Behavior of Domestic Animals Quiz 4

Sexual receptivity in females is ______ in nature

• Cyclic

Polyestrous

• Continuously repeated cycles; cycle until conception​

  • Examples: Cows & Sows​

Seasonally Polyestrous

• Continuously repeated cycles, but only during certain seasons of the year​

  • Examples: Ewes (sheep), Does, Mares, Queens​

Monoestrous

• Only having one estrous cycle during a given season or year​

  • Example: Female dog

Polyestrus

• The period of time in which females begin to show signs of sexual interest &

produce olfactory cues.​

Estrus (aka “True Estrus”)

• The period of time in which a female will allow copulation/mating.​

Metestrus

• The period of time immediately following estrus, when sexual interest is waning; will NOT allow copulation/mating.​

Diestrus

• Period of time between metestrus & beginning of next proestrus.​

Anestrus

• Period of time (seasonally) when females are not cycling at all.​

Sexual behavior is ____________ with physiological changes to the reproductive system!​

• Synchronized

Successful mating in the female also depends on

• Attractiveness

• Proceptivity

• Receptivity

Attractiveness

• The extent to which a female evokes sexual responses from males; includes odor and visual cues​

Proceptivity

• The extent of the female’s invitation/soliciting behavior​

Receptivity

• The willingness of the female to accept courtship and copulatory/mating attempts​

Individual qualities can vary, and are___________ during estrus!​

• Maximized/most evident

The introduction of males or male pheromones can _______ ___ _____of

estrus in many domestic species. ​

• facilitate the onset

  • Helps to synchronize a group of females

The “Ram Effect”

• 50% of ewes will ovulate by the 3rd day after ram introduction into the flock!​

• Can advance the onset of seasonal estrous cyclicity by 2 weeks – 2 months!​

The “Whitten Effect”

• Mice

• Improved return cyclicity in post-partum/nursing BEEF cattle​

  • Helps maintain 12-month reproductive cycle for ideal 1 calf/year goal​

  • NOT effective in diary cattle  - WHY?​

Overt Estrus

• Obvious disturbances in the usual routines of behavior​

  • Reduction of feed intake​

  • Decreased resting periods​

  • More locomotive, investigative activity​

  • Increased vocalizations

Silent Estrus

• Changes in behavior (as a result of cyclicity) are virtually undetectable​

• Sows, Cows and Mares most often affected​

• Most common just after puberty, post-partum & beginning of the season​

• Repeated rectal palpation of the ovaries in cows and mares by a veterinarian helps detect cycle stage! ​

Sub Estrus

• Very subtle, low intensity behavioral changes occur as a result of cyclicity​

• Repeated rectal palpation of the ovaries in cows and mares by a veterinarian helps detect cycle stage! ​

Willingness to stand immobile = MOST IMPORTANT! When does it occur?

• Occurs just before and/or during ovulation

Seeking (soliciting behaviors)

• Visual displays, auditory cues & olfactory cues.

• aka proceptive behavior

Female-female mounting

• Cattle, goats, swine

• May try to mount males too

Female sexual visual cues

• Periodic tail wagging (Sheep & Goats)​

• Raised tail + Clitoral “wink” + Urination Stance (Mare)​

• Lordosis + ground treading (Cat)​

• Crouching (Poultry)​

Female control of mate choice

• Tend to avoid young, inexperienced males​

• May reject overly vigorous courting behavior​

• Other reasons for being “picky” are largely unknown​

  • Dogs & Cats​

• Lack of social experience (proper socialization) can inhibit sexual behavior​

• Social facilitation plays a role in ewe sexual behavior​

3 Stages of Parturition

• Pre-partum behavior

• Birthing

• Post-partum behavior

• “Parturition” = the act of giving birth

Female behavior is highly influenced by ________ _________ changes!

• Internal physiological

Pre-partum behavior: Ruminants

• Separation from the herd/group

  • 1-2 hours prior

• Failure to keep up with grazing drift

• Seek out long vegetation or shelter

• Exception: Merino Ewes

  • Like to stay with the group, strong flock cohesion.

