Search

Made available in DSpace on 2020-12-12T02:38:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-01 Asociación Universitaria Iberoamericana de Postgrado Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The objective of this study was to evaluate the effects of sex on the daily net requirements of calcium (NCam), phosphorus (NPm), potassium (NKm), and magnesium (NMgm) for maintenance in Saanen goats from 5 to 45 kg BW. Two datasets were used: the first dataset was composed of 154 individual records (53 castrated males, 46 females, and 55 intact males) from three studies, and was used to estimate the NCam, NPm, NKm, and NMgm using the comparative slaughter technique (CST). The second dataset was assembled from 160 individual records (67 castrated males, 45 females, and 48 intact males) from four feeding trials, and was used to estimate the NCam, NKm, and NMgm in Saanen goats, using the minimum endogenous losses method (MEL). A meta-analytic approach was applied using a mixed model, in which sex was considered a fixed effect and study a random effect. Using the CST, the results revealed that sex did not affect NCam, NPm, or NKm (21.1, 22.8, and 4.0 mg/kg BW, respectively; P > 0.10), but NMgm of intact males was greater than for castrated males or females (2.6 versus 1.4 mg/kg BW; P = 0.077). On the other hand, sex did not affect the NCam, NKm, or NMgm (38.0, 25.2, and 7.4 mg/kg BW, respectively; P > 0.10), when MEL was used. The findings of this study suggest that Ca, P, and K requirements for maintenance in goats are not influenced by sex. Conversely, Mg requirement for maintenance should be discriminated by sex. Also, that P requirements for maintenance were significantly lower than current feeding system recommendations. Department of Animal Science UNESP - Universidade Estadual Paulista School of Environmental and Rural Science University of New England Department of Animal Science UNESP - Universidade Estadual Paulista Asociación Universitaria Iberoamericana de Postgrado: 1 Asociación Universitaria Iberoamericana de Postgrado: 166754 FAPESP: 2014/14734 FAPESP: 9

The aim of this study was to investigate the effects of sex on the net requirements of growth for Ca (NCa), P (NP), Na (NNa), K (NK), and Mg (NMg) in Saanen goats from 5 to 45 kg BW, with or without consideration of the degree of maturity. A database containing 209 individual records for Saanen goats (69 castrated males, 71 intact males, and 69 females) was generated from 6 comparative slaughter studies. Total amounts of Ca, P, Na, K, and Mg in the body were fitted to logarithmized allometric equations using empty BW (EBW) or degree of maturity (EBW/mature EBW) as regressors. The equations were fitted using a mixed model, where sex was considered a fixed effect and study was considered a random effect. Net requirements were estimated by the first derivative of the logarithmized allometric equations. Then, a Monte Carlo simulation was used to assess the uncertainty of calculated net requirement values. Without considering the degree of maturity, sex did not affect NCa, NP, and NNa ( > 0.10). Conversely, considering the degree of maturity, NCa and NP of intact males were 5% and 2%, respectively, greater than those of castrated males and females ( 0.10), NK decreased by 26% (i.e., without considering the maturity degree) or 27% (i.e., considering the degree of maturity) from 5 to 45 kg BW. Therefore, the consideration of maturity stage highlights differences across sexes in the net macromineral requirements for growth in goats. Elucidation of sex effects on macromineral requirements for growth may be useful for improving the accuracy of recommendations for mineral requirements for dairy goats.

