Effects of feeding untreated, pasteurized and acidified waste milk and bunk tank milk on the performance, serum metabolic profiles, immunity, and intestinal development in Holstein calves

Background: The present experiment was performed to assess the effects of different sources of milk on the growth performance, serum metabolism, immunity, and intestinal development of calves. Eighty-four Holstein male neonatal calves were assigned to one of the following four treatment groups: those that received bunk tank milk(BTM), untreated waste milk(UWM), pasteurized waste milk(PWM), and acidified waste milk(AWM) for 21 d.Results: Calves in the BTM and AWM groups consumed more starter(P < 0.05) than those in the UWM group.Average daily gain in the UWM group was the highest(P < 0.05). Calves exhibited the highest(P < 0.05) serum total protein, albumin, total cholesterol, high density lipoprotein, triglycerides, growth hormone, immunoglobulin(Ig) A and Ig M concentrations in the UWM group, highest malondialdehyde and tumor necrosis factor-α in the PWM group(P < 0.05), and highest glutathione peroxidase and Ig G in the BTM group(P < 0.05). The jejunum and ileum of the calves in all treatments presented a slight inflammatory response. The jejunal inflammation scores were higher(P < 0.05) in the UWM and AWM groups than the BTM group; the ileal inflammation scores increased more(P < 0.05) in the AWM group than the BTM group. Jejunal immunohistochemical scores(IHS) were higher(P < 0.05) in the PWM and AWM groups than the BTM group. Compared to the other three groups, calves feeding on BTM had lower(P < 0.05) ileal IHS. Jejunal interleukin(IL)-1β, IL-8, and IL-10 mRNA expression in the UWM group was the highest(P < 0.05). Calves fed AWM increased(P < 0.05) mRNA expression of IL-8 and toll like receptor 4(TLR-4) in the jejunum and IL-8, IL-1β, IL-6, IL-8, and IL-10 in the mesenteric lymph nodes.Conclusions: Overall, bunk tank milk is the best choice for calf raising compared to waste milk. The efficiency of feeding pasteurized and acidified waste milk are comparable, and the acidification of waste milk is an acceptable labor-saving and diarrhea-preventing feed for young calves.

The effects of step-wise improvement of forage combination in total mixed rations on fatty acid profile in the rumen and milk of Holstein cows

Five lactating Holstein cows in a 5×5 Latin square experiment were fed five high-concentrate total mixed rations(TMRs) to investigate the effects of step-wise improvement of forage combination on ruminal and milk fatty acid profiles. The ratio of concentrate to forage was fixed as 61:39, and the step-wise improvement of forage combination was applied as: TMR1, a ration containing corn stover; TMR2, a ration containing corn stover and ensiled corn stover; TMR3, a ration containing ensiled corn stover and Chinese wild ryegrass hay(Leymus chinensis); TMR4, a ration containing the ryegrass hay and whole corn silage; TMR5, a ration containing the ryegrass hay, whole corn silage and alfalfa hay. The TMRs were offered to the cows twice daily at 0700 and 1900 h. The entire experiment was completed in five periods, and each period lasted for 18 days. Diurnal samples of rumen fluids were collected at 0100, 0700, 1300 and 1900 h(day 16); 0300, 0900, 1500 and 2100 h(day 17); and 0500, 1100, 1700 and 2300 h(day 18). The step-wise improvement of forage combination increased energy and crude protein contents and decreased fibre content. As a result, the step-wise improvement of forage combination increased dry matter intake and milk yield(P<0.05). The step-wise improvement increased dietary content of linolenic acid(C18:3 n-3), but did not alter dietary proportions of palmitic acid(C16:0), stearic acid(C18:0), oleic acid(C18:1 cis-9), linoleic acid(C18:2 n-6) and arachidic acid(C20:0). In response to the forage combination, ruminal concentration of C16:0, C18:2 n-6 and C18:3 n-3 linearly increased against their dietary intakes(P<0.10). The step-wise improvement increased milk contents of C10:0, C12:0, C14:0, C16:0, C18:2 n-6 and C18:3 n-3(P<0.10) and decreased milk contents of C18:0 and C18:1 cis-9(P<0.05). Milk yields of C16:0, C18:1 cis-9, C18:2 n-6 and C18:3 n-3 were linearly increased by the increase of these fatty acids in the rumen(R2≥0.79, P<0.05), and milk yields of C18:2 n-6 and C18:3 n-3 were also positively correlated with dietary intake of these fatty acids(R2≥0.85, P<0.05). The step-wise improvement increased the transfer efficiencies from feed to milk for C18:2 n-6 from 11.8 to 14.2% and for C18:3 n-3 from 19.1 to 22.3%. In a brief, along with the step-wise improvement of forage combination, more dietary linoleic and linolenic acids might escape microbial hydrogenation in the rumen and consequently accumulated in milk fat though these fatty acids were present in low concentrations in ruminal fluids. The step-wise improvement of forage combinations could be recommended as a dietary strategy to increase the transfer efficiency of linoleic and linolenic acids from feed to milk.

