Keeping in view the projected demand for the milk in future and the existing productivity of our animals, we need to define clear strategies to substantially improve the productivity of individual animals. While India produces about 16 per cent of the world’s total milk production from 17 per cent of the world’s bovine population, USA is producing 12.5 per cent from merely 6 per cent of the world cattle population. The livestock population is increasing and the land for feed and fodder cultivation is shrinking. There is need to reduce the population of low yielding cows and buffaloes.

The promising technologies should be propagated among the stakeholders for their wide spread use to achieve desirable improvement in milk production. Since our country is the best example for “production by masses” and not “mass production”, a single strategy may not be suitable for different production systems. The technologies have to be fine tuned to match with the production system since almost 70 per cent of the total milk comes from “smallholder dairying” system. This paper presents the advances in the areas of dairy animal breeding, feeding and management through technologies developed at the National Dairy Research Institute (NDRI) through its mandate oriented and well structured research programmes.

 

ADVANCES IN DAIRY ANIMAL MANAGEMENT

Although smallholder continues to be the backbone of Indian dairy industry, with the growth of organised milk processing sector, dairy farms with more than 1000 animals have been established. Traditionally, livestock management decisions have been based almost entirely on the observation, judgment and experience of the farmer. However, increasing scale of operations and enhanced productivity of animals require the monitoring of individual animal through decision support systems. Success stories from a number of countries prove that for productivity enhancement programmes to be implemented in a scientific way, it is necessary to know more about individual animal’s performance.

 

Management information systems

Management Information Systems (MIS) in the livestock system can be applied in areas like animal production and management, nutrition, animal herd health, breeding and genetics, animal products processing and marketing. The term MIS is often used as synonym for DSS (Decision Support System) which is an interactive computer based system that support decision makers, compile useful information from a combination of raw data, documents and knowledge. These systems provide real time access to the farm database and enhance economic and managerial decision making. For example, the production profile of the herd, such as quantity of milk produced per animal, the shape of the lactation curve, etc. can be analysed using various DSS software. Most of the available DSS are developed in the foreign countries based on their farm conditions and management practices, which may not be suitable in Indian conditions. Therefore, it is necessary either to make suitable changes in the existing DSS or develop new software according to our management practices.

 

Precision management tools

In precision dairy farming, the use of information technologies for managing individual animals rather than group management shifts from human observation to automation that increase efficiency, reduce costs, improve product quality, minimize adverse environmental impacts, and improve animal health and well-being. The main objectives of precision dairy farming are maximising individual animal potential, early detection of disease, minimising the use of medication and apply preventive health measures. Some of the precision management tools in use are: daily milk yield recording, milk component monitoring (example fat, protein, and SCC), pedometers, automatic temperature recording devices, milk conductivity indicators, automatic estrus detection monitors, daily body weight measurements, etc. Specific technologies that can be included in the broad category of precision livestock management include:

  • Electronic identification systems and associated management software.
  • Automatic sorting systems.
  • Robotic milking systems.
  • Robotic calf-feeding systems.
  • Pedometers/activity monitors for heat detection, lameness detection and health monitoring.
  • Rumination monitors.
  • Step/gait analyzers to detect lameness.
  • Electronic scales to assess body weight changes.
  • Temperature sensors.
  • Automated feed delivery systems.
  • In-line sensors to assess milk quality and composition, and animal health and reproductive status.

 

Recombinant bovine somatotropin

Recombinant bovine somatotropin (rBST) is a recombinant protein produced through recombinant DNA technology. Somatotropin is naturally produced by the pituitary gland and it is a major galactopoietic hormone in ruminants. It regulates milk production through coordination of the metabolism in body tissues and diversion of more nutrients towards milk synthesis. rBST was approved by U.S. Food and Drug Administration during 1993 and its commercial use began in 1994. It is recommended for lactating cows after 60 days of lactation. Supplementation of rBST to cows causes increase of milk production. It has been approved for commercial use by more than 20 countries. It is, however, prohibited in the European Union, New Zealand, Japan, Canada and Australia. The reasons for not having approval of rBST are mostly due to animal welfare, safety and differential production systems in those countries. The efficacy of rBST has been well proved in lactating cows across the globe. Administration of rBST to lactating dairy animals increases the yield (8.5 to 17.6 per cent). Report of an earlier study conducted at NDRI, Karnal indicated that buffaloes receiving 25 and 50 mg rBST showed net increase in milk yield of 16.8 and 29.5 per cent over control. Other studies conducted in India also found that weekly average milk yield increased from 25 to 33 per cent in rBST treated group over the control group.

