M3 Flashcards
systematic examination of the eyes and surrounding areas, jaws, mouth and teeth, limb structure, joints, stance, gait
Physical soundness
BBSE four key components
physical soundness
scrotal size
semen assessment
serving ability
inner lining of sheath and is the pink mucosa
prepuce
major factors influencing scrotal size
genotype
age
Liveweight
Nutrition
Timing of nutritional stress
forms the basis of livestock improvement as it allows the transfer of genetic
material from one generation to the next and can greatly influence genetic gain
reproduction
In severe environments where nutrition
is a major stress factor, improvements of 5–10% in weaning rates are possible through?
improving nutrition and management
measures for the bull?
- physical and structural soundness
- scrotal size and sperm production capacity
- semen quality, including morphology
- serving ability/serving capacity.
measures for the cow?
- weight and age at first estrous cycle
- the inter-calving interval
- lactation status at subsequent pregnancy diagnosis.
measures for the herd?
- branding and/or weaning rates
- kilograms of calf weaned per 100 kg of cow mated.
- conception rates determined by pregnancy diagnosis (PD)
this can help to identify areas of loss
calculating a number of reproductive rates
bull costs per calf weaned will depend on?
1.) purchase price
2.) bull salvage value at ultimate sale
3.) number of breeding seasons that involve the bull
4.) whether bulls are checked annually for soundness and fertility.
5.) number of cows per bull
6.) weaning percentage achieved;
7.) bull mortality rates;
common conditions that interfere with fertility
- unequal size of testicles
- hardness of one or both testicles
- thickened scrotal skin.
- softness and flabbiness of testicles and tail of epididymis
often collected as part of a routine BBSE conducted by a veterinarian and examined crush-side under a
microscope to assess factors such as volume, color,
density and motility
semen and spermatozoa
sexual desire of a male to serve a receptive female
libido
it provides an indication of the bull’s ability to serve
serving-capacity test
time when a bull is capable of producing 50 million live sperm per milliliters
puberty
factors influencing when bulls reach puberty
genetic effects and nutritional influences
may be transmitted through sexual intercourse to females, affecting female
fertility, or may indirectly affect male fertility
diseases
can limit the normal testicular function of thermoregulation and result in poorer quality
semen.
nutrition
Such wastage can be due to a large number of factors, including:
- structural defects resulting in lameness and sometimes inability to serve
- degenerative conditions (such as arthritis) limiting serving ability
- age structure in the bull team, with increased proportion of physically unsound older bulls
- reproductive abnormalities, particularly in the testes, penis and prepuce
- infertility due to testicular degeneration, the incidence of which increases with age
- infertility due to disease effects
- traumatic injuries due to fighting.
True or False.
It is not therefore important to keep the age of the bull team as young as possible, not only to gain
benefits from genetically superior sires, but also to ensure the highest level of fertility in the team by
eliminating older and unsound bulls.
False.
A veterinarian should carry out a BBSE to examine bulls for soundness— prior to sale or
purchase, and annually for existing bulls. Such an examination involves:
- checking that the bull’s overall structure including legs, feet and external reproductive organs are
free from defects - assessing the sheath, scrotum and testicles
- measuring and recording scrotal circumference to ensure it is within the acceptable limits
- palpating of the testicles to check for normal tone, size and function.
- collecting a semen sample and a microscopic examination to assess the quality and percentage of
normal sperm
hormonally driven and influenced by genetics, nutrition and management factors
reproduction of female
hormonally driven and influenced by genetics, nutrition and management factors
reproduction of female
True or False.
the female is born with her lifetime quota of ‘ova’, which she sheds
during estrus cycles throughout her reproductive life
True
Reproductive events in the female are marked by:
- expression of estrus (heat) in the presence of a fertile male
- ovulation and fertilization of the ovum (egg)
- implantation, growth and survival of the embryo and fetus
- maintenance of pregnancy
- birth and survival of a viable calf
- adequate lactation for calf survival and good calf growth through to weaning
- early return to reproductive activity after calving to achieve the next pregnancy.
True or False.
