow. For cubicles, a width of 127 cm (4.2 feet) and length 275 to 300 cm (9 10 feet) is recommended. Feeding space per cow: 75 cm (2.5 feet) (large breeds) Giving attention to every cow Giving attention to every single cow Frequent checking of close-up cows is crucial. Post calving disorders can be avoided by providing a good environment and appropriate feeding, and by giving full attention to every single cow during close-up and calving thus ensuring early detection of problem cows. Signs of a healthy cow Good appetite Filled rumen Breathing steadily at a frequency of ~ 30 breaths / minute, mouth closed) Watching you with clear eyes Clean and dry No signs of lameness, wounds or disease

11 DeLaval calf management Lifetime productivity starts when the calf is born 11 Birth Do A comfortable and clean calving area is a must in order to prevent problems during and after calving Follow standard operating procedures for supervision and intervention at calving Early removal of the calf from its mother reduces the risk of disease transmission Before a new cow or group is moved to the calving area it should be cleaned, and dry Regular supervision ensuring early detection of abnormal calvings Avoid More than 10 days between 1st and last calving date in a multiple calving pen Stressing cows during calving as this may delay delivery

12 12 DeLaval calf management Lifetime productivity starts when the calf is born Standard operating procedures Successful calving is the first step towards successful calf rearing. Many calves can die during calving and many more may suffer from oxygen deprivation and bruising, which will adversely affect their start in life. Written calving protocols should be in place for farm staff to follow. Such a protocol is called a standard operating procedure (SOP) and calving management is one of the areas where developing an SOP is recommended. Calving staff should be trained to recognise signs of calving progress, reference times for intervention, good hygiene practices at calving, and strategies to correct abnormal presentation, position, or posture where necessary (e.g. in the event of calving difficulties). During labour cows should be monitored with as little disturbance as possible. SOPs for the management and hygiene of the calving area, moving cows, supervision and intervention at calving should be developed. Calving pen requirements Calving pen The newborn calf is almost unprotected against infectious diseases. Hence, proper cleaning and disinfection of the calving area between deliveries is extremely important in order to prevent the transfer of microbes that live in the calving area surroundings. Calving boxes, whether single or multiple, should be spacious and kept clean and well-bedded with a daily addition of 10 to 12 kg fresh bedding per cow. The flooring should provide sufficient grip to facilitate the calving process. Climate and ventilation within the building must be adequate to avoid high humidity and prevent the bedding from becoming excessively wet. If your knees are wet after kneeling it is not dry enough for your calving cows. Other things to consider are the importance of enabling the necessary supervision, assistance and care of the cow and calf after delivery. Cleaning and disinfection should be carried out between each calving or group, allowing the pen to dry properly afterwards. Close-up pen Calving pen Feeding space 2.49ft/0.76m of linear bunk space per cow Each individual pen has feed and water, group pens have at least the same space as close-up cows Lying space 1 lying stall per cow in freestall or 120ft² (11m²) per cow in bedded pack or compost barn Clean and sanitary, 160ft² (15m²) of lying space per cow Flooring Soft, non-slip flooring (e.g., straw pack or soft rubber) Soft, non-slip flooring (e.g., straw pack) Disturbance/ seclusion N/A Quiet, secluded area with little disturbance during labour Training/ protocol Identify signs of labour Identify signs of labour, reference times for intervention, good hygiene practices, strategies for dystocia Ref. Specific recommendations taken from the Code of Practice for the Care and Handling of Dairy Cattle, National Farm Animal Care Council, Canada.

13 DeLaval calf management Lifetime productivity starts when the calf is born 13 Individual pen Cows are preferably housed in an individual pen/ box that provides sufficient space. Pens may be built entirely of gates to facilitate supervision and good cleaning and disinfection between every calving. The ease of moving cows or opening a partition when assistance is needed during calving are also important aspects. A square pen is preferred since it allows freer movement of the cow and people. The absolute minimum required space for a calving pen is 11.2m 2 (120 sq ft), however, the more space the better the working environment and increasing the calving pen area to 16m 2 or 170 sq ft is recommended. Group calving pen If handled correctly, housing calving cows on straw bedded yards can provide a comfortable and calm environment for the cow. The recommendation is at least 11 m 2 (120 sq ft) straw area per cow with 40% extra space to accommodate surges of calving. If seasonal calving patterns or seasonal fluctuations due to heat stress, etc. are anticipated, a space planning calculation, taking the seasonality into account, should be done. If the same multiple boxes are used for both closeup and calving purposes it is important to keep the group consistent, to avoid adding new cows and to select cows close to calving dates. If this is impossible, the space per cow should be enlarged considerably to mitigate stress and the entrance of new cows should be limited to once weekly. Heifers and weak animals should preferably be kept in smaller groups with less stress and enhanced supervision. Immediate removal of the calf is recommended to avoid transmission of disease and to secure provision of colostrums from the dam. Pasture A well kept grass pasture with minimal manure contamination is a good area for cows to calve in. Pasture calving forms part of an overall system and a part of how to manage and graze cows. Mud should be avoided and if water is visible on the ground surface it is not dry enough for calving cows. Supervision and accurate feeding in this system is more difficult, and if cows need assistance, proper restraint and availability of clean water may be a problem. Individual pen Pasture Group calving pen

