A simple and fast sampling method for chemical analyses and densitometry of bones through rib biopsies in cattle

Abstract

RESUMO.-[Uma técnica simples e rápida de amostrar costelas para análises químicas e densitométricas por meio de biópsias em bovinos.] No presente estudo foi desenvolvida uma técnica para se obter, de forma rá-pida e simples, amostras da 12ª costela bovina por meio de biópsias. Avaliou-se a recuperação pós-operatória (durante 15 dias), o consumo de matéria seca (CMS) e o ganho de peso diário (GMD) de 36 novilhos Nelores, sendo nove animais controles e 27 submetidos à biópsia. A cada 30 dias biópsias de costelas foram realizadas em nove animais, usando uma furadeira elétrica acoplada a uma serra-copo com uma broca-guia de 3mm de diâme-tro. Esta técnica de biópsia permitiu obter amostras ós-seas de forma rápida, com o cirurgião operando sozinho e com os animais levemente sedados e em estação. Ao término do experimento (116 dias) o CMS e o GMD não foram afetados pelo procedimento cirúrgico. As amostras obtidas foram adequadas para exames radiográficos e subsequentes análises químicas. O conjunto de informações adquiridas com a técnica de biópsia de costelas permite aumentar a exatidão no diagnóstico da deficiência de fósforo em bovinos criados em pastagens e também realizar estudos sobre metabolismo ósseo em animais experimentais. We developed and evaluated a fast and simple method to obtain suitable bone samples for densitometry and chemical analysis through biopsies of the 12th rib of cattle. The postoperative recovery, dry matter intake (DMI) and average daily weight gain (ADG) was evaluated in 36 Nellore steers, nine of which were randomly selected for the control group and 27 others were rib biopsied. Every 30 days, rib biopsy was performed in nine steers, using a corded-electric pistol-grip drill coupled with a hole saw of a 3mm diameter pilot drill bit. This rib biopsy technique provided a suitable sample obtained in a fast way and allowed the surgeon to work alone with the animal slightly sedated and restrained in the crush. Dry matter intake (DMI) was not affected in biopsied animals. At the end of the experimental period (116 days) the average daily weight gain (ADG) was similar in the steers biopsied or not. The described method provided rib samples from cattle suitable for densitometry and chemical analysis of bone tissue without effects on health and performance. This information could greatly increase the accuracy for the diagnosis of phosphorus deficiency in cattle raised on pasture and allow the evaluation of bone metabolism in experimental animals.INDEX TERMS: Sampling method, chemical analysis, bone densitometry, rib biopsy, cattle, bone mineral density, Bos indicus, mineral deficiency, phosphorus.

Evaluation of an inexpensive needle test for the diagnosis of phosphorus deficiency and management of phosphorus supplementation for cattle: A multiple case study

“…This problem becomes especially predominant in natural or naturalized grassland areas and can lead to large differences. The evaluation of the % P in bone ash, CT, BSG and BMD requires the use of rib biopsies, which are invasive procedures (Malafaia et al 2017) and requires postoperative care which can complicate routine farm work specifically under extensive livestock conditions, which are predominant in Brazil. According to Jackson et al (2012) current dietary P status (deficient or adequate) can also be obtained from analyses of the faeces of cattle, which are grazing tropical pastures.…”

“…The rib samples were collected to obtain samples of a circular shape, with bone average weight of 3 g (Malafaia et al 2017). Rib samples were stored in clean plastic bags and frozen at -20°C.…”

“…Existing methods for the diagnosis of P deficiency involve chemical analysis of P in soil, forage, blood, faeces, and in bone (Read et al 1986, Suttle 2010, Jackson et al 2012, bone specific gravity measurements by Archimedes principle (Little 1972), bone mineral density estimation through radiographs of 12 th samples of ribs coupled with an aluminum step wedge (Malafaia et al 2017 or by single photon absorptiometry (Murray et al 1994, Coates et al 2015. These methods are time consuming, inaccurate and/or imprecise, invasive, expensive and because of their technical sophistication not easily done on farm.…”

Compensatory and catch-up growth in cattle

“…In cattle, bone biopsies have been mostly used for the diagnosis of mineral deficiency such as Ca, P and Mg (Little, 1972;Read et al, 1986;Malafaia et al, 2017). There are currently two in vivo methodologies of bone biopsy being used in cattle namely, rib and coccygeal vertebrae biopsy.…”

“…A more recent variation of this methodology collects a larger diameter biopsy (25 vs 15 mm) than the original method with the outer, medullary cavity and inner cortical layers collected in-tact (Malafaia et al, 2017). Biopsies collected under the method of Malafaia et al (2017) can also be utilized for densitometry by X-ray examination. However rib bone contains a much larger proportion of cortical 54 bone than trabecular bone.…”