Effect of daily diet change from the start of lactation to the peak of lactation diet on ruminal pH with pH courses and changes during the feed day

The aim of the study was to find the effect of daily diet change from the start of lactation diet (SL) to the peak of lactation diet (PL) taking account into the lactation number (2nd lactation – groups S2L, P2L; 3rd lactation – groups S3L, P3L) using continuous monitoring of ruminal pH using e-bolus at school experimental farm in Oponice. Animals (7 Holstein cows) were fed once with Total Mix Ratio ad libitum (between 4:00 and 5:00) and milked 3 times per day (6:00, 12:00 and 18:00). The bolus which was implemented through Esophagus measured pH and temperature values every 15 minutes (96 data points per day) with accuracy ± 0.1 pH. Data were downloaded and collected with HathorHBClient v. 1.8.1 and statistically evaluated with IBM SPSS v. 20.0 (One-way ANOVA, Tukey Test, Indipendent Samples T-Test). The statistically significant difference (0.74%; P < 0.01) in the daily pH mean between SL and PL diet was found. Dairy cows in the SL group had average pH 6.30 ± 0.34 and in the PL group 6.25 ± 0.33. The daily pH mean of dairy cows in the 2nd lactation 6.45 ± 0.28 (S2L), 6.39 ± 0.25 (P2L) and in the 3rd lactation 6.14 ± 0.32 (S3L), 6.14 ± 0.34 (P3L) was determined. In the S3L (1.12 ± 1.20%) and P3L (1.19 ± 1.19%) group faster decrease of pH values during 6 hours after feeding than in the S2L (0.75 ± 0.41%) and in the P2L (0.55 ± 0.34%) group was found. During night better recover ability of pH values in the S3L (1.62 ± 0.88%) and P3L (2.10 ± 0.90%) group than in the S2L (1.00 ± 0.57%) and in the P2L (1.11 ± 0.70%) group per hour was observed. Overall 8.9% of measured pH under 5.8 in the SL group and 11.9% in the PL group was found. The S2L group had pH under the threshold 5.8 from measured values 1.6% and P2L group only 1.1%. On the other side the pH values in the S3L group formed 16.3% and in the P3L group 20.8%

Apparent in vivo nutrient digestibility of maize silages in horses

The aim of the experiment was to analyzed coefficients of digestibility of the maize silage nutrients in horse feeding. Horses of Slovak warmblood breed engaged in the research were 2.5 ± 0.5 years old. Horses in boxes without bedding to avoid eating it and excrement contamination were stabled. Horses individually with ad libitum access to water were housed. The boxes with trough for corn silage were equiped. The corn silage contained 362.3 g of dry matter, 74.1 g of crude protein, 27.1 g of crude fat and 948.2 g of organic matter in kg of dry matter. The feed twice a day, in the morning and in the evening was given. The feed intake and leftovers were weighed every day. Excrements immediately after excreting to avoid urine contamination into plastic containers were collected and weighed. The content of nutrients in the feed intake and in the excrements were analysed. In analysed samples the gravimetric dry matter amount by drying at 103 ± 2 °C, crude protein content by Kjeldahl method, fat content by extraction method according to Soxhlett – Henkel, ash content by burning the sample at 530 ± 20 °C in muffle furnace and organic matter content by calculation were determined. Coefficients of apparent digestibility in percent from taken in and excreted nutrients were calculated. In maize silage for horse feeding an average coefficient of digestibility of dry matter 61.94%, of crude protein 56.03%, of crude fat 72.34% and of organic matter 65.19% was found