Mineral requirements for growth of wool and hair lambs

Abstract

The present study was conducted to determine the body composition and the mineral requirements for growth of wool and hair lambs. A total of 34 castrated lambs with an initial body weight (BW) of 19.9±0.8 kg were used; 17 of these lambs were of the genotype Ideal × Ile de France and 17 were Santa Inês. Ten lambs (5 of each genotype) were slaughtered at the beginning of the experiment to establish their initial body composition. The remaining lambs were assigned to one of three diets (40% roughage and 60% concentrate, 60% roughage and 40% concentrate, or 80% roughage and 20% concentrate) in a 2 × 3 factorial arrangement of treatments. All of the diets were provided ad libitum. When the group under 40% roughage and 60% concentrate reached 35 kg BW, all of the animals were slaughtered. Linear regressions were used to determine the relationship between the shrunk BW and the empty body weight (EBW) for each genotype. These equations were compared and revealed differences between the genotypes. The allometric equations were calculated using the relationship between the amount of minerals and the EBW. The equations of a given mineral for each genotype were compared to verify if they were statistically different. The equations for calcium, phosphorus, magnesium and sodium differed between genotypes. The same equations were used to estimate the major body mineral composition per kilogram of EBW. The net requirement for gain of the fleece-free Ideal × Ile de France lambs ranged from 7.77 to 6.80 g Ca, 4.54 to 4.14 g P, 0.30 to 0.27 g Mg, 1.18 to 1.07 g K and 0.84 to 0.76 g Na per kg BW gain, and the requirements of the Santa Inês animals ranged from 9.57 to 8.37 g Ca, 5.39 to 4.91 g P, 0.36 to 0.33 g Mg, 1.18 to 1.07 g K and 0.90 to 0.81 g Na per kg BW gain for the lambs weighting 20 to 35 kg. Santa Inês lambs showed higher requirements for Ca, P, Mg and Na.

Mineral Metabolism in Singleton and Twin-pregnant Dairy Goats

“…Factors such as age, physiological stage and genotype affect the mineral demands of animals. The different genotypes are known to exhibit differences in body composition and metabolism (Teixeira et al, 2013). The particularities of the genotypes have been rarely considered in studies on nutritional demands, especially regarding the mineral needs of small ruminants (NRC, 2007).…”

“…Additionally, mineral requirements are also affected by the genotype of the animals (Teixeira et al, 2013), but in the literature do not exist reports comparing dairy goat breeds. The world's largest dairy herd consists of the Saanen breed, and in some countries Oberhasli goats are among the main breeds in their dairy goats herd (Irano et al, 2012).…”

Trace mineral requirements for growth of Moxotó goats grazing in the semiarid region of Brazil

“…In this study, we found that when the Zn, Fe, Cu, and Co contents were expressed based on the metabolic weight (mg/kg 0.75 of EBW) (Table 3), a linear increase was observed in response to the increased level of supplementation. This concentration pattern may have been a reflection of the increased mineral intake and weight gain, which led to a better body development of the animals as the increase in BW has been noted as one of the main discriminating factors in body composition (Mahgoub and Lu, 1998;Bellof and Pallauf, 2007;Fernandes et al, 2007;Araújo et al, 2010;Fernandes et al, 2012;Teixeira et al, 2013). Silva et al (2013) observed that trace element concentrations in the empty body of Canindé goats increased as feed intake levels increased.…”

“…These findings indicate that the manganese net requirements for growth are higher in goats than in sheep. Animals of different genotypes are well known to exhibit differences in their mineral requirements due to the differences in their body composition (Teixeira et al, 2013).…”

Macromineral requirements of Dorper×thin-tailed Han crossbred female lambs

“…Factors such as gender, genotype, age, and physiological state influence the animals' mineral requirements (Bellof et al 2006;Bellof and Pallauf,. 2007;Fernandes et al 2012;Teixeira et al 2013), because lambs in various situations may have different body composition , and at the same time the mineral distribution changes depending on the tissue type (Bellof et al 2006;Ji et al 2012), but such differences in requirements have rarely been considered in studies. Chizzotti et al (2009) reported no differences in the net requirements for growth of all macrominerals among genders in bulls, steers, and heifers of Nellore and Red Angus crossbreds, and feeding systems for sheep including the recommended mineral requirements are also independent of the genotype and gender (ARC 1980;NRC 2007;CSIRO, 2007;Suttle, 2010).…”