Module 4 Flashcards
The single most economically viable traits of livestock in a sustainable system, can be positively influenced by proper management likewise hindered by poor practice.
Ability to reproduce
Of all the major livestock species they have the greatest potential for advancement in reproductive efficiency.
Goat and sheeps
Is defined as being low input and often utilizing larger tracts of land
Extensive production
Is one of the primary differences in intensive versus extensive production
Reproductive management
Will generate larger lamb and kid crops but an added production cost.
Lambing and kidding generally occurs in a facility or small paddock under daily management.
Intensive operation
Is typically more precise in intensive management and often include PEDIGREE, HEALTH, PERFORMANCE INFORMATION AND DATES FOR BREEDING, LAMBING)KIDDING AND WEANING OF individual animals.
Record keeping
Are typically more higher in intensive management but the adoption of technology to improve efficiency is also more prevalent in this system
Labor output
Usually focuses on group of animals as opposed to the individual.
Ewes and nannies often give birth outside and under limited supervision.
Extensive production
Have both approximately 39 million sheep
Tropical Sudan and temperate New Zealand
Australia primarily arid and semi-arid have how many million of sheep?
95 million
Throughout the world sheep production can vary from what?
from strictly pastoral systems ( to)
Nomadic production (to)
Total confinement
in some extensive production systems, a female sheep or goat is manage to produce how many offspring?
3-5 offspring in their lifetime
Some intensive production systems may produce how many offspring?
3-5 offspring per breeding female annually
Differentiate extensive and intensive production system
Intensive operation will generate larger lamb and kid crops, but an added production cost.
Extensive usually focuses on group of animals as opposed to the individual.
Extensive production systems -3-5 offspring lifetime
Intensive production systems -3-5 offspring per breeding female annually
Four main breeding system commonly employed in the goat and sheep industry
Hand mating
Pen breeding
Artificial insemination
Out-of-season breeding
This method involves selecting the buck/ram for the doe/ewe and mating them. This method has the advantage of allowing the exact breeding recorded. However quite labor intensive, requiring the manager to accurately identify the doe/ewe in heat and facilitate in mating.
Hand mating
In pen breeding the buck/ram is put in a pen of does/ewe in heat to facilitate their mating this method relies on the male to detect females in heat. It is significantly less labor intensive when compare to hand breeding
Pen breeding
A yearling male should be placed with how many females?
10-25 females
A mature male can be placed with how many females?
15-40
Offers the advantage of introducing superior genetics cost effective
Artificial insemination
Currently the most reliable results of artificial insemination in goats and sheeps are obtained by what?
Inseminating trans-cervically with fresh semen
The most reliable though costly method involves using artificial lighting
Out of season breeding
During winter months male and female does and ewes exposed to how many hours of light?
20 hours of light for 60 days
To ensure prevention of production losses due to infertility, a breeding soundness examination should be performed in the what day?
30-60 days prior to the breeding season
Various factor that can determine when and how often operations choose to lamb or kid.
Available labor
Breed
Seasonality
Available forage
Targeted market
Once a year mating is referred to as what?
Annual production
Alternate forms of production
Opportunistic and accelerated schemes
Is the most common practice in sheep and goat production.
Once a year mating or annual
Typically offers conditions that are most conductive to lamb/kid survival
Springtime
Can be described as bucks or billies being with females year-round. This scheme, usually more extensive in production style, is a reduce labor alternative for some producers and survival of offspring can often be dictated by climatic events.
Opportunistic production
In this system of production it becomes more challenging for the producer’s to determine variation in ewe or doe fertility, and this the practice of culling is typically not regimented.
Opportunistic production
The 2 most common accelerated programs.
8 months and STAR
Is the simpler among two methods of accelerated programs. Typically there is a predetermined schedule of joining males with females twice during a more natural breeding season and once during the aseasonal period
8 months accelerated cycle
Allow approximately 90 days for lactation and rebreeding to occur.
Short one-cycle window
Is slightly more demanding on the ewes with a maximum number of births per ewe per year of 1.67 versus 1.5 in an 8-months
STAR method
Three groups of star that are manage simultaneously
Breeding and gestation period
Lambing and lactation group
Weaned lamb group
In the star system breeding of GROUP 1 occurs simultaneously with lambing in Group 2, which happens five times per year at how many days intervals?