Made available in DSpace on 2019-10-04T12:33:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01. Added 1 bitstream(s) on 2019-10-09T18:33:45Z : No. of bitstreams: 1 S1516-35982018000100618.pdf: 561491 bytes, checksum: a2ca38f27714aef67bc8f7426fee863e (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Asociacion Universitaria Iberoamericana de Postgrado (AUIP) The objective of this study was to investigate the multivariate relationship among body protein, fat, and macrominerals in Saanen goats of different sexes (castrated males, females, and intact males) using canonical correlation analysis. Individual records of 274 Saanen goats combined from 10 studies was used. Two sets of body constituents were established: the first one contained variables related to body protein or fat (canonical variate U) and the second contained variables related to body calcium, phosphorus, magnesium, sodium, or potassium (canonical variate V). Two canonical pairs were identified for each sex. However, irrespective of sex, first canonical pairs accounted for more than 87% of variance of the dependent variables, these only being used for the analysis. For canonical variate U 1, canonical weights for protein were greater than that for fat (in castrated males, protein = 0.62 and fat = 0.41; in females, protein = 0.96 and fat = 0.039; and in intact males, protein = 0.81 and fat = 0.20). For canonical variate V 1, in males, the highest canonical weights were for potassium and phosphorus, whereas the lowest were for calcium (in castrated males, potassium = 0.485 > phosphorus = 0.259 > magnesium = 0.206 > sodium = 0.129 > calcium = 0.081, and in intact males, potassium = 0.499 > phosphorus = 0.459 > sodium = 0.105 > magnesium = 0.024 > calcium = 0.001). On the other hand, in females, the highest canonical weights were for potassium and calcium, whereas the lowest was for magnesium (potassium = 0.539 > calcium = 0.201 > phosphorus = 0.178 > sodium = 0.088 > magnesium = 0.081). The current results may help to understand the role of sex on strength and nature of the association among body protein, fat, and macrominerals in growing Saanen goats. Univ Estadual Paulista, Dept Zootecnia, Jaboticabal, SP, Brazil Univ Estadual Paulista, Dept Zootecnia, Jaboticabal, SP, Brazil FAPESP: 2014/14734-9 Asociacion Universitaria Iberoamericana de Postgrado (AUIP): 166754-1

Requirements for growth in the different sexes remain poorly quantified in goats. The objective of this study was to develop equations for estimating net protein (NPG) and net energy (NEG) for growth in Saanen goats of different sexes from 5 to 45 kg of body weight (BW). A data set from 7 comparative slaughter studies (238 individual records) of Saanen goats was used. Allometric equations were developed to determine body protein and energy contents in the empty BW (EBW) as dependent variables and EBW as the allometric predictor. Parameter estimates were obtained using a linearized (log-transformation) expression of the allometric equations using the MIXED procedure in SAS software (SAS Institute Inc., Cary, NC). The model included the random effect of the study and the fixed effects of sex (intact male, castrated male, and female; n = 94, 73, and 71, respectively), EBW, and their interactions. Net requirements for growth were estimated as the first partial derivative of the allometric equations with respect to EBW. Additionally, net requirements for growth were evaluated based on the degree of maturity. Monte Carlo techniques were used to estimate the uncertainty of the calculated net requirement values. Sex affected allometric relationships for protein and energy in Saanen goats. The allometric equation for protein content in the EBW of intact and castrated males was log10 protein (g) = 2.221 (±0.0224) + 1.015 (±0.0165) × log10 EBW (kg). For females, the relationship was log10 protein (g) = 2.277 (±0.0288) + 0.958 (±0.0218) × log10 EBW (kg). Therefore, NPG for males was greater than for females. The allometric equation for the energy content in the EBW of intact males was log10 energy (kcal) = 2.988 (±0.0323) + 1.240 (±0.0238) × log10 EBW (kg); of castrated males, log10 energy (kcal) = 2.873 (±0.0377) + 1.359 (±0.0283) × log10 EBW (kg); and of females, log10 energy (kcal) = 2.820 (±0.0377) + 1.442 (±0.0281) × log10 EBW (kg). The NEG of castrated males was greater than that of intact males and lower than that of females. Using degree of maturity for estimating NPG and NEG, we could remove the differences between sexes. These results indicate that NPG and NEG differ among sexes in growing Saanen goats, and this difference should be accounted for by feeding systems. Including the degree of maturity as predictor cancels out those differences across sexes in protein and energy requirements.