Developing a Cost Structure of Frozen Semen Production and Performance of Artificial Insemination for Sheep Breeding Program

Artificial insemination (AI) has its glorious commercial reputation and success for the genetic makeup since the 1940s in the cattle herds (Parish and Riley, 2011). In sheep, AI is a new technique by no means. It has been practiced for over 50 years in the Soviet Union, has been in routine use along with some limitations in France, Ireland, Australia, New Zealand and until recently, the insemination was performed with fresh diluted semen. The development of trans-cervical and intrauterine laparoscopic insemination has now rendered the use of frozen semen in sheep a viable proposition (Evans, 1988). AI is one of the most cost-effective ways to improve a gene pool because high-quality semen can be purchased without the investment in and any expenses that are associated with buying a ram, as in boar, or bull (Gillespie et al., 2004). It offers many well-known benefits for producers (Salamon and Maxwell, 2000; Nuti, 2007; Shipley et al., 2007). Moreover, AI takes all privilege of the oestrus synchronization, accuracy of expected dates of parturition, the possibility of out-of-season breeding, etc.; furthermore, it avoids disease transmission, effective and efficient use of male decreases genetic variability, defects, uncontrolled diseases and increase in the inbreeding coefficient affecting the maternal traits (Faigl et al., 2012). The advent of AI with frozen semen has led to propagation, long term and use of germ plasm of superior males (Pandit and Jain, 2003). Till to date, among all the fundamental systems of animal breeding exercise such as random mating, inbreeding, line breeding and outbreeding, artificial insemination has proved to be the best and efficient method for the rapid improvement of livestock for maximum use of best sires on numerous dams (Choji, 1995; Rozeboom, 2007). But a new technology requires sufficient information, description and way of application for its adoption and dissemination. In addition, monetary information is of outstanding importance when it is new technology like artificial insemination breeding in sheep. Moreover, the farmers favor to practice low input technology in their extensive farming system (Bora and Das, 2013). In Bangladesh, preliminary work on artificial insemination in sheep breeding program has been performed by many researchers (Rekha et al., 2016; Naher et al., 2016; Jha et al., 2020). Till to date, there is found no information about the cost structure of frozen ram semen as well as performance artificial insemination. Therefore, the aim of this study is to explore or develop the cost composition of frozen ram semen production and the performance cost of artificial insemination in sheep breeding.

Study location
 
Frozen ram semen production and artificial insemination were performed at the reproduction lab of the Department of Surgery and Obstetrics, Bangladesh Agricultural University (BAU) and sheep farms of the village Nilakkgir Char, nearer to the research station under Sadar upazilla, Mymensingh district. The study was conducted in a period of September to November; 2019. These two sites are located at N 24.73 latitude and E 90.44 longitude, where annual mean rainfall is 174 mm and temperature varied from 16.46 to 29.13°C.
 
Animal management
 
A flock of 15 rams were maintained in a separate herd at Sheep Research Farm, Bangladesh Agricultural University, Mymensingh, of which best 4 rams used for semen production and breeding purpose. Rams were grazed freely for 6 to 7 hours on natural pasture with approximately 300 gm. of supplement mixture, consist of maize, oil cake, wheat offal, salt and mineral mixture at the rate of 52, 8, 37, 1 and 2%, respectively per head daily following the feed formula by Akinbobola (2018). They were three times free excess of safe drinking water ad-libitum and dewormed with broad spectrums anthelmintics.
 
Semen extender
 
Tris (hydroxymethyl) aminomethane, citric acid and fructose (Research-lab Fine Chem Industries, Mumbai, India) at the rate of 3.93, 1.70 and 0.20%, respectively were used by w/v and 10% Gentamycin (The ACME Laboratories Ltd. Dhaka, Bangladesh) was used by v/v to make tris-fructose-citric acid common extender (pH 6.8). This extender then divided into two parts, A part was without glycerol and B part was prepared with glycerol (Merck, Germany) at the rate 5% for sole diluent volume by v/v. Finally, the churned egg yolk (15%) was added to complete the diluent preparation (Acharya, 2017) and kept in a water bath at 37°C to use in semen dilution.
 