73 days intervals
Breeding occurs how many times during the natural breeding season of sheep?
Three times
Breeding occurs how many times during aseasonal period?
Twice
Tropically developed hair sheep breeds, which originated closer to the equator and thus experience minimal day length changes and well-suited in what kind of production systems?
Accelerated cycles
Numerous factors influence reproduction in sheep and goats
Nutritional status
Genetic potential
Age
Season
Are examples of programs that analyze data and generate estimated breeding values for various economically relevant traits, including production
Sheep genetics (AUSTRALIA)
SHEEP IMPROVEment LIMITED (new Zealand)
Signet ( united Kingdom)
Is the percentage of lambs produced compared to the number of ewes or does exposed to males.
Lamb crop
Is often the measuring stick for the annual success of an operation, but may be impacted by many other factors than simply reproduction.
Lamb crop
Are generated within contemporary groups as a way of eliminating environment factors.
EBVs
Can allow for quicker genetic progress than simply selecting replacement form large litters
Selecting rams with improved lamb crop
It is critical to track this to accurately predict genetic potential
Multigenerational pedigrees
Difference between fertility and fecundity
Fertility is the ability of animals to reproduce whole an fecundity is the number of offspring an animal produces as a result of mating.
Is often correlated to the timing of puberty in sheep and goats, as those that reach puberty quicker tend to remain more fertile throughout their lifetime.
Fertility
Found in the Booroola Merino sheep was the first gene identified that is related to fecundity in sheep. It is a single gene trait that greatly increases the prolificacy of sheep.
FecB mutation to the BMPR-1B gene
Increases lambing rate by 100% and two copies increase lambing rate by 200% or more.
A single copy of the FecB allele
Are prominently found in Belclare, Romney, and Lacaune breeds
BMP15 gene
Is imperative for a female to become pregnant and raise her offspring.
Proper body condition
Will be disadvantage for maintaining her own condition and should be culled
Ewe with broken mouth
Residual knots and abscesses exist indicates what? present in a prior lactation the female should be considered for culling.
Mastitis
Is particularly important to both meat and diary production
Udder quality
For various abortion-causing diseases may also be a beneficial practice, particularly in more intensive production where there will be considerable contact among animals during the birthing season.
Vaccination
During gestation may be needed to control aborting agents when a vaccine is not available or is not fully effective.
Oral or injectable antibiotics
Is a general term for increasing plane of nutrition to females for 2-6 weeks prior to breeding.
This strategy can increase ovulation and subsequently embryonic survival
Flushing
Are seasonally anestrous
Rams or bucks
BSE should be be recommended to conduct in what day? to allow enough time for a follow up BSE in 30 days
60 days before breeding season
Enlargement of the epididymis is a sign of what?
Ovine Epididymis from a Brucella Ovis infection.
Testicular minimum threshold recommendation cm circumference measurements of young and mature rams and bucks
Young rams -30 cm circumference
Mature bucks- 33 cm circumference
Is highly correlated with semen production and fertility.
Testicular size
Should be collected and evaluated for sperm motility and morphology
Semen sample
Equipment used to collect semen sample
Artificial vagina and electro-ejaculator
Percent of semen being motile to be considered as satisfactory
30%
Percent of sperm morphology and shape to be considered as satisfactory
50%
The breeding window should set approximately at how many months?
5 months
Gestation ranges of sheep and goats
145-155 days
Difference of single sire and multi sire mating
Single sire mating is one male per breeding group of females, ensures that a mating results in offspring with a desired pedigree.
While multi sire mating generally results in a greater pregnancy rate.
The estrous cycle of ewe last for how many days
17 days
The estrous cycle of doe last for how many days?
21 days
It is common to leave the males in a minimum of how many days to ensure that each female has had two periods of estrus.
34-42 days
Generally are seasonally polyestrous, a short-day breeder
Sheep and goats
It is secreted by pineal gland
Melatonin
Is one of strategy to capture a higher value for offspring.
Aseasonality or out of breeding season
Hair breeds that tends to be more reproductively aseasonal
Ancestry form Merino and Dorsets
Are goats breeds noted for their ability to experience estrous cycle year-round or have an extended breeding season.
Boer, Pygmy, and Creole
Of the diary breeds is the least seasonal however have been shown to experience an anestrous period when exposed to a temperate photoperiod.
