Lucas Teixeira Costa

Análise econômica da adição de níveis crescentes de concentrado em dietas para vacas leiteiras mestiças alimentadas com cana-de-açúcar

Sixteen crossbred Holstein × Zebu cows (groups from ½ to ¾ of Holstein × Zebu) at third of fourth lactation were allotted to four 4 × 4 Latin squares to evaluate the economical viability of increasing dietary concentrate level. Cows presented previous milk yield from 2,500 to 3,000 kg, adjusted for 300 days, and grazed pasture during the rainy season, and with 110 days of laction in the beginning of the experimental period. Because of the prices of milk and concentrate during the experiment, it is not interesting to use concentrate in the diets of milk cows fed sugar cane. If the productive and economical aspects toghther and the prices of R

Comportamento ingestivo de vacas em lactação alimentadas com cana-de-açúcar ou feno da parte aérea da mandioca

0.70 and R

Viabilidade econômica do uso de fontes lipídicas na dieta de vacas em lactação

0.50 for the milk and the concentrate, respectively are considered, the use of 24% concentrate in the diet is the most interesting option for dairy cows fed sugar cane.

Análise Econômica do Sistema de Manejo de Vacas Mestiças Ordenhadas na Presença ou Ausência de Suas Crias

The effect of diets containing sugar cane or different percentages of cassava aerial portion hay (FPAM) inclusion on dairy cows ingestion behavior was evaluated. Sixteen cows were used, including twelve lactating and four dry, which were fistulated and divided into four 4 x 4 Latin squares. Diets were formulated in an attempt to be isoenergetic, with four percentages of FPAM in the diet (0, 33, 67 and 100% of diet total DM), replacing the sugar cane treated with 1% of a mixture of urea and ammonium sulfate (9:1 parts). The ingestion behavior was evaluated for 24 consecutive hours, with observations at five minute intervals. A quadratic effect (P 0,05) for numbers and periods of feeding and rumination was observed. The ingestion behavior evaluation constitutes a tool for measuring the amount and quality of diets consumed, since it demonstrates their ingestion response by cattle diet provided.

Ingestive behavior of lactating cows fed sugarcane and crude glycerin levels on the diet.

The objective was to evaluate the economic viability of using different lipid sources in the diet of lactating cows. The experiment was done in an area of 42ha, divided into eight paddocks with an average size of approximately 5.3ha each, consisting of Brachiaria brizantha. Twelve Holstein x Zebu crossbred cows were distributed in three 4 x 4 Latin Squares. The four treatments consisted of different lipid sources, as follows: no extra source of dietary lipids, diet with cottonseed, diet with soybean oil, and diet with soybean frying oil. The diets were formulated to meet the requirements for maintenance and production of 15 kg/day, with 3.5% fat. To study the effect of economic analysis, two economic indicators were used: net present value and internal return rate. A one year simulation was produced to study economic characteristics, computing the depreciation of facilities and machinery in this period. The total cost per animal and per liter of milk produced increased with the use of lipid sources in the diet. All treatments had positive values for profit per animal, with observed values of R

Avaliação do comportamento ingestivo de vacas leiteiras em pastejo de Brachiaria brizantha recebendo diferentes teores de concentrado na dieta

2.82, R

Teores de concentrado em dietas a base de cana-de-açúcar para vacas mestiças em lactação

2.68, R

Comportamento ingestivo de vacas alimentadas com cana-de-açúcar e diferentes níveis de concentrado

2.39 and R

Performance, digestibility, production and composition of milk from crossbred cows receiving different levels of concentrate in the diets based on sugar cane.

2.09, for treatments without lipid source; soybean frying oil as lipid source; cottonseed as lipid source and soybean oil as lipid source, respectively. The internal return rate was more advantageous when no fat source was used in the diet, demonstrating that this treatment is economically better for an investor, generating 0.73% per month. The net present value calculation shows that this investment is viable for all treatments with a 6% discount rate. Treatment without lipid source had a lower production cost and therefore is more cost-effective. Milk production is not viable for any treatment with return rates of the net present value of 10 and 12%.

Economic viability of crude glycerin in diets for lambs finished in feedlot

Avaliou-se o custo do sistema de manejo de vacas mesticas ordenhadas na presenca ou ausencia de suas crias. O experimento foi conduzido no setor de Bovinocultura de Leite do Curso de Zootecnia da UESB, no municipio de Itapetinga, BA. Foram utilizadas 20 vacas mesticas Holandes x Gir, distribuidas em um delineamento em blocos casualizados, com 10 repeticoes para cada tratamento sendo o periodo experimental de aproximadamente 300 dias. Utilizou-se para efeito de estudo da analise economica, dois indicadores economicos, o valor presente liquido e a taxa interna de retorno. Os parâmetros economicos demonstram que a utilizacao do sistema de ordenha de vacas com presenca de suas crias, com o preco do quilo de leite igual a R