Comparison of rumen bacteria distribution in original rumen digesta, rumen liquid and solid fractions in lactating Holstein cows

Background: Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions vary from each other and need to be better established.Methods: To compare bacterial profiles in each fraction, samples of rumen digesta from six cows fed either a high fiber diet(HFD) or a high energy diet(HED) were collected via rumen fistulas. Rumen digesta was then squeezed through four layers of cheesecloth to separate liquid and solid fractions. The bacterial profiles of rumen original digesta, liquid and solid fractions were analyzed with High-throughput sequencing technique.Results: Rumen bacterial diversity was mainly affected by diet and individual cow(P > 0.05) rather than rumen fraction. Bias distributed bacteria were observed in solid and liquid fractions of rumen content using Venn diagram and LEf Se analysis. Fifteen out of 16 detected biomarkers(using LEf Se analysis) were found in liquid fraction, and these 15 biomarkers contributed the most to the bacterial differences among rumen content fractions.Conclusions: Similar results were found when using samples of original rumen digesta, rumen liquid or solid fractions to assess diversity of rumen bacteria; however, more attention should be draw onto bias distributed bacteria in different ruminal fractions, especially when liquid fraction has been used as a representative sample for rumen bacterial study.

Repeated inoculation with rumen fluid accelerates the rumen bacterial transition with no benefit on production performance in postpartum Holstein dairy cows

Background The dairy cow’s postpartum period is characterized by dramatic physiological changes,therefore imposing severe challenges on the animal for maintaining health and milk output.The dynamics of the ruminal microbiota are also tremendous and may play a crucial role in lactation launch.We aim to investigate the potential benefits of early microbial intervention by fresh rumen microbiota transplantation(RMT)and sterile RMT in postpartum dairy cows.Twelve fistulated peak-lactation dairy cows were selected to be the donors for rumen fluid collection.Thirty postpartum cows were divided into 3 groups as the transplantation receptors respectively receiving 10 L fresh rumen fluid(FR),10 L sterile rumen fluid(SR),or 10 L saline(CON)during 3 d after calving.Results Production performance,plasma indices,plasma lipidome,ruminal microbiome,and liver transcriptome were recorded.After fresh and sterile RMT,we found that the molar proportion of propionic acid was increased on d 7 in the FR and SR groups and the bacterial composition was also significantly changed when compared with the CON group.A similarity analysis showed that the similarities between the CON group and FR or SR group on d 7 were 48.40%or 47.85%,whereas the similarities between microbiota on d 7 and 21 in the FR and SR groups were 68.34%or 66.85%.Dry matter intake and feed efficiency were not affected by treatments.Plasmaβ-hydroxybutyrate concentration in the FR group was decreased and significantly different lipids mainly included phosphatidylcholine and lysophosphatidylcholine containing polyunsaturated fatty acids.Hepatic transcriptomics analysis indicated acutephase response pathways were upregulated in the SR group.Conclusions Our study suggests that RMT can shorten the transition process of the ruminal microbiota of postpartum dairy cows with no benefit on dry matter intake or feed efficiency.Inoculation with rumen fluid may not be a useful approach to promote the recovery of postpartum dairy cows.

EffectS of sequence of nylon bags rumen incubation on kinetics of degradation in some commonly used feedstuffs in dairy rations

Nowadays,most available information on the degradative behaviour of feeds in ruminants is based on in situ incubation in the rumen,and it is adopted by many feed evaluation systems currently in use for ruminants.However,the outcome of this technique might be affected by many factors such as sequence of nylon bags incubation in the rumen.The objective of current study was to investigate effects of sequence of nylon bag incubation on degradative behavior of dry matter(DM),crude protein(CP),neutral detergent fiber(NDF) and acid detergent fiber(ADF) in some feed ingredients commonly used in dairy rations,including alfalfa haylage,corn silage,corn grain and soybean meal.Four multiparous Holstein lactating cows fitted with permanent ruminal cannulas were used.The nylon bags containing feed samples either were placed in the rumen at once and removed at designated time intervals(all in-gradually out method;AG) or were placed in the rumen at designated time points and retrieved at once(gradually in-all out method;GA).Fractional rate of degradation of potentially degradable fraction,lag time and effective rumen degradability(ED) of DM and CP were significantly higher in the AG compared to the GA method(P<0.05).Fractional rates of DM and CP degradation was higher in alfalfa haylage samples incubated in the rumen using the AG method compared to that using the GA method(0.138 h^(-1) vs.0.073 h^(-1)and 0.002 h^(-1) vs.0.1125 h^(-1),for DM and CP,respectively;P<0.05).Due to a higher fractional rate of degradation(K_d)of DM and CP,the ED of DM and CP at different fractional passage rates were higher in the AG than those in the GA method(P<0.05).Potentially degradable fraction and lag time of NDF were higher in the AG method compared to the GA method(P<0.05).Placing all bags in the rumen at once and removing them at designated time intervals compared with introduction of bags in reverse sequence and removing them all at once led to a lower undegradable fraction(U)of NDF in alfalfa(1.8%vs.4.0%,respectively;P<0.05) and corn silage(3.3%vs.6.7%,respectively;P<0.05) samples.Potentially degradable fraction of ADF was significantly higher in the AG method compared with the GA method(P<0.05).Bag incubation sequence had profound effects on kinetics of degradation of DM,CP and NDF in situ in the feed samples studied.The effects were more evident in the forages(especially alfalfa haylage) than in the concentrate ingredients namely corn grain and soybean meal.This experiment is the first time to investigate effects of two methods under the same experiment conditions,providing basic data for the determination of ED.

