Effects of levels of crude protein and ground corn cobs in total mixed ration on intake, rumen fermentation and milk production in crossbred Holstein Friesian lactating dairy cows

Abstract

Four, multiparous Holstein Friesian dairy crossbred cows with an initial body weight of 421.3 ± 44.3 kg and day-in-milk 62 ± 4.2 days were arranged according to a 4 × 4 Latin square design to evaluate the effect of levels of crude protein (CP) and ground corn cobs (CCs) in total mixed ration (TMR) on feed intake, rumen fermentation and milk production. The crude protein levels in TMR used in this experiment were 12%, 14%, 16% and 18% of dry matter (DM). Ground CCs and rice straw (1:1) were used as roughage sources and mixed with concentrate at 40:60 ratios. It was found that increasing CP in TMR resulted in linearly increasing voluntary DM intake (12.2, 12.7, 12.6 and 14.3 kg/d), protein intake (1.4, 1.8, 2.0 and 2.5 kg/d) and organic matter intake (11.2, 11.7, 11.6 and 13.0 kg/d). Digestion coefficients, ruminal pH and total volatile fatty acids were not different among dietary treatments (P > 0.05). However, ruminal ammonia-nitrogen and blood urea-nitrogen were increased when levels of CP in TMR increased (P < 0.05). Daily milk yield (11.5, 12.1, 12.3 and 13.1 kg/hd/d) and milk protein (3.2%, 3.2%, 3.4% and 3.6%) were increased with incremental additions of CP (P < 0.05), while there was no further improvement in milk fat content and feed efficiency beyond 16% CP (P > 0.05). Results indicate that TMR containing highest CP were excessive in N utilisation. It is, therefore, concluded that TMR contained 14% of CP in the diet meets the protein requirement for lactating cows producing 11-13 kg milk/d.

Effect of ground corn cobs as a fiber source in total mixed ration on feed intake, milk yield and milk composition in tropical lactating crossbred Holstein cows

“…In addition, the digestibility values for all of the rations were lower than expected from most published values for ration components. However, the digestibilities were similar but slightly lower than those reported by Wanapat and Cherdthong (2009) and Wachirapakorn et al. (2014) in a similar experiment involving GCC.…”

“…This means that if a slightly poorer RS, which would probably be the quality of RS on most dairy farms, had been used for comparison, GCC would have compared even more favorably with RS than occurred in our study. Rice straw on most dairy farms is generally of lower quality than used here ( Wachirapakorn et al., 2014 ) and GCC could be expected to compare even more favorably than in this study. The apparent digestibility of nutrients was not altered by the GCC:RS ratio ( P > 0.05).…”

The Dairy Cow Slurry Composition Used as Organic Fertilizer Is Influenced by the Level and Origin of the Dietary Protein

“…The highest starch intake was seen in diets based on legume silages, probably due to the fact that faba bean and the field pea were harvested when both species were in the phenological stage of pods with grain. The apparent digestibility of DM, OM, and NDF was not affected by the protein level as in other studies comparing 15.8% or 18.3% of CP in the diets [37,38]. However, Edouard et al [21] reported that the animals fed diets with 12% CP had a significant reduction of 2.5% in DM digestibility compared to when fed diets with 18% of CP.…”

Designing and evaluation of urea microcapsules in vitro to improve nitrogen slow release availability in rumen

“…The buoyancy of the microcapsules depends on density, and a higher porosity increases the microcapsule dispersion . Therefore, as evaporation of DCM inside the polymer microcapsule is the cause of permeable formation, a higher concentration of DCM‐20 mL improved buoyancy in comparison with the lower concentration of DCM‐15 mL ( p < 0.05) . The buoyancy of the microcapsules was over 50% after 12 h of agitation for both CSU and ACU, producing significant differences in the volume of the organic phase factor.…”