Ênio Rosa Prates

Melhoria organizacional na produção de bezerros de corte a partir dos centros de custos

The production cost in cow-calf was designed by a standard methodology that can be able to measure the production cost of calves and, simultaneously to validate the method in a production system. Within this context, the present paper discusses, initially, the relevance of the implementation of methodology in cost centers as a support decision-making, due to the need for a segmented analysis of the processes, specialized in cow-calf production systems. The stages for implementation of this method are described. A production system, typical of the Southern of Brazil, was defined from technical indicators reported in reviews. It was simulated the application of this methodology of the subjected system, where it was viewed the production costs of the different productive centers: bulls, cows, rearing of heifers and weaning of calves, enabling to understand the impact that determinates process and/or technologies bring on to the system. Consequently, to calculate the production cost of calves from the methodology based on the cost centers was feasible to be used in production systems based on cow-calf.

Taxa de prenhez de vacas Nelore x Hereford em ambiente subtropical sob restrição alimentar

This experiment was conducted to evaluate factors affecting pregnancy rate of 117 crossbred Nelore x Hereford beef cows with age varying from 2 to 20 years, different gene proportion from Nellore breed (25.0, 37.5, 50.0, and 100.0%), calved between 08/11/03 and 12/23/03 and bred by natural service, between 12/10/03 and 03/12/04. The effects of July calving date (JCD), birth weight (BW) and calf sex (S) from previous calving, parity order (PO), hip height (H), weight (WM) and body condition score at the beginning of the mating season (BCS), daily gain during the mating season (DGM), gene proportion from Nellore (GPN) and calf 205-d weight (WW205) from previous calving were all investigated on the probabilities of pregnancy and conception. Data were analyzed by Logistic Regression using SAS to identify the effects of each variable. The average pregnancy rate was 43.2%. The probability of pregnancy and conception were affected by changes on JCD, WM, BCS and DGM. The pregnancy odd changing to each increase on the variable were based on the odds ratio estimative by OR = exp (bk), considering that odd is ratio between the probability of the event occur and not occur. No significant effects of BW, S, PO, H, GFN and WW205 were observed. Pregnancy rate in beef cows can be increased by improving body condition score at the beginning of breeding season and weight gain during the breeding season. Both can be achieved by pre and postpartum nutritional management.

Macrominerais para bovinos de corte nas pastagens nativas dos Campos de Cima da Serra - RS

The present study was conducted to determine the mineral status of natural range pastures of the Campos de Cima da Serra region, State of Rio Grande do Sul, Brazil, in different months of the year, to compare them to beef cattle requirements (NRC, 1996). The project was carried out in twenty private farms, in Cambara do Sul county, on grazing areas without improvements (except burning) in the lastest twenty years. Pasture samples were collected in the several seasons during one year to determine its iron, manganese, copper and zinc levels. Effect of the season was verified on all analyzed minerals. The Mn and Fe contents on grass samples were higher than the beef cattle requirements. However, in some samples Fe and Mn levels were higher than the maximum tolerable for cattle. Cu contents were deficient in some months evaluated and Zn contents were lower than the required for cattle.

Replacing corn by cassava bagasse in concentrate mix fed to growing cattle. 2. Apparent digestibility, digestible nutrients intake, live weight gain and feed:gain ratio

The objective of this study was to evaluate the effect of the substitution of corn by cassava bagasse in concentrate on apparent digestibility, digestible nutrient intakes, average daily gain (ADG) and feed:gain ratio (F:G) in growing cattle. Sixt een cossbred bulls, were allotted to a completely randomized block design and in two periods. Four types of concentrade were tested, in association with an ad libitum allowance of oat/ryegrass hay (Avena strigosa, L.; Lolium multiflorum, L.) and an average concentrate suplemetation of .83% LW. The concentrates fed to the animals were different by the substitution level of corn by cassava bagasse: T1 0,0; T2, 33,0; T3, 66,0; e T4, 99,0. There was no effect of the substitution of corn by cassava bagasse on the apparent digestibility coefficients of the studied nutritive fractions. The digestible acid detergent fiber intake (DADF) linearly increased with the substitution of corn by cassava bagasse. There wa s no effect of the treatments on the intakes of digestible dry matter (DDM), digestible organic matter (DOM), digestible neutral detergent fib er (NDF), digestible energy (DE) and metabolizable energy (ME), which were, respectively, for T1, T2, T3 and T4, 53.51; 54.50; 53.63 and 53.69 (g DDM kg 0.75 ·day), 51.77; 52.37; 51.27 and 51.23 (g DOM/ kg 0.75 ·day, 30.13; 30.93; 30.46 and 30.88 (g DNDF/ kg .7 5•day), 224.13; 228.51; 224.77 and 225.33 (kcal DE/ kg .75 ·day), 183,75; 287,56; 184,38 and 184,43 (kcal ME/ kg .75 • • • • •day). The results obtained for ADG were 1.10; 0.95; 1.12 and 0.75 kg/animal·day, and for F:G 4.61; 6.17, 4.58 and 7.98, respectively for T1, T2, T3 and T4. The values of ADG and F:G, for the substitution of 99% of corn by cassava bagasse in concentrate, were lower t han those obtained by the levels of 0 and 66%, however, they were similar to the 33% of substitution level of corn by cassava bagasse in the concentrate.