14 14 DeLaval calf management Lifetime productivity starts when the calf is born Calving Calving targets A calm cow that feels comfortable in the calving area Maximum chance of normal unassisted calving Infections and injuries of the cow and calf prevented by the use of standard procedures Strangulation with the umbilical cord prevented for backward positioned calves Breathing of calf after birth facilitated Viable, strong newborn calves Moving the cow Stages of calving SOP for calving supervision and intervention Moving the cow to the calving pen Moving the cow from her group may cause stress and, thereby, greater risk of a delayed and subsequently prolonged calving process. Move the cow to the calving pen 1 day before expected calving at the earliest but before labour begins, as this may disrupt normal calving behavior and labour. Signs of calving Decreased appetite Cow separating from the group Signs of discomfort Relaxed pelvic bands Stages of a normal calving Monitoring ongoing calving is more important than most other tasks in the operation and should be prioritised. Everyone on the farm dealing with calving should understand the basic terms used in order to communicate with each other and with the veterinarian in cases of difficult or abnormal births. To limit the chance of transmitting diseases from cow to calf, it is necessary that the calving be performed under hygienic conditions. The three stages of the calving process 1 Dilation of the Cervix In general, this stage lasts from two to three hours in mature cows and four to six hours in heifers. It begins with initial labour and ends when the cervix is fully open and the calf has entered the birth canal. The cow may show kicking at her belly and restlessness due to contractions. At the end of stage 1 the water sac becomes visible. The cow may separate from the group and urinate frequently. This is often more evident in heifers. 2 Delivery of the Calf The second stage is characterised by the progression of the calf through the birth canal and ends with delivery of the calf. After the head has passed through, little extra effort is required to expel the rest of the body. This stage may last from two to 10 hours. A common mistake is to pull on the forelegs of the calf unnecessarily or too early. The calf must enter the birth canal in a certain position. Both forward (coming forward with both front legs and head extended into the birth canal) and backward (coming backward with soles of the hooves up and toes pointed down) presentations are considered normal. The latter is a high risk calving because the umbilical cord is pinched off before the calf's head is delivered. If the calf is presented in other positions this is considered an abnormal calving. 3 Expulsion of the Placenta During the third stage, the afterbirth is expelled from the uterus. Normally, the afterbirth should be expelled within 12 hours of birth. Example of a standard procedure (SOP) for calving supervision and intervention* Calving management is one of the areas where adoption of a protocol for hygiene management, supervision and intervention is called for. An example of such a protocol is shown below. Monitor an ongoing calving regularly and record the time when the outer water sac bursts. Increase inspection frequency to at least once an hour and note labour contractions and any progress. Record time of bursting of the inner water sac and which parts of the calf are visible. Increase inspection frequency to at least twice an hour. * Standard operating procedures Växa Sweden 2014

15 DeLaval calf management Lifetime productivity starts when the calf is born 15 Do not offer assistance too quickly as this could lead to stress with some cows and delay the birthing process. Never intervene in a calving if you are in doubt of solving the situation or if you do not understand the problem. Instead, immediately call a veterinarian. Intervention recommended when: The water sac has been visible for 2 hours the cow has no or weak labour contractions without progress. The calf is still not visible 30 minutes after burst of inner water sac. Intense labour contractions without progress for 30 minutes. Determine position of calf If head and two front legs present normally, no assistance is needed. If in backward position, careful supervision and traction to prevent strangulation of umbilical cord is often needed. Stop in case of abnormal position. Intervention Clean the cow's hindquarters and udder with water, soap and a disinfectant. Clean and disinfect your hands and arms carefully and use obstetrical gloves. All delivery equipment used should be clean and disinfected. Use lubricant if needed. Place one chain on each leg of the calf above the ankle joint and dew claw. Pull the calf gently, one leg and then the other alternately and follow the rhythm of the contractions. After exposing the head and shoulders, pull downward at a 45-degree angle. If in backward position and the hocks are level with the vulva, provide traction back and downwards following contractions. When the calf is born remove mucus from nostrils and mouth of calf and check for breathing. If the calf is unresponsive, rub it briskly to stimulate it, or use a piece of straw or hay to tickle its nostrils to stimulate its breathing.

