MANAGEMENTAL STRATEGIES FOR REDUCING CALVING INTERVAL IN FARM ANIMALS

1. MANAGEMENTAL STRATEGIES FORMANAGEMENTAL STRATEGIES FOR
REDUCING CALVING INTERVAL INREDUCING CALVING INTERVAL IN
FARM ANIMALSFARM ANIMALS

2. CATTLE BREEDING
 Cattle’s rearing is an important subsidiary to
agriculture in India.
 It has been playing a significant role in India's rural
economy.
 Despite its vast cattle population, India's place
regarding cattle productivity is at the bottom to
other countries, especially western ones.
 One of the major reasons for this is the lack of good
breeding stock as well as technologies in our villages.

3. Reproductive Management
 Reproductive management begins well in advance of
breeding with proper selection and development of
breeding herd replacements.
 Follow development programs with good
management of mature breeding cattle and effective
culling criteria to meet reproductive goals.

4.  Establish and maintain appropriate herd health and
nutrition programs for all cattle in the herd.
 Evaluate reproduction from both the male and female
side.
 One or both may contribute to reproductive failure

5.  Reproduction is an important consideration in the
economics of cattle production.
 In the absence of regular breeding and calving at the
appropriate time cattle rearing will not be profitable.
 A healthy calf each year is the usual goal.
 This is possible only by increasing the reproductive
efficiency of the animals.

6.  Successful reproduction encompasses the ability to mate,
the capacity to conceive and to nourish the embryo and
deliver the viable young ones at the end of a normal
gestation period.
 In fact, interruption in this chain of events leads to failure
of the cow either to conceive or the embryo to die or to
have a premature delivery of the foetus.

7.  The reproductive efficiency is a complex
phenomenon controlled by both genetic and non-
genetic factors, the non- genetic factors being climate,
nutrition, and level of management.
 The reproductive efficiency varies not only between
species and breeds but also among the animals within
the Same breed.
 Even the best feeding and management can not meet
performance beyond the genetic limit of an inferior
animal.

8.  Improving the genetic merits of livestock populations is
important at all levels of management.
 A sound breeding programme is a necessary part of the
total animal production system.
 It is absolutely imperative to improve the productive
capacity and physical appearance of the animal population.

9. CALVING INTERVAL:
THE AVG TIME INTERVAL BETWEEN SUCCESSIVE
CALVINGS
DAYS OPEN:
The period between calving and conception

10.  Calving interval has been extensively analysed and
reported. It is probably the best index of a cattle herd's
reproductive effeciency
 Calving interval can be divided into three periods:
gestation, postpartum anoestrus (from calving to first
oestrus) and the service period (first postpartum oestrus
to conception)effeciciency.

11.  The "days open" period should not exceed 80-85 days if a
calving interval of 12 months is to be achieved (Peters, 1984).
 This requires re-establishment of ovarian activity soon after
calving and high conception rates.
 The duration of this period is influenced by nutrition
(Wiltbank et al, 1962), season, milk yield, parity (Buck et al,
1975), suckling and uterine involution.

12. Factors Affecting
calving interval

13. Effects of year and season
 Oliveira (1974), working with Nellore cattle, observed that animals calving
in the dry season had an average subsequent calving interval of 13.9
months, compared with 14.5 months for those that calved in the wet
season.
 Oyedipe et al (1982), working with White Fulani heifers, found calving
intervals of 15.3 and 18 months for the dry and wet seasons, respectively.
 The authors suggested that the difference was due to the fact that cows
calving in the dry season could take advantage of improved nutritional
conditions during the subsequent rainy season to meet their total
requirements for maintenance, growth and lactation.

14.  In addition, a larger proportion of dry-season calves
die due to inadequate nutrition. Both factors lead to
earlier re-establishment of oestrus in cows that calve
in the dry season

15. 2 Genetic effects
 Borsotti et al (1976) observed that genotype had a significant effect on the
calving interval of Brahman cows In Mexico,
 Valesio (1983) found calving intervals of 18.1 months for Gir and InduBrazil
cattle, 18.8 months for Brown Swiss x zebu crosses and 20.3 months for
pure Brown Swiss cattle.
 The long calving interval of the Brown Swiss probably reflects lack of
adaptation to the humid environment.
 Nodot et al (1981) reported that calving interval was affected by maternal
grand sire. However, Duarte et al (1983) found no significant effect of
genetic grouping (proportion of zebu blood) among cows.

