Maximising Lucerne (Medicago sativa) Pasture Intake of Dairy Cows: 2—The Effect of Post-Grazing Pasture Height and Mixed Ration Level

The effects of lucerne (Medicago sativa) post-grazing residual pasture height on pasture utilisation (vertical and horizontal), pasture intake and animal production were investigated in a sub-tropical partial mixed ration dairy system. The study took place at the Gatton Research Dairy, Southeast Queensland (−27.552, 152.333), with a 26-day adaptation period followed by two 8-day measurement periods during August and September 2018. A quantity of 30 multiparous Holstein-Friesian dairy cows were offered two levels of mixed ration, 7 and 14 kg dry matter (DM)/cow/day for low and high levels respectively, and five levels of pasture allocation, to achieve decreasing residual pasture heights. Pasture allocations measured from 5 cm above ground level for the low mixed ration groups averaged 12.7, 15.9, 19.8, 35.3 and 49.2 kg DM/cow/day, and for the high mixed ration groups averaged 5.0, 8.3, 10.3, 18.6, and 25.2 kg DM/cow/day, respectively. As pasture allocation decreased, cows were forced to graze further down into the pasture sward, and therefore residual pasture height declined. Total intake (kg DM/cow/day) declined as residual pasture height (expressed as % of the initial height) declined, irrespective of mixed ration level, decreasing by 0.5 kg DM/cow/day for every 10% decrease in residual pasture height. Low total intakes were associated with high non-esterified fatty acid (NEFA) levels in plasma, indicating mobilisation of fat tissue to maintain milk production. In the high allocation treatments, an area of pasture remained ungrazed and cows were only grazing the top leafy stratum where pasture intake rate and intake were highest. Therefore, to maximise intake in sub-tropical partial mixed ration (PMR) systems, lucerne pasture should be allocated so that cows are always grazing the top leafy stratum. This can be achieved by ensuring the pasture around faecal patches remains ungrazed.

Maximizing Lucerne (Medicago sativa) Pasture Intake of Dairy Cows: 1-the Effect of Pre-Grazing Pasture Height and Mixed Ration Level

The effect of lucerne (Medicago sativa L.) pre-grazing pasture height on pasture intake and milk production was investigated in a sub-tropical partial mixed ration (PMR) dairy system in south-east Queensland, Australia. The experiment involved a 26-day adaptation period followed by an eight-day measurement period during April and May 2018. Twenty-four multiparous Holstein-Friesian dairy cows were offered a mixed ration at either 7 (low) or 14 (high) kg dry matter (DM)/cow/day and allocated pastures at pre-grazing heights ranging from 23 to 39 cm. The targeted pasture intake was 14 and 7 kg DM/cow/day for cows offered the low and high mixed ration allowances respectively, with a total intake target of 21 kg DM/cow/day. Pasture structure did not limit pasture intake as the all groups left at least 12% of the allocated area ungrazed, and therefore could selectively graze pasture. There was no significant difference in intake between mixed ration levels, however intake had a positive linear relationship with pre-grazing pasture height. For every one cm increase in pasture height, intake increased by 0.3 kg DM/cow/day. Using a grazing strategy that ensures the some pasture remains ungrazed and the pre-grazing height of lucerne is approximately 39 cm above ground level will maximise pasture intake in sub-tropical PMR dairy systems.

PENGARUH IMBANGAN PROTEIN DAN ENERGI TERHADAP PERFORMA DOMBA GARUT BETINA (The Effect of Protein and Energy Balance on Garut Sheep Females Performances)

Abstrak Penelitian ini bertujuan untuk mengetahui Pengaruh Imbangan Protein dan Energi terhadap Performa Domba Garut Betina. Penelitian dilaksanakan di BPPTDK Margawati, Desa Margawati Kecamatan Garut kota Kabupaten Garut pada bulan Mei 2017 sampai September 2017.Penelitian menggunakan metode eksperimental dengan Rancangan Acak Lengkap (RAL) terdiri atas 3 perlakuan dan 6 ulangan. Jenis perlakuan yang dicobakan yaitu tingkat protein ransum 13% dengan berbagai tingkat energi yang dinyatakan dalam Total Digestible Nutrients (TDN), P1 (Protein 13 % dan TDN 60%), P2 (Protein 13 % dan TDN 65%) dan P3 (Protein 13 % dan TDN 70%). Data hasil penelitian dianalisis menggunakan analisis ragam terhadap konsumsi bahan kering ransum, pertambahan bobot badan dan konversi ransum. Apabila hasil analisis ragam menunjukkan pengaruh nyata, maka dilanjutkan dengan Uji Jarak Berganda Duncan. Hasil penelitian menunjukkan bahwa imbangan protein dan energi dalam ransum secara statistik tidak berpengaruh nyata terhadap konsumsi bahan kering ransum, pertambahan bobot badan dan konversi ransum. Kata kunci : protein, energi, domba garut Abstract This study aims to determine The Effect of Protein and Energy Balance on Garut Females Performance. The research was conducted in BPPTDK Margawati, Margawati Village, Garut City Sub-district, Garut Regency in May 2017 until September 2017. The research used experimental method with Completely Randomized Design (CRD) consisted of 3 treatments and 6 replications. Treatment type was 13% protein ration level with various energy level stated in Total Digestible Nutrients (TDN), P1 (Protein 13% and TDN 60%), P2 (Protein 13% and TDN 65%) and P3 (Protein 13 % and TDN 70%). The data of the research were analyzed using the analysis of the variety of consumption of dry matter ration, body weight gain and the conversion of the ration. If the results of the variance analysis show a significant effect, then proceed with Duncan Multiple Range Test. The results showed that the protein and energy balance in the ration did not significantly affect the consumption of dry matter ration, body weight gain and ration conversion. Keywords : protein, energy, garut sheep

RESEARCH OF LINEAR TRANSLATION DEVICES WITH STEPPER MOTOR / LINIJINIŲ POSLINKIŲ ĮTAISŲ SU ŽINGSNINIAIS VARIKLIAIS TYRIMAS

In order to ensure accuracy of motorized linear translation stages theoretical and experimental investigations were performed, that allow to establish moving platform vibration level depending of operating modes (different velocities) and used lubricant in the system. Lubricants had different viscosity, which has effect to the system moving smoothness, sound level and vibration level of the stage. Such work gives possibility to done conclusions: with what lubricant or with what viscosity of the lubricant motorized linear translation stage works smoother, with less noise and vib-ration level, and also show best movement characteristics. Siekiant užtikrinti linijinių poslinkių įtaisų tikslumą, buvo atlikti linijinio poslinkio įtaiso su žingsniniu varikliu teoriniai ir eksperimentiniai dinamikos tyrimai. Buvo nustatytas judamosios platformos virpesių lygis priklausomai nuo darbo režimų (skirtingų greičių) ir mazge naudojamo tepalo. Tepalai skiriasi savo klampumu. Šis parametras turi įtakos įtaiso judėjimo sklandumui ir virpesių lygiui mazge.