Starter protein content and supplemental soybean oil or hydrogenated palm fatty acids in Holstein dairy calves: growth performance, protozoa population, and nitrogen utilization efficiency

The study hypothesized that a 24% protein starter diet supplemented with inert fat (palm fatty acids; PLFs) instead of triglyceride-rich soybean oil (SBO) would promote the growth of dairy calves. The effects of different protein contents (20 vs 24% CP) and fat sources (SBO vs PLF at 2.5% DM) on growth, digestibility, blood metabolites, rumen protozoa and urinary nitrogen in dairy calves were investigated. A total of 52 female dairy calves (mean age 3 days and BW 40.7 kg) were allocated to the following treatments in a completely randomized design: (1) 20% CP starter diet supplemented with SBO (20CP-SBO), (2) 20% CP starter diet supplemented with PLF (20CP-PLF), (3) 24% CP starter diet supplemented with SBO (24CP-SBO), and (4) 24% CP starter diet supplemented with PLF (24CP-PLF). Calves were weaned on day 53, and the study ended on day 73. The 24CP diets enhanced starter feed intake, average daily gain (ADG), withers height, hip width, organic matter (OM) digestibility, and preweaning blood glucose compared to the 20CP diets. In contrast, SBO supplementation reduced feed intake, ADG, withers height, OM and CP digestibility, and pre- and postweaning blood glucose and beta-hydroxybutyrate levels, while increasing preweaning aspartate aminotransferase, compared to PLF. SBO supplementation led to lower urinary excretion of purine derivatives and microbial protein synthesis postweaning, and a reduction in protozoa population both pre- and postweaning. Calves fed PLF had higher starter intake than those fed SBO, regardless of the diet being 20CP or 24CP. Calves fed the 24CP-PLF diet had the highest ADG, while calves fed the 20CP-SBO diet had the lowest ADG. Calves fed the 20CP-SBO diet had lower feed efficiency than calves fed the other diets during the preweaning period and throughout the experimental period. Calves fed the 24CP-PLF diet had higher hip heights at weaning and on day 73 than calves fed the other diets. Calves fed the 20CP-SBO diet had lower neutral detergent fiber digestibility than calves fed the other diets. Calves fed the 24CP-SBO diet had higher postweaning blood urea nitrogen concentration than calves fed the other diets. Feeding the 20CP-SBO diet to dairy calves decreased urinary allantoin excretion and rumen microbial protein synthesis but increased urinary nitrogen excretion during the preweaning period. Our results suggest that PLF is more suitable than SBO in calf diets, especially when calves fed 24% CP, possibly due to improved nutrient digestibility.

Environmentally friendly preparation of lignin/paraffin/epoxy resin composite-coated urea and evaluation for nitrogen efficiency in lettuce

Novel lignin/paraffin/epoxy resin composite coated urea (LPECCU) was successfully prepared. Paraffin and epoxy resin (ER) were used to improve the slow-release properties of the lignin-based polyurethane (LPU) coated urea. The relationships among the N release characteristics, liquid-solid rate, -CNO/-OH molar rate and film formation rate in the coating material of LPECCU were investigated. The results showed that the water contact angle (WCA) of the LPU-paraffin increased with the rate of liquid-solid rate (73.61-88.19°) and -CNO/-OH molar rate (65.17-82.24°) increased. The average particle hardness of LPECCU decreased with the increased of liquid-solid rate (57.10-66.80 N) and the reduced of -CNO/-OH molar rate (48.11-63.00 N). The LPECCU emerged compact micro-structure, low sustained release and high compressive resistance by adding paraffin and ER. The coating material of LPECCU appeared excellent biodegradability in the soil. The optimal N cumulative release rate (72.49 %) of LPECCU was obtained (liquid-solid rate of 1.43, -CNO/-OH molar rate of 2, and the film formation rate of 6.66 %). The lettuce growth study was conducted to further evaluate the pot application of the LPECCU. In comparison to conventional urea, LPECCU could improve the total dry matter accumulation and N use efficiency of the lettuce.

Different dietary starch patterns in low-protein diets: effect on nitrogen efficiency, nutrient metabolism, and intestinal flora in growing pigs

Background

Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed low-protein (LP) diets. Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrogen efficiency. Dietary starch patterns modulation may improve this situation.