16.  Calving interval can be influenced by the sex of the calf (Plasse
et al, 1968). In a study of zebu cows in Kenya, Reinhardt (1978)
observed that cows with male calves had a longer calving
interval than those with female calves (430 vs 383 days).

17.  Calving interval may be influenced by placenta expulsion
time (Choudhuri et al, 1984) and uterine pathology.
 They attributed the shortness of the calving interval to
the absence of brucellosis, which reduced abortion rate,
and stringent culling of infertile cows.

18. Effect of nutrition
 Underfeeding delays puberty in taurine heifers Joubert, 1954a) and stops
oestrus and ovarian activity in heifers that are already cycling (Bond et al,
1958;Terqui et al, 1982).
 Wiltbank et al (1962) demonstrated the same effect inThe cows were fed
a high- or a low-energy ration before calving; half of the animals in each
group were then fed a high- or low-energy ration after calving.The
resulting pregnancy rates were 95, 77, 95 and 20% on the high-high, high-
low, low- high and low-low ration, respectively.
 These results, indicate that level of feeding after calving has a greater effect
on subsequent pregnancy than level of feeding before calving. mature
Hereford cows.

19.  The high level of feeding after calving shortened the interval from first
breeding to conception and thus reduced calving interval.

20. Number of ova
 The first limitation on the breeding efficiency of
fertility of an animal is the number of functional ova
released during each cycle of ovulation.
 Ovulation is the process of shedding of ovum from
the Graffian follicle.
 In the case of cow, usually a single ovum is capable
of undergoing fertilization only for a period of 5-10
hours.
 Therefore, the time of mating in relation to ovulation
is important for effective fertilization.

21. Percentage of fertilization
 The second limitation is fertilization of ova.
 Failure to be fertilized may result from several
causes.
 The spermatozoa may be few or low in vitality.
 The service may be either too early or too late.
 so that the sperms and eggs do not meet at the
right moment, to result in fertilization.

22. Embryonic death
 From the time of fertilization till birth, embryonic
mortality may occur due to a variety of reasons.
 Hormone deficiency or imbalance may cause failure
of implantation of fertilized ova which die
subsequently.
 Death may occur as a result of lethal genes for which
the embryos are homozygous.
 Other causes may be accidents in development, over-
crowding in the uterus, insufficient nutrition or
infections in uterus.

23. Age of first pregnancy
 Breeding efficiency may be lowered seriously by
increasing the age of first breeding.
 Females bred at a lower age are likely to appear stunted
during the first lactation, but their mature size is affected
little by their having been bred early.

24. Frequency of pregnancy
 The breeding efficiency can be greatly enhanced by
lowering the interval between successive pregnancies.
 The wise general policy is to breed for the first time
at an early age and to rebreed at almost the earliest
opportunity after each pregnancy.
 In this way the lifetime efficiency is increased. Cows
can be rebred in 9-12 weeks after parturition.

25. Longevity
 The length of life of the parent is an important part of
breeding efficiency, because the return over feed cost
is greater in increased length of life.
 Also, it affects the possibility of improving the breed.
 The longer the life of the parents, the smaller the
percentage of cows needed for replacement every
year.

26. Management Practices to Improve
Calving interval:
 Keep accurate breeding records of dates of heat, service
and parturition.
 Use records in predicting the dates of heat and observe
the females carefully for heat.
 Breed cows near the end of heat period.
 Have females with abnormal discharges examined and
treated by veterinarian.
 Call a veterinarian to examine females not settled after
three services.

27.  Get the females checked for pregnancy at the
proper time after breeding.
 Buy replacements only from healthy herds and test
them before putting them in your herd.
 Have the females give birth in isolation, preferably
in a parturition room and clean up and sterilize the
area once parturition is over.
 Follow a programme of disease prevention, test and
vaccination for diseases affecting reproduction and
vaccinate the animals against such diseases.