Pre-partum behavior: Nest Building

• Sows

  • Depends on availability of materials

  • May change locations more than once

  • Lots of pawing

• Poultry

  • 1-2 hours prior to oviposition​

  • Triggered by estrogen & progesterone release at ovulation​

  • Prefer dark, secluded areas​

  • Experience effects preference ​

  • May nest gregariously​

2 Biological Advantages of isolation Birthing

• Risk of interference by herd mates is reduced

• Promotes bonding of newborn with it’s mother

Sows in farrowing crates

• Increased restlessness!​

• Frequent altering of position:​

• Right → Left​

• Standing → Lying Down​

• Intermittent grunting​

• Champing of the jaws​

• Increased respiratory rate​

• Phantom nest-building

Pre-partum behavior: Other behaviors

• Tail swishing​

• Looking at sides​

• Pawing at the ground​

• Less ___________behavior​

• Interest in other’s young (________________)​

• More common in high stocking densities!​

• Mares may look “colicky”

Timing of Parturition (Birthing)

• Higher incidence @ night!​

  • Horses (80%)​

    • Stabled: Just before midnight​

    • Free-Range: Early morning hours​

• Pigs​

  • Overnight – commercial setting especially but overall at night​

• Cattle​

  • Mostly birth at night, feeding times change this​

• Sheep​

  • Same as cattle​

Distension of the uterus, cervix, and vagina → ?

• Oxytocin release!

  • Systemic vs centrally

  • Oxytocin initiates maternal behavior

Birthing general info

• Dog, cat, pig (litters), Horse and cow (singles)

• Rupture of chorio-alatosis (outer fetal membrane) → bulging of amniotic sac into vaginal canal

• Uterine contractions + abdominal contractions

  • Rest periods (~2 mins)

  • Progress quickly after passage of head and shoulders

• Position of the female varies

  • Lateral recumbency vs standing vs crouching

Complications

• Cows without complications will remain recumbent throughout the birthing process

• Cows with complications/difficulty will be more likely to stand up!​

• Retained fetus may dangle from vulva, then drop to ground​

• Dystocia = Difficult birth; labor obstruction​

Post-partum behavior: Expulsion of the placenta (1)

• Usually within 1-2 hours after birth​

• Cows and Sows are plactentophagic (mother consumes placenta)! ​

• Mares are NOT!​

Post-partum behavior: Grooming (2)

• Grooming starts at the head dorsally → ventrally​

  • Removes amniotic fluid​

  • Reduces heat loss​

  • Imparts pheromone identification via saliva​

  • Draws neonate’s attention to it’s mother​

• Increased vocalizations occur between mother and neonate while grooming:​

  • Enhances the bond b/w the two​

    • Mares: Low nicker​

    • Cows: Bellow + low grunts​

    • Ewes: Low-pitched gurgling​

    • Does: Low-pitched bleats​

    • Sows: Rhythmic grunts​

• PROLACTIN INFLUENCED!

• EARLY SENSITIZATION OF THE MOTHER TO HER NEWBORN IS VERY IMPORTANT

• Exception: Pigs

  • Rarely groom their young!​

  • Will use fore limbs to “scoop”piglets toward udder​

  • Nervous sows can become cannibalistic!​

Post-partum behavior: Decision to stay or go from birthing site?

• Hiders (cow/deer, hide babies in high vegetation) vs. Followers (mares/ewes, baby stays with mom at all times)​

• Some precocial young are hiders! ​

• Goal is to protect from predators

Grooming time and experience

• Decline in licking is due to decreased maternal response/attraction to amniotic fluid on calf​​

• Inexperienced mothers of twins may be more likely to ignore the 2nd born​

A good mother should assist in the ___-______ of the newborn!