N-carbamylglutamate restores nitric oxide synthesis and attenuates high altitudeinduced pulmonary hypertension in Holstein heifers ascended to high altitude

Background: High-altitude pulmonary hypertension(HAPH) is a life-threating condition for animals in high altitude,and disturbance of endothelial nitric oxide(NO) synthesis contributes to its pathogenesis. N-carbamylglutamate(NCG), which enhances arginine synthesis, promotes endogenous synthesis of NO. In this study, we determined the effects of NCG on alleviating HAPH in Holstein heifers that ascended to Tibet(Lhasa, 3,658 m).Methods: Exp. 1, 2,000 Holstein heifers were transported from low elevation(1,027 m) to Lhasa. After being exposed to hypoxia for 1 yr, Holstein heifers were assigned to a healthy group(Control, n = 6) with mean pulmonary hypertension(mPAP) < 41 mmHg, and an HAPH affected group(HAPH, n = 6) with mPAP > 49 mmHg.Lung tissues were collected to evaluate histopathological changes and the expression of endothelial nitric oxide synthase(eNOS). Exp. 2, ten healthy heifers and 10 HAPH affected heifers were supplemented with NCG(20 g/d per heifer) for 4 wk. Physiological parameters were determined and blood samples were collected on d-1 and d 28 of the feeding trial.Results: Expression of e NOS in small pulmonary arteriole intima was higher in the healthy than HAPH group(P = 0.006), whereas HAPH group had significantly thicker media and adventitia than healthy group(all P < 0.05). The mRNA of eNOS and protein level of eNOS were higher in the lungs of heifers in the healthy group than in the HAPH group(both P < 0.001), whereas endothelin-1 protein levels were higher in HAPH group than in the healthy group(P = 0.025). NCG supplementation decreased mPAP and ammonia(both P = 0.001), whereas it increased the expression of eNOS, arginine, and plasma NO(all P < 0.05).Conclusions: The expression of eNOS was decreased in Holstein heifers with HAPH. NCG supplementation decreased m PAP through the restoration of eNOS and endogenous NO synthesis.

Heat stress on calves and heifers: a review

The current review is designed with aims to highlight the impact of heat stress(HS) on calves and heifers and to suggest methods for HS alleviation. HS occurs in animals when heat gain from environment and metabolism surpasses heat loss by radiation, convection, evaporation and conduction. Although calves and heifers are comparatively heat resistant due to less production of metabolic heat and more heat dissipation efficiency, they still suffer from HS to some degree. Dry matter intake and growth performance of calves and heifers are reduced during HS because of redistributing energy to heat regulation through a series of physiological and metabolic responses, such as elevated blood insulin and protein catabolism. Enhanced respiration rate and panting during HS accelerate the loss of CO2, resulting in altered blood acid-base chemistry and respiratory alkalosis. HS-induced alteration in rumen motility and microbiota affects the feed digestibility and rumen fermentation. Decreased luteinizing hormone, estradiol and gonadotrophins due to HS disturb the normal estrus cyclicity, depress follicular development, hence the drop in conception rate. Prenatal HS not only suppresses the embryonic development by the impaired placenta, which results in hypoxia and malnutrition, but also retards the growth, immunity and future milk production of newborn calves. Based on the above challenges, we attempted to describe the possible impacts of HS on growth, health, digestibility and reproduction of calves and heifers. Likewise, we also proposed three primary strategies for ameliorating HS consequences. Genetic development and reproductive measures, such as gene selection and embryo transfers, are more likely long-term approaches to enhance heat tolerance. While physical modification of the environment, such as shades and sprinkle systems, is the most common and easily implemented measure to alleviate HS. Additionally, nutritional management is another key approach which could help calves and heifers maintain homeostasis and prevent nutrient deficiencies because of HS.