28.  Practice a general sanitation programme.
 Supply adequate nutrition.
 Employ the correct technique.
 Provide suitable shelter management.
 Detect silent or mild heat, by using a teaser bull.

29. Management of reproduction for optimum
efficiency
 Genotypes, records and general management
 The genotypes of animals which are raised in
smallholdings must be compatible with the environment
and the available resources, including the knowledge and
skills of the farmers.

30.  Thus cows must be served with bulls or semen of the
appropriate genotype and replacement stock must be
selected on defined criteria.
 In-breeding should be avoided.
 It should be the responsibility of the service providers
(state extension services,AI organisations, and co-
operatives) to provide the necessary information to
smallholders.

31.  Since most reproductive traits have a low heritability, it is
generally not feasible to select for high fertility under
smallholder conditions.
 However, it is essential that selection against infertility
takes place by eliminating genetically abnormal or infertile
animals from breeding, by culling.

32.  This is not easy in situations where herd size is very
small and the farmer may have only one replacement
heifer.
 In such situations schemes such as subsidized heifer
exchange programs need to be considered.

33.  Other aspects which need addressing are:
 Appropriate feeding of calves, heifers and cows; minimizing
the negative effects of suckling and cow-calf interactions;
provision of adequate water for drinking; alleviation of
heat stress, particularly in buffalo; and control of parasites
and diseases.

34. Breeding programmes
 Breeding programmes could play a key role in helping to
reduce calving intervals within herds. But she farmers
needed to use the most appropriate protocol for their
cows.

35. Synchronise heifers
Meanwhile farmers wishing to tighten their calving interval to
calve heifers at the start of the block.
 “Synchronise heifers to calve at least two weeks early, because
they have the highest genetic potential within the herd.
 “Heifers have a lot more to deal with [compared to cows].
They need to join a different social group, grow and carry on
rearing their calf, so they need an extra two weeks to recover
and for their ovaries to start cycling again.”

36.  reduce the interval calving-conception in dairy cows by administration of
two different hormonal protocols for estrus synchronization and fixed-time
artificial insemination (FTAI). In conclusion: there was significant reduction
of the interval calving/conception in treated cows) and better pregnancy
rate regarding
 To reduce the period of postpartum anestrus, hormonal treatments may be
used, such as the administration of progesterone (P4) or gonadotropin-
releasing hormone (GnRH) combined with prostaglandin F2 alpha (PGF2
alpha), estradiol benzoate (EB) or equine chorionic gonadotropin (Bo et al.,
2008).

37.  The duration of postpartum anestrus involves several physiological
mechanisms, acting individually or together, preventing ovulation, which can
be reduced by hormone treatment (Rabassa et al., 2007). Bartolome et al.
(2004) investigated cows using the Ovsynch protocol (D0 GnRH - D7 PGF2α -
D9 GnRH) in postpartum period,
It was concluded that it is possible to reduce the interval calving-conception
in dairy cows by use of hormonal protocols with EB or GnRH and FTAI
with significant advantages, mainly in regarding to pregnancy rate.

38. Body condition scoring (BCS)
 Poor body condition is a precursor for poor fertility, she
warned.
 A good BCS beef cow will ovulate the dominant follicle
after 20-30 days, but a poor BCS beef cow may not
ovulate the dominant follicle until 70 days
 Therefore, all herds should run a separate condition can
be maintained at the correct score in the run-up to
calving. dry-cow group so body

39. Heat Detection
 The most common cause of poor heat
detection is failure to watch for heat periods
 Cows should be watched at least three times
daily.
 Before the morning milking starts.
 In early afternoon.
 After work is finished in the evening.

40. Efficiency of heat detection

41. Commonly used heat detection aids
1) Marking crayons which are used on the rump of the cow
and then smeared if the cow is ridden.
2) Pressure-sensitive pads
3) Chin-ball markers which are used on bulls with penis
amputated or deflected and cows or steers treated with
testosterone

42. Automared heat detection set up

43. New techniques in heat detection
 Electronic Heat Mount Detectors
 Vaginal Conductivity
 Pedometers and Activity Meters
 Video Cameras and Recording
 Heat Expectancy Charts
 Electronic Odour Detectors
 Temperature Measurement
 Milk Progesterone Detection
 Milk yield fluctuation

44.  In such systems cows should be checked at least three
times per day.
 Sometimes the only signs visible may be swelling of the
vulva and a discharge of clear mucus.