It is believed that rBST-mediated higher milk production is due to higher (2.7 to 11.2 per cent) feed efficiency (kg milk produced per kg feed consumed) of the animal and/or decreased proportion of energy usage for body maintenance. However, the actual amount of feed consumed by rBST-treated cow increases (10 to 20 per cent more grain and forage) to meet the increased nutrient demands. Further, the effect of rBST on milk production depends upon biological variation, stage of lactation and management practices. Unlike in USA where high input-high output system is prevalent, India is following medium input-medium output or no input-low output system in dairy animals. On the other hand, it is well known that rBST is more profitable on a nutritionally well-run farm than farm with poor feed basis or unsatisfactory conditions. Therefore, rBST technology needs to be evaluated thoroughly, across different production systems, before large scale application in India.

 

Advancing age at puberty and sexual maturity in indigenous cattle & buffaloes

The average age at puberty in exotic cattle is around 18 months and in the indigenous breeds it is around 25-30 months. Similarly the Italian buffaloes attain puberty at 18 months while Indian Murrah buffaloes attain sexual maturity at around 30 months. Delayed age at sexual maturity is the biggest problem in buffaloes and indigenous cattle especially under field conditions. On an average a farmer lose around 10-12 months of productive life of a buffalo or cattle and thus reduced overall production and reproduction.

Targeted body weight gain and hormonal manipulation protocols can be used to reduce the age at sexual maturity in indigenous cows and buffaloes. A study conducted at NDRI, wherein one group of the animals was fed extra concentrate to attain a targeted growth rate of 400-500 g/day, the second group was administered gonadotropio-releasing hormone (GnRH) (at low dose – 4 µg/month single injection) and the third group was given both targeted growth (TG) rate and GnRH. The results were compared with routine feeding and management practices (Control group). Promising results were obtained in both GnRH administration and targeted growth + GnRH group. In Sahiwal heifers, GnRH supplementation could bring down the age at puberty from 25.5 months to 22 months and age at first conception from 29 months to 23.4 months. The developed protocol is significant in view of its effectiveness and an advantage of 5-6 months reduction in age at first conception in Sahiwal and 4-5 months reduction in age at first conception in Murrah buffaloes. This can readily be applied at field and organised farm conditions.

 

Synchronisation of estrus for controlled breeding

Through estrus synchronisation, a group of females in the herd can be brought into heat at a time and inseminated at fixed time to improve the fertility. Estrus synchronisation allows breeding the females at a fixed time so that errors in estrus detection and subsequent improperly timed AI can be avoided. The basic principle underlying estrus synchronisation is to artificially reduce or extend the luteal phase of the estrous cycle so that all the animals in the treatment group enters the follicular phase of the cycle at the same time.

(A) Estrus synchronisation by reducing the luteal phase

Prostaglandin F2α (PGF2α) is used for this purpose. Regularly cycling animals have a functional corpus luteum during the luteal phase of the estrus cycle. Administration of PGF2α from 5-17 days of estrous cycle regress the active corpus luteum and the animal enters into the follicular phase. Generally, the treated animals exhibit estrus within 2-5 days of treatment.

 

Table: Estrus synchronisation using prostaglandin F2α.

Day of treatment Two injection method One injection method without palpation One injection method with palpation
Day 0 PGF2α injection PGF2α injection Rectal examination for presence of corpus luteum (CL)
CL present – PGF2α injection CL absent – No treatment
Day 3 & 4 – Breed the animals in heat Breed the animals in heat –
Day 11 PGF2α injection PGF2α injection in animals that were not inseminated – PGF2α injection
Day 14 & 15 Insemination at 72 and 96 hours after PGF2α injection.

