João Pedro Velho

Componentes do peso vivo e órgãos viscerais de bezerros machos de origem leiteira ao nascimento, 50 e 110 dias de vida

The work was carried out to evaluate the to growth in kg and in relation to live weight (% LW) and to empty body weight (% EBW) of the viscera and other corporal components with increase of the age of Holstein male calves. Eighteen animals distributed in three slaughter age (six at birth, six at 50 days and six at 110 days of age), weighing between 30 and 100 kg LW or 27.57 and 74.27 kg EBW were slaughtered. After the slaughter, the viscera and corporal components were retired and heavy. Data were submitted to a correlation and regression analyses. An increment of absolute weight was observed of the viscera and other components of the live weight in agreement with the increase of LW and EBW, in intense way to the 50 days and moderated of the 50 to the 110 days of age. However, there was a decreased of the relative weight (% LW and % EBW) in accordance that the animals grew, for the stomach, intestines and content gastrintestinal relative weight that stayed growing until the 110 days of age.

Desenvolvimento de Estômago de Bezerros Holandeses Desaleitados Precocemente 1

The present work was carried out to evaluate the growth of stomach compartments of early weaned Holstein calves. The animals were fed concentrates and hay from the second and third week of age respectively. Eighteen animals were allotted to a completely randomized design, with three treatments (slaughter age). Six calves were slaughtered at birth, at 50 days at 110 days of age; the stomachs were withdrawn and the weight and volume of each compartment measured. Data were submitted to correlation and regression analysis through the SAS statistical program, (1996). An increase of the capacity of all the stomachs compartments was verified with the progress of the age of the calves, but with growth rates differentiated among the compartments. The increase of the reticulo- rumen growth and the decrease of the abomasum growth with increase of age were observed. Up to 50 days of age the proportion of the reticulo-rumen and abomasum stomach compartments was changed, but the omasum maintained a constant rhythm of development.

Composição corporal e exigências líquidas de proteína e energia para ganho de peso de bezerros machos de origem leiteira do nascimento aos 110 dias de idade

The work was carried out to evaluate the body composition and the net requirements of protein and energy for weight gain of dairy calves in the beginning of the productive life were determined. Eighteen Holstein bulls calves at newly born to 110 days of age weighing between 30 and 100 kg were used. Six animals were slaughtered at the beginning of the experiment (to birth) and other twelve animals were full fed until a pre-established slaughter of age. Six animals were slaughtered when completed 50 days and six when completed 110 days of age. Regression analysis of the logarithm of protein, fat and energy corporal amount in function of the empty body weight (EBW) logarithm were fitted. The net requirements of protein and energy for weight gain were obtained by derivation of the prediction equations of corporal composition. The body content of protein, fat and energy increased in according to the LW increase. The net requirements of protein and energy for empty body weight gain (EBWG) increased as the empty body weight changes from 27.57 to 74.27 kg. The net requirements changed from 200.60 to 229.21 g/kg EBWG for protein, from 1.93 to 2.99 Mcal/kg EBWG for energy.

Características Quantitativas, Composição Física Tecidual e Regional da Carcaça de Bezerros Machos de Origem Leiteira ao Nascimento, 50 e 110 Dias de Idade 1

The study was carried out at the Animal Production Department of the Universidade Federal of Santa Maria-RS, to evaluate the effect of age on carcass characteristics and composition of carcass regions (forequarter, rib, hindquarter and section 9 a - 11 a ribs) at newly born calves. Eighteen animals distributed in three slaughter age (six at birth, six at 50 days and six at 110 days of age), were used. The quantitative characteristics of slaughter live weight (40.8; 59.7 and 87.0 kg), hot (22.7; 30.9 and 41.9 kg) and cold carcass weight (21.8; 30.1 and 40.7 kg), carcass length (63.8; 75.0 and 82.8 cm), round thickness (9.3; 10.0 and 12.2 cm), hand perimeter (18.2; 22.1 and 23.3 cm) and Longissimus dorsi muscle area (16.8; 20.2 and 22.4 cm 2 ) were increased linearly, according to the age increase. Hot (55.4; 51.6 and 48.1%) and cold (53.2; 50.3 and 46.7%) carcass dressing percentage decreased linearly with age increase. As the animals grew the proportions of forequarter (37.9; 35.4 and 35.0%) and bone tissue in carcass (29.8; 28.6 and 25.5%) were reduced and those of hidquarter (47.3; 50.6 and 51.0%) and fat carcass tissue (4.9; 5.4 and 7.3%) were increased.

