Animal Science Journal最新文献

Dietary nitrate (NO₃⁻) is an alternative non-protein nitrogen (NPN) source and has mitigation effects on enteric methane emission in ruminants. This study investigated the effects of NO₃⁻ supplementation on rumen fermentation, nutrient digestibility, and nitrogen (N) utilization, focusing on urea-N and amino acid metabolism in sheep fed a high-forage diet. Six Suffolk wethers were assigned to a 2 × 2 crossover design conducted over two periods of 40 days each. Dietary treatments included supplementation with either urea (1.4% dry matter [DM]) or calcium nitrate tetrahydrate (5.8% DM). Each supplement contributed 32% of the daily crude protein supply (12% of DM). Intake, nutrient digestibility, N balance, ruminal volatile fatty acid (VFA) profiles, and plasma fluxes of urea-N and phenylalanine were not affected by NO₃⁻ supplementation, with a trend (p = 0.075) toward reduced DM digestibility. Ruminal ammonia-N (p = 0.004) and plasma urea-N (p < 0.001) concentrations were lower, whereas ruminal NO₃⁻-N (p = 0.045) and plasma glucose, triglycerides, and cholesterol concentrations were higher (p < 0.001) with NO₃⁻ supplementation compared to urea. These results demonstrate that NO₃⁻ can substitute for urea as an NPN source without affecting intake, ruminal VFA profiles, and urea-N production in sheep.

The purpose of this study was to examine the influence of neutral electrolytic water (NEW) on the growth performance, slaughter performance, bone development, and cecum microbiome of Arbor Acres Plus (AA+) broilers. A total of 120 broilers were raised in an environmentally controlled room with four rows of battery cages, each equipped with a water line housing 30 broilers. Two lines supplied normal water (CK), and the other two supplied NEW (TRT), with 10 broilers per cage (six replicates per group) over a 42-day trial. Results showed that broilers in the TRT group had significantly higher average daily gain (ADG) (p < 0.05) and lower feed consumption-to-gain ratio (F/G) (p < 0.05) at 22–42 and 1–42 days compared with the CK group. NEW consumption had no significant impact on slaughter performance or bone development (p > 0.05). The TRT group increased cecal flora diversity and abundance, with Lactobacillus as the dominant genus at the genus level. Correlation analysis revealed Oscillospira abundance was significantly positively correlated with F/G (R > 0.6, p < 0.05). Lactobacillus abundance was significantly positively correlated with ADG and average daily feed intake (ADFI) (R > 0.6, p < 0.05) and significantly negatively correlated with F/G (R < −0.6, p < 0.05). In summary, NEW improved growth performance, enhanced cecal flora diversity, and increased Lactobacillus abundance in AA+ broilers.

In tropical and subtropical regions, stylo (Stylosanthes guianensis) is a main silage material, but there are some problems like poor fermentation quality and effluent production during ensiling due to its high-moisture content after harvest. This study aimed to investigate the impact of incorporating dried soybean curd residue (SR) into high-moisture stylo at different percentages (0%, 3%, 6%, or 9% of fresh grass weight) to silage production. The findings revealed that adding SR, even at a 3% rate, significantly enhanced the fermentation quality and aerobic stability, and reduced the protein degradation during ensiling, compared with the control (p < 0.01). Effluent production resulted in the losses of dry matter and crude protein during the initial ensiling phase (3–15 days, p < 0.01), while no significant changes occurred during 30–60 days (p > 0.05). Notably, the addition of SR at a 3% rate effectively eliminated effluent production (0.00- vs. 30.4-mL·kg⁻¹ FM). These results indicate that the inclusion of SR presents a promising and efficient strategy for producing high-quality stylo silage without effluent.