 

(B) Estrus synchronisation by extending the luteal phase

The principle behind this method is to maintain the cow under the influence of progesterone beyond the normal period of CL regression by administering exogenous progestins. As the progesterone is withdrawn, the animal enters into follicular phase and exhibit estrus within 2-5 days. This method involves long-term and short-term administration of progestogen, which continues to exert negative feedback on LH secretion after CL has regressed. After withdrawl of the progestogen treatment, estrus is exihibited at around 48 hours. The advantage with progestogen is that it can be used for estrus synchronisation at any stage of estrous cycle unlike PGF2α, which requires mature CL for its action.

Synchromate B system

A small hydron polymer implant impregnated with 6mg norgestomet (progestin) is inserted subscutaneously on the back of the ear. At the same time, 5 mg estradiol valerate and 3 mg norgestomet are injected intramuscularly. The implant is removed after 9 days, leading to rapid decrease of progestin in blood and allows animal to come into heat in 2-3 days. The animal is bred after 48 to 60 hours after removal of implant. Fixed time AI at 48 and 60 hours or 48 and 72 hours after implant removal is recommended for high conception rate.

Controlled internal drug release (CIDR) system

CIDR is a T-shaped silicon rubber impregnated with progesterone and molded over a nylon spine. A small nylon tail is attached at the end of the CIDR, which protrudes from the vulva allowing its easy removal. The CIDR is inserted into the vagina using the applicator and left for 7-10 days in place. In cyclic animals, a capsule containing 10mg estradiol benzoate is also inserted along with CIDR. Alternately, estradiol can be administered intramuscularly at the time of insertion. Prostaglandin may be administered one day prior to the withdrawal of CIDR. Fixed time AI at 48 and 72 hours after removal gives good conception rate.

Progesterone releasing intravaginal device (PRID)

It is a stainless steel flat coil coated with an inert silicon rubber containing 1.55 g progesterone and 10 mg estradiol benzoate capsule. PRID is inserted into the anterior vagina and left for 12 days in situ and then withdrawn. Estrus occurs within 2-3 days after withdrawal and the animal is inseminated at 48 and 72 hours after withdrawal.

 

Synchronisation of ovulation

Protocol for synchronisation of ovulation is commonly referred as “OVSYNCH”. It allows fixed time insemination without estrus detection in dairy cows and buffaloes. This 10-day protocol uses a strategic combination of GnRH (2 injections) and PGF2α (1 injection) to initiate the growth of new follicle, induce luteolysis and synchronize ovulation. First injection of GnRH is given at an undetermined stage of estrous cycle, followed by injection of PGF2α after 7 days and 2nd dose of GnRH on 9th day and AI is performed 16 hours and 40 hours after second GnRH injection. First GnRH injection may/may not induce ovulation depending on presence or absence of dominant follicle at time of injection. Regardless, this injection serves to initiate the growth of a new follicular wave. One follicle from this new wave becomes dominant by Day 7 and ovulates in response to 2nd dose of GnRH facilitating fixed time AI without estrus detection. Pregnancy rates to Ovsynch protocol are maximum when it is started in mid luteal phase. In modification of this protocol an “Estradoublesynch protocol” has recently been developed at NDRI. In this protocol, PGF2α is injected at any stage of estrous cycle. It will be designated as Day 0. Then GnRH is injected on Day 2, followed by PGF2α injection on Day 9 and estradiol benzoate injection on Day 10. The purpose behind injecting estradiol on the 10th day is augmentation of LH surge.

 

Short-term cooling: A method to improve conception rate in buffaloes during low breeding season

The conception rate (CR) in buffaloes is poor (about 25-30 per cent only) as compared to cattle (40-50 per cent). The CR further drops down during hot and humid months (low breeding season). Buffaloes are more sensitive to solar radiation and high ambient temperature due to poor thermal tolerance because of dark body colour, relative less number of sweat glands per unit area of skin and thick epidermal layer of skin which reduce heat loss by evaporative cooling. Since heat stress during oocyte maturation and near ovulation and from 8 to 16 days or 27 to 40 days of estrus cycle has deleterious effects on embryonic development or conception rate, the effect of cooling the animal around the time of AI on CR has been studied.

