Choosing the right bull can shape the future of any herd, but for stud breeders the stakes are even higher. When faced with options ranging from young auction bulls to older, proven sires, it can be difficult to know which route offers the best long-term value and the least risk. In this Q&A, Dr Danie Odendaal helps a new Nguni stud breeder navigate this important decision, addressing concerns about fertility, disease risks, and what to look for when testicles don’t hang evenly.

The Dilemma: Auction Bulls vs Proven Sires

Question: I am currently experiencing a wonderful challenge in the form of managing my own Nguni stud herd on land outside Grahamstown. I am running the stud as a hobby but approaching it with the same seriousness as any full-time farmer. I have to purchase my first registered bull within the next 30 days. All my female animals, at present either pregnant or having very young calves, are running with stud bulls on a neighbouring farm as part of an agreement. I have two choices. I could buy a bull at a stud auction soon to be held in Grahamstown. Good young bulls and one or two tried and tested sires will be on offer. I could, however, also buy an SP bull out of hand. He has already made his mark at a nearby stud and has to be replaced. One of my first registered heifers is pregnant by him. Should I take the risk of buying auction bulls that could fetch very high prices (supply and demand) or should I buy the SP bull, which has only to walk across the road, at an extremely reasonable price? The SP bull will at least be able to service my cows for the first two years until I am able to expand further.

The Testicle Concern: A Red Flag or Normal Variation?

The issue that makes me doubtful is the fact that one of the SP bull’s testicles is higher in the scrotum than the other. The testicles are, however, the same size, and the bull mates without missing a cow. He also produces beautiful calves. In addition, the bull has already adapted. He is a small-framed Nguni and had a 5/5 sperm count/quality in an earlier fertility test. The bull is almost seven years old and is as tough as old leather. I know what I will get. What do you think about the testicles that are the same size but do not hang level? The bull has already been inspected and registered by the Nguni Stud Society as a “Studbook Proper” bull. Could the testicles that are the same size but do not hang level, affect the fertility of his female progeny negatively? This is the only issue I still have to consider before deciding.

The Two Critical Factors When Buying Any Bull

Answer: When you buy a bull, two factors – apart from the bull’s genetic make-up – need to be considered. These are the bull’s suitability for breeding, and reducing the risk of any diseases the bull could introduce to the cows.

Quality Control: Why Genesiological Examinations Matter

A genesiological examination of a number of young bulls before they are sold should be seen as part of the breeder’s quality control measures. Quality control, such as post-weaning examination in terms of specific indices, is carried out throughout the breeding process for stud bulls, and so is an additional examination based on a phase C or a phase D test and the certified performance test results as provided by SA Studbook.

The final hurdle the young bulls have to jump is a genesiological examination and the certification of suitability for breeding, both of which are done by a vet. Only bulls that pass this examination are certified. This is important for young bulls because 2% to 10% of them do not meet the minimum requirements for breeding suitability. Part of the examination is intended to ensure the bulls are not infected with sexually transmitted or other diseases, and to test for these.

Risk Management: The Older Bull Advantage for Nguni Breeders

This part of the examination could be considered an aspect of risk management. Usually, a farmer would be dissuaded from buying a fully-grown bull that has already serviced a herd, because sexually transmitted diseases are a greater problem in bulls older than six years. Doing so could be considered in the case of Nguni bulls, however, because good sires are relatively scarce and the average seven-year-old Nguni bull can still be used effectively for a further two to three years.

Disease Testing: Your Non-Negotiable Checklist

The most important risks that have to be eliminated are sexually-transmitted diseases. First of all, you need a written declaration from the seller that the bulls in the herd were tested for vibriosis and trichomonosis during the previous year, and that the results were negative. A vet should also test the specific bull for these two diseases. If the herd from which the bull originates was not tested the previous year, or if a bull tests positive, the bull you buy will have to be tested three times for the sexually-transmitted diseases before you introduce him into the herd.

Addressing the Testicle Issue: What to Look For

With regard to one testicle hanging higher in the scrotum than the other, when the vet tests the bull, ask that the testicles also be palpated thoroughly as part of the genesiological examination.

There is always a question mark when there is any deviation from the norm. In Nguni bulls it is extremely important to rule out hypoplasia in the testicles. This is when one testicle is markedly smaller than the other and it seems as if one is hanging higher than the other. This deviation is very heritable and is a problem in the Nguni breed. The vet will determine whether the testicles are the same size, if their elasticity is the same, if both move freely in the scrotum and if there are any hard areas or nodules in the testicles or spermatic cord.

Semen Evaluation: Beyond the 5/5 Rating

The rest of the genesiological examination consists of collecting semen and evaluating the mobility and conformation of individual spermatozoa. If the previous test was 5/5, it usually indicates a mass movement of the sperm. This is very good, but the conformation of the individual spermatozoa has also to be determined, especially in cases where there is now a deviation in the height of one testicle. A semen smear needs to be taken and stained and 100 individual spermatozoa examined.

The minimum requirement is that 75% or more of them should be normal.

The Complete Package: Full Breeding Suitability Examination

A thorough examination for breeding suitability, conducted by a vet, will also include a general examination of the bull; this is particularly important in older bulls. Included are examinations of the mouth, teeth, eyes and limbs, and whether the bull is still functionally capable of covering a cow.

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