«Dairy cattle husbandry Agrodok 14 - Dairy cattle husbandry More milk through better management Agrodok 14 Dairy cattle husbandry More milk through ...»
Feeding till weaning Milk is a complete and natural feed for the young calf that needs about 10 % of its body weight per day during the first 3 to 4 months of its life. Too little milk will hamper the development of the calf, too much may cause diarrhoea. Stick to the right amount and the calf will make a good start. To train the calf to drink from a bucket, let the calf suckle on a finger and lead it towards the milk in the bucket; after a few times it will drink all by itself. Clean buckets and strict hygiene are required, otherwise the calf will get diarrhoea.
From the second week onwards a small portion of concentrates and some roughage should be offered. A special calf concentrate is preferDairy cattle husbandry able, but any good concentrate will do provided that it does not contain urea and cottonseedcake. At the beginning, the concentrate can be given in the same bucket as the milk. Once the calf starts eating it readily, it should be given in a special feed trough.
Roughage, preferably hay of a good quality, will stimulate rumen development. It can be tied with a piece of rope to the side of the pen when the calf should start eating it suckle-wise. Once the calf begins to really eat the roughage it may be given in a rack and ad libitum.
Fresh roughage should be supplied, preferably twice a day. Make sure the calf has water available at all times and, at a later stage, some minerals.
Although very detailed feeding schedules exist, an effective and simple system is to give the calf 2 kg milk in the morning and 2 kg in the afternoon for 12 weeks at least, or about 300 litres in total. This is a minimum, feasible only if the calf consumes an adequate amount of concentrates. If concentrates are not available, more milk per day must be given for a longer period. At weaning, calves of improved breeds (500 kg mature weight) should weigh at least 70 kg and consume 1.5 kg of concentrates per day. After weaning, the calf still needs good quality roughage and concentrates to continue its development. Often concentrates are considered too expensive for calves, but remember that the nutritive value of 1 kg good quality concentrates is equal to that of some 3 to 4 kg milk.
Bull calves On most dairy farms bull calves are neither used nor needed. Rearing them costs money, so unless needed to stimulate their dams’ milk letdown, sell or slaughter them as soon as possible.
Suckling Many local and crossbred cows will not let down their milk without their calf being present. This does not necessarily mean that the calf has to suckle first, often its close presence will do. If this is the case the cow will stop producing if her calf dies. Therefore try milking the Calf and young stock rearing cow without the calf. Some farmers allow the calf to suckle the last milk for 10 to 15 minutes. This may help to reduce mastitis, but as the last milk contains the most fat, the calf may get too much fat. Better leave (part of) one quarter or teat for the calf, but not always the same teat.
In some areas milk is only collected in the morning in which case the calf can join its dam for suckling after the morning milking till midday. From then on until the next morning milking, calf and dam remain separated.
Points to bear in mind when calf rearing:
? Immediate provision of colostrum to the newborn calf is essential.
? Feed an adequate amount of milk from a clean bucket, right after milking the dam.
? Introduce special or good quality concentrates at about one week of age.
? Start giving roughage during the second week, preferably good quality hay.
? Make sure the calf pen is dry, draught free with a slatted floor or adequate, tick free, bedding.
? Provide the calf with fresh and clean water from early age onwards.
7.3 Young stock rearing After weaning at an age of 3 to 4 months, many calves are fed on roughage alone, which is not enough for adequate growth because their rumen is not yet fully developed. Generally, roughage needs to be supplemented with calf or young stock concentrates till the age of 1 year at least, though this depends on roughage quality and season.
With good quality roughage, a growth of 200 to 300 grams per day is feasible. However, the required growth for a heifer to conceive at about 20 months is 450 to 500 grams per day, necessitating the providing of supplements of at least 1 kg of concentrates per day.
58 Dairy cattle husbandry Many farmers give the best quality roughage to their dairy cows and the young stock gets what is left. This hampers their development and they might remain stunted for the rest of their lives. Young animals need adequate nutrition and this investment will be repaid once the animal starts producing milk.