Análise da sensibilidade da metodologia dos centros de custos mediante a introdução de tecnologias em um sistema de produção de cria

A bioeconomical simulation model was developed in a traditional cow-calf production system (TPS) for the application of cost center methodology with the objective of evaluating its sensibility by the introduction of early weaning technologies in primiparous cows (EWS), improved pasture for primiparous cows and half lot of secundiparous cows (IPS) and protein supplementation for replacement heifers (PSS). All technologies were used to increase the pregnancy rate in this system (TPS). Data on biological performance was obtained from a bibliographic review on production indicators and cost and economic values were obtained from market. The inputs of the model were: herd structure, production costs and production technology. The outputs of the model were: operational cost (OC); expenditure cost (EC); production costs per center (PCC); unitary cost per calf (UCC); cost per weaned kilo (WC/kg); annual cost per cow (ACC); financial break-even (FBE), operational margin (OM), pregnancy rate (PT), calf crop (CC), productivity/cow (P/C), number of weaned calves (NWC), calves break-even (CBE) and total production in kilos (TP/kg). The use of the cost center methodology was sensitive in identifying variations in the technical economic indicators and in the costs of each productive center. The introduction of EWS, IPS and PSS showed in the increase of technical indicators and in the operational margin, presented a straight relation with the changing in the cost centers, proving the sensibility of the costs methodology in relation to the impact in TPS.

Use of cassava bagasse in substitution of corn in concentrate for growing cattle. 1. Dry matter, organic matter and crude protein intake.

RESUMO - O objetivo deste trabalho foi avaliar o efeito da substituicao do milho por bagaco de mandioca, no concentrado das racoes, sobre o consumo de materia seca (MS), materia orgânica (MO) e proteina bruta (PB) de bovinos em crescimento. Dezesseis bezerros mesticos machos inteiros foram distribuidos em delineamento em blocos casualizados completos, em dois periodos. Quatro tipos de concentrado foram testados em associacao com o fornecimento a vontade de feno de aveia/azevem (Avena strigosa, L.; Lolium multiflorum, L.) e suplementacao media de concentrado de 0,83% PV. Os concentrados fornecidos aos animais diferenciaram-se pelo nivel de substituicao do milho por bagaco de mandioca: T1 = 0,0, T2 = 33,0, T3 = 66,0 e T4 = 99,0%. A substituicao do milho por bagaco de mandioca no concentrado apresentou relacao quadratica com o consumo de MS, MO e PB. O consumo maximo de MS, MO e PB foi, respectivamente, 88,53; 82,34; e 10,61 g/kg0,75. Os niveis de substituicao de milho por bagaco de mandioca que geraram os consumos maximos foram 48,74; 44,14; e 43,75%, respectivamente, para MS, MO e PB. Niveis mais altos de substituicao do milho por bagaco de mandioca no concentrado reduziram o consumo dos componentes estudados.