Methods

Growing barrows (29.7 ± 2.0 kg) were randomly allotted into 5 dietary treatments with LP diets consisting of different purified starches. Treatments included: waxy corn starch (W LP), corn starch + waxy corn starch (C + W LP), corn starch (C LP), pea starch + waxy corn starch (P + W LP) and pea starch (P LP). In the experiment, growth performance, protein deposition, nutrient metabolism, and fecal microbial community of pigs were investigated. In vitro starch digestion was used for predicting the in vivo glucose response.

Results

Dietary starch in vitro glucose release profile was determined by starch source and the ratio of amylopectin and amylose. C + W LP treatment showed decreased total nitrogen excretion and plasma citrulline concentration and improved plasma leptin concentration among treatments (P < 0.05). Besides, the highest nitrogen apparent biological value, whole-body protein deposition and growth performance and lowest urinary nitrogen excretion were also observed in C + W LP treatment. Compared with the other groups, C + W LP and C LP showed increased plasma pyruvate, IGF-1, and lipase concentrations (P < 0.05). The W LP group presented dramatically increased plasma alanine and urea nitrogen concentration and decreased aldolase and leptin concentrations (P < 0.05). Dietary starch patterns did not make an impact on bacterial richness and diversity, but changed the taxonomic and functional structures of the microbial communities. Microbial protein fermentation product (isobutyrate and isovalerate) presented increased in P LP treatments compared with the other treatments (P < 0.05).

Conclusions

Dietary starch patterns modulation can regulate dietary glucose release profile, nutrient metabolism, protein turnover, and fecal microbial fermentation in pigs. The optimal dietary glucose release profile effectively strengthened whole-body protein deposition and improve nitrogen efficiency and growth performance in growing pigs fed LP diets.

Responses of nitrogen efficiency and antioxidant system of summer maize to waterlogging stress under different tillage

Waterlogging was one of the main abiotic stresses affecting maize yield and growth in the North China Plain, while ridge tillage effectually improved soil environment, enhanced crop stress resistance to waterlogging, and increased grain yield of waterlogged maize. In order to explore the responses of nitrogen (N) efficiency and antioxidant system of summer maize to waterlogging stress under different tillage, a field experiment was conducted to explore N use efficiency, leaf activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and malondialdehyde (MDA) content of waterlogged maize Denghai 605 (DH605) and Zhengdan 958 (ZD958) under different tillage system (ridge planting and flat planting). Our results showed that ridge tillage was beneficial to ameliorate waterlogging damages on antioxidant system by increasing SOD, POD, and CAT activities, and decreasing MDA content. Moreover, ridge tillage significantly increased N efficiency of waterlogged maize. N translocation amount (NTA), N translocation efficiency (NTE), N contribution proportion (NCP), N harvest index (NHI), and N use efficiency (NUE) of waterlogging treatment under ridge planting system (W-V3+R) for DH605 was increased by 108%, 69%, 60%, 8% and 16%, while ZD958 increased by 248%, 132%, 146%, 13% and 16%, respectively, compared to those of waterlogging treatment under flat planting system (W-V3). Ultimately, ridge tillage led to a significant yield improvement by 39% and 50% for DH605 and ZD958, respectively, compared to that of W-V3. In conclusion, ridge tillage was conducive to retard leaf aging, and enhance nitrogen efficiency, thereby resulting in a yield improvement of waterlogged summer maize.

Multi-carbohydrase enzymes improve feed energy in broiler diets containing standard or low crude protein