Semen collection and frozen production
 
Semen was collected using an artificial vagina by a known associate in a friendly environment from the previous evaluated best 4 rams out of 15. The rams incurred the capability of producing a mean semen volume of from 0.6 to 0.8 ml, ≥3600 × 10⁶ and ≥75% initial motility, were assigned for frozen semen production. On the day of frozen production, fresh extender was made early in the morning before semen collection. Semen was immediately diluted with the calculated volume of extender (part A) and transferred to the refrigerator for cooling for 2 h at 5°C.  Then the rest of the volume of extender (part B) was added and glycerol equilibrated for further 2 h in the same temperature (5°C). The diluted semen samples possessed good sperm motility in equilibration stage, were used in straw filling and sealing with polyvinyl alcohol powder. Then the semen straws were frozen by manual freezing technique into a Styrofoam box (37.5 × 25.5 × 20.5 cm) with a net (35 × 22 cm) wireframe (Fig 1) according to developed protocol by Jha et al., (2019).
 

 
Cost assumption of frozen production
 
The cost of per dose frozen semen was estimated following the guideline of Kumar and Singh (2018). Briefly, the expense components were broadly divided into fixed and variable expenses. The fixed expense comprised mainly of salary of staff in this study. The variable expenses included ram management, semen processing and preservation costs. The ram management was further sub-divided into general management cost, feed cost and labour cost. Semen processing and preservation cost was further divided into straws, extender, liquid nitrogen and other consumables expenses. Feed cost was calculated based local market price of feed ingredients. Labor cost and salary of staffs were calculated on daily basis as per project guideline approved by the Bangladesh Agricultural University Research System (BAURES), Mymensigh. The extender and other expenses were calculated based on available market prices. Local Govt. office supply price was considered for liquid nitrogen expense. Semen was frozen twice a week for a period of a month. Based on capacity of the net wireframe, each freezing produced a trial of cryo-freezing 50 frozen straws and about 400 semen straws each month.
 
Field trial of artificial insemination
 
The field trial for artificial insemination was performed in ewes congregated in a selected place by farmers of the village, Nilakhir char. On a date, early in the morning, the ewes were injected Prostaglandin (PG) hormone (Ovuprost®, Ranata Ltd., Netherland) at the dose rate of 0.7ml i/m for induction of estrus. On the day of artificial insemination, after a period of about 48 h, the estrus was detected by an aproned ram. A total of 10 synchronized ewes were selected and separated for artificial insemination. Then trans-cervical artificial insemination was performed with an AI assistant and a labor using two straws of frozen straws for ewe breeding each (Fig 3). Consumed time (h) was recorded for each insemination and mean time was used in cost calculation.
 

 
Cost assumption of artificial insemination
 
The cost assumption represents the expense items associated with the sheep artificial insemination protocol.  These were the syncrhronization hormone, semen cost, AI sheath or piptte cost and other AI expenses- tissue papers, KLY gelly, alcohol spray etc (Fig 2), labor cost and breeding charge. All the consumable expenses were calculated based on available market prices.
 

 
Data analysis
 
The obtained data was presented descriptively and in percentage. The total cost was calculated using a formula by Bragg (2018) as (Average fixed cost + Average variable cost) × Number of units = Total cost.

Cost of frozen semen production
 
Table 1 contains information on the cost of all items associated with frozen ram semen production at the reproduction laboratory of the department of surgery and obstetrics, Bangladesh Agricultural University, Mymensingh. The cost function of the frozen ram semen production is estimated by examining each operation within the production system and estimating the fixed and variable costs of that operation as in study by Kumar and Singh, (2018). In some cases, the costs are estimated per item and then aggregated by the number of samples involved.
 