Reducing enteric methane (CH₄) emissions from cattle is a priority in the agricultural sector. The total amount of CH₄ emissions from beef cattle is larger than that from dairy cattle in Japan, and thus, it is important to quantify CH₄ emission from beef cattle. The objective of this study was to investigate the physiological traits associated with methane-related traits and to develop a prediction equation that accounts for these physiological traits in Japanese Black cattle. Enteric CH₄ emission (L/day) was predicted from the concentration of CH₄ to carbon dioxide (CO₂) ratio obtained by the Sniffer method in 156 Japanese Black cattle (111 heifers and 45 steers). In regression tree analysis, methane-related traits, including CH₄, were used as dependent variables, and physiological traits were used as independent variables. Main physiological traits such as ruminal ammonia, propionate, butyrate, beta-hydroxybutyrate, creatine kinase, urea, and valine, which are associated with methane-related traits, were selected through regression tree analysis. The newly developed equations, which include not only feed intake and growth traits but also physiological traits, demonstrate improved prediction accuracy in Japanese Black cattle. These findings indicate that physiological traits can be utilized to develop accurate prediction equations for methane-related traits in Japanese Black cattle.

This study investigated the genetic correlations of somatic cell traits with longevity and fertility traits across lactation stages in primiparous Holsteins. Particularly, a previously defined trait, ML_SCS,DSCC, derived from the expected milk loss (ML) conditional on test-day somatic cell score (SCS) and differential somatic cell count (DSCC), was compared with SCS. Data consisted of 121,316 test-day records from 36,706 cows, along with records for overall stayability, stayability until second lactation, days to first service, conception rate at first service, and days open. The genetic parameters were estimated using multi-trait linear animal models via Gibbs sampling. Heritability of ML_SCS,DSCC was generally higher than SCS, especially in mid-to-late lactation. Both traits showed negative genetic correlations with overall stayability, with ML_SCS,DSCC showing stronger correlations in late lactation, likely related to its greater sensitivity to chronic mastitis. However, genetic correlations between ML_SCS,DSCC and fertility traits were weaker than those observed for SCS, possibly due to the negative relationships between milk yield and fertility. These findings support that selection for low ML_SCS,DSCC can improve longevity by enhancing mastitis resistance. Further refinement of ML_SCS,DSCC may be achieved by accounting for the effects of SCS and DSCC on functional traits beyond milk production.

This study aimed to evaluate the effects of a fermented total mixed ration (TMR) on feed intake, digestibility, rumen fermentation, and milk production in dairy cows in a hot environment. The experiment was conducted twice, with four multiparous Holstein cows used in each trial. Fresh and fermented TMR were used as dietary treatments in a crossover experimental design. Fresh and fermented TMR had the same diet composition. Fresh TMR was prepared every morning. Fermented TMR was prepared by baling fresh TMR and sealing it with a bale wrapper, followed by storage outdoors. Dry matter intake and digestibility did not differ between groups. Cows fed fermented TMR showed increased intake and digestibility of crude protein and non-fiber carbohydrate. Rumen total volatile fatty acids and propionate concentration were higher in cows fed fermented TMR than in those fed fresh TMR. Milk yield tended to increase in the cows fed fermented TMR. These results indicated that feeding fermented TMR to dairy cows in a hot environment altered feed digestibility and rumen fermentation and increased milk production. Therefore, fermented TMR is a suitable feed for lactating cows in a hot environment and is an effective technology for heat management.

The aim of this study was to evaluate the effect of different protein sources on the fattening performance and carcass characteristics of finishing bulls. Thirty HF bulls in three feeding groups were fed diets with different protein sources: rapeseed meal (RSM), Vicia faba seeds (VFB), and lupine seeds (LP). The proportions (g/kg DM) of feed ingredients in the diets were as follows: group RSM-MS (maize silage) 620, TG (Triticale grain) 210, and RSM 150; group VFB-MS 620, TG 170, and VFB 190; group LP-MS 620, TG 190, and LP 170. Bulls fed RSM were characterized by the highest ADG and feed intake, and the most desirable FCR (p < 0.05). Carcass conformation and fatness scores were higher in group RSM than in groups VFB and LP. Tannins contained in V. faba seeds did not exert a positive influence on feed intake, average daily gain (ADG) or the feed conversion ratio (FCR). The value of WBSF was lowest in group VFB, indicating superior meat tenderness (p < 0.05). The inclusion of feed component containing tannins resulted in lower (p < 0.05) redness and higher pH stability of their meat during storage.