|
|
|
|
|
| Dornelles,Mariana de Almeida; Rorato,Paulo Roberto Nogara; Gama,Luis Telo Lavadinho da; Breda,Fernanda Cristina; Bondan,Carlos; Everling,Dionéia Magda; Michelotti,Vanessa Tomazetti; Feltes,Giovani Luis. |
| ABSTRACT: The objective of this study was to compare the functions of Wilmink and Ali and Schaeffer with Legendre polynomials in random regression models using heterogeneous residual variances for modeling genetic parameters during the first lactation in the Holstein Friesian breed. Five thousand eight hundred and eighty biweekly records of test-day milk production were used. The models included the fixed effects of group of contemporaries and cow age at calving as covariable. Statistical criteria indicated that the WF.33_HE2, LEG.33_HE2, and LEG.55_HE4 functions best described the changes in the variances that occur throughout lactation. Heritability estimates using WF.33_HE2 and LEG.33_HE2 models were similar, ranging from 0.31 to 0.50. The LEG.55_HE4... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ali and Schaeffer function; Classes of residual variance; Lactation curve; Legendre polynomials; Wilmink function. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016000901649 |
| |
|
|
| Cruz,Diego Augusto Campos da; Savegnago,Rodrigo Pelicioni; Santana,Annaíza Braga Bignardi; Peixoto,Maria Gabriela Campolina Diniz; Bruneli,Frank Angelo Tomita; Faro,Lenira El. |
| ABSTRACT: The aim of this study was to explore the pattern of genetic lactation curves of Guzerá cattle using cluster analysis. Test-day milk yields of 5,274 first-lactation Guzerá cows were recorded in a progeny test. A total of 34,193 monthly records were analyzed with a random regression animal model using Legendre polynomials to fit additive genetic and permanent environmental random effects and mean trends. Hierarchical and non-hierarchical cluster analyses were performed based on the EBVs for monthly test-day milk yield, peak yield, lactation persistency, and partial cumulative and 305-day yields. The heritability estimates for test-day milk yields ranged from 0.24 to 0.52. Cluster analysis identified animals in the population that belong to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Breeding values; Lactation curve; Random regression. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016000701281 |
| |
|
| |
|
|
| KAWATA, Yukichika; 河田, 幸視. |
| This paper reviewed existing lactation models which are mainly applied to dairy cows. There are many related papers; in 50 papers, 90 lactation curves are presented. The most frequently used model is Wood’s (1967), which was quoted in 75 papers. In general, the earlier the year of the model presented in the paper, the higher its frequency of quotation. Wood’s (1967) model was followed by other models from Brody et al. (1923), Sikka (1950), Nelder (1966), Dave (1971), Cobby et al. (1978), Ali et al. (1987), Wilmink (1987), and Grossman et al. (1988); these models were quoted 9, 8, 17, 11, 9, 12, 18, and 11 times, respectively. The classic models, which have been mainly described as the function of time, have less room for improvement and have become... |
|
Palavras-chave: Lactation curve; Classic model; Test day model; Review; Cows; 泌乳曲線; Test day model; レビュー; 乳牛. |
| Ano: 2011 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3113 |
| |
|
|
| 山口, 諭; 河原, 孝吉; 後藤, 裕作; 増田, 豊; 鈴木, 三義. |
| 本分析では，乳量，乳脂量，無脂固形分量，乳タンパク質量，乳脂率，無脂固形分率，乳タンパク質率および体細胞数スコア（SCS）の8形質に対し，泌乳曲線モデルの適合性を検討した．データは，2000年から2004年に社団法人北海道酪農検定検査協会に集積されたホルスタイン346，221頭の初産から11産までの検定日記録5,645,976が使用された．適合性を検討した23種類のモデルとは，1次から5次のルシャンドル多項式モデル（L1，L2，L3，L4およびL5），ルシャンドル多項式にWilminkの指数関数を加えたモデル（L1W，L2W，L3W，L4WおよびL5W），さらに，対数関数と周期関数を組み合わせた3次から5次の13種のモデルである．泌乳曲線モデルの適合性の検討には，赤池の情報量規準（AIC），ベイズ流情報量規準（BIC），決定係数および平均誤差の中で，パラメータ数のみならず観測値数も考慮してモデルの適合性を判断できるBICを主に使用した．乳量，乳脂量，無脂固形分量および乳成分率における泌乳曲線は，L4，L3W，L4WおよびL5Wのモデルが高い適合性を示した．乳タンパク質量およびSCSに関して適合性が高い泌乳曲線は，対数関数および周期関数の組み込まれたモデルであった．本研究で選択された泌乳曲線を用いることにより，標準泌乳曲線として飼養管理の有益な指標として活用できる． |