Taxas de prenhez em novilhas de corte acasaladas aos 18 e 24 meses de idade

The effects of the mating age and weight class on the pregnancy rate (PR) of Hereford heifers (n=119) at 18 (18M) or 24 months (24M) of age were evaluated. The heifers were divided into classes as light (18ML=260kg; 24ML=280kg) or heavy (18MP=300kg; 24MP=330kg). The breeding seasons were: 18M: 04/05 - 05/21 (fall) and 24M: 11/04 - 12/21 (spring). The traits analyzed were live weight (LW) and body condition score (BCS) at the beginning of the mating season and the average daily gain (ADG) on the pregnancy rate (PR). The PR were 73.3% (18MP), 72.4% (24ML), 83.3% (24MP) (P>0.05) and the 18ML heifers have shown lower PR (26.7%) (P<0.05). The 24M heifers showed higher ADG (0.664 vs 0.537kg/d) than the 18M heifers and in this group the open heifers had lower ADG (0.429 vs 0.621kg/d) than the pregnant heifers. The BCS were higher (P<0.10) for the pregnant heifers (3.50) than the open (3.24) heifers. A quadratic effect of LW on the PR (Y= -993.03 + 6.4543LW - 0.0097LW2; R2=0.98) was observed.

Desempenho reprodutivo de novilhas de corte acasaladas aos 18 ou aos 24 meses de idade

A 45-d experiment was conducted to evaluate two breeding ages of Hereford heifers, 18 (18M) or 24 months (24M), using natural mating. The following parameters were studied: pregnancy rate (PR), body condition score at the beginning of the mating season (BCS), and average daily gain in the mating season (ADG). It was also calculated the productivity (P) = total kg of weaned calf per number of heifers bred and efficiency (E) = productivity per 100 kg of heifers mated. The breeding seasons were from 04/05/2000 to 05/20/2000 (fall) and from 11/04/2000 to 12/19/2000 (spring) for 18M and 24M heifers, respectively. The 24M heifers showed higher PR and BCS than those bred at 18M of age (86.7% vs. 52.2% and 3.86 vs. 3.59, respectively). Conversely, breeding season did not affect the ADG comparing 24M (0.728 kg/d) with 18M (0.724 kg/d) heifers. The 24M heifers had greater P (135.2 vs. 76.2 kg) and better E (38.6 vs. 26.6 kg) than heifers mated at 18M. It can be concluded that decreasing the breeding age from 24M to 18M requires higher body weight at beginning of the mating season in order to improve the reproductive parameters evaluated in the current trial.

Effect of crude glycerol on in-vitro ruminal fermentation kinetics

O interesse na utilizacao da glicerina bruta na alimentacao animal ressurge, devido ao aumento na disponibilidade e preco favoravel, como consequencia da expansao das industrias de biocombustiveis. O objetivo deste trabalho foi avaliar os efeitos da substituicao do milho por diferentes niveis de glicerina bruta na dieta sobre a fermentacao ruminal atraves da digestibilidade in vitro verdadeira. As dietas experimentais consistiram na substituicao do milho por glicerol (0; 4; 8 e 12%) na materia seca da dieta (MS). As dietas eram compostas por 60% de feno de alfafa e 40% de grao de milho e o glicerol foi adicionado, substituindo o milho nas dietas. Alem de trabalhar com as 48 horas tradicionais, foram utilizados diferentes horarios de digestibilidade in vitro (0; 4; 8; 16; 48; 72 e 96 horas), com a finalidade de estudar a cinetica da digestao. A substituicao do milho por niveis crescente de glicerina bruta na dieta nao afetou a concentracao de N-NH3, o teor de energia metabolizavel, as digestibilidades in vitro da materia orgânica da fibra em detergente neutro, bem como os parâmetros da degradacao ruminal. Portanto, esse subproduto da producao do biodiesel deve ser testado in vivo como uma alternativa energetica na formulacao de dietas para ruminantes.

Digestibilidade determinada pelo método indireto usando o n-alcano C35

An experiment was conducted, on extraction and analysis of n-alkanes, to investigate the use of n-alkane (C35) present in forages as an internal marker for the digestibility determination. Samples of forages and feces were taken from conventional digestibility trials, which were previous conducted from 1978 to 1982. The C35 underestimated the dry matter and organic matter digestibilities, presenting an average difference in relation to in vivo of 4.68 (± 0.69) and 4,43 (± 0.85) perceptual units, respectively. The coefficient of regression did not differ from the unit, indicating that both methods were equivalent, having, however, the necessity of a correction factor. The coefficients of correlation observed for the dry and organic matter between the two methods were 0.87 and 0.85, respectively. The average fecal recovery of C35 was 91.76% (± 7.94), and this contributed to the bias of the method.