• Teat-seaking

  • She should positively orient her body to accommodate the exploratory efforts of the newborn​

  • She should stand still!​

• Inexperienced or poorly socialized heifers may kick, butt or turn towards the newborn​

  • Overcorrection can also be an issue, too!​

• Once the bond is established, the mother will care for and defend her young intensely!​

Separation of mom and child

• Separation of the newborn from the mother should be strictly avoided within the first 1 hour of life!​

  • Initial 20-30 minutes is crucial small ruminants!​

  • Removal of a newborn from it’s mother will lead to rejection!​

  • Handling of the newborn by a human will not necessarily affect maternal acceptance​

• Development of the maternal bond is crucial early on for maintenance of maternal motivations long-term. ​

• Maternal motivations in cows are very strong, as long has the cow has exposure to the newborn for the initial 24 hours.​

  • If the newborn calf dies, strong maternal motivations remain for up to 5 days thus making fostering/acceptance of an orphan calf possible.​

Ewe fostering

• Ewes can be convinced to take a foster lamb.

• Masking of the orphan lambs own odor​

  • Application of amniotic fluids​

  • Fresh or frozen/thawed​

  • Fleece of ewe’s dead lamb​

• Stretching of the ewe’s cervix prior to introduction​

• Restraint of ewe during nursing attempts​

Post-partum maternal behavior toward handlers

• Aggressive behavior toward humans could lead toward aggressive behavior toward young!​

  • Example: Aggressive → Cannibalistic Sows​

  • Sedation may correct​

• Some mothers will conceal the newborn, only returning for feedings, during the first few days. ​

  • Allows further necessary development of the newborn​

  • Example: Cows hiding calves in tall grass​

• Social hierarchy may affect lactation quantity and quality!

Colostrum

• The first lacteal secretion produced by mothers (female mammals) directly after birth. It is a nutrient-dense fluid that serves as a “starter kit” for newborns with high concentrations of antibodies. ​

• Vital Timing​

  • It is crucial for a newborn to receive colostrum within the first 4 to 12 hours​

• Functions and Benefits of colostrum include gut health, immune protection, nutritional support and laxative​

  • Contains growth factors to stimulate maturation of the gastrointestinal tract​

  • High in proteins, vitamins, and minerals​

  • Lower in fat and sugar than mature milk, making it easier to digest​

  • Helps clear meconium which can reduce the risk of jaundice​

How is libido measured?

• First, remove performance (ie copulatory behavior) as a confounding variable!​

1. Measure time spent near females (ie motivation to seek out potential mates)​

2. Measure time engaged in pre-mating behavior + mounting​

Evolutionary considerations of male sexual behavior

• How has intensive artificial selection in controlled breeding programs affected the sexualperformance of male domestic (and/or captive bred) animals?​

  • Not all males exhibit adequate sexual performance when exposed to a female.​

  • Males may be selected without concern for sexual performance. ​

    • Natural selection for libido is decreased​

      • 8/27 (17%) of stallions (McDonnell, 1986)​

      • 20% of U.S. boars​

  • Increased focus on other phenotypic characteristics in meat animals ​

    • Increased body size​

      • Example: Turkeys & AI​

Male mating: Advantages of social dominance

• Dominant males can inhibit the sexual activities of subordinates merely by their presence!​

• Blockey’s 1979 Study: Comparison of reproductive success of mixed-age and same-age bull groups:​

  • Mixed Age = 1 Five-year-old, 2 Two-year-olds​

  • Same Age = 3 Two-year-olds​

    • Subordinate males interrupted 87% of the time by the older bull in the mixed group​

    • Subordinate males interrupted 20% of the time in the same age group​

    • Increased age was not necessarily a reproductive advantage, though. ​

      • Conception and pregnancy rates higher for same-age (younger) group! – WHY???​

Libido and successful breeding programs

• Maintenance of individual animal libido is essential to an efficient breeding program!​

• It is normal for breeding males to exhibit a temporary increase  in libido after each ejaculation.​

