Last month we discussed four management procedures or processes that we should follow in order to increase the productivity of beef cattle. In this issue Dr Dave Midgley focusses on cow management.

Back to the cows:

Our aim or objective is to get as many cows as possible to calve within the first cycle, or 21 days of the calving season, with 83% calving within the first 42 days of the calving season. Our second aim is to get 86% of the heifers to calve within the first 42 days of the calving period.

After calving, the following processes should receive attention:

Involution of the uterus and how well it progresses. Every uterus is inspected in terms of the period after calving and how complete the shrinking to the normal size is. Therefore, the first requirement for a thorough examination is a complete list of the cows to be examined with their calving dates.

Next the ovaries are evaluated for “activity” – what we are, in fact, trying to establish, is whether the hormone system has “kicked in”. This is done by palpating the ovaries, feeling either follicles or corpus lutea (yellow bodies). Two kinds of cysts can upset a cow’s hormone cycle:

Follicular cysts that may cause cows to come on heat irregularly or sometimes for longer periods = “Nelly the Nymph”.

Luteal cysts that release the hormone, progesterone, which makes cows think they are with pregnant, causes them not to come on heat and to skip cycles. Luteal cysts can be broken down with prostaglandin injections, so that normal cycles can recommence.

Sometimes, valuable cows experiencing difficulties to become pregnant are treated with a combination of hormones – according to the discretion of the veterinarian involved.

The activity and size of the reproductive tract is measured on a scale from 1 to 5 and is referred to as reproductive tract scoring (RTS).

While doing the rectal examination the pelvic size is also determined – this is especially important in heifers. A “pelvic score” is given on a scale of 1 to 5.

Next, the cows are examined internally with a speculum. The exterior genitals are washed properly and a vaginal examination is performed.

In this way, discharges that may differ in substance and colour may be detected. These infections prohibit the implantation of the embryo. Cows with infection still come on heat, but do not conceive. Cows and ewes need two to three “cleaning cycles” before introducing them to the bulls or rams again. This is yet another reason for a shorter calving period, allowing more time between calving and breeding for this to take place.

Cows with infections often also have retained corpora lutea (“persistent CL”) which, like a luteal cyst, prevent normal cycles. Treatment will depend on the veterinarian’s decision:

Sometimes, systemic treatment with the right antibiotics may suffice. The time span since calving is the determining factor in the decision on which antibiotics to use. It is best to take samples for culturing in a laboratory to determine exactly which bacteria or organisms are causing the problems on a particular farm. An antibiogram can also be performed to determine the best antibiotics to combat the specific organism(s).

In most cases an “installation” is performed, placing the “medicine” inside the uterus by means of a pipette. Should the presence of a remaining corpus luteum be felt of suspected, a prostaglandin injection is also given. A combination of all these treatments is mostly done.

During the mating season, these cows come on heat and are served normally, sometimes by more than one bull. At the same time other cows may also be on heat, and the “infection” is thus transmitted from cow to cow preventing implantation and subsequent pregnancy.

Between mating and pregnancy testing, a few “cleaning cycles” may occur and many cows may clean themselves. Re-introduction of bulls leads to cows that calve late or out of season.

I am a firm believer in “preventative medicine”. Traditional pregnancy testing is done on many farms, but in my opinion it occurs far too late in the breeding cycle to be regarded as a preventative measure.

By the time you discover a low conception rate or other problems like uterine infections at pregnancy testing, you have lost an opportunity to calve down at the time of your choice.

This could mean missing the best time to market your calves and/or that you have to give expensive supplements to the cow in order to raise a good sized calf.

Strictly speaking, pregnancy testing is thus a reactive measure rather than being pro-active.

I fail to understand why farmers do not routinely perform pre-mating checks, not to even mention why not before AI and embryo programmes.

• The ideal situation is to also weigh each cow and to allocate a condition score to her before breeding. Weight alone means very little, as a 450 kg cow could either be a big thin one or a small fat cow! Condition scores are given on a scale of 1 to 5. Halves are allowed when you are in doubt. The ideal condition score at breeding would be 3 to 3,5.
• In the summer rainfall areas, cows develop winter coats which are shed during springtime. Bonsma, in his book “Man Must Measure” devotes a whole chapter to this subject. Cows shedding their coats early in springtime are also the most fertile ones. Cows in a bad condition with thick winter coats still on them are the ones who do not conceive. Early observation and detection leads to either implementing preventative treatment or to culling of those animals before performing other costly procedures on them. The hair coat is also scored on a scale of 1 to 5.
• The last score that I give while the cows are in the kraal, is the “docility score”. Apart from aggressive cows being dangerous, research has shown that there is a definite link between docility and beef quality, with docile animals having more tender and juicy beef.

Dr Dave can be contacted by e-mail at dave.midgley@vodamail.co.za for more information in this regard.