Predição da composição física e química da carcaça a partir da composição das diferentes regiões corporais de bezerros machos de origem leiteira até os 110 dias de vida

O presente estudo foi desenvolvido com o objetivo de desenvolver equacoes de estimativa da composicao fisica e quimica da carcaca de bezerros de origem leiteira, no inicio da vida produtiva. Foram usados 18 bezerros da raca Holandes, machos, nao castrados, pesando entre 30 e 100 kg. Seis animais foram abatidos no inicio do experimento (ao nascimento), seis aos 50 dias e seis aos 110 dias de idade. Foi realizada a divisao da carcaca em dianteiro, costilhar, traseiro e seccao 9a-11a costelas e procedida a separacao fisica total de todos os constituintes da carcaca. Foi determinada a composicao fisica e quimica por um metodo direto e ajustadas equacoes de predicao para estimar a composicao fisica e quimica da carcaca, por um metodo indireto. Os dados de composicao fisica da seccao 9a-11a costelas tambem foram tabulados nas equacoes propostas por Hankins e Howe, para testar a utilizacao das mesmas em animais jovens e imaturos. O traseiro foi a regiao que melhor representou a composicao fisica de osso, musculo e gordura, assim como a composicao quimica de agua e cinzas da carcaca. No entanto, a composicao energetica e proteica foi mais bem representada pela composicao energetica e proteica do dianteiro. A composicao fisica e quimica do corte da 9a-11a costelas nao foi um bom estimador da composicao fisica e quimica da carcaca de animais imaturos fisiologicamente ou extremamente jovens.

Composição corporal e exigências líquidas de macroelementos inorgânicos (Ca, P, Mg e K) para ganho de peso de bezerros machos de origem leiteira do nascimento aos 110 dias de idade

O presente estudo foi conduzido para avaliar as mudancas na composicao corporal e estudar as exigencias liquidas de materia mineral total (MM), calcio (Ca), fosforo (P), magnesio (Mg) e potassio (K) para ganho de peso de corpo vazio (GPCVZ) e ganho de peso vivo (GPV) de bezerros do nascimento ate os 110 dias de idade. Foram usados 18 bezerros da raca Holandes, machos, nao castrados, pesando entre 30 e 100 kg. Seis animais foram abatidos ao nascimento, seis aos 50 dias e seis aos 110 dias de idade. Foram ajustadas equacoes de regressao do logaritmo da quantidade de MM, Ca, P, Mg e K retidos no corpo, em funcao do logaritmo do peso de corpo vazio (PCVZ). As exigencias liquidas dos macroelementos para ganho de peso foram obtidas por derivacao das equacoes de predicao da composicao corporal. Ocorreu acrescimo na concentracao de todos macroelementos no PCVZ e no GPCVZ do nascimento aos 110 dias de vida, entretanto, as exigencias destes elementos para GPV decresceram neste mesmo periodo. As exigencias liquidas para 1 kg de GPCVZ, para o intervalo de PCVZ de 27,57 a 74,27 kg, variaram de 69,76 a 74,33 g para MM; 24,24 a 24,67 g para o Ca; 14,64 a 16,06 g para o P; 0,48 a 0,53 g para o Mg e de 3,18 a 3,61 g para o K. As exigencias liquidas para 1 kg de GPV, para o intervalo de PV de 30 a 100 kg, variaram de 63,37 a 55,20 g para MM; 22,02 a 18,32 g para o Ca; 13,30 a 11,93 g para o P; 0,44 a 0,39 g para o Mg e de 2,89 a 2,68 g para o K.

Relationship between climatic variables and the variation in bulk tank milk composition using canonical correlation analysis

A number of studies have addressed the relations between climatic variables and milk composition, but these works used univariate statistical approaches. In our study, we used a multivariate approach (canonical correlation) to study the impact of climatic variables on milk composition, price, and monthly milk production at a dairy farm using bulk tank milk data. Data on milk composition, price, and monthly milk production were obtained from a dairy company that purchased the milk from the farm, while climatic variable data were obtained from the National Institute of Meteorology (INMET). The data are from January 2014 to December 2016. Univariate correlation analysis and canonical correlation analysis were performed. Few correlations between the climatic variables and milk composition were found using a univariate approach. However, using canonical correlation analysis, we found a strong and significant correlation (rc = 0.95, p value = 0.0029). Lactose, ambient temperature measures (mean, minimum, and maximum), and temperature-humidity index (THI) were found to be the most important variables for the canonical correlation. Our study indicated that 10.2% of the variation in milk composition, pricing, and monthly milk production can be explained by climatic variables. Ambient temperature variables, together with THI, seem to have the most influence on variation in milk composition.