This study evaluated the effect of multi-carbohydrase (MC) on energy and nitrogen (N) balance and gene expression in broilers fed diets with different crude protein (CP) contents. The study employed a 2 × 2 factorial arrangement of treatments. The factors were presence or absence of MC, and standard (SCP) or low (LCP) dietary CP concentration. A 3-phase feeding program was used, including starter (0 to 7 d), grower (8 to 17 d) and finisher (18 to 28 d) phases. The study was undertaken in closed calorimetry chambers. Each of the 4 dietary treatments was replicated 8 times in total across 2 runs, with 2 birds per replicate (n = 64). Data for energy partitioning and N balance were collected from d 25 to 28. On d 28, birds were euthanized to collect muscle and intestinal tissue samples for gene expression. The results showed that the MC increased apparent metabolizable energy (AME, P < 0.01) and net energy (NE, P < 0.05), and reduced the feed conversion ratio (FCR, P < 0.01) in all diets. The proportion of energy retained as fat per total energy retention (REf/RE) was positively correlated with feed AME and NE (r = 0.541, P < 0.01 and r = 0.665, P < 0.001, respectively), suggesting that feed energy augmented with increased fat gain. Muscle ATP synthase subunit alpha (ATP5A1W) gene expression had a positive correlation with REf/RE and feed NE (r = 0.587, P < 0.001 and r = 0.430, P < 0.05, respectively). Similarly, muscle peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1A) expression was negatively correlated with weight gain and positively correlated with FCR (r = −0.451, P < 0.05 and r = 0.359, P < 0.05, respectively). These correlations show that over-expressions of muscle genes related to energy production reduce bird performance. This study demonstrated that MC increase dietary energy utilization, regardless of dietary CP concentration. However, the energy released by the enzymes increases feed energy-to-CP ratio, meaning there is excess energy that is then deposited as body fat. This suggests that supplemental MC in broiler feeds is beneficial if diets are formulated to contain marginal energy levels.

Effects of supplemental fat sources and forage feeding levels on growth performance, nutrient digestibility, ruminal fermentation, and nitrogen utilization in dairy calves

Knowledge regarding the potential interactions between supplemental fat source and fiber level in starter diet of dairy calves is lacking. The aim of the present study was to investigate the effects of supplemental saturated fat [palm fat (PLF) containing 86% palmitic acid (C16:0)] vs. unsaturated fat [soybean oil (SBO) containing 51% linoleic acid (C18:2)] and forage level on feed intake, growth performance, ruminal fermentation, nutrient digestibility, and metabolic traits in dairy calves. Forty newborn Holstein female calves (BW = 39.7 ± 1.8 kg) were assigned to 1 of 4 treatment groups (each consisting of 10 animals) in a 2 × 2 factorial arrangement of fat source [soybean oil vs. palm fat; 3% of starter based on DM basis] and alfalfa hay level (0 vs. 15%, on DM basis): SBO or PLF with (AH) or without (NAH) alfalfa hay. Calves had ad libitum access to water and starters throughout the study and a constant amount of milk was offered among experimental calves during the pre-weaning period. All calves were weaned on day 63 of age and remained in the study until day 73 of age. The results showed that the lowest and the highest starter intake and average daily gain during pre-weaning period was observed when calves received SBO-AH and PLF-AH, respectively. Accordingly, the lowest wither and hip heights at weaning time (day 63) and final wither height (day 73) were observed in SBO-AH group across treatments. Calves received PLF-AH had the highest weaning and final BW compared to other groups. Feed efficiency tended to be higher in PLF groups compared with SBO calves. Calves fed SBO-AH had the lowest digestibility of organic matter and neutral detergent fiber and also total short chain fatty acid concentrations in rumen compared with other groups. The SBO calves had lower urinary allantoin, urinary purine derivatives, and microbial protein synthesis than PLF calves; however, urinary nitrogen increased with SBO supplementation. In summary, the supplementation of SBO rich in C18:2 and AH during the pre-weaning period resulted in negative responses on growth performance, digestibility, and ruminal fermentation profile. Therefore, the inclusion SBO rich in C18:2 along with forage in the starter is not recommendable for young dairy calves.

Giant milkweed (Calotropis gigantea): A new plant resource to inhibit protozoa and decrease ammoniagenesis of rumen microbiota in vitro without impairing fermentation

This study screened six different species of forest plants and then further evaluated the most promising plant, giant milkweed (Calotropis gigantea), for the potential to improve nitrogen utilization efficiency (NUE) through inhibiting rumen protozoa in vitro. Ground leaves of giant milkweed at 1.6 and 3.2 mg/mL decreased the counts of Entodinium cells by 41.30% and 58.89%, respectively, and damaged their cell surface structure. Dasytricha, Isotricha, Epidinium, Ophryoscolex, and Diplodinium were not affected, while total bacterial and archaeal populations did not decrease. Ammonia nitrogen (NH₃-N) concentration decreased by 50.64% and 33.33% at 1.6 g/mL and 3.2 mg/mL, respectively. Volatile fatty acid (VFA) production and methane production remained unaffected, but butyrate production increased. The giant milkweed leaves contained (per gram of dry matter) 3636 μg phenolics including 205.9 μg of 3-hydroxybenzoic acid, 2079 μg flavonoids including 1197.5 μg of quercetin and 91.4 μg of myricetin, and 490 μg alkaloids including 219.8 μg of anthraquinone glycosides. The effective inhibition of Entodinium was accompanied by a decrease in NH₃-N concentration, and methane production did not increase except for the dose of 1.6 mg/mL. Giant milkweed may be used as a new feed additive or an alternative to chemicals or antibiotics for sustainable animal husbandry enhancing NUE in ruminants.