16 16 DeLaval calf management Lifetime productivity starts when the calf is born First day of life Do Newborn calves must be taken care of immediately after birth Make sure that the calf is dried to avoid heat loss Ensure protection from cold climate by providing adequate amounts of dry bedding Dip the navel with an approved iodine solution Weigh the calf Give at least 4L (10% of body weight) high-quality colostrum within 2 hours of birth (See section on colostrum) Keep the environment draught-free Design and follow hygiene protocols to avoid disease transmission After difficult birth, follow a special treatment routine for those calves Have clear monitoring routines in place Check the status and temperature of the newborn calf every 2 hours Move the calf to an individual pen (according to farm protocol no later than 24 hrs after birth) Identify problems in an early stage and take immediate action Avoid Wet calves Not immediately attending newborn calves Providing bad quality or insufficient amounts of colostrum Leaving weak calves unattended

17 DeLaval calf management Lifetime productivity starts when the calf is born 17 From uterus to pen Facing a world full of infectious agents, climate and nutritional challenges outside the uterus demands fairly rapid adaptation by the calf, effective management and a good environment. First hours of life A calf adapting to the outer world will: Alter its blood flow Start breathing Produce its own body heat Stand up Search for the udder to get fed Suckle for milk, nutrition no longer for free via the navel Avoid infections from the dam and the environment After normal delivery, the newborn calf will automatically start breathing shortly after rupture of the umbilical cord. At this time (immediately after delivery) normal calves are very active and try to get up immediately. This should result in standing up within 1 or 2 hours after birth. The suckling reflex is there from the start and is strongly expressed, even before the calf can stand. The calf is normally alert, responsive and active. Factors delaying the process of getting up are severe weather conditions, injuries, illnesses and/or exhaustion and oxygen deprivation from a difficult birth. Wet hair cannot insulate the calf, and as the water evaporates, it takes heat with it and is extremely energy costly in young calves at colder temperatures. By licking, the cow will, to some extent, dry the newborn calf and stimulate breathing, blood circulation, defecation and general activity. However, at cold ambient temperatures the calf should be dried directly after birth. This is particularly urgent if wind speed is high. A newborn calf is cold stressed when the temperature is below 13 C and a heat source (infrared lamp, or panel heater, etc.) should be provided. Air speed at the surface of the skin also considerably influences the amount of heat loss. A rule of thumb is that it should not be possible to feel air movement on the back of one's hand at calf level, where air speed should be less than 0.25m/s (50ft/min). When handling calves, treat them carefully and make them associate positive feelings with humans. A good way of doing this is to stay with the calf when feeding it during the first 3 5 days. If a calf associates pain and fear with humans, the handling of the calf now and later as heifer and cow will be more difficult. Assessment of the newborn calf Time until the calf can stand: preferably within an hour and always less than two Constant temperature ( C) Shivering calf: take action: shelter, blanket and/or heating lamp Calf is lethargic and has trouble maintaining body temperature: check the reasons and add shelter/heat Is the calf actively suckling?: place your finger in the mouth to check if the calf is warm and has the suckling reflex Keep the calf dry

18 18 DeLaval calf management Lifetime productivity starts when the calf is born Moving the calf Moving the calf to a pen Separation from the dam Calves are very sensitive to pathogen exposure. Once the calf is ready to stand and walk, the chances of being exposed to more pathogens increase. As soon as the calf is dry and has been given the first colostrum, (see section on colostrum) it can be moved to a single or twin pen environment. A good management practice is to separate the calf from the dam at this point. However, depending on the disease situation in the herd it could be an option to wait with the moving up to 24 h, but no longer. In such cases, it is crucial to understand that the feeding of colostrum must be done manually to ensure provision of enough volume and quality (see section on colostrum). It is recommended to house the calf in a clean, dry single calf pen/box/hutch for the first one to two weeks (depending on local regulations and/ or calf performance) to facilitate the build-up of a strong immune system and prevention of diarrhoea and respiratory disease. After a few naps the calf will get up again and will already have periods when it will stand and walk around. In the first days calves lie down up to 75% of the time. Welfare concerns about the early separation of the calf from the cow have been raised. However, a balance must be struck. The longer you wait the bigger the risk of transmitting diseases to the calf and of increasing stress levels for both cow and calf when the separation eventually occurs. On the other hand, you do get a somewhat sturdier calf if everything works as it should. But as mentioned earlier, manual feeding of colostrum is essential.