|
Palavras-chave: Holsteins; Lactation curve; Legendre polynomial; Logarithm; Wilminks exponential. |
| Ano: 2007 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2596 |
| |
|
|
| Franzoni,Ana Paula Saldanha; Gloria,Joana Ribeiro da; Costa,Anna Luiza Belli de Souza Alves; Martins,Ronaldo Alves; Amaral,Thiago Fernandes; Azevedo,Rafael Alves de; Campos,Ernane Ferreira; Coelho,Sandra Gesteira. |
| Abstract: The objective of this work was to describe the effect of genetic composition on body condition score (BCS), on total lactation production, and on metabolic and hormone profiles of Holstein x Gyr cows under the same pre- and postpartum management conditions. The genetic groups ½ (n=8), – (n=10), and ≥⅞ (n=10) Holstein x Gyr (HG) were evaluated within the same farm, and all of them showed typical lactation curves. The time required to reach peak production did not differ between groups. The groups also did not differ as to time to reach the lowest BCS after calving or to recover BCS after calving, nor as to their BCS values in the week of first ovulation, number of weeks required for first ovulation, and service period. However, ½ HG cows had... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bos indicus; Bos taurus; GH; IGF-1; Lactation curve; Transition period. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000300371 |
| |
|
|
| Peixoto,Maria Gabriela Campolina Diniz; Santos,Daniel Jordan de Abreu; Borquis,Rusbel Raul Aspilcueta; Bruneli,Frank Ângelo Tomita; Panetto,João Cláudio do Carmo; Tonhati,Humberto. |
| The objective of this work was to compare random regression models for the estimation of genetic parameters for Guzerat milk production, using orthogonal Legendre polynomials. Records (20,524) of test-day milk yield (TDMY) from 2,816 first-lactation Guzerat cows were used. TDMY grouped into 10-monthly classes were analyzed for additive genetic effect and for environmental and residual permanent effects (random effects), whereas the contemporary group, calving age (linear and quadratic effects) and mean lactation curve were analized as fixed effects. Trajectories for the additive genetic and permanent environmental effects were modeled by means of a covariance function employing orthogonal Legendre polynomials ranging from the second to the fifth order.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bos indicus; Covariance functions; Lactation curve; Test-day model. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2014000500372 |
| |
|
|
| Contreras,Víctor Inocencio Pacheco; Bracamonte,Gaspar Manuel Parra; Bustamante,Luis Arístides López; Medina,Víctor Ricardo Moreno; Rincón,Ana María Sifuentes. |
| To determine the effects of a number of non-genetic factors on milk components and estimate their indirect relationships with weaning weight (WW205), the percentages of protein, fat, lactose and solids non-fat in Charolais cows from Mexico were estimated. Lactation period (LP) and calving season (CS) had significant effects on protein and fat, whereas lactose and solids non-fat were only affected by the LP. Sire line and age of the dam had significant effects on calf birth weight, while CS affected WW205. Residual correlations between milk components and WW205 suggest a low but significant correlation with lactose. These results demonstrate the importance of several non-genetic factors on the composition of milk from Charolais cows managed under extensive... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beef cattle; Lactation curve; Milk components. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982015000600207 |
| |
|
|
|