The buffalo heifers were cooled for short term on the day of estrus or AI, that is three hours before AI and three hours after AI, by keeping animals inside the environmental chamber by using one air conditioner, two wall fans and one exhaust fan. The effectiveness of this facility in controlling the body temperature and on CR was monitored. Besides enhancing the conception rate (from 33.33 to 68.75 per cent), short term cooling also reduced stress to the animal (as revealed by low levels of cortisol in cooled animals).

 

Highlights

  • Increase in conception rate by 35 per cent
  • Reduced stress to the animal
  • Cooling facilities can be created at nominal costs in organised farms to have better returns
  • Some of the farms have already started using this practice

 

Figure 1: Short term cooling (3h before and 3h after) around the period of AI results in improved conception rates in buffaloes.

 

Post-partum follow-up protocol for reducing uterine infection

In most of the cases uterine infection is diagnosed when it becomes clinical, which leads to more investment on therapy and takes more time to cure. The practice of monitoring rectal temperature for at least the first few days post-calving is to be strictly implemented to identify the possible problematic cows at an early stage. Depending upon the visual appraisal (bright and alert or dull, depressed) and body temperature, further evaluation (rectal/vaginal) is to be decided. Depending upon results of each of the evaluation criteria, a set protocol is to be established for therapeutic applications.

 

 

Figure 2: Peri-partum follow-up of cattle and buffaloes can minimize uterine infection and improve post-partum reproductive efficiency.

 

The current approach in addressing metritis in dairy cattle is to monitor body temperature and cow behavior. If a cow’s body temperature exceeds 39.5°C, then a systemic antibiotic is administered. Procaine penicillin or ceftiofur (long acting) are approved for treatment of metritis and have been found to be efficacious. Non-steroidal anti-inflammatory drugs may also be used in combination with systemic antibiotics, if deemed necessary based on animal evaluation. Most veterinarians in developed countries have moved away from intrauterine antibiotics in treating metritis or retained placenta, although this issue is often debated. Growing evidence suggests a lack of efficacy from use of intrauterine antibiotics, as measured by no change in reproductive performance. The following post-partum follow up protocol is used at NDRI for early identification of developing uterine infection so that necessary measures could be taken up at an early time. This protocol has been tested in both cattle and buffaloes and found successful in reducing the post-partum uterine infection.


Wireless sensor based pedometer for accurate heat detection in dairy animals

Figure 3: Indigenously devised wireless sensor based pedometer system for oestrus detection and timing of insemination in cattle and buffaloes.

 

Pedometer principle and equipment is being used for heat detection in organised dairy farms in developing countries. The efficiency, accuracy and reliability in heat detection and their use in reproductive management is gaining importance due to increased labour cost of heat detection in large dairy farms and efficiency of pedometer. With the advent of reliable communication and computational technologies, it is now actually becoming more popular to use wireless sensor network, which alerts the farm manager about the animals in heat and also suggests the optimum time for insemination. These systems not only detect animals in heat but also other parameters which can be analysed with computer algorithm for disease prediction. NDRI in collaboration with the Indian Institute of Technology (IIT), New Delhi has developed a leg based pedometer system using three-axis accelerometer as sensor, which is able to identify the oestrus animal as well as collect activity every hour round the clock through wireless communication. When the average activity per hour increases around 70 per cent of the threshold value of that particular animal in a particular segment of the days, the animal is detected to be in heat. These pedometers activity chart, in controlled studies, has been found to predict 100 per cent natural as well as induced heat in cows.

