Profitability of commercial dairy farms

Pakistan is basically an agricultural country with seventy percent of its population residing in rural areas. Livestock is the major component of this agricultural based economy which contributes 55 percent of its total share and contributes 11.5 percent to the national GDP.

It provides directly or indirectly livelihood to over 30 percent of its rural population. The productivity of these livestock need to substantially increase to meet the future challenges of continuously increase in human population. Eighty percent of livestock are raised by landless and small holders. Future increase in animal productivity can play marked role in poverty alleviation in the country.

With the passage of time where other technologies are developed and adapted in livestock sector, breeding system of animals also changed and modern biotechnologies adapted, one of them is Artificial Insemination (AI).Presently, commercial dairy farming is one of the major fast growing industries of Pakistan. This needs proper managemental systems of nutrition, health care and reproductive health control.

Effective reproduction in dairy animals is a key to their profitability and a cow must give birth to a calf every year. Low fertility rate in dairy animals is a major issue. The prolong service period (duration from the day of parturition to successful animal breeding) results in longer calving interval due to anestrous (without heat signs) or poor expression of heat signs which are commonly recorded in high milk yielding cows.

The long calving intervals result in keeping the unproductive cows for long periods. To avoid the problem of heat detection for AI purpose, many protocols have been developed. The first protocol was the use of two injections of Prostaglandin F2α given at the start day of this protocol and animals were observed 72 hours for signs of heat after injection and inseminated at proper time (12 hours after the onset of heat signs).

Those animals which did not respond to first injection of the protocol received second injection ten days after first injection and observed for heat signs and inseminated. Using this protocol treated animals responded poorly and variation in time to onset of heat. This protocol needs special care to be applied as it causes abortion in early pregnant animals. Other protocols are applied for AI purpose but all require detection of the estrus by the farmers and then animals inseminated at proper time.

To avoid the problem of heat detection in AI, the protocol ovulation synchronization (ovsynch) was applied in the year 1995, where animals were inseminated at fixed time without arranging any prevalent program of heat detection. This protocol needs two injection of Gonadotrophin releasing hormone (GnRH) administered seven days before and 48 hours after a Prostaglandin (PGF2α) injection and animals are inseminated 16 to 20 hours after the second injection of GnRH. This brought synchrony in follicular maturation and regression of Corpus Luteum (a structure in the ovary which controls the duration of estrous cycle of a female animal).

The induced ovulation by second GnRH permits Timed Artificial Insemination (TAI). This protocol gave acceptable fertility results without worrying for heat detection. Keeping in view, a research project was designed at UVAS to compare double ovsynch protocol with standard ovsynch.

For this purpose, animals were divided into three groups (Group 1 taken as control with ovsynch; Group 2 was administered double ovsynch with 50 micrograms in all GnRH injections while Group 3 was administered double ovsynch with 100 micrograms in final GnRH). All the animals were inseminated 16 hours after the last injection of the protocol. Twelve days after AI, blood samples were collected for progesterone hormone (maintain the pregnancy) levels in the laboratory.

There was no significant difference of progesterone level was observed in all three groups, while pregnancy rate in group 3 treated with double ovsynch with 100 micrograms in final GnRH was significantly higher. It is therefore, concluded that farmers can improve pregnancy rate of their dairy animals by adopting the third protocol of the study which do not need any heat detection program.

DR AIJAZ ALI CHANNA

UVAS, Lahore