19 DeLaval calf management Lifetime productivity starts when the calf is born 19 Colostrum is the key to calf survival Colostrum management plays a major role in keeping mortality down on the farm. Calves underserved with colostrum run an increased risk of disease and death. Do Feed calves with high-quality colostrum Milk the cow as soon as possible after calving (1 2 hours) Check quality before giving the colostrum to the calf Give at least 4L (10% of body weight) high-quality colostrum within 2 hours of birth Maintain strict hygiene Store and freeze excess good-quality colostrum Test lgg status of calves 2 to 7 days after colostrum feeding on a regular basis to ensure colostrum management is working In case of shortage of good-quality colostrum, use a complementary colostrum supplement Letting the calf suckle the first meal of colostrum from the dam Routine tube feeding Avoid

20 20 DeLaval calf management Lifetime productivity starts when the calf is born A calf is born unprotected Colostrum = protection During pregnancy the calf only receives a small amount of protective substances through the placenta. Furthermore, a newborn calf s immune system is still developing and the calf has little or no protection from germs (infective agents) in their environment. Calves are extra vulnerable immediately after birth. The milk from the first milking following delivery is called colostrum. Colostrum of the right quality and quantity given to the newborn calf at the right time it is the cornerstone of success for calf survival in any herd. It contains important nutrients: vitamins, minerals, energy and protein, besides antibodies (immunoglobulins lgg) and many other important substances. Calves that get sufficient amounts of good-quality colostrum in their first few hours gain passive immunity against germs, thus protecting the calf through its first weeks until its own immune system becomes fully active. Risks associated with inadequate provision of colostrum Long term risks: lower weight gain, later first insemination, lower milk production The antibody level in blood 2 7 days after birth indicates how successful colostrum provision has been and can be measured. At this time, calves should have at the very least 8g antibodies/litre blood. Calves with low levels of immunoglobulin absorption will experience the consequences for the rest of their lives. Studies have shown that as many as 35% of dairy calves will have low levels of serum immunoglobulins. This number can go up to 61% if calves are allowed to nurse with the dam. Among the short term risks are increase in neonatal mortality due to diarrhoea, respiratory disease and an increase in veterinary costs and use of antibiotics. Long term risks are not fully understood and usually largely underestimated. Heifers will have lower daily weight gain and thus a higher age at first insemination. These heifers will also have lower milk production and a higher culling rate during first lactation. These facts, once again, emphasise the crucial role of good colostrum management. Studies have shown that as many as 35% of dairy calves will have low levels of serum immunoglobulins. This number can go up to 61% if calves are allowd to nurse with the dam.

21 DeLaval calf management Lifetime productivity starts when the calf is born 21 Colostrum quality varies considerably The composition of colostrum is different from that of normal milk and changes rapidly after calving. The protective value decreases with each milking and only the first milking is considered true colostrum. The following milkings are often high in antibodies and extra nutrients and are referred to as transition milk. The quality of colostrum may also vary considerably (from <10 to 235 g IgG/L) due to circumstances such as: Age of cow: colostrum from cows at lactation one and two often has fewer antibodies Time of first milking since calving Leakage from the udder before calving Short dry period (<3 weeks) Breed and milk yield Dry cow ration: cows fed restricted amounts of protein and energy have less antibodies High levels of bacteria in colostrum have been shown to reduce the uptake of antibodies by the calf and increase the risk of diarrhoea Due to the wide variation in quality, suitable colostrum is not always readily available. Goodquality colostrum may and should be frozen for future use. As it is impossible to visually detect whether colostrum contains sufficient antibodies, it is recommended that it be tested. Alternatively, use of a complementary colostrum supplement may be considered. However, it is important to ensure that the product has been independently tested and is proven to be successful. Note that this will not replace colostrum, merely fortify its effect. Prevention and handling of variation in colostrum quality Composition of colostrum and whole milk from Holstein cows Component 1 st milking 2 nd milking 3 rd milking Milk Colostrum Dry matter % Lactose % Fat % Protein % IgG (g/l) Average composition of colostrum (1 st, 2 nd and 3 rd milking) and normal milk from Holstein cows. Ref. Van Saun RJ. Transition Cow Nutrition and Management: The Key to Herd Reproductive Performance. Pennsylvania State University.