Metabolic markers as a tool for predicting post-partum complications

The biggest bottleneck in achieving higher milk production with crossbreeding and intensive genetic selection is the decline in reproductive performance in high yielders. The incidence of puerperal problems, such as retention of foetal membrane, puerperal metritis and clinical metritis, followed by clinical and sub-clinical endometritis are more in high yielders as compared to low yielders. Hence early identification and treatment of metritis is a critical component of dairy herd. Per-rectal veterinary examination of uterus and rectal temperature are commonly employed for diagnosis of postpartum metritis, but such examinations are relatively infrequent in most of the dairy farms and metritis goes unnoticed. There are some bio-molecules circulating in the peripheral blood and indicating the health status of the cow. Assessment of concentrations of these molecules would give us an idea about the ensuing disease status. For instance, higher concentration of non-essential fatty acids (NEFA), blood β-hydroxybutyrate (BHBA) and NEFA:total cholesterol ratio and lower concentration of glucose and total cholesterol is good indicator of negative energy balance, where as the Blood Urea Nitrogen (BUN):BHBA ratio is a good indicator of energy protein imbalance. A study conducted at NDRI revealed that the metritic cows had higher plasma NEFA during peri-partum period but higher BHBA level during post-partum period. The cows with higher peripartum NEFA concentrations and post-partum BHBA concentrations were more likely to develop metritis. The cut off values for NEFA and BHBA were established, based on which the animals at the risk of post-partum complications can be identified.

 

Figure 4: Peri-partum blood NEFA and BHBA concentrations can aid in identifying cows at the risk of developing post-partum uterine infection.

 

Smart bucket system for identification of subclinical mastitis at early stage

Mastitis in dairy bovine is associated with huge economic loss to the farmers due to temporary or permanent loss of milk production, poor milk quality, discarding of milk after antibiotic treatment and pre-mature culling or reduced productive life. Generally either milk pH or EC or SCC is used to identify the mastitis in dairy animals. However, when these parameters are combined, it will help is improving the accuracy of identification.

 

Figure 5: Wireless smart bucket system for individual animal milk yield and electrical conductivity recording.

 

NDRI is in the process of developing a “Smart bucket system” for prediction of ensuing mastitis (sub-clinical). The initial results indicate that the system is found to work properly and help identifying minute changes in pH and EC of milk. Since this system is handy and can be taken to any place (wheels are fitted), the same can be used at co-operatives and at individual farmer’s level once validated on large scale.

 

“Cow-side” tests for detecting metabolic disorders

High yielding cows are at risk of developing metabolic diseases such as hepatic lipidosis, ketosis and displaced abomasum especially during the transition period. Generally, the dairy farmers have traditionally relied on veterinarians to aid in the diagnosis and treatment of these diseases. The diagnostics for these conditions have relied upon veterinary examinations and clinical analysis of blood samples. When the dairying is changing from traditional to commercial mode with large heads of cattle per farm, it became increasingly important to detect the metabolic diseases at very early time so that preventive measures can be taken up. To carry out these tests routinely, depending upon the diagnostic laboratories is not a viable and practically suited option. Development of “cow-side” tests that could estimate the metabolic status and identify the animals at risk of developing metabolic diseases would benefit the dairy farmers. In fact, some kits are already available in the market to estimate some of the metabolites in less time and at the farm itself.

  • Ketosis: Cow side tests for the diagnosis of ketosis may be used to confirm the diagnosis of ketosis in an individual sick cow, identify a cow with sub-clinical ketosis for possible treatment, or be used to screen groups of cows to discover herd incidence rates of subclinical ketosis. The cow side tests commonly used on dairy farms measure either acetocetate or β-hydroxybutyrate and test urine, milk, or blood for their concentrations.
  • Negative energy balance: To monitor a herd’s transition cow program, it is useful to measure blood concentrations of non-esterified fatty acids (NEFA). Elevated NEFA concentrations prior to calving indicate a negative energy balance and an increased risk for fatty liver and metabolic diseases.
  • Sub acute rumen acidosis: Determination of the pH of urine or rumen contents, using simple pH papers or pH meter could help the farmer in identifying the cows at the risk of developing sub acute rumen acidosis.

 

ADVANCES IN ANIMAL BREEDING: THE GENETIC BASIS

 

Genome-based animal breeding

Genomic tools can be used by animal breeders to increase the quality of the dairy animals. It is feasible to generate reference genomes, i.e. gene sequences that can be used to study and compare animals’ genetic traits. Breeders would get a picture of the genetic diversity in the whole population of animals, by taking samples of DNA from many animals throughout several regions and observing and recording their traits (“good milk producer”, for example). By associating the DNA with the traits, breeders can construct the theoretical genetic pedigree of a farm animal with the most desirable traits. Equipped with this information, conventional breeding methods can go forward at a much faster pace. The rapid improvements in high-throughput single nucleotide polymorphism (SNP) genotyping technologies, ever-denser SNP arrays accompanied by reduced costs for genotyping and for sequencing, open the possibility of using genomic information in livestock selection. The industry is thus facing the new paradigm of “genomic selection” to reduce costs and accelerate genetic gain by reducing generation intervals.

