Net mineral requirements for the growth and maintenance of Somali lambs

Abstract

Minerals are limiting factors in animal production, and the knowledge of mineral requirements for livestock is crucial to the success of a commercial enterprise. Hair sheep may have different mineral requirements than those presents by the international committees. A study was carried to evaluate the net calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), potassium (K), zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) requirements for the growth and maintenance of Brazilian Somali lambs. A total of 48 hair lambs (13.5±1.8 kg) aged 60±15 days were allocated to individual pens. Eight animals were slaughtered at the beginning of the experiment to serve as a reference group to estimate initial empty BW (EBW) and initial body composition. The remaining lambs (n=40) were assigned to a completely randomized design with eight replications in five levels of metabolizable energy (ME; 4.93, 8.65, 9.41, 10.12 and 11.24 MJ/kg DM). When the lambs of a given treatment reached an average BW of 28 kg, they were slaughtered. Initial body composition was used to calculate the retention of minerals. Mineral body composition was fit using a logarithmic equation in the form of a nonlinear model. The maintenance requirements were estimated from regressions of mineral retention in the empty body on mineral intake. The body mineral concentration decreased in lambs with a BW ranging from 15 to 30 kg. The net mineral requirements (100 g/day of average daily gain (ADG)) decreased from 0.52 to 0.51 g for Ca, 0.28 to 0.23 g for P, 0.02 to 0.02 g for Mg, 0.09 to 0.08 g for Na, 0.11 to 0.09 g for K, 1.30 to 1.08 mg for Zn, 3.77 to 3.22 mg for Fe, 0.08 to 0.06 mg for Mn and 0.09 to 0.08 mg for Cu when BW increased from 15 to 30 kg. The daily net requirements for maintenance per kilogram of BW were 30.13 mg of Ca, 27.58 mg of P, 1.26 mg of Mg, 4.12 mg of Na, 8.11 mg of K, 0.133 mg of Zn, 0.271 mg of Fe, 0.002 mg of Mn and 0.014 mg of Cu. The results of this study indicate that the net mineral requirements for weight gain and maintenance in Brazilian Somali lambs are different than the values that are commonly recommended by the main evaluation systems for feed and nutritional requirements for sheep. These results for the nutritional requirements of minerals may help to optimize mineral supply for hair sheep.

Macromineral and trace element requirements for Santa Ines sheep

“…In tropical scenarios, the nutritional requirements recommended by international committees may not be adequate to meet the physiological needs at different stages of animal life. Factors such as mathematical, environmental conditions 3 , genotype 16 , body composition, sex, and feed quality 7 may influence the mineral requirements. In our study, the higher DM and mineral intake in sheep fed ad libitum resulted in greater performance (final BW, EBW, and ADG), indicating that the animals’ response was directly influenced by the level of intake.…”

“…In general, the dataset of those committees is based on data obtained from trials using wool sheep. However, it is unknown whether the requirements of hair sheep in the tropics have been carefully considered, especially given their phenotypic differences, potential for weight gain, and body composition, which are known to affect the nutritional requirements of animals 7 .…”

Net micromineral requirements for maintenance and growth of ewe lambs at the latter fattening period

“…Taking into consideration of accuracy, environmental safety and strong operability [9,10], comparative slaughter has recently been accepted as a better method to estimate mineral require ments for sheep and goats [8,1115]. Previous studies have mostly addressed the trace element requirements of lambs during their initial stages of growth [12,15], however, such reference data are suboptimal for lambs' diet formulations in their latter fattening periods, as the mineral requirements vary with the gender, breed, final body weight (BW), and developing stages [1,16]. Therefore, this work estimates the net requirements of micro minerals (Cu, Fe, Mn, Zn) for the maintenance and growth of Dorper × Jinzhong crossbred female lambs at the latter fattening period.…”

“…Net mineral requirements for maintenance of ruminants can be estimated by various methods including endogenous losses, comparative slaughter, and radioisotopes [ 8 ]. Taking into consideration of accuracy, environmental safety and strong operability [ 9 , 10 ], comparative slaughter has recently been accepted as a better method to estimate mineral requirements for sheep and goats [ 8 , 11 – 15 ]. Previous studies have mostly addressed the trace element requirements of lambs during their initial stages of growth [ 12 , 15 ], however, such reference data are sub-optimal for lambs’ diet formulations in their latter fattening periods, as the mineral requirements vary with the gender, breed, final body weight (BW), and developing stages [ 1 , 16 ].…”

Determination of the trace minerals requirements for maintenance and growth of 35–50 kg Dorper × Hu crossbred ram lambs

“…In addition, feeding a high level of Cu and Zn exaggerates the excretion of these minerals, which is a potential threat to the environment (Underwood and Suttle 1999). Hence, a precise determination of trace mineral requirements together with their balanced feeding could minimise their excretion and consequently contribute to environment protection (Chizzotti et al 2009; Costa e Silva et al 2015;Castro et al 2019;Pereira et al 2019).…”