22 22 DeLaval calf management Lifetime productivity starts when the calf is born Principles of successful colostrum feeding To achieve successful passive transfer of IgG, the calf must first consume a sufficient mass of antibodies in colostrum and then be able to successfully absorb a sufficient quantity of these molecules into its circulation. Major factors affecting the amount of IgG consumed by the calf include the quality and volume of colostrum fed. The major factor affecting the absorption of IgG molecules into circulation is how promptly first colostrum feeding is provided after birth, and the cleanliness of the colostrum. 5 golden rules to colostrum feeding 1 Quick The calf should get colostrum as quickly as possible after birth. The ability of the intestine to absorb antibodies from colostrum into the blood is most efficient during the first four to six hours of life. At about 12 hours after birth the absorption of immunoglobulins is reduced by 50% and after 24 hours the calf can hardly absorb any antibodies at all. Milk the cows as soon as possible after calving to assure adequate delivery of antibodies to the calf. If you wait to milk the cow for the first time, antibody content of colostrum will decrease by dilution. 2 Quantity To provide the calf with enough energy, nutrients and antibodies, calves should get as much colostrum as possible as soon as possible. Protein, fat and sugars from colostrum help to increase the calf s metabolism and heat production. Moreover, colostrum intake facilitates the first stool (meconium). Ideally calves should receive 10% of their body weight, i.e. three to four litres of colostrum within one to two hours after birth and another two to three litres within six hours after birth, depending on weight. The antibodies absorbed in the first hours will help to protect the calf against infection for three to four weeks. The calf s own production develops over the first four to six weeks. The amount of colostrum intake is, therefore, crucial. 3 Quality Always test the antibody content and use or freeze the best quality. Colostrum should at least contain 50g/L of IgG. Colostrum with <50 g/l IgG will not provide an adequate amount of protection to the newborn calf, even if it is fed shortly after birth. Collect and feed colostrum in clean, disinfected buckets. Ideally, colostrum should be given to the calf directly after milking the cow for the first time. Fresh colostrum can be stored in the refrigerator for up to 24 hours and in the freezer for 1 year if refrigerated or frozen within 1 hour after collection. Frozen colostrum should be thawed slowly in a hot water bath at a temperature of 50 C. Avoid use of colostrum from cows that have been on the farm for less than six weeks as their colostrum may not contain sufficient antibodies to farm-specific germs. Do not give calves colostrum from cows with mastitis. Calves are extremely vulnerable to disease during their first days of life. Before gut closure, germs may be taken up from the gut into the calf s bloodstream. To increase the content of relevant antibodies in colostrum, cows can be vaccinated against relevant infective agents prior to calving. This will reduce the risk of serious infections. If only low-quality or insufficient colostrum is available, or if the dam is known as a high shedder of Johne s disease or other diseases, a commercial colostrum supplement can be used. 4 Frequency The calf should receive multiple colostrum feedings by bottle during the first day of life. Research has proven that calves that are stressed when receiving colostrum will not absorb the protective antibodies as efficiently as those that are calm. Thus a stressed calf would require more colostrum in order to achieve the same level of immunity as a calf that was not stressed. This is one of the reasons why routine use of an oesophagal tube is not recommended, except when, after several attempts, the calf refuses to drink from the bottle. 5 Cleanliness Strict hygiene standards for cleaning and sanitation should be observed when milking a fresh cow. The udder as well as the recipient should be thoroughly cleaned. If this is not done the colostrum can expose the gut of the newborn calf to a high level of bacteria, thereby decreasing the absorption of immunoglobulins.

23 DeLaval calf management Lifetime productivity starts when the calf is born Max serum lgg (g/l) Age at first feeding (hours) The calf's ability to absorb antibodies declines rapidly in the first 24 hours. Ref. Journal of Dairy Science 62: G.H Stott, D.B Marx, B.E Menefee, G.T Nightengale lg lg lg lg lg lg If bacteria reach the intestine before colostrum does, they often enter the blood and may be fatal. The bacteria also can prevent antibodies from reaching the calf s blood.