Genetic markers, or SNP, are highly abundant in the genome, and high-throughput molecular technologies allow the inheritance of hundreds of thousands of such markers to be traced through generations. Even if the mutations themselves do not directly affect the phenotype, they can track for the variability of causal mutations in their vicinity. By summing the effects assigned to each SNP, we can create a numeric value (genomic breeding value) that allows the genetic potential of a breeding animal to be assessed. This is an enormously valuable tool for choosing breeding animals as parents of the next generation. In addition, genomic selection may allow the identification of superior individuals for traits not currently considered in animal breeding plans because of technical difficulties. For example, the fatty acid composition of dairy products, increased disease resistance (and thus increased animal welfare), and decreased methane emissions in cattle help to address the needs of consumers and society for sustainable and cost-effective food production. The animal breeding industry is currently adapting selection procedures in each species to include this innovative tool. This is causing a worldwide restructuring of the animal breeding industry.

 

Cloning

Cloning is an extension of the assisted reproductive technologies that livestock breeders have been using for several decades, such as artificial insemination, embryo transfer and in vitro fertilisation. Reproductive cloning generally uses “somatic cell nuclear transfer” to create similar populations of genetically identical individuals. The cloning of animals has many important commercial implications since it allows an individual animal with desirable features, such as a cow/buffalo that produces a lot of milk or a bull with extra ordinary potential, to be duplicated several times.

Cloning in animals requires two kinds of cells. A somatic cell containing complete DNA or genetic blueprint of the animal it came from. The other kind of cell required is an egg cell (oocyte), which is collected from a female of the same species. The nucleus of the oocyte is removed and then the nucleus taken from the somatic cell of the animal to be copied is electro fused with enucleated oocyte, leading to formation of transfusant cells. The fused cell then begins to develop normally, using genetic information from the donated DNA upon further culturing. The resulting embryos are grown in the laboratory until they reach the blastocyst stage and transferred to the surrogate mother where the embryo develops into fetus. After a full-term pregnancy, the recipient gives birth to an animal that is essentially the identical twin of the genetic donor.

NDRI is known across the globe and came in lime light for production of world’s first buffalo cloned calf. It pioneered the cloning of buffalo using the novel technique called “Hand-guided Cloning Technique” by making modifications in the “Conventional Cloning Technique”. In the “hand guided cloning technique”, oocytes are isolated from ovaries and are matured in vitro. These are then denuded and treated with an enzyme to digest the thick outer covering called ‘zona’. The oocytes are then cultured so that their genetic material gets shifted to one side to form a protrusion cone. This cone can be cut off with the help of a “hand held fine blade” to remove the original genetic material of the oocyte. The modified technique does not require sophisticated and expensive equipment like micromanipulators, etc, which are essentially required for conventional method of cloning.

 

Since the birth of world’s first cloned buffalo on February 6, 2009, NDRI is continuing this frontier technique for producing a series of cloned animals. The second cloned calf “Garima” was born on June 6, 2009 with the birth weight of 43 kg.

Subsequently, NDRI produced two cloned calves namely Garima-II and Shresth on August 22, 2010 and August 26, 2010, respectively. Shresth was produced from ear cell of 2 week old while Garima II was produced from embryonic stem cell. Shresth attained sexual maturity earlier than his counter parts and has been performing excellent in terms of libido, semen quality and cryotolerance of spermatozoa. Garima-II also attained early sexual maturity at 19 months of age compared to her contemporaries (around 28 months) and was inseminated with frozen-thawed semen, which resulted in conception. Her gestation was normal and on January 25, 2013 she gave birth to a female calf “Mahima”. The newborn “Mahima” is keeping very good health. In the world, she is the first calf born from cloned buffaloes, produced through hand guided cloning technique.