       
Based on our estimated total cost (Tk. 16665.22), the ram maintenance cost per  cent (53.69%) was higher than the fixed cost and semen processing and preservation costs were to be 33.38 and 12.93%, respectively. No studies were found available to discuss the cost of frozen ram semen straw production. However, the higher proportion of ram maintenance cost and the fixed cost was supported by Thirunavukkarasu (2009), who reported a higher proportion of bull maintenance cost in District Livestock Farm (DLF), Abhishepatty (67.61%) comparatively than other semen producing stations and again, the proportion of the total fixed cost to the total cost of semen production in ECBF, Eachenkottai (19.81%). The average cost of frozen semen production per straw was estimated to be Tk. 41.66. No studies were matched to describe the cost of frozen ram semen straw production. However, Arun and Jain (2002) estimated the cost of frozen bull semen to be Rs 16.55 to Rs 17.18 per straw, which was a somewhat lower cost of the currently frozen ram semen production cost. This variation may be due to species-specific, large volume of semen production in bull and production capacity of box or manual freezing.
 
Cost of artificial insemination
 
Table 2 contains information on the cost factors associated with the artificial insemination of the current study. In this study, a total of 10 ewes underwent artificial insemination with produced frozen semen. All the cost factors of artificial insemination are estimated by examining each operation within the breeding system. In some cases, group or sole price was divided into the single unit price and then aggregated by the number of cost factors involved with each operation. Based on the cost assumption model (Table 2), the one ewe costs approximately Tk. 217.31 that goes through the protocol for the performance of artificial insemination in a 10 ewes-flock.
 

       
Analysis of the data revealed that the semen dose (38.34%), AI sheath / Pipette (23.00%) and synchronization hormone (19.33%) cost were the top areas of expenses in artificial insemination. No such studies were found available to describe the cost of artificial insemination in sheep breeding. The higher cost of semen dose can be reduced by a large number of frozen semen dose production from multiple rams using bio freezer. Most AI in ewes and does perform using a diluted, inexpensive low dose of fresh semen since the small ejaculate volume. But the obvious disadvantage of liquid semen is the limited lifespan, restricted transportation over large distances and prevented long-term storage. While the frozen semen permits the transport of semen over long distances, allows large numbers of females to be inseminated over extended periods of time or at different times of the year (Faigl et al., 2012).
 
Higher hormone cost can be minimized through performing artificial insemination in sheep in natural estrus. Although, sheep in estrus detection is a little-bit incomprehensive to farmers as its heat is in silent-nature and this can be made easy by keeping so-called treasure rams in the flocks. Moreover, the food safety policy in some EU countries is becoming ever stricter with the use of the hormone in animal reproductive purpose, pushing livestock raising towards ever cleaner and greener production systems. But sheep-goat is of a seasonal breeder in nature and hormonal treatment is still the main tools employed in the effort to achieve fertility outside of the normal breeding season (Lopez-Sebastián et al., 2014). 
       
Efficient artificial insemination is of great technician dependence. Therefore, the selection and placement of a trained and skilled AI technician can assist in reduce expenses by performing the increase in the quantum of artificial insemination. The theme refers to the higher the number of insemination, the lower the technician cost/expense margin in artificial breeding. In our current finding the technician cost for artificial insemination (8.18%) was considerably high and this can be minimized or decreased with the maximum use of skill ness of a technician for a herd-breeding in a day.

Unit production cost calculation is directly dependent on the quality and accuracy of input data. Henceforth, data quality is of significant importance in ensuring the validity of unit cost calculations. Misconceptions about the true costs of production from poor data quality have a direct or indirect influence on the stakeholder’s decisions. Moreover, the unit cost production calculation should be separated from farm operating costs in order to make further confirmation in the accuracy. In regard, the current study takes the privilege of the use of more accurate data in the frozen semen production and performance of artificial insemination cost calculation.
       
The cost estimates of semen and artificial insemination can provide valuable information to breeders as well as stakeholders in making decisions about the breeding technology. These can also assist the farmers to accept and adopt new reproductive technology in their sheep breeding. Researchers may use this basic information on frozen ram semen and artificial insemination in their future works, suggestions and recommendations. Future work incorporated with expected returns and costs will provide breeders with the capacity to identify the best structures to meet the optimal breeding programs.