Get 20% Off + $20 Signup Bonus ! Limited Time, Hurry !
Get 20% Off + $20 Signup Bonus ! Limited Time, Hurry !
Securing Higher Grades Costing Your Pocket? Book Your Assignment at The Lowest Price Now!
Add File

Error goes here

Files Missing!

Please upload all relevant files for quick & complete assistance.

VETS90096 Veterinary Professional Practice

tag 0 Download 11 Pages / 2,627 Words tag 26-10-2020


Development of a Practical Method of Predicting the Presence of Long Spermatids in Alpacas.

Inroads have been made into the development of more advanced breeding technologies in camelids around the world (Vaughan, 2002, Abraham, 2015). The aim of this research is to act as an adjunctive and practical method for the early selection of the best quality sperm particularly in alpacas.

The urogenital tract including testicular anatomy in camelids has been described by others (Brown, 2000, Sumar, 1996).

The aims of this study are to add to an emerging body of work contributing to prediction/selection of the suitability to breed in male alpacas. To attempt to further equip farmers with practical advice in choosing the best sires they can. This will assist in narrowing in on the best genetic gains for alpacas in Australia by choosing for desirable traits for fleece diameter and colour and also males with higher fertility potential. Due to the relatively slow genetic gain in this species, sire choice is paramount. In both cattle and sheep, testicular size has direct correlation to the volume of sperm the animal can produce. It is then reasonable to expect that camelids are similarly correlated. 80 pairs of alpaca testicles were measured in this study. According to results found by D. B. Galloway in 2000 that total scrotal width was the best predictor for the amount of spermatozoa present. He recommended that male alpacas can then be ranked according to the onset of testicle development.   

Solidification of an easy and repeatable method of testicular cell maturation prediction is important to advance the alpaca fibre industry in Australia and further afield. The 80 pairs of testicles were measured in situ and then assessed histologically to aid in defining the measurable characteristics of highly fertile potential sires.

Traditionally sires have been selected on the basis of early prepuce-penis liberation as yearlings. Only 8% of males have achieved this at age 1. Sumar states that sires are also chosen by their testicular size based on an assumption that there would be a direct relationship as seen in other species (Sumar 1996)

A Swedish study found that as a single measure, testicular length was a good predictor of the presence of sperm (Abraham et al 2016).

Materials and methods:

Castration of 80 animals took place on a property at Merrijig in North-East Victoria, Australia.

Before surgical castration:

The ear tag number, birth date, weight, thoracic circumference, whithers height and body condition score was recorded for each animal. It was ensured that both testicles were present and then the length and width of both the right and left testicles were measured – both length and width using digital calipers.  


Anaesthesia and analgesia – buccalgesic designed to have oral xylazine added (10mg/ml oral meloxicam) with oral xylazine (20mg/ml) added for sedation. Overall concentration once mixed were 8mg/ml of meloxicam and 4mg/ml of oral xylazine.

Standing surgical castration, consisting of two scrotal incisions parallel to and 1cm lateral to the median raphe. Incision length was sufficient to remove the testicle and to allow for good post-operative drainage. Closed castration method, removing the adipose from the wound to minimise the risk of infection or delayed healing. An angiotribe was applied for one minute prior to testicle removal, to crush the cord. This method was used to guard against the risk of pulling the testicular artery off the aorta. If it was deemed that the oral analgesia was not effective enough for some individuals, 1ml lignocaine was injected into each spermatic cord.

Post surgical care:

Trisolfen was sprayed onto/into the surgical incisions post castration.

All castrated animals were turned out onto clean, dry, good quality pasture. Alpacas were walked around for five minutes twice a day to keep wounds open and draining well. Walking the animals helped in detection of reluctance to move and these animals could be re-examined. Animals were observed at 24 and 48 hours post surgery, then again at 10 and 24 days post surgery by Dr Jane Vaughan.

Sample collection and preparation:

Testicles were immediately stored in Bouin’s fixative. A sharp scalpel blade was used to take a single 5mm longitudinal section from the left and right testicles. All samples were then stored in Bouin’s fluid for 24 hours, so to preserve the cellular nuclear integrity within the delicate tissue. Sections were then transferred to 70% alcohol before histological preparation.

Microtome slices were then prepared with Haematoxylin and Eosin stain.

Each microscope slide was then examined for the stage of spermatogenesis in the seminiferous tubules. 40 seminiferous tubule cross-sections were examined per testicle slice, one slice per testicle.


The data was split into two age groups, animals below three years and those equal to 3 years and above (see table 1 for details).

Table 1:

Age group



Mean age

(years ± sem*)

Range (years)

Mean weight

(kg ± sem)

Mean testicular length

(cm ± sem)

Percent of males with spermatids

Mean percent (± sem) of tubules with spermatids


< 3


2.4 ± 0.03


46.2 ± 1.09

3.57 ± 0.07


51.4% ± 4.59


≥ 3


3.5 ± 0.07



59.7 ± 1.32

3.98 ± 0.06


75.4% ± 3.53



Every alpaca > 3.2 years (n=25) had long spermatids present. Within the older group of alpacas, 80% of animals have over 70% long spermatids (71.25%-93.75% ave=82.86%).

Every male with mean testicular length > 3.38 cm was producing long spermatids.

Possibly 10 animals with unilateral hypoplasia (8% with at least 0.5 cm [range between 0.5-0.7 cm] variation between R & L testes length).

