Performance and incidence of diarrhea in suckling Jersey calves supplemented with mineral-vitamin complex and Virginiamycin.

The rearing of calves is an essential activity of a dairy system, as it impacts the future production of these animals. This study aims to evaluate the incidence of diarrhea, performance, and blood parameters of suckling calves that received mineral-vitamin supplementation in milk plus virginiamycin that was offered in milk (via the abomasum) or by esophageal tube (via the rumen). Twenty-seven calves were used, from the first week to 60 days of age, submitted to the following treatments: CONTROL, without supplementation; MILK, supplementation of 20 g of a mineral-vitamin complex with 100 mg of virginiamycin, diluted in milk; RUMEN, supplementation of 20 g of a mineral-vitamin complex diluted in milk and 100 mg of virginiamycin in gelatin capsules via an esophageal applicator. MILK and RUMEN calves had lower fecal consistency scoring, fewer days with scores 2 and 3 throughout the experimental period, and lower spending on medication compared to the CONTROL animals. Supplemented calves had higher fat and protein intake and reached feed intake of 600 g earlier than CONTROL animals, but did not differ in performance and hematological parameters. Supplementation with virginiamycin and vitamin-mineral complex for suckling calves reduced the incidence and days of diarrhea, and reduced medication costs, with no difference in performance, but the supplemented animals had higher initial protein and fat intake and reached targeted feed intake earlier to begin the weaning process.

Growth performance, reproductive parameters and fertility measures in young Nellore bulls with divergent feed efficiency.

The growth, sexual maturity and fertility-related parameters related of young Nellore bulls with divergent residual feed intake (RFI) raised on pasture were evaluated. After classification of 48 young males as low and high RFI (more and less efficient, respectively), the animals were evaluated for growth and reproductive parameters at 28-day intervals from 14.3 to 24.6 months of age. The semen was cryopreserved in the last sampling and fresh and post-thaw semen samples were evaluated. Low RFI bulls exhibited higher initial and final body weight (P < 0.05), but feed intake, body condition score and growth measures evaluated by carcass ultrasound were unaffected by RFI (P > 0.05). The scrotal circumference, sperm concentration, defects, and quality of fresh semen, and ultrasonographic testicular characteristics were unaffected by RFI (P > 0.05). However, velocity parameters such as average path and curvilinear velocities determined by computer-assisted sperm analysis of thawed semen submitted to the rapid thermoresistance test were improved (P < 0.05) in low RFI bulls, but this improvement in quality did not enhance in vitro sperm fertilizing ability. Our results demonstrated significant differences in metabolism and growth performance between bulls of divergent RFI. In addition, there was slight improvement in the semen quality of bulls with low RFI bulls, but this did not enhance in vitro fertilizing ability. Selection of beef bulls for RFI can be performed, which will result in economic benefits by improving the growth performance of the animals without affecting reproductive parameters.

Sexual maturity and fertility-related measures in young Nellore bulls receiving long-term dietary supplementation with rumen-protected polyunsaturated fatty acids.

The objective of this study was to evaluate the effects of long-term supplementation with rumen-protected fatty acids (FA) on growth and reproductive parameters of young Nellore bulls in a grazing regime. Forty-eight young bulls were distributed into two groups: FA (supplemented with rumen-protected polyunsaturated FA); and control (control fat-free supplement). The animals were supplemented from 14.3 to 24.6 months of age and growth and reproductive parameters were evaluated at 28-day intervals. The semen was cryopreserved in the last collection and fresh and post-thaw semen samples were evaluated. Feeding FA did not affect (P > 0.05) growth, reproductive parameters (scrotal circumference, sperm concentration per mL of ejaculate, percentage of sperm defects, sperm quality and fertility in vitro), or testicular ultrasonographic characteristics. However, thawed semen from bulls fed FA exhibited better quality (P < 0.05) than control semen for the following parameters evaluated by computer-assisted sperm analysis: average path velocity [µm/s: 90.48 vs. 79.66 post-thaw and 74.81 vs. 72.80 post-rapid thermoresistance test (TRT)], straight-line velocity (µm/s: 72.37 vs. 65.20 post-thaw and 64.96 vs. 63.25 post-TRT), and curvilinear velocity (µm/s: 148.44 vs. 131.31 post-thaw and 115.68 vs. 113.35 post-TRT). In addition, feeding FA increased peripheral concentrations of testosterone, leptin, total cholesterol and high-density lipoprotein. In conclusion, the increase in testosterone concentrations in bulls fed FA was not related to variations in growth parameters and sexual maturity. In addition, post-thawing sperm velocities were enhanced by diet, however, such increases were not related to better in vitro embryo production rates.

