Long-term growth of body, body parts and composition of gain of dairy goat wethers

Araújo, Raphael Pavesi; Vieira, Ricardo Augusto Mendonça; Rocha, Norberto Silva; Abreu, Matheus Lima Corrêa; Glória, Leonardo Siqueira; Júnior, Nardele Moreno Rohem; Fernandes, Alberto Magno

doi:10.1017/s0021859615000532

Cited by 9 publications

(5 citation statements)

References 45 publications

(94 reference statements)

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“…This decrease occurs in response to a large addition of another constituent in the body; namely fat. Similarly, Araujo et al (2015) reported that the protein content in the EBW of castrated dairy goats decreased as BW increased. Their findings might be related to the large range of BW evaluated (from 5 ± 1.4 to 84 ± 6.5 kg of BW), allowing them to observe fat content up to 396 g/kg of EBW (which was similar to the maximum body fat proportion observed in females herein, 390 g/ kg of EBW).…”

Section: Discussionmentioning

confidence: 87%

Sex effects on net protein and energy requirements for growth of Saanen goats

Souza

St-Pierre

Fernandes

et al. 2017

Journal of Dairy Science

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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 (NP) and net energy (NE) 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 log protein (g) = 2.221 (±0.0224) + 1.015 (±0.0165) × log EBW (kg). For females, the relationship was log protein (g) = 2.277 (±0.0288) + 0.958 (±0.0218) × log EBW (kg). Therefore, NP for males was greater than for females. The allometric equation for the energy content in the EBW of intact males was log energy (kcal) = 2.988 (±0.0323) + 1.240 (±0.0238) × log EBW (kg); of castrated males, log energy (kcal) = 2.873 (±0.0377) + 1.359 (±0.0283) × log EBW (kg); and of females, log energy (kcal) = 2.820 (±0.0377) + 1.442 (±0.0281) × log EBW (kg). The NE of castrated males was greater than that of intact males and lower than that of females. Using degree of maturity for estimating NP and NE, we could remove the differences between sexes. These results indicate that NP and NE 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.

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Section: Discussionmentioning

confidence: 87%

Sex effects on net protein and energy requirements for growth of Saanen goats

Souza

St-Pierre

Fernandes

et al. 2017

Journal of Dairy Science

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“…It has been reported that the inflection point of a growth curve represents puberty (the stage of sexual maturation) and afterwards, the growth rate decreases quickly until it reaches zero (Araújo et al ., 2015). In the current study, the inflection point of the BW growth curve occurred at 147 days (4.9 months) for females and 111 days (3.7 months) for castrated males and intact males.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, the variance for the model selected for each variable was modelled according to Araújo et al . (2015):where c and φ are the parameters, and μ is the predicted value of the weight of a specific organ. Following these tests, the models with modelled error structure were evaluated using the lowest value of AICc.…”

Section: Methodsmentioning

confidence: 99%

Visceral organ growth patterns in Saanen goats

et al. 2019

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Visceral organs play an important role in animals' energy requirements, so their growth must be well understood. The objective of the current study was to fit and compare growth curves that best describe body and visceral organ growth over time in Saanen goats of different sexes. Data were synthesized from seven studies in which curves were fitted to visceral organ growth over time for female, intact male and castrated male Saanen goats from 5 to 45 kg body weight. The liver, pancreas, spleen, rumen–reticulum, omasum, abomasum, small intestine, large intestine and mesenteric adipose tissue (MAT) data were fitted to eight models: simple linear regression, quadratic, monomolecular, Brody, Von Bertalanffy, logistic, Gompertz and Richards. The best-fit model was chosen based on the corrected Akaike information criterion and the concordance correlation coefficient. Model parameters for each sex were compared. Overall, the model that best described visceral organ growth was the logistic model. Sex did not influence the parameters that predicted organ growth (g), except for MAT, where females presented a lower tissue deposition rate and greater inflection point than males. Irrespective of sex, at the beginning of the growth curve, the liver accounted for 28 ± 1.1 g/kg of empty body weight, and the inflection point occurred at 1.7 months. The rumen–reticulum and large intestine presented higher growth rates in the first 2 months of life. Knowledge of the visceral organ growth curve is useful in improving the understanding of the effect of nutritional requirements for goats and must be used to optimize the nutritional plans.

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“…The parameter σ refers to the standard deviation, and the term σ 2 refers to the random error variance; thus, Equation 7 represents the homogeneous variance with the assumption of homoscedasticity (25,26). In this case, the homogeneous (Equations 7 and 10), exponential (Equations 8, 11, 13, and 15), and Power-of-the-Means (Equations 9, 12, 14, and 16) variance functions were tested, as they are the most commonly used (27)(28)(29). An attempt to accommodate heteroscedasticity was performed with Equations 8 to 16.…”

Section: Description Of Variance Functions and Combinationsmentioning

confidence: 99%

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

Herbster

Abreu²,

Neto³

et al. 2023

Front. Vet. Sci.

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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.

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Long-term growth of body, body parts and composition of gain of dairy goat wethers

Cited by 9 publications

References 45 publications

Sex effects on net protein and energy requirements for growth of Saanen goats

Sex effects on net protein and energy requirements for growth of Saanen goats

Visceral organ growth patterns in Saanen goats

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

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