Testicular length was chosen as the best measurement due to there being more variation with age. The width is not as variable between age groups. (1.59cm is difference between the mean testicular length age groups, 0.44cm is the difference between the mean testicular width age groups) There was also a good correlation between testicular length and the presence of long spermatids.


The intention of this research was to discover a good practical method for predicting the fertility potential in male alpacas. While there was a correlation between testicular width and the percentage of long spermatids visualised, the correlation between testicular length and percentage long spermatids was stronger. The correlation was still not as strong as expected After reviewing the data, it was found that alpacas are much more varied than other production animals when it come to body size and testicular size relating to each other or age or to the types of cells present in the testicles. This study has found the best correlation to be between testicular length and percentage of long spermatids (r2=0.49). Some general cut off measurements can be used to make management decisions. This is useful, as just with rams and bulls, alpaca testicles can be measured as part of a breeding soundness exam.

Some general cut off measurements can be used to make management decisions also. It was demonstrated that all animals with testicular length exceeding 3.38cm had long spermatids.  Further in this cohort, all animals over 3.2 years of age were producing long spermatids, supporting historical choices to mate 3 year old males (Sumar, 1996)

Ideally, young alpacas with longer testicles should be selected for breeding. This is a practical in vivo measurement which can be used by veterinarians and experienced alpaca farmers alike.

Download Sample Now

Earn back the money you have spent on the downloaded sample by uploading a unique assignment/study material/research material you have. After we assess the authenticity of the uploaded content, you will get 100% money back in your wallet within 7 days.

Unique Document

Under Evaluation

Get Money
into Your Wallet

Total 11 pages

Cite This Work

To export a reference to this article please select a referencing stye below:

My Assignment Help (2020) Veterinary Professional Practice [Online]. Available from:
[Accessed 24 May 2022].

My Assignment Help. 'Veterinary Professional Practice' (My Assignment Help, 2020) <> accessed 24 May 2022.

My Assignment Help. Veterinary Professional Practice [Internet]. My Assignment Help. 2020 [cited 24 May 2022]. Available from:

Many students find an annotated bibliography to be troubling. Adding to that, it takes a lot of time for listing out citations in articles, books and documents. If you have any query regarding how to write an annotated bibliography, feel free to contact To make your job easier, we can help you understand the bibliography format thoroughly.
We feel proud to announce that we have advanced level plagiarism software that will help to make your academic paper free of plagiarism.

Latest Management Samples

MPM755 Building Success In Commerce

Download : 0 | Pages : 9
  • Course Code: MPM755
  • University: Deakin University
    icon is not sponsored or endorsed by this college or university

  • Country: Australia

Answers: Introduction The process of developing a successful business entity requires a multidimensional analysis of several factors that relate to the internal and external environment in commerce. The areas covered in this current unit are essential in transforming the business perspective regarding the key commerce factors such as ethics, technology, culture, entrepreneurship, leadership, culture, and globalization (Nzelibe, 1996; Barza, 2...

Read More arrow

SNM660 Evidence Based Practice

Download : 0 | Pages : 8
  • Course Code: SNM660
  • University: The University Of Sheffield
    icon is not sponsored or endorsed by this college or university

  • Country: United Kingdom

Answers: Critical reflection on the objective, design, methodology and outcome of the research undertaken Assessment-I Smoking and tobacco addiction is one of the few among the most basic general restorative issues, particularly to developed nations such as the UK. It has been represented that among all risk segments smoking is the fourth driving purpose behind infections and other several ailments like asthma, breathing and problems in the l...

Read More arrow Tags: Australia Maidstone Management Business management with marketing University of New South Wales Masters in Business Administration 

BSBHRM513 Manage Workforce Planning

Download : 0 | Pages : 20
  • Course Code: BSBHRM513
  • University: Tafe NSW
    icon is not sponsored or endorsed by this college or university

  • Country: Australia

Answer: Task 1 1.0 Data on staff turnover and demographics That includes the staffing information of JKL industries for the fiscal year of 2014-15, it can be said that the company is having problems related to employee turnover. For the role of Senior Manager in Sydney, the organization needs 4 managers; however, one manager is exiting. It will make one empty position which might hurt the decision making process. On the other hand, In Brisba...

Read More arrow

MKT2031 Issues In Small Business And Entrepreneurship

Download : 0 | Pages : 5
  • Course Code: MKT2031
  • University: University Of Northampton
    icon is not sponsored or endorsed by this college or university

  • Country: United Kingdom

Answer: Entrepreneurial ventures Entrepreneurship is the capacity and willingness to develop, manage, and put in order operations of any business venture with an intention to make profits despite the risks that may be involved in such venture. Small and large businesses have a vital role to play in the overall performance of the economy. It is, therefore, necessary to consider the difference between entrepreneurial ventures, individual, and c...

Read More arrow Tags: Turkey Istanbul Management University of Employee Masters in Business Administration 

MN506 System Management

Download : 0 | Pages : 7

Answer: Introduction An operating system (OS) is defined as a system software that is installed in the systems for the management of the hardware along with the other software resources. Every computer system and mobile device requires an operating system for functioning and execution of operations. There is a great use of mobile devices such as tablets and Smartphones that has increased. One of the widely used and implemented operating syste...

Read More arrow Tags: Australia Cheltenham Computer Science Litigation and Dispute Management University of New South Wales Information Technology 

Content Removal Request

If you are the original writer of this content and no longer wish to have your work published on then please raise the content removal request.

5% Cashback

On APP - grab it while it lasts!

Download app now (or) Scan the QR code

*Offer eligible for first 3 orders ordered through app!

callback request mobile
Have any Query?