In the month of July 2014, NDRI made a history by recreating a bull that was no more. The clone named as “Rajat” was created from a donor cell that was taken from frozen semen of the bull. The donor bull was born on December 10, 1995 and remained at NDRI till March 21, 2004, after which it was withdrawn from the service. The bull ranked ‘first’ in 5th set of all India progeny-testing programmes and had 22.29% superiority. This new achievement would help us to address the problem of acute shortage of outstanding bulls and facilitate faster multiplication of elite germplasm.

NDRI is further strengthening the research efforts in the field of reproductive cloning, so that it can be exploited at the earliest for the benefit of farmers and/or the development agencies. The dream “Buffalo National Milch Herd” could be realised using the cutting edge high tech reproductive interventions like cloning.

 

Ovum pick up

In vitro embryo production is one such tool that allows us to effectively utilize the superior germplasm. Ovum pick-up (OPU) is one of the cutting edge techniques in reproduction, where oocytes are harvested from live animals by trans-vaginal ultrasound guided aspiration. Then the oocytes are subjected to in vitro maturation, in vitro fertilisation and In vitro embryo production until they reach blastocyst stage, which can either be transferred non-surgically into recipients or frozen for further use. This non-invasive technique enables repeated collection of oocytes from live animals on a weekly or biweekly basis over long periods of time. Advantageously this technique can also be applied on genetically superior sub-fertile, infertile animals and those animals that do not respond to conventional multiple ovulation and embryo transfer technique thus enables utilisation of their genetic potential, which would otherwise remain underutilised. Using this technique, oocytes can also be obtained from genetically superior pre-pubertal heifers and early pregnant animals to reduce the generation interval.

 

NDRI has also applied the OPU-IVF technique in Sahiwal cattle and successfully produced a calf named “Holi”. Since cow slaughter is banned in the country, this technique is a boon to harvest oocytes from elite cows and to produce more offspring in short time. Further, this technique could also be very useful for obtaining calves from infertile, aged/tired and problematic, yet valuable animals.

 

Sexing of spermatozoa

The availability of superior breeding bulls is very limited in the country and a wide gap exists between the production and demand of total doses of semen. The research and development on selective use of sexed semen in cattle will not only increase the genetic progress from the daughter-dam path but also helps in producing good male germplasm from elite bulls for future breeding. In India, the need to pre-select the gender of young one in dairy cattle is gaining momentum and further attention day by day owing to:

  • limited availability of elite bulls,
  • large number of unproductive young bulls,
  • ban on slaughter of cattle,
  • very large proportion of unproductive cows and bulls giving tough competition on limited feed and fodder resources, and,
  • shortage of feed and fodder.

To realize the projected demand of milk, we need to gear up and increase substantially the number of the elite females, which can be achieved by shifting the sex ratio towards female using sex sorted semen. Several attempts have been made, elsewhere in the globe, to develop a method that efficiently separates bovine semen into fractions containing higher concentrations of X- or Y-bearing sperm. These technologies include sex specific antibodies, centrifugation, and flow cytometry. Of these attempts, the only method proven to be commercially viable is flow cytometry. However, the machine and the process of sex sorting is under patent and only two firms (Sexing Technology and Lumisort), as on date, are producing and supplying the machine on royalty basis. Despite more than 20 years of development, commercial operations that utilize sperm sorting by flow cytometry to pre-select the sex of offspring and its availability remains limited. Till date, flow cytometry sorting method is not 100 per cent efficient, but it does shift the ratio to about 85 to 90 per cent of the desired sex. As with any other market-driven technology, sex sorting may evolve to become more efficient and less costly and research are being continuously taken up to fine tune the technology to reach maximum efficiency and accuracy.

Searching for an indigenous methodology and researching on its efficiency would definitely reduce the cost of production. However, due to the pressing need of time, the pragmatic approach could be to source the machine, procure it and start producing sexed semen after standardisation of the process for indigenous and crossbred cattle bulls. Further, the conception rates in artificial insemination using sex sorted semen are lower than those with unsorted semen. If we immediately start using the sexed semen under field conditions, it is expected that the conception rates would still go down since we have not yet standardised the insemination methods for our cattle breeds and, as on date, expertise is not available to handle and inseminate the sex sorted frozen-thawed semen. Similarly we also need to frame a stringent policy for using sexed semen otherwise uncontrolled use of sex sorted semen would skew the sex ratio towards one sex and lead to problems.