A well-developed heifer can be serviced at about 20 months of age and in this way she will calf-down at about two and a half years or 30 months. The pregnant heifer should grow at least 500 grams a day and this cannot be achieved on the basis of roughage alone, so she needs supplements as well. Any setback in nutrition and health will affect her development, her pregnancy and her future milk production. Such a setback is difficult to compensate later on, the animal will remain a poor producer for the rest of her life.
Once the heifer has calved and started her productive life, rearing is not yet complete. She will continue growing and developing during the first lactation. The extra feed required, the ‘youth allowance’, is about 20% TDN and CP above the daily maintenance requirements.
This youth allowance must be taken into account to enable the cow to develop her production potential. Cows reach full maturity at 4 to 5 years of age, depending on the breed.
Clean milk saves lives; dirty milk may kill people.
Practical reasons for proper and hygienic milking and milk handling in
? To produce clean milk of good keeping quality.
? To prevent and control mastitis, a contagious disease that affects the production and the quality of milk.
? To deliver good quality milk to consumers and processors.
Milk is an ideal environment for microorganisms like bacteria to multiply, especially in warm conditions. Microorganisms may cause souring of the milk and hence rejection by the consumer or the milk collector. Filtering the milk after milking removes visible dirt like hairs and larger pieces of soil and dung, but not the very fine dirt particles or the invisible bacteria.
Good standards of hygiene are of the utmost importance for the quality of the milk and its products, as well as for the producer since the milk price often depends on quality; poor quality milk will be rejected.
The consumer wants a safe product and the processor needs good quality milk for processing.
The handling of milk strongly affects the quality of the finished product. On leaving the udder milk from a healthy cow contains a negligible quantity of bacteria and no dirt. If good hygiene is practised the contamination outside the udder can be kept to a minimum.
Good quality milk:
? Is produced by healthy cows.
? Is not contaminated with water, dirt, antibiotics, detergents and bacteria during nor after milking.
? Does not smell or taste bad.
60 Dairy cattle husbandry ? Has not deliberately been adulterated with water, sugar, salt or flour.
Addition of water, in particular, may cause contamination by microorganisms and pose a threat to human health.
? Is a healthy food.
8.1 Clean milk Clean milk production depends on the milker, the cow, the milking utensils and equipment used, the shed including the milking place and the handling of milk.
The milker The milker should be healthy, clean, have short and clean fingernails and wear clean clothes. He or she should milk the cow paying full attention to the task and not smoke, spit or cough while milking. The cow should be milked as quickly and completely as possible, and preferably always milked by the same person. By calm and gentle handling, touching the cow, talking to her and maintaining routine actions during milking, she will feel at ease. If the cow is fed concentrates, do it during milking.
The cow To prevent dirt from dropping into the bucket during milking it is advisable to shave the hairs of the udder twice a year, especially around the teats. Brush the hair on the flank of the cow on the milker’s side frequently. The tail should also be washed and clipped if necessary to avoid adherence of dirt and dung.
Utensils and equipment Buckets, milk cans and cloths for cleaning the udder and cloths used for straining the milk are frequently the source of bacterial contamination of the milk. The surface of the milk utensils like buckets and cans should be smooth and without seams and have rounded edges to make them easy to clean. Stainless steel is the best material but is expensive.
Good plastic buckets can be used if well taken care of. Aluminium Clean milk production milk cans are often used for transport. Special care should be given to cleanliness, lid included.
Udder cloths and straining cloth need careful cleaning too. Paper towels for udder cleaning and disposable cotton pads for straining the milk are advisable, but may be expensive or not available. A strip cup for routine mastitis testing can be made from an empty tin and a piece of black inner tube.