24 24 DeLaval calf management Lifetime productivity starts when the calf is born Testing of colostrum quality How to measure colostrum quality Because of the large variation in colostrum quality it is important to test it before feeding it to the calf. Colostrum containing 50 mg/ml of antibodies (IgG) or more is considered to be of high quality for newborn calves. Refractometer Refractometer The Brix refractometer optical or digital is a valuable tool that can easily be used on the farm to measure the immunoglobulin content of colostrum. The scale on these tools is designed to measure the amount of sucrose in a solution, but the Brix values can be related to the IgG content in colostrum. A Brix value of 22% corresponds to 50 mg/ml IgG; this percentage can be used as a cutoff point to decide whether colostrum quality is sufficient or not. The advantages of using a refractometer over a colostro-meter are that refractometers are less fragile than colostrometers and that refractometer readings are not temperature dependent. Digital and optical Brix refractometer Colostrometer Colostrometer Colostrometers or densitometers measure colostrum density, which indicates the concentration of antibodies in the colostrum. The colostrometer is placed in a cylinder containing colostrum and is allowed to float freely. Colostrum that tests green contains >50mg/ ml IgG and is safe to feed to newborn calves. Yellow or light green contains 20 to 50 mg/ml IgG. This colostrum can be fed to one or two day old calves. If this is fed to younger calves, a colostrum supplement should be used. If the sample is in the red band, it contains <20 mg/ml of IgG. This is poor quality colostrum and should always be used with a colostrum supplement. For greatest accuracy the colostrometer should be used with colostrum at room temperature (25 30 C o, o F) as the temperature affects density. IgG content is overestimated at lower temperatures and under-estimated at higher temperatures. Colostrometer floating in colostrum sample. This sample tests green and contains >50 mg/ml of IgG. Store and freeze excess colostrum of good quality Good quality colostrum can be refrigerated for 1 day (24 h) with acceptable hygienic quality Colostrum can be frozen at -20 C for up to 1 year without losing its protective properties Always date label Store in bottles or zip-closure bags in 1,2 or 4 litre portions in flat packages When necessary, a portion can be thawed placing it in a warm (50 C) water bath Do NOT use a microwave since this can destroy the antibodies After thawing, gently mix the colostrum and immediately give it to the calf

25 DeLaval calf management Lifetime productivity starts when the calf is born 25 Pasteurisation of colostrum and raw or waste milk Colostrum Pasteurisation can be applied to reduce the number of bacteria in colostrum and raw milk. This is important since colostrum can transmit many important diseasecausing pathogens like Mycobacterium avium paratuberculosis (Johne s disease), Salmonella, Mycoplasma, Listeria, Escherichia coli. The most commonly used technique is batch pasteurisation, heating the colostrum to 60 C for 30 minutes. It is extremely important to carefully monitor time and temperature as antibodies can be destroyed. Another advantage of pasteurisation is that it will improve the efficiency of immunoglobulin absorption by about 10%. Observe that milk intended to be pasteurised should be cooled after milking to avoid the growth of bacteria and be used directly after pasteurisation for the same reason. Pasteurisation of colostrum and raw milk Raw or waste milk Follow the same rules as for colostrum (above). It is important not to add new milk to the pasteurised batch and to clean the equipment carefully between batches. Do not use milk containing antibiotics.

26 26 DeLaval calf management Lifetime productivity starts when the calf is born First week(s): getting the calf ready for life Do Avoid Choose a calf rearing system that suits your farm and ensures the following: Good ventilation: clean air and a draughtfree environment Good bedding management and cleaning routines A stable temperature: avoiding cold and heat stress at the calf level Develop standard routines for feeding that includes: Cleaning and disinfection routines to ensure best hygiene at all times Feed colostrum or transition milk for at least 4 days A milk feeding set-up that allows the calf to suck easily in the natural posture Access to clean water and feeding highquality starter and hay from the first week Start feeding and handling the youngest calves and end with the oldest to avoid spread of infections Check calf health at least twice daily and record, inform and act immediately on issues House sick or weak calves separately until they have recovered and are vigorous Wet calves and wet bedding Feeding unpasteurised milk and waste milk containing antibiotics Allowing calves to drink milk in incorrect position Rapid change of milk type and concentration of milk replacer Fecal or other contamination of milk, feed or water Using milk replacer not adapted for young calves Feeding or handling young calves after older animals Exposing sick or weak calves to temperature stress (warm or cold)