Respostas do híbrido de sorgo-sudão às adubações nitrogenada e potássica: características estruturais e produtivas / Nitrogen and potassium fertilization effects on a sorghum hybrid: forage production, structural traits

A pesquisa foi instalada no Setor de Forragicultura da FCAV/UNESP-Jaboticabal, para avaliar o híbrido de sorgo-sudão AG 2501C no outono e inverno. O manejo da pastagem foi conduzido, simulando o sistema de lotação intermitente. O experimento foi desenvolvido de março a setembro de 2002. A forrageira foi submetida a nove tratamentos: três doses de N (100, 200 e 300 kg/ha) e três doses de K (0, 80 e 160 kg/ha de K2O), em delineamento experimental de blocos casualizados com três repetições em esquema de parcelas subdivididas. As características estudadas foram massas, secas, inicial de planta inteira, folha e colmo e massa seca residual; relação lâmina/colmo; índice de área foliar (IAF); interceptação da radiação fotossinteticamente ativa (RFA) e coeficiente de extinção luminosa. Os tratamentos não influenciaram a massa seca inicial (MSI) e residual (MSR) da planta inteira, folha e colmo e massa seca residual. Os resultados médios para MSI, MSR, folha e colmo foram 2801,2; 964,7; 1462,8 e 1085,2 kg/ha de MS, por ciclo de pastejo, respectivamente. Houve redução da relação lâmina/colmo e da porcentagem de folhas, enquanto a porcentagem de colmos aumentou. Houve interação entre N e K para IAF, interceptação de luz e coeficiente de extinção.

This research was carried out in the Forage Section of FCAV/UNESP-Jaboticabal, to evaluate hybrid sorghum AG 2501C (Sorghum bicolor x Sorghum sudanense) during autumn/winter. Pasture management was accomplished by a simulation of intermittent stocking. The experiment was developed from March to September of 2002. The forage was submitted to nine treatments: three doses of N (100, 200, and 300 kg/ha) and three doses of K (0, 80, and 160 kg/ha of K2O) in a randomized block design with three replications in a split plot scheme. Characteristics including forage mass before grazing (FMBG), after grazing (residual), leaf and stem, leaf/stem ratio, leaf area index (LAI), interception of light, and light extinction coefficient (LEC) were evaluated. No differences for FMBG, residual, leaf, and stem were found. The averages were 2801.2, 964.7, 1462.8, and 1085.2 kg/ha of DM, per grazing cycle for FMBG, residual, leaf, and stem. There was significant interaction (p<0,01) between N and K for LAI, interception of light, and LEC.

Resposta do híbrido de sorgo-sudão à adubação nitrogenada e potássica: composição química e digestibilidade in vitro da matéria orgânica / Nitrogen and potassium fertilization effects on a sorghum hybrid: chemical composition and in vitro digestibility of organic matter

A pesquisa foi instalada no Setor de Forragicultura da FCAV/UNESP-Jaboticabal, objetivando avaliar a composição química e a digestibilidade in vitro da matéria orgânica (DIVMO) do híbrido de Sorgo-sudão cv. AG 2501C, no outono e inverno. O manejo da pastagem foi conduzido simulando o sistema de lotação intermitente. O experimento foi desenvolvido de março a setembro de 2002. A forrageira foi submetida a nove tratamentos: três níveis de nitrogênio (100, 200 e 300 kg de N/ha) e três níveis de potássio (0, 80 e 160 kg de K2O/ha), em delineamento experimental em blocos casualizados e parcelas subdivididas. A adubação nitrogenada e potássica não foram significativas para a DIVMO. O nitrogênio influenciou a proteína bruta (PB) com valores de 15,1; 16,4 e 15,7 por cento, a fibra em detergente neutro (FDN) com valores de 65,3; 65,8 e 64,5 por cento e fibra em detergente ácido (FDA) com 35,5; 37,8 e 39,6 por cento para 100; 200 e 300 kg N/ha. O potássio aumentou significativamente a lignina das plantas. O melhor nível obtido foi 100 kg/ha de nitrogênio, sem potássio.

The research was carried out in the Forage Section of FCAV/UNESP-Jaboticabal, to evaluate the chemical composition and the in vitro digestibility of organic matter (IVDOM) of the hybrid sorghum cv. AG 2501C (Sorghum bicolor x Sorghum sudanense) during autumn/winter. The management of pasture was conducted by a simulation of a rotational stocking. The experiment was developed from March to September 2002. The forage was submitted to nine treatments: three nitrogen levels (100, 220 and 300 kg/ha) and three potassium levels (0, 80 and 160 kg/ha) in a randomized blocks design and split plot. No effect of nitrogen and potassium fertilization on IVDOM was found. Nitrogen had influence on crude protein with values of 15.1, 16.4 and 15.7 percent of CP and 65.3, 65.8 and 64.5 percent of neutral detergent fiber (NDF) and 35.5, 37.8, 39.6 percent of acid detergent fiber (ADF), for 100, 200 and 300 kg N/ha. The potassium fertilization increased the lignin of plant. We concluded that, the best level was 100 kg/ha of nitrogen fertilization, without potassium.