Nubian
Tend to experience a transitionary period
tend to experience a transitionary period between anestrous/anovulatory periods and seasonal estrous where spontaneous estrus can occur, especially when exposed to a male (Buck Effect).
Goat
In less seasonal breeds, this can stimulate estrous cycles during the entire anestrous period
Buck Effect
can often lead to higher valued offspring as lamb and kids are being produced and sold when supply is low.
Aseasonal reproduction
Several management tools that can be utilized to induce aseasonal reproduction in sheep and goats
.
• Light exposure protocols and/or melatonin treatment
• Exogenous progesterone via oral or intravaginal devices for a period of 11-14 days (sheep) or 18- 21 days (goats)
• Reintroduction of males to females
• Female nutritional status
• Genetic selection for out of season reproductive capability
have been effective at inducing estrus in females as well as increasing testicular size and sexual activity in males.
Light exposure protocols and/or melatonin treatment
are common methods to supply progesterone to sheep and goats. It is common to provide prostaglandin F2-alpha (PGF2-α) or
gonadotropins immediately following exogenous progesterone supplementation to induce the onset of estrus.
Progesterone impregnated sponges or Controlled Intravaginal Drug Releasing (CIDR) devices
is important for out of season pregnancy rates.
Reintroduction of males to females
is pheromone-induced estrus in anestrous females.
Ram effect
is a vasectomized male, prior to breeding as females tend to be more fertile the second cycle after introduction to males and thus a tighter breeding window can be achieved for the group.
Teaser
Undernourished ewes are at risk for several issues including?
pregnancy toxemia,
small and/or weak lambs
decreased milk production
a compromised immune system
are a major issue for most sheep and goat producers in the world.
Internal parasites
occurs when the parasite cannot complete its lifecycle outside of the animals.
periparturient rise in parasites
reproductive traits are lowly heritable ranging from what and thus breeding for aseasonality can
take several generations of selection.
0.05 to 0.15
Parturition signals round worms
Haemonchus contortus
The ideal time period to ultrasound ewes/does for pregnancy and litter size
between 50- and 90-days gestation
allows farmers to better supply the appropriate nutritional support to pregnant versus open females.
Pregnancy determination
are often culled or allowed to lamb out of season and managed in a separate flock or herd.
Open ewe
This provides a much more sanitary environment for lambing as fluid and feces caught in the wool may lead to fly strike.
Shearing and crutching
allows for a cleaner lambing environment while still offering protection to the ewe from harsh weather until later in the spring when cold temperatures are not as frequent.
Crutching
will result in a cleaner wool clip and will also stimulate the appetite of the ewe, which is beneficial during late gestation and lactation.
Shearing
are most susceptible to death loss.
Neonates
the practice of having ewes or does give birth outside of a confined facility or paddock without continual human supervision. This can be in a pasture of any size or on the open range, such as flocks grazing communal land.
Range lambing/kidding
usually leaves the female under limited to no supervision during birth, so females must be selected for natural maternal instinct.
Range lambing/kidding
allows for protection from the elements and predators. Feed, labor, and facilities are all required for shed lambing, assisting with difficult births and helping lambs and kids nurse if required.
Shed lambing/kidding
allows for better record keeping and productivity of dams and offspring can be easily quantified.
Shed lambing/kidding
Once females have given birth, they are moved to a “jug”, what is the measurement of a jug?
1.5 x 1.5 m pen
Is use to aide in the bonding and nursing process.
Jug
Dams and offspring will remain in the jug for how many hours to allow
offspring to nurse and gain strength.
24-48 hours
have been developed that are very effective at rearing large numbers of lambs or kids with limited labor resources.
Automated milking machines
allows the dam to recover her body condition in time to breed the following season.
Weaning
when can a lamb/kid be wean?
Early as 5 weeks to greater than 6 months.
Factors that can influences weaning time
.
marketing goals of the offspring, size, condition of the dam, risk of predation, and facilities available.
Most producer target when weaning
60-90 days of age 20 kg
peak lactation of the commercial ewe (non-dairy)
between 21 and 30 days
The practice of offering grain to lambs/kids that have not yet been weaned, can help the eventual transition off of milk to a post-weaning diet and can reduce stress at weaning time.
Creep feeing