Assessment prior to mating should focus on obvious structural faults that will impede the animal
and its progeny from functioning normally and effectively.
True
defined as the age (or weight) at first estrus when ovulation also occurs; onset of sexual maturity
puberty
major factor influencing puberty
nutrition
it leads to s smaller pelvic opening and increased risk of calving difficulty
conception at a younger age
it leads to s smaller pelvic opening and increased risk of calving difficulty
conception at a younger age
signs of estrus
- behavioral changes (i.e., chin resting, mounting and being mounted by other animals, congregation
into groups of estrus cows, restlessness) - swelling and reddening of the vulva
- vaginal mucus discharge adhering to tail and legs
- abrasion of skin and rub-marks on tail heads and pin bones
- ruffling of tail hair
- increased tone in the uterus and cervix on palpation.
More care in estrus detection is needed for cattle of _______ origin or content, because in these
breeds duration of estrus is usually shorter and more variable, and intensity of estrus displayed is often
lower.
Bos indicus
More care in estrus detection is needed for cattle of _______ origin or content, because in these
breeds duration of estrus is usually shorter and more variable, and intensity of estrus displayed is often
lower.
Bos indicus
average duration of estrus of cows
6-18 hours
length of estrus is affected by?
breed, nutrition, temperature stress, age, transport stress, ovarian abnormalities, uterine infections
In cattle, ovulation occurs _____ hours after the end of estrus, with heifers tending to ovulate a
little earlier than cows
10–15
Behavioral estrus (heat) may recommence from ______ days after calving
35–45
embryo leaves the fallopian tubes (oviduct) and
enters the uterus at about day six or seven, attaching to the uterine wall a few days later
pregnancy
Ultrasound examination of the reproductive tract from about ____ days after mating will detect
the presence of fluid in the uterus.
21
In ultrasound examination, in what days a fetus can be identified?
10-15 days, after 21 days of mating
From about _____ after mating, rectal palpation by experienced operators will enable an accurate diagnosis of pregnancy (or non-pregnancy) and stage of pregnancy
6 weeks
duration period in cattle?
270-295 days (average 282 days)
gestation period of Bos indicus
290 days
The options for retaining or culling will range from:
- retaining all pregnant females
- retaining only lactating pregnant females
- retaining only those pregnant or lactating females that are expected to wean a calf within a defined
period.
About ____ days after calving the reproductive tract and ovaries of a cow should return
to normal and reproductive cycles recommence
35–45
a condition when a cow do not recommence cyclic activity for up to 7 months after calving
post-partum anestrus
most important non-genetic
factor influencing conception in beef cows
nutrition
True or False.
Growth rates are not correlated with pasture quality and availability.
False.
options to achieve good body conditioning score (4)
supplementation, grazing management and adjustment of the stocking rates, paddock rotation, and weaning to reduce nutritional demand of the breeder
Bone structure of shoulder, ribs, back, hooks and pins sharp to touch and easily visible. Little
evidence of fat deposits or muscling.
emaciated
Beginning of fat cover over the
loin, back and fore ribs. Backbone
still highly visible. Processes of the
spine can be identified individually by
touch and may still be visible. Spaces
between the processes are less
pronounced.
thin
12th and 13th ribs are
not visible to the eye unless animal
has been shrunk. The transverse
spinous processes can only be felt
with firm pressure to feel rounded –
not noticeable to the eye. Spaces
between the processes not visible and
only distinguishable with firm pressure.
Areas on each side of the tailhead are
Fairly well filled but not mounded.
moderate
Cow appears fleshy and
obviously carries considerable fat. Very
spongy fat cover over ribs and round
tailhead. ‘Rounds’ or ‘pones’ becoming
obvious. Some fat around vulva and in
pelvis
good
Cow has lost definition. Contours
disappear across back and sides as
cow takes on a smooth, block-like
appearance. Tailhead and hips buried
in fatty tissue and look blocky; ‘rounds’
or ‘pones’ of fat are protruding. Bone
structure no longer visible and barely
palpable. Large fatty deposits may even
impair animal’s mobility.
fat
two practical techniques available to maintain body condition scores of breeder
- Reduce the nutritional trough by the use of supplement
- Weaning
reduce the energy requirement of the dam by almost half
weaning the calf
True or False.