Effects of moisture content or particle size on the in situ degradability of maize silage and alfalfa haylage in lactating dairy cows

A study using four Holstein cows with ruminal cannulas was conducted to evaluate the degradability of different moisture content or particle size of maize silage and alfalfa haylage. The maize silage(MS; 20-mm length) and alfalfa haylage(AH; 40-mm length) samples were wet(wet maize silage, MSW;wet alfalfa haylage, AHW), dried(dried maize silage, MSD; dried alfalfa haylage, AHD), or ground to pass through a 2.5-mm screen(dried ground maize silage, MSG; dried ground alfalfa haylage, AHG). Samples were incubated in the rumen for 2, 6.12, 24.36.48, and 72 h. Cows were fed ad libitum and allowed free access to water. High moisture content treatment of MSW expressed a lower rinsing NDF and ADF degradability at 2 h(P < 0.05) compared with dried samples(MSD and MSG). Different moisture content and particle size had a significant impact(P < 0.05) on the NDF degradability at 72 h, ADF degradability at36.48, and 72 h, and ruminally degradable ADF. All of the highest values were observed in small particle size and low moisture content AHG treatment. Based on this study, sample processing, such as drying and grinding, should be considered when evaluating nutritive values of forages.

Nuciferine protects against high-fat diet-induced hepatic steatosis and insulin resistance via activating TFEB-mediated autophagy——lysosomal pathway

Nonalcoholic fatty liver disease(NAFLD) is characterized by hepatic steatosis and insulin resistance and there are currently no approved drugs for its treatment.Hyperactivation of mTOR complex1(mTORCl) and subsequent impairment of the transcription factor EB(TFEB)-mediated autophagy-lysosomal pathway(ALP) are implicated in the development of NAFLD.Accordingly,agents that augment hepatic TFEB transcriptional activity may have therapeutic potential against NAFLD.The objective of this study was to investigate the effects of nuciferine,a major active component from lotus leaf,on NAFLD and its underlying mechanism of action.Here we show that nuciferine activated ALP and alleviated steatosis,insulin resistance in the livers of NAFLD mice and palmitic acid-challenged hepatocytes in a TFEB-dependent manner.Mechanistic investigation revealed that nuciferine interacts with the Ragulator subunit hepatitis B X-interacting protein and impairs the interaction of the Ragulator complex with Rag GTPases,thereby suppressing lysosomal localization and activity of mTORC1,which activates TFEB-mediated ALP and further ameliorates hepatic steatosis and insulin resistance.Our present results indicate that nuciferine may be a potential agent for treating NAFLD and that regulation of the mTORCl-TFEB-ALP axis could represent a novel pharmacological strategy to combat NAFLD.

Gossypol detoxification in the rumen and Helicoverpa armigera larvae:A review

Gossypol,a phenolic compound found in the cotton plant,is widely distributed in cottonseed byproducts.Although ruminant animals are believed to be more tolerant of gossypol toxicity than monogastric animals due to rumen microbial fermentation,the actual mechanisms of detoxification remain unclear.In contrast,the metabolic detoxification of gossypol by Helicoverpa armigera(Lepidoptera:Noctuidae)larvae has achieved great advances.The present review discusses the clinical signs of go ssypol in ruminant animals,as well as summarizing advances in the study of gossypol detoxification in the rumen.It also examines the regulatory roles of several key enzymes in gossypol detoxification and transformation known in H.armigera.With the rapid development of modern molecular biotechnology and-omics technology strategies,evidence increasingly indicates that research into the biological degradation of gossypol in H.armigera larvae and some microbes,in terms of these key enzymes,could provide scientific insights that would underpin future work on microbial gossypol detoxification in the rumen,with the ultimate aim of further alleviating gossypol toxicity in ruminant animals.

Patterns of dairy manure management in China

The dairy industry in China is rapidly developing,particularly in terms of the upscaling of dairy farms.However,nutrient-rich manure brings challenges to the sustainability of the dairy industry.This study investigated and reviewed the patterns of dairy manure management in China,and the results indicate that dairy manure could be used as an organic fertilizer because of its high organic nutrient content and low metal content.However,legislation prohibits the application of untreated(raw)dairy manure.An existing technology for handling animal slurry is the separation into a liquid and a solid manure fraction.The solid fraction can be used as compost and bedding materials,and it has limited environmental risk.However,the emissions from the storage of liquid manure need further attention.The cycle of manure production,collection,transportation,separation and storage can only be closed if the nutrients are eventually applied to grass and arable land according to crop needs.Therefore,distribution of knowledge on nutrient levels,crop needs and nutrient management plans,supported by legislation on maximum application standards,is needed.In this way,an environmentally friendly development of dairy manure management might be possible.