It is essential to use clean water for utensil cleaning. The procedure is
? Immediately after milking, rinse all the utensils with cool water to remove any milk residues. It is rather difficult to clean utensils after the milk has dried and sticks to them. Use cool water, as hot water for rinsing will make the butterfat stick to the utensils. Rinse the milk can with cool and clean water immediately after milk delivery.
? Brush all utensils thoroughly with hot water and detergent or soap.
Keep separate brushes for the inside and outside of the utensils.
? Rinse all utensils with clean, cool water to remove dissolved dirt and detergent.
? A second rinsing with a disinfectant may be considered.
? If no disinfectant is used or available, the utensils should be left drying upside down on a rack in the sun. The sun kills bacteria and acts as a disinfectant. Rinse again with cool water before use to remove dust. If a disinfectant is used the utensils can be stored inside, upside down. Never dry utensils with a towel or cloth.
? Cloths should be washed or boiled with hot water and soap, rinsed and left to hang drying outdoors, exposed to the sun.
The shed and milking place Cleanliness is important within the dairy shed. Special attention should be given to the stand where the animals are resting, to keep animal and udder as clean as possible. Especially tie-stalls with high feed troughs cause very dirty udders as the cow may lay with its udder in the manure. Use clean and dry bedding material in the resting place, 62 Dairy cattle husbandry but watch out for tick infestation. The floor in the milk stand is easier to clean if made of concrete. The shed should be built in clean surroundings with proper drainage and a facility for storing manure, in order to prevent muddy and dirty conditions. Maintain high standards of hygiene in and around the place, also important for fly control.
8.2 Milking Milk let-down Milking deserves full attention, because it affects the yield, lactation period, butterfat percentage of the milk and the health of the udder.
Milking should take place in a quiet place without shouting and yelling so that the cows feel at ease. This is achieved through a routine process with the usual milker who talks and acts quietly. Feeding of roughage or concentrates and rattling of utensils will help. Kicking, beating and twisting of the tail are bad. A good cleaning and massage of the udder is necessary for the cow to feel at ease and stimulate milk let-down. The pressure in the teats is the sign to start milking. Sometimes the presence or even the suckling of a calf is necessary to stimulate milk let-down. Milking should not start before let-down has occurred. The let-down lasts for about 5 to 10 minutes and milking should be completed within that period. If the cow experiences pain or is stressed, this process will be disturbed and milk let-down will not occur.
Preparation Inspect each quarter for mastitis before milking starts, by squirting the first 2 draws of milk of each teat in a stripcup (see Chapter 5.7). Some watery first milk is normal; the trained eye can recognise abnormal milk, that, may show discoloration, flakes, clots or wateriness. The colostrum may contain some blood or blood clots.
It is best to sit on a stool, preferably on the right side of the cow, to prevent ‘hanging’ on the teats and to enable the milker to keep the bucket between the legs. This will give the milker a stable position and prevents the cow from kicking the bucket, or dirt falling into it.
Clean milk production Proper milking Full hand milking is recommended. Stripping is slower than the ‘fullhand’ method and may cause more damage to the teat and udder tissue and hence increase the risk of mastitis.
In ‘full-hand’ milking you close your thumb and index finger around the teat and extract the milk by squeezing progressively with each finger in turn, starting with the index finger and using minimum traction on the teat. In this way the milk is squeezed out of the teat and is prevented from flowing back into the udder.
Figure 18: Hand milking. A: full hand milking. B: stripping.
The two front-teats are milked first, then the two hind teats. At the end, the rest milk is milked and massaged out of the forequarters and then the hindquarters. If the udder is not milked out completely, the drying-off process will be accelerated. This means that the milk production of the cow will gradually drop and the length of the lactation will shorten. The cow is thus ‘milked dry’ as she adjusts her production to the amount of milk removed during milking.
It is better to use the dry method when milking. This means that during milking the milker should not dip the fingers in the milk in order to wet the teats. This is unhygienic. Although udder cream is frequently used to make the teats supple, it is better to apply it after milking.