In most circumstances it is cheaper to
feed the weaner than to supply supplement to the lactating cow.
True.
Controlled mating is really the ultimate goal in breeder cow management, if it can be achieved
economically. The following hints may help.
1.) Removal of bulls on a particular day is not essential IF pregnancy testing with fetal aging is performed at the appropriate time of the year.
This will provide a safety net in case of bull failure, and the producer doesn’t have the worry of bull
security for such a long period of the year.
2.) A good heifer management program to ensure heifers are aligned with the main breeder herd right
from the start will help ensure a compact calving.
3.) Implement a good bull testing (BBSE) program.
4.) Gradually change from a continuous calving pattern to a compact joining period over a number of years.
5.) Early weaning and breeder supplementation may be required in drought years.
Once the calving pattern has been set, there are techniques available to help maintain it. Some of these include the following:
(1) first-calf heifers are the most difficult breeders to get back in calf as they are still growing as well as
producing milk etc.
(2) aim to have cows calve out in Condition Score 3 or above
In some years early weaning can be used to help maintain the condition on the back of a pregnant cow. (3)
1) if the spring is dry, then a protein supplement can be fed to help improve conception rates
(2) have in place an adequate vibriosis/leptospirosis program
(3) ensure adequate ‘bull power’.
In some years early weaning can be used to help maintain the condition on the back of a pregnant cow. (3)
1) if the spring is dry, then a protein supplement can be fed to help improve conception rates
(2) have in place an adequate vibriosis/leptospirosis program
(3) ensure adequate ‘bull power’.
it involves buying a sire that will add genetic improvement and the only extra is the
marginal cost of the superior sire over the average
cheap
passed on from one generation to the next
permanent
the improvement made this year will be in addition to the improvements made last year
cumulative
genetic makeup of an animal
genotype
sum of observable, measurable traits of an animal—for example, coat color and growth rate
phenotype
comprises all the non-genetic factors that influence the animal, such as nutrition, climate and health status.
environment
comprises all the non-genetic factors that influence the animal, such as nutrition, climate and health status.
environment
occurs when one member of a gene pair masks the effect of the other member of the gene pair
dominance
In an animal breeding context, it usually refers to the difference among individuals within a population.
variation
defined as the proportion of superiority in a trait that is transmitted to the offspring. This means the difference can be attributed to gene differences, not environmental factors
heritability
Factors influencing rate of improvement in a trait are:
- heritability
- variation
- intensity of selection and/or selection differential
- generation interval
- accuracy of selection.
Factors influencing rate of improvement in a trait are:
- heritability
- variation
- intensity of selection and/or selection differential
- generation interval
- accuracy of selection.
If both of these are low, there is a little chance of genetic improvement.
heritability and variation
e difference between the mean of those selected to be parents and the mean of all potential parents.
selection differential
e difference between the mean of those selected to be parents and the mean of all potential parents.
selection differential
e difference between the mean of those selected to be parents and the mean of all potential parents.
selection differential
average age of the parents when their offspring are born or in simple terms, the time interval between the same stage in the life cycle of two successive generations
generation interval
This process has limited use in achieving improvement in most production traits and it
has minimal value in selecting for carcass traits.
visual selection
measures of genetic differences between animals,
expressed as the unit for each trait in positive or negative terms
estimated breeding values
measures of genetic differences between animals,
expressed as the unit for each trait in positive or negative terms
estimated breeding values
uses computer technology to find the best fit for all the pieces of information, for all the traits in question and all the animals in the analysis simultaneously
best linear unbiased prediction (BLUP)
program that provides a genetic description of cattle for a range of traits in the
major areas of growth, carcass performance and fertility
breddplan
allows for comparison of animals across herds
group breedplan
an amalgamation of all available EBVs using appropriate weighting calculated for individual beef producers in different environments, targeting different markets
index selection
These provide a means of assessing the true genetic merit of an animal, by ‘marking’ the
presence of an individual gene. They give the industry the potential to identify and select animals for specific traits at an early age.
gene marking
e method of mating between individuals which are more closely related, such as brothers and
sisters and of sires with daughters
inbreeding
increases the genetic purity of the stock produced, but reduces performance
inbreeding
It is a practice of breeding the farm animals which are not closely related within the same breed.