45.  The most important aid to heat detection is a record of
when a cow has been in heat previously.
 Once heat has been detected the next step is to ensure
that the cow is mated at the optimum time, which is
during the latter part of the heat period or around 12 to
18 hours after the start of heat.
 If hand-mating is done with a bull, two services with an
interval of six to 12 hours is recommended.

46.  When AI is used, cows detected in heat during the
morning should be served in the afternoon of the same
day and cows detected in heat during the afternoon or
evening should be served the next morning.
 Mated cows should not be subjected to undue
excitement, rough handling or heat stress for at least one
week.

47.  As it has been clearly shown that a rise in body
temperature during this period can result in death of the
embryo.
 If a cow continues to show heat signs for more than 12
to 24 hours after mating, a repeat mating should be
carried out.

48.  If blood discharge is observed in a non-pregnant heifer or
cow which had not been seen in heat over the past three
to four days (met-oestrus bleeding), it usually means that
the animal either had a silent ovulation or the farmer
missed the heat.
 Such animals should be closely observed again starting
17 days later.

49. Care of pregnant and parturient animals
 Pregnant cows should be managed so as to prevent
stress and accidents.
 They must be dried off two months before the expected
calving date (seven months after conception in cattle and
eight months after conception in buffalo) and fed well
during the dry period to allow accumulation of body
reserves.

50.  Cows due to calve should be washed and moved to a
separate clean pen if possible.
 Reproductive problems which occur during pregnancy or
around parturition can sometimes be very serious and
therefore should receive prompt veterinary assistance.

51. For a successful breeding programme
 Proper nutrition
 Minimising stress
 Efficient heat detection
 Timely inseminations

52.  In order to maintain optimum reproductive health in a
herd, veterinary assistance should be obtained if the
following conditions occur in heifers or cows:
 Abnormal discharges persisting more than 15 days after
calving
 No heat observed by 60 days after calving (90 days in
some systems)

53.  No conception after more than three repeated services
 Abnormal discharges at time of heat, for example, flaky
mucus, or at other times, for example, pus
 Difficult calving, retained placenta or other reproductive
disorders.

54.  Reproductive rates greatly influence cow-calf operation
productivity and profitability.
 In addition to the management aspects described
previously, a variety of assisted reproductive technologies
are available to improve reproductive function, decrease
the generation interval, and/or improve the availability
and influence of superior genetics.

55.  These technologies include AI, estrous synchronization,
embryo transfer, sex-sorted semen, in-vitro fertilization,
cloning, and transgenics
 Plan breeding and calving programs for reproductive
success.

56.  Constantly look for signs of potential reproductive
problems, and then investigate likely causes.
 A veterinarian can assist with managing infectious causes
of infertility.
 Proper nutrition, animal handling, and genetic
management are essential to establishing and maintaining
high reproductive rates in the herd.

57. Thumb rules to increase the reproductive
efficiency and C.I –Farm level
 Heifer - 2 yrs of age, the farmers should observe the heat
symptoms.
 Even after 30 months of age the heifers have not
exhibited heat symptom, they should get examined by a
vet to know the stage of development of genital organ.
 Female calves - fed properly - beginning of the birth -
desired body weight and maturity at an early age.

58.  Mineral mixture, concentrate and green forages.
 Livestock farmers - educated and trained in modern profitable
animal husbandry practices - feeding, management and care of
growing calves and heifers.
 They should also be trained to keep record to see that the
calving interval does not exceed 15 months.

59.  After parturition if thereis no heat up to 2 1/2 to 3 M ,
the veterinarian should be called.
 History of the previous calving - retained placenta,
dystocia, metritis etc.
 No heat should be missed and insemination should be
done by trained person and timely to achieve optimum
pregnancy result.
 Post insemination confirmation of pregnancy at 60 days.