Macromineral requirements for maintenance and growth in male and female hair sheep

Abstract

A better understanding of the nutritional requirements of sheep, especially in terms of minerals, is crucial for improving production. We estimated the net requirements for Ca, P, K, Mg, and Na for gain (NCag, NPg, NKg, NMgg, and NNag) and maintenance (NCam, NPm, NKm, NMgm, and NNam) in male and female hair sheep. Six datasets with 248 individual records of hair sheep (139 non-castrated males, 75 castrated males and 34 females) were used to estimate the net macromineral requirements for gain. To estimate the net macromineral requirements for maintenance, 52 observations (26 non-castrated and 26 castrated males) were used. A meta-analytical approach was applied, using non-linear mixed effects models and the study as a random effect. Based on information criteria for model selection, heterogeneous variance functions were more likely to describe mineral requirements with a low level of model selection uncertainty. The adopted criteria allowed the choice of the best models to represent the macromineral requirements. The chosen models explained the observed variability in the sex, and the choices were based on a low level of uncertainty (w ≥ 0.90). Irrespective of sex, NCag and NPg decreased with increasing BW from 10 to 30 kg and average daily gain (ADG) of 150 g/day, ranging from 1.71–1.38; 1.83–1.57; 1.82–1.51 of Ca and 0.86–0.66; 0.92–0.78; 0.92–0.75 of P for non-castrated males, castrated males, and females, respectively. The NKg remained constant, with mean values of 0.26 g/day. The NNag range was 0.17 to 0.14 g/day for non-castrated males, 0.20 to 0.25 g/day for females, and constant (0.18 g/day) for castrated males with an increase in BW from 10 to 30 kg and an ADG of 150 g/day. Macromineral requirements for maintenance (mg/kg BW) and retention (%) were 23.70 and 54.30 for Ca, 25.33 and 79.80 for P, 11.74 and 5.00 for K, 2.63 and 8.50 for Mg, and 7.01 and 8.10 for Na for males. The International Committees did not provide inferences about the sex influence on mineral requirements. Our study indicates that sex is one factor that influences the macromineral requirements for gain. The information generated in this study can be used to optimize the mineral management of hair sheep in the growing phase in tropical regions.

Calcium Requirement of Yunnan Semi-fine Wool Rams (Ovis aries) Based on Growth Performance, Calcium Utilization, and Selected Serum Biochemical Indexes

“…Based on the total endogenous loss of Ca, the ARC (1980) estimated that the daily net Ca requirement for the maintenance of sheep is 0.016 g/kg of BW [ 8 ]. Recent research carried out by Herbster et al [ 11 ] suggests that the daily net Ca requirement for the maintenance of wool sheep is 0.024 g/kg of BW, which is 50% greater than that of the ARC (1980) value but slightly lower than the results in our study. In this study, the net Ca requirement for maintenance is similar to that reported by Pereira et al for Somali lambs [ 10 ], and it is lower than that reported by Sousa et al for Santa Ines sheep, which is 0.036 g/kg of BW [ 27 ].…”

“…The daily total Ca requirement was estimated to be 0.676 g/kg of BW 0.75 based on the group with the highest ADG (278.43 g/d), which resulted in the total Ca requirement of 10.75~12.71 g/d for 40-50 kg YSW rams. The NRC (2007) recommends a Ca requirement of 4.80–4.90 g/d for 8-month-old growing rams of 40–50 kg with a daily gain of 250 g [ 9 ], and Herbster et al [ 11 ] suggested a total Ca requirement of 4.70~5.16 g/d for 30 kg sheep gaining 200 g/d. The total Ca requirement value calculated in this study is almost twice the values calculated by the NRC (2007) and Herbster et al In addition, Ma et al reported that the Ca requirement of 35~50 kg Dorset × thin-tailed Han rams is 10.70–11.60 g/d [ 14 ], which is close to our results.…”

“…Pereira et al [ 10 ] reported that the net Ca requirement for the maintenance of Somali lambs is 0.030 g/kg of BW, which is nearly twice the value reported by ARC (1980). Herbster et al [ 11 ] suggested that the net Ca requirement for the maintenance of male hair sheep is 0.024 g/kg of BW, which is 50% greater than the value reported by ARC (1980). Additionally, some studies have demonstrated that the net Ca requirements to achieve weight gain in growing German merino lambs and Dorper crossbred sheep are 14.00 g/kg of EBWG [ 12 ] and 10.52~12.35 g/kg of EBWG [ 13 ], respectively.…”