Artificial insemination in pig: a way to bridge the supply demand gap of superior quality pig in Nagaland

Mahak Singh, R. Talimoa Mollier and D.J.Rajkhowa ICAR-ICAR Research Complex for NEH Region,

Nagaland Centre, Medziphema

  Introduction

Like other North Eastern state, Nagaland is inhabited by tribal communities which are mostly non-vegetarian and hence, the demand for animal protein is much more compared to other parts of the country. About 80% of the population lives in the rural areas in close contact with the domestic animal population. Pig is one of the most important livestock which plays an integral role in improving the economic status of the tribal and weaker section of the society. The small scale pig sector occupies an important position in farming system as it is closely interlinked with the other agricultural operation performed by the tribal people for their livelihood. Pig alone accounts for 55.38 per cent of the total livestock population in Nagaland, but still a wide gap exists between the demand and availability of pork mainly due to traditional production system. As per the 2012 livestock census the swine population of Nagaland is 503.69 thousand of which 122.97 thousand is indigenous and the rest are either cross bred or exotic. The pig rearing scenario in Nagaland is almost completely traditional and very few organized farms have been set up to supply quality pork. Of these constraints the availability of superior germplasm and good breeding boars as and when required is one of the most important.  

Artificial insemination (AI) of swine is widely practiced in countries with intensive pig production. In Western Europe, more than 90% of the sows have been bred by AI for more than two decades. When compared with natural mating, AI is a very useful tool to introduce superior genes into sow herds, with a minimal risk of disease. The outcome of AI largely depends on the timing of insemination, semen quality and the insemination procedure. In practice, fresh diluted semen for intracervical insemination is mostly used in pigs. Semen is obtained from boars on farms or from specialised AI-centres. In line with the state pig breeding policy, ICAR Research complex for NEH Region, Nagaland Centre, Medziphema, Dimapur is popularizing the superior exotic and crossbreed germplasm of pig in Nagaland through supply of quality piglets and artificial insemination in the farmers field.  

Three important aspects should be considered. Firstly, only semen from healthy boars should be used, as diseased boars may ejaculate semen that is contaminated with pathogens. Strict regulations and guidelines to prevent disease spreading are therefore implemented on porcine AI-centres. The second important aspect is the fertilizing capacity of the produced semen doses. The fertilizing potential of a semen dose is inherently linked to the quality of the spermatozoa itself. Examination of the ejaculates is therefore necessary. A third important aspect of AI centres is the semen processing procedure. This is not only important to guarantee a low microbial presence but even more to obtain high quality sperm, namely viable spermatozoa in ready-to-use semen doses that can be used for several days.  

Benefits of Artificial Insemination in pig

1. No need of keeping male pig at farm for breeding purpose. 2. Semen of superior and crossbreed or exotic breed male can be used for insemination for getting quality piglet. 3. Easy to do- Farmer can do it easily. 4. Cheaper than natural breeding. 5. More number of piglets born. 6. Semen pack can be taken to far flung area.

 

Collection of semen, dilution and processing

Semen is mostly collected by the gloved hand technique from a boar trained to mount a dummy sow. Dummy sows should be solid in construction without sharp edges, and located in a quiet designated semen collection room with a non-slippery floor. A prewarmed (38°C) collection container is used. The top of the container is covered with cheesecloth to filter out gel portion of the semen. After collection, the filter with gel should be discarded, and the collection container should be placed in warm water. The semen should be extended within 15 min. after collection. The extension process should be done in a warm room with clean and sterile equipment. The extender is added to the semen, and cold shock should be avoided by diminishing the temperature gradually. A normal ejaculate usually contains enough sperm to inseminate 15 to 25 sows using conventional AI. Each dose should contain 2-3 billion spermatozoa in 80- 100 ml.    

Storage of liquid semen

Freshly diluted semen (liquid semen) is widely used for AI on the day of collection or in the following days. For storage of liquid boar semen, two factors are very important: the temperature of collection and storage, and the composition of the storage medium. To avoid the cold shock, prediluted ejaculates are better left at temperatures above 15°C for several hours to induce cold resistance. When semen doses are to be transported, special precautions are taken to avoid temperature fluctuations. Further storage of diluted semen is done at 17°C, at which temperature semen metabolism is reduced, a condition necessary to extend storage time. The storage media for liquid boar semen aim to prolong sperm survival, to provide energy to the cells, to buffer the pH of the suspension and to avoid the growth of bacteria. Depending on the composition of the extender, semen can be stored for 2 to 3 days in short-term extenders and up to five days or longer in long-term extenders. Signs of estrus/heat in pig:  

Back end: vulva appears normal (swelling and redness subsides), sticky discharge from vulva, clitoris red and protruding, tail upright whilst standing and flicks up and down, poor appetite, pricked ears, stand with arched back, glazed eyes, trembling, attracted to stockperson, seek boar contact, stand rigid if mounted and very vocal sound with repeated grunts or long growls.    

Insemination strategies

The management of AI is very important to determine the success of the procedure and the reproductive performance of the sows. Correct timing of insemination requires careful detection of oestrus at regular intervals. Accurate heat detection is essential for the correct timing of insemination; however, heat is often missed or misdiagnosed because the signs are overlooked.  

Conclusions

AI of swine is widely practiced and is a very useful tool to introduce superior genes into sow herds, with minimal risk for disease transmission. Taking into the account of pig production system of Nagaland, AI can be proved a transformational step if implemented properly in making the pig production system sustainable. Because of the difficult terrain and non availability of good quality breeding boar in remote areas; setting of the satellite pig AI centre which will cater to the need of pig breeder is the real way to enhance the resilience and sustainability of farming community of Nagaland. Interested farmers for readymade AI kit or for training can contact ICAR Research Complex for NEH Region, Nagaland Centre, Medziphema, Nagaland.