  • = The Recovery Period​

  • Increases after each successive breeding of an individual female​

  • Introduction of a new, receptive female???​

    • Polygamous Mating Systems​

Male mating: Hand-mating

• when males and females are brought together solely for the purpose of mating. ​

  • Used in Equine, Swine, Dairy Goats and Companion Animals​

  • Very time consuming if libido is low​

• Consider Mader & Price’s 1984 study:​

  • Sexually experienced, 22-month-old bulls tested​

  • 4 treatment groups​

    • Spectator​

    • Watched​

    • Restrained​

    • Control​

  • 87% more completed copulations in spectators​

  • Mild improvement in performance for watched and restrained groups​

Male mating: “Spectator effect”

• Repeated/observed in Dairy Goats​

• NOT Repeated/Observed in Sheep – WHY?​

• Cows & Does participate in female-female mounting behavior when in heat, and Ewes DON’T​

• Bulls & Billies are attracted to females engaged in mounting behavior (bulling)​

• Cows & Does are sexually receptive for a much shorter period of time compared to Ewes​

  • 2-3 services vs. many​

Male mating: Sperm count

• Males with high sperm production have an increased selective advantage​

• Multiple services with high concentration of sperm (sperm count) increases the likelihood of pregnancy​

• Semen collection easily reveals individual sexual fatigue​

  • Decreased “reaction time”​

  • Decreased # of ejaculations per collecting session​

  • Varying recovery times​

Sensory influences on male sexual behavior

• Female Pheromones are very important!​

  • Vaginal flora (microbiome) changes during estrus ​

  • Flehmen Response​

    • All domestic farm species (including boars!)​

    • Not seen in dogs or rodents​

• Visual cues important at close range.​

  • Immobility of female when approached by male​

  • Mares are very animated​

What happens when a male is castrated?

• Effects vary by species​

• Effects vary by age at the time of castration​

  • Reduced libido​

  • Decrease or loss of ejaculatory reflex​

  • Male dogs unable to form copulatory lock​

  • Adults (castrated later in life) may still be attracted to females in estrus and attempt to mount​

  • Male cats lose all interest in females​

Physiological influences on male sexual behavior

• Young males will express some sexual activity/behaviors prior to the onset of puberty​

  • Mounting causes tactile and thermal stimulation to the penis inside of the prepuce​

  • Low levels of testicular testosterone production → Sexual differentiation of the brain!​

• Adult males produce way more testosterone than actually necessary​

  • Levels DO NOT correlate with libido or performance!​

• Sensory stimulation from the genitalia is important in maintenance of libido​

  • Katz & Price’s 1986 Study: Neurectomized vs. Deviated Bulls​

  • Metzler’s 1988 Study: Neurectomized Billies ​

Do male animals show preference?

• Yes! Most males do show preference for certain females.​

  • In multi-female groups, some will receive many more inseminations than others. ​

  • Rams actually prefer older ewes!​

  • Stallions may prefer certain colors and odors in mares. ​

Male-male mounting

• DEBATE: Sign of dominance or sexual libido and/or just general stimulation?​

  • Simply moving bulls to a new location may trigger male-male mounting​

• ~ 2.5% of steers in a feedlot will stand to be mounted by other males​

  • “Buller” steers: those being mounted  attempt avoidance behavior; often injured by persistent riders​

  • “Rider” steers: those doing the mounting → will stop when buller is removed​

  • Estrogen-based growth implants may play a role​

  • Watching of riders may stimulate other steers to follow suite ​

Male Sexual Vices

• Masturbation is common among domestic species.​

  • No correlation with sperm count or quality​

  • All male bulls do this – especially during periods of inactivity ​

  • Bulls: Arched back w/ pelvic thrusts, causing penis to move in and out of the prepuce, ejaculation occurs​

  • Stallions: Flip/Thump penis against ventral abdomen, ejaculation does not typically occur​

  • Puppies: Use inanimate objects, decrease with proper socialization, eliminated by castration​

  • Often a sign of dominance in canines ​