Energy metabolism of pregnant zebu and crossbred zebu dairy cattle.

The purpose of this study was to determine the energy partition of pregnant F1 Holstein x Gyr with average initial body weight (BW) of 515.6 kg and Gyr cows with average initial BW of 435.1 kg at 180, 210 and 240 days of gestation, obtained using respirometry. Twelve animals in two groups (six per genetic group) received a restricted diet equivalent to 1.3 times the net energy for maintenance (NEm). The proportion of gross energy intake (GEI) lost as feces did not differ between the evaluated breeds and corresponded to 28.65% on average. The daily methane production (L/d) was greater for (P<0.05) F1 HxG compared to Gyr animals. However, when expressed as L/kg dry matter (DM) or as percentage of GEI there were no differences between the groups (P>0.05). The daily loss of energy as urine (mean of 1.42 Mcal/d) did not differ (P>0.05) between groups and ranged from 3.87 to 5.35% of the GEI. The metabolizable energy intake (MEI) of F1 HxG animals was greater (P < 0.05) at all gestational stages compared to Gyr cows when expressed in Mcal/d. However, when expressed in kcal/kg of metabolic BW (BW0,75), the F1 HxG cows had MEI 11% greater (P<0.05) at 240 days of gestation and averaged 194.39 kcal/kg of BW0,75. Gyr cows showed no change in MEI over time (P>0.05), with a mean of 146.66 kcal/kg BW0. 75. The ME used by the conceptus was calculated by deducting the metabolizable energy for maintenance (MEm) from the MEI, which was obtained in a previous study using the same cows prior to becoming pregnant. The values of NEm obtained in the previous study with similar non-pregnant cows were 92.02 kcal/kg BW0.75 for F1 HxG, and 76.83 kcal/kg BW0.75 for Gyr (P = 0.06). The average ME for pregnancy (MEp) was 5.33 Mcal/d for F1 HxG and 4.46 Mcal/d for Gyr. The metabolizability ratio, averaging 0.60, was similar among the evaluated groups (P>0.05). The ME / Digestible Energy (DE) ratio differed between groups and periods evaluated (P<0.05) with a mean of 0.84. The heat increment (HI) accounted for 22.74% and 24.38% of the GEI for F1 HxG and Gyr cows, respectively. The proportion of GEI used in the basal metabolism by pregnant cows in this study represented 29.69%. However, there were no differences between the breeds and the evaluation periods and corresponded to 29.69%. The mean NE for pregnancy (NEp) was 2.76 Mcal/d and did not differ between groups and gestational stages (P>0.05).

Análise da contaminação parasitária em compostos orgânicos produzidos com biossólidos de esgoto doméstico e resíduos agropecuários / Analysis of parasitological contamination in organic composts with sewage sludge and agricultural residues

Este estudo avaliou a contaminação por ovos de helmintos, cistos e oocistos de protozoários em compostos orgânicos utilizando lodo de esgoto doméstico e resíduos agropecuários. Foram realizadas análises parasitológicas em amostras de 25 diferentes compostos orgânicos, antes e após tratamento térmico a 60°C durante 12 horas. Os resultados demonstraram elevada contaminação parasitária em todos os compostos analisados antes do tratamento e a não redução dessa contaminação após o tratamento térmico. A identificação das larvas obtidas em coproculturas antes e após o tratamento térmico dos compostos indicou que os gêneros mais freqüentemente observados foram Cooperia e Trichostrongylus, que são nematóides gastrintestinais de ruminantes. Estes resultados demonstram que ovos de helmintos podem permanecer viáveis mesmo após o processo de compostagem e o tratamento térmico. Os compostos produzidos com lodo de esgoto doméstico e resíduo agropecuários, utilizando esses processos de tratamentos, podem constituir riscos de contaminação para humanos e animais.

This research aimed at evaluating the cysts, oocysts and eggs contamination before and after thermal treatment of 60°C for 12 hours, in 25 different organic composts produced with biosolids from domestic waste-water treatment and animal and agricultural residues. The results showed high parasitological contamination for all organic composts before the treatment and these contaminations were not reduced after thermic treatment. The larva identification in coprocultures before and after thermic treatment showed Cooperia spp. and Trichostrongylus spp. were the most prevalent nematodes. These results demonstrated that helmintus’ eggs can remain viable even after the composing and thermic treatment. The obtained composition with sewage sludge and agricultural residues through these treatment processes can establish contamination risks for humans and animals.