ARTICLE | doi:10.20944/preprints202112.0125.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: cows; milk fat; ruminal fluid; milk fatty acids; energy balance
Online: 8 December 2021 (14:08:31 CET)
The trials were performed on 20 multiparous cows of Holstein breed (39.7 ± 0.75 kg of milk) at the end of the first phase of lactation this different milk fat (4.1-2.8%). The aim of the research was to study the characteristics of nutrition, metabolism and biosynthesis of milk components in highly productive dairy cows with normal and low milk fat levels and the timing of their productive use. Study the characteristics of fermentation of scar formation substrates and their use in energy metabolism and biosynthesis of the milk components. Found that low fat milk is not associated with a lack of formation of acetate in the rumen (6.1 vs. 6.6 mmol/dl in the contents of the rumen, р>0.05) and the non change in the hormonal profile, but depends on the reduction of fatty acids synthesis de novo in mammary gland, regulated by conjugated higher fatty acids. The result is a reduction in the need of cows in the exchange energy (reduction of heat transfer by 6.2 MJ), a shorter service period (109.5 vs.139 days) and the prolongation of their productive use (the number of lactations correlated back with the level of fat in milk (r=-0.68, p<0.05, n=1300).
ARTICLE | doi:10.20944/preprints202110.0043.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Grass; Greenhouse Gases; Ruminal Degradation; Secondary Metabolites; Tropical Livestock Systems
Online: 4 October 2021 (10:40:05 CEST)
Enteric methane (CH4) emitted by ruminant species is known as one of the main greenhouse gases produced by the agricultural sector. The objective of this study was to evaluate the chemical composition, in vitro gas production, dry matter degradation (DMD), digestibility, CO2 production and CH4 mitigation potential of five tropical tree species with novel forage potential including: Spondias mombin, Acacia pennatula, Parmentiera aculeata, Brosimum alicastrum and Bursera simaruba mixed at two levels of inclusion (15 and 30%) with a tropical grass (Pennisetum purpureum). Crude protein content was similar across treatments (135 g kg-1 DM), while P. purpureum was characterized by a high content of acid detergent fiber (335.9 g kg-1 DM) and B. simaruba by a high concentration of condensed tannins (20 g kg-1 DM). Likewise, A. pennatula and P. aculeata were characterized by a high content of cyanogenic glycosides and alkaloids respectively. Treatments SM30-PP70 (30% S. mombin + 70% P. purpureum) and BA30-PP70 (30% B. alicastrum + 70% P. purpureum) resulted in superior digestibility than P. purpureum, while in the AP30-PP70 (30% A. pennatula + 70% P. purpureum) was lower than the control treatment (P≤0.05). At 24 and 48 h, treatments that contained P. aculeata and B. alicastrum produced higher CH4 ml g-1 DOM than P. purpureum (P≤0.05). The inclusion of B. simaruba at 30% reduced CH4 at 25% compared to P. purpureum. Tropical tree species can improve the nutritional quality of ruminant rations and reduce CH4 emissions to consequently contribute to the development of sustainable ruminant production systems that generate diverse ecosystem services.
Subject: Biology, Animal Sciences & Zoology Keywords: CTs molecular weight; ruminal fermentation; bio-hydrogenation; milk compositions; goat
Online: 20 September 2020 (14:44:56 CEST)
The aim of this study was to investigate the effect of condensed tannin (CTs) with differing molecular weight on their capacity to modify the fatty acid profile in milk. Twenty multiparous crossbred lactating dairy goats were assigned in a randomized complete block design (RCBD), and were subjected to receive the dietary treatments as followings; T1: control (with no CTs supplementation), T2: supplemented with mangosteen peel in a concentrate as a source of low molecular weight CTs at level of 3.0 %DM of CTs equivalent, T3: supplemented with the same diet with T2 but added with polyethylene glycol (PEG, as tannin inactivator) as the control of T2, and T4: supplemented with quebracho CT extract (UNITAN ATO, Buenos Aires, Argentina; 75-77 % tannins) in a concentrate as a source of high molecular weight CTs at level of 3.0 %DM of CTs equivalent, and T5) supplemented with the same diet with T4 but added with PEG as the control of T4. No significant change was detected for feed intake and nutrient digestibility indicate that CTs at level of 3.0 %DM of diet did not showed the detrimental effect to feed intake and nutrient digestibility, however, ruminal fermentation parameters and milk yield and milk compositions did not affected by different source of CT inclusion.
ARTICLE | doi:10.20944/preprints202012.0422.v1
Subject: Biology, Anatomy & Morphology Keywords: Fresh cassava root; pellet containing high sulfur; ruminal characteristics; blood thiocyanate; Thai native beef cattle
Online: 17 December 2020 (09:16:26 CET)
The objective of this experiment was to study the effect of feeding pellet containing high sulfur (PELFUR) diet and fresh cassava root (FCR) to Thai native beef cattle on feed use efficiency, ruminal characteristics, and blood metabolites. Four male Thai native beef cattle (150 ± 15.0 kg of body weight (BW)) were allocated with a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. Factor A was FCR supplementation at 15 and 20 g/kg of BW. Factor B was the sulfur level in the PELFUR ration at 15 and 30 g/kg of dry matter (DM). No interaction effect was found among FCR supplementation and PELFUR in terms of feed intake and nutrient intake (p > 0.05). Cyanide intake was significantly increased based on FCR supplementation (p < 0.05), whereas sulfur intake was increased by level addition of PELFUR levels (p < 0.05). There were interaction effects among FCR supplementation and PELFUR on digestibility coeﬃcients of DM and organic matter (OM) (p < 0.05). FCR supplementation at 20 g/kg BW with PELFUR 30 g/kg demonstrated the highest digestibility of DM and OM. Moreover, interactions were observed between FCR and PELFUR for bacterial populations (p < 0.01). The populations of bacteria were highest in FCR supplementation at 20 g/kg BW with PELFUR 30 g/kg at various feeding times. An interaction effects from among feeding FCR with PELFUR was found on blood thiocyanate concentrations at various feeding times (p < 0.01). The highest mean values of blood thiocyanate were observed when feeding FCR at 20 g/kg BW with PELFUR at 30 g/kg. No interaction effect was found between FCR and PELFUR on total volatile fatty acids (VFA) and their profiles (p >0.05). However, the proportions of the total VFA at 0 and 4 h post-feeding were increased when FCR at 20 g/kg BW was supplemented (p < 0.01). FCR at 20 g/kg BW could enhance propionate (C3) at 4 h post-feeding when compared with FCR at 15 g/kg BW (p < 0.01). Moreover, supplementation of PELFUR at 30 g/kg increased the total VFA at 0 and 4 h post-feeding, whereas the concentration of C3 at 4 h post-feeding was enhanced (p < 0.05). However, no significant changes were found for any parameters among treatments and between the main effect of FCR and PELFUR supplementation (p > 0.05). In conclusion, feeding of two combinations (FCR 20 g/kg BW with PELFUR 30 g/kg) could promote the nutrient digestibility, the bacterial populations, and the rate of disappearance of cyanide without having any adverse effect on rumen fermentation.