It is popular system of breeding the dairy herds with average production and small livestock owners.
outbreeding
It is the mating of the animals belonging to two different breeds. It is done to take advantage of
good qualities of two or more breeds.
cross breeding
It is mating of pure-bred males of established breed with nondescript females successively over
several generations to produce a progeny that resembles and performs similar to the pure breed.
grading up
It is mating of pure-bred males of established breed with nondescript females successively over
several generations to produce a progeny that resembles and performs similar to the pure breed.
grading up
Mating of the unrelated pure breed animals, within the same breed.
out crossing
The cross bred females obtained by crossing two breeds are mated to males from one of the two
parental breeds.
back crossing
males from one of the pure breeds are used in alternate generations to breed
the cross bred females
rotational crossing
increase in production achieved when mating one or more pure breeds
heterosis
methods provide good permanent identification for a record program (5)
ear tattoo, hot iron brand, freeze brands, chemical brands, ear notching
second in use to the ear tattoo as a permanent means of individual animal identification
number brand
probably the most widely used method of temporary identification.
soft-type plastic ear tags
probably the most widely used method of temporary identification.
soft-type plastic ear tags
preferred over bull calves in the feeder market
steer calves
most positive method of castration and is preferred by many stockmen
surgical castration
(2) bloodless method of castration
emasculating or clamping
elastration
Crossing cows with a bull that is homozygous for
the polled trait is an often-over-looked solution to
dehorning.
genetic
A caustic paste or stick can be used
on very young calves (up to two or three weeks of age) where only a button can be felt.
chemical dehorning
Creep feeding may be worthwhile in the following situations:
- periods of drought
- poor milking cows
- calves from first-calf heifers and old cows
- cows on poor pasture or toxic fescue
- just before weaning to teach calves to eat
- calves being fed for slaughter at weaning.
Situations under which creep feeding is probably not profitable are:
- cows with good milking ability
- pastures high in quality and abundant, such as clover-grasses
- calves to be grazed or backgrounded at relatively low rates of gain after weaning
- heifer calves being raised for replacements
it is not profitable when calves are receiving sufficient feed from other
sources to grow at their genetic potential, although sometimes purebred beef cattle producers find it
advantageous to creep-feed calves to be sold for breeding stock
creep feeding
distress period for both calf and cow; calves are made to break the nursing habit and rely on feedstuffs other than milk for their growth and subsistence by separation from their mothers
weaning
weaning process in which the calves are removed from their dams but are allowed to see, hear and smell their dams
fence in line
weaning process in which the calves are removed from their dams but are allowed to see, hear and smell their dams
fence in line
implanted into the ear
growth-stimulating implants
can be generally described as a component of the diet that does not fall
within the basic nutrient categories: protein, fat, carbohydrates, mineral or vitamin
feed additives
special types of medicated feed additives called ionophores
monensin and lasalocid
These products are available as a top-dress
anthelmintics
These products are available as a top-dress
anthelmintics
included as feed additives to suppress horn flies
larvacides
added to feedlot heifer rations stops the normal hormone production sequence that produces estrus
melengestrol acetate
utilized toward the final days on feed and
increase lean deposition and weight gain
beta-agonist
being studied to improve health such as sustaining a higher ruminal pH under concentrate feeding to prevent sub-acute acidosis, yeast cultures are being studied as specialized nutrients for the rumen microbes, and yeast cell wall is being studied for binding properties to toxins
direct-fed microbials
being studied to improve health such as sustaining a higher ruminal pH under concentrate feeding to prevent sub-acute acidosis, yeast cultures are being studied as specialized nutrients for the rumen microbes, and yeast cell wall is being studied for binding properties to toxins
direct-fed microbials