ADVANCES IN ANIMAL NUTRITION

Availability of good quality feed (forage/roughage and concentrate feed) throughout the year is a major limitation for increased milk production, especially when better breeds are reared. The projected dry fodder, green fodder and concentrate demand for 2020 is 468, 213 and 81 million tonnes on dry matter basis where as the estimated availability stands at 417, 138 and 44 million tonnes leaving a short fall of 11, 35 and 45 per cent, respectively. During a large part of the year, there is inadequate availability of feed and fodder; further the nutritive quality of whatever is available is generally poor to support animal maintenance and production; a common problem is low protein and high fibre content. In order to meet the nutritional requirements of animals, particularly high yielding animals, there is a need to increase the bioavailability of the feeds and fodders by increasing the research efforts in the area of feed processing using chemical, biological and biotechnological approaches.

 

By Pass nutrient technology

By pass Fat: In this technology, the lipids are protected using some physical or chemical agents; these lipids do not undergo lipid hydrolysis or bio-hydrogenation in rumen, but by pass rumen and get digested in the lower tract. Apart from increasing the energy density of the diet, there is an added advantage of feeding protected unsaturated fatty acids in milk fat, which makes a softer butter, being safe for humans, especially the heart patients.

By pass Protein: When the highly degradable proteins are protected from ruminal degradation, proteins by pass rumen and more amino acids reach lower tract, and there is more supply of amino acids to the various body tissues. The excess supply of amino acids as a result of feeding bypass protein can partly be used for synthesis of milk proteins in mammary gland and partly used for the synthesis of glucose in liver. By pass fat and proteins have been shown to improve growth and milk production of dairy animals by improving feed conversion efficiency of nutrients resulting in better economic returns.

Complete feed block

Complete feed block consists of roughages and concentrate mixtures. They are advantageous on terms of controlling the ratio of components, i.e. roughage, concentrate, protein, energy, minerals, etc., can be maintained at a desired ratio in complete feed. This also helps in avoiding the selective feeding by the animals and provides optimum conditions for rumen fermentation. Feed blocks are easy to handle and to transport to long distances also. The complete feed system would also help in utilising the locally available crop residues, agro-industrial by products and wastes that are fit for animal feeding.

For preparing complete feed, forage, concentrate ingredients and additives/ supplements are blended together to get the required quantity of protein/energy/minerals/vitamins. Usually roughage and concentrate ratio is being maintained as 60:40. Complete feed provides the best avenue to incorporate the urea in the ration of livestock. For high yielding cows 50:50 ratio of roughage and concentrate is usually adequate. For preparing blocks, mixture of chopped roughages and concentrate ingredients are pressed in a block of desired shape and weight.

 

Novel feed additives

Most important feed additives used are probiotics, prebiotics and synbiotics. Probiotics are most commonly used in livestock while synbiotics are effective in monogastric animals. Probiotics play a role in maintaining intestinal health in the pre-ruminant. At the rumen level, probiotics have been shown to improve anaerobiosis, stabilise pH and supply nutrients to microbes in their microenvironment. When an antibiotic is fed to animals, it stops the activity of both the harmful as well as useful microorganisms while the probiotic is proposed to stimulate the activity of useful bacteria, thereby helping the animal in stabilising a correct consortium of microbes to colonize the gastro intestinal tract. S.cerevisiae and lactobacilli cultures have been tested at the Indian Veterinary Research Institute (IVRI) for their tolerance to low pH, various concentrations of a mixture of acetic, propionic and butyric acids and bile salts. The best two strains of S.cerevisiae (NCDC 42 and NCDC 49) showing maximum resistance towards the above factors have been further tested for their efficiency to increase the in vitro dry matter digestibility. Although the effect of pro-biotic supplementation has been shown to improve the growth of calves and beef cattle, information on the effect probiotic supplementation on milk yield is limited.