elbs brainscape unit three livestock husbandry part two Flashcards
Fertilisation
Sperm meets egg and they fuse. This takes place in the oviduct
Embryo
Fertilised egg turns into this
Placenta
Pad of flesh which lets the mother’s blood get close to the offspring. Oxygen and food go into the embryo, CO2 and waste come out.
Umbilical cord
joins placenta to offspring
Amniotic sac
full of liquid to protect offspring
Birth process
Vulva swells, udder fills, waters break. Cervix dilates, offspring are pushed out by contractions of the uterus wall. Offspring may need manipulating to get them out the right way (not backside first)
Signs that signify that an animal is on heat,
reddened enlarged vulva, seeking out males, standing to pressure, calling , mounting others
artificial insemination (AI)
semen in a catheter, thaw it out and place it into the uterus when the animal is on heat
AI advantages and disadvantages
Advantages – don’t have to keep a male, can choose the best males, can choose different breeds. Disadvantages – disease needs trained operative
Embryo transfer
Inject female with a hormone to cause lots of eggs to ripen. Fertilise them with AI. Flush out the uterus while the fertilised eggs are still small. They can be frozen for future use or put into surrogate mothers.
Advantages and disadvantages of AI
Advantages – good mothers can have lots of offspring per year.
Disadvantages – disease, needs a trained operator, can be expensive.
Ethical issues for AI and embroyo transfer
Ethical issues are to do with right and wrong. Some people regard AI as unnatural. Also by using lots of sperm from a single donor animal or lots of eggs from a female which is undergoing embryo transfer you will narrow the gene pool, reducing the variety of animals to choose to breed from. Welfare implications include having to constrain and anaesthetise animals while you perform the various necessary operations on them could be seen as being cruel.
milk producing organs
Mammary glands produce milk from alveoli which feed in to ducts then a cistern. The teats lead out from this. A big blood supply is needed so they have a big artery and a milk vein to supply the udder
lactation curve
Graph of how much milk a cow gives over the year
Lactation curve changes
Cows produce more milk early in their lactation, especially when put out onto spring grass. The production drops off over the rest of the year until they are dried off for a couple of months prior to calving.
Milk production and stress
Cows like routine and quiet conditions. If there is a change to routine, loud unfamiliar noises or strangers present they may not give as much milk as they usually would.
principal components of milk differ during lactation
The cow starts to give milk as soon as it has given birth. The first milk is called colostrum and is very rich in fats and contains antibodies which protect the offspring from infection. A couple of weeks after birth the cow are producing her maximum. This is called peak yield. From there the yield slowly drops off over the year. It may go up a bit when the cow is turned out onto fresh grass in the spring. The cow is dried off for a couple of months before the next calving. Protein level is highest at the start, mineral levels higher later on.
characteristics
Features of an organism
DNA
Chemical which code information from one generation to the next
chromosomes
coiled strands of DNA
mutations
Random changes in genes
alleles.
alternative versions of the same gene e.g blue eyed, brown eyed
genotype
Combination of alleles eg BB, Bb , bb
phenotype
What the organism actually looks like
dominant
Some alleles are stronger than others and if present will always be expressed (they will show in the offspring)
recessive
Some alleles are weaker than others and will only be expressed if no dominant allele is present.
F1
The first cross of offspring from true breeding lines
monohybrid inheritance
where there are dominant and recessive alleles, applied to breeding livestock. Cattle may lack horns. This is called “polled”. The dominant allele (no horns) =P. The recessive allele (horns) = p. If we take a true breeding polled and cross it with a true breeding horned:-
Parents phenotype Horned X Polled
Parent’s genotype pp X PP
Gametes p p X P P
P P p pP pP p pP pP
Cloning
Making copies of an organism which are genetically identical to each other
Plant clones
Many plants can be cloned by taking a part off a plant and growing it on (e.g. taking cuttings)
Animal clones
In animals clones can be made by taking the nucleus from an adult and placing it into an egg cell which has had the nucleus removed then growing it on into an embryo.
Ethical problems with cloning
Ethical issues mean whether something is right or wrong. There are ethical concerns regarding cloning such as the suffering of the animals involved, viewing animals as objects and commodities as opposed to sentient (feeling) beings. Cloning often goes wrong, causing painful defects in the animals.
Risks of cloning
risks can include high risk of death during pregnancy and during the period shortly after birth, plus the possibility of defects. There can be a question over the safety of animal products from cloned animals e.g. meat and milk.
Benefits on cloning
benefits include the ability to reproduce large numbers of animals identical to superior specimens or disease resistant ones, and to allow breeding from animals that can no longer reproduce naturally e.g. old bulls. Zoos can use cloning to reproduce endangered animals.
Selective breeding
Selective breeding means deliberately choosing animals to breed from which have a characteristic which you want to improve. Careful record keeping must be done over many generations so it takes lots of years to make a difference
yield
the amount of useful product you end up with e.g. milk of meat
disease resistance
how well they can fight off infections
hardiness
the ability to survive harsh conditions
conformation
their body form
Example of selective breeding
Belgian Blue cattle have been selectively bred to produce a lot more muscle than ordinary cattle. A mutation in the gene which controls muscle growth has been selected for over many generations
Hybrid vigour
when you cross two breeds together – they thrive better and are more vigorous and hardy than pure bred animals
inbreeding
which can cause health problems to animals e.g. crossed beaks in chickens, hip problems in pure bred cattle. This is because recessive alleles are more common and can combine to get expressed in the phenotype.
gene pool
. Rare breeds are important in maintaining a wide genetic base (gene pool)
Rare Breeds Survival Trust
Certain breeds have fallen in popularity over time due to changes in farming practices (more intensive these days) and in eating habits (less fatty animals are required) It is important to preserve these rare breeds because they may have genes which will be of use to us to breed from in the future
How to approach, move and transport farm livestock safely
Let the animal know you are there by talking quietly, - Avoid sudden movements and noise, - Approach from the front or side so they can see you,
- Use the flight zone and point of balance to move the livestock without hitting them or frightening them.
weigh an animal
guide them into a crush (a small enclosed metal framed box where they can’t move much) with an electronic balance underneath. With small animals they can be weighed by putting them into a sack and using a scale. With large animals an estimation of weight can be made by calculating using a tape measure to gauge their length and girth and reading their approximate weight from a table.
Hazards of poor handling
disease (tetanus is a bacterial disease which caused muscle spasm, salmonella is another bacterial disease which causes vomiting and diarrhoea), parasites (e.g. lice, fleas, worms, blowfly maggots).
Animal handlers can be hurt by being crushed, bitten or stepped on.
Control of hazards
These hazards may be reduced by carefully planning the movement of animals and good hygiene (washing hands with soap and water, wearing overalls and boots, regular cleaning of bedding etc.)
Legislation regarding keeping animals
To keep livestock you must register with DEFRA and have a registered county parish holding number (CPH) and record births, deaths and when animals move onto or off the holding. This is so that movements can be traced in case of disease, food poisoning etc. Animals must be identified by an ear tag which has the holding number and the flock or herd number on it.
Cruelty to animals ( the five freedoms - from hunger and thirst, from discomfort, from pain, injury and disease, from fear and distress, and the freedom to normal behaviour) The RSPCA enforce the regulation which go along with these. There are also some diseases you have to tell the authorities about if you get them on your farm e.g. foot and mouth.
Moving animals
If you are moving animals you need to comply with regulations as to how long they can travel without food or water, how far they can go without rest.
There are movement licences which have to be filled in. This is to avoid the animals suffering.