The market for amino acids: understanding supply and demand of substrate for more efficient milk protein synthesis

For dairy production systems, nitrogen is an expensive nutrient and potentially harmful waste product. With three quarters of fed nitrogen ending up in the manure, significant research efforts have focused on understanding and mitigating lactating dairy cows’ nitrogen losses. Recent changes proposed to the Nutrient Requirement System for Dairy Cattle in the US include variable efficiencies of absorbed essential AA for milk protein production. This first separation from a purely substrate-based system, standing on the old limiting AA theory, recognizes the ability of the cow to alter the metabolism of AA. In this review we summarize a compelling amount of evidence suggesting that AA requirements for milk protein synthesis are based on a demand-driven system. Milk protein synthesis is governed at mammary level by a set of transduction pathways, including the mechanistic target of rapamycin complex 1 (mTORC1), the integrated stress response (ISR), and the unfolded protein response (UPR). In tight coordination, these pathways not only control the rate of milk protein synthesis, setting the demand for AA, but also manipulate cellular AA transport and even blood flow to the mammary glands, securing the supply of those needed nutrients. These transduction pathways, specifically mTORC1, sense specific AA, as well as other physiological signals, including insulin, the canonical indicator of energy status. Insulin plays a key role on mTORC1 signaling, controlling its activation, once AA have determined mTORC1 localization to the lysosomal membrane. Based on this molecular model, AA and insulin signals need to be tightly coordinated to maximize milk protein synthesis rate. The evidence in lactating dairy cows supports this model, in which insulin and glucogenic energy potentiate the effect of AA on milk protein synthesis. Incorporating the effect of specific signaling AA and the differential role of energy sources on utilization of absorbed AA for milk protein synthesis seems like the evident following step in nutrient requirement systems to further improve N efficiency in lactating dairy cow rations.

Effect of Two Nutritional Strategies to Balance Energy and Protein Supply in Fattening Heifers on Performance, Ruminal Metabolism, and Carcass Characteristics

Latin America is an important contributor to the worldwide beef business, but in general, there are limited studies considering strategies to reduce nitrogen contamination in their production systems. The study's goal was to assess the effect of two nutritional strategies to balance energy and protein supply in fattening heifers on performance, ruminal metabolism, and carcass characteristics. A total of 24 crossbred heifers (initial body weight 'BW 'of 372 ± 36 kg) were used to create two blocks (based on live weight) of two pens each, that were equipped with individual feeders. Within each block, half of the animals were assigned to a diet based on tabular Crude Protein (CP) requirements denominated Crude Protein Diet 'CPD' but without a ruminal degradable protein balance. The other half received a diet denominated Metabolizable Protein Diet 'MPD', formulated with the metabolizable protein system, balanced for the ruminal degradable protein. Both diets had the same ingredients and as well as similar synchrony indexes (0.80 and 0.83, respectively). For nitrogen concentration in feces and urine as well as microbial crude protein synthesis, a total of 12 heifers (three per pen) were randomly selected to collect samples. The dataset was analyzed as a randomized complete block design with a 5% significance. No diet × time interaction was observed for Average Daily Gain 'ADG' (p = 0.89), but there was an effect of the time on ADG (p ≤ 0.001). No differences were observed neither for final weight, dry matter intake 'DMI', and feed conversion rate (p > 0.05). Heifers fed with CPD showed greater cold carcass weight (p = 0.041), but without differences in ribeye area, backfat thickness, pH, dressing %, and marbling (p > 0.05). Differences between diets were observed for the in vitro parameters as well as for the Total Volatile Fatty Acids 'VFA' and NH3 (p < 0.05). Total N concentrations (urine + feces) of heifers fed with MDP was lower than in those fed with the CPD (p < 0.01), but no differences were observed in microbial protein, purine derivatives, and creatinine (p > 0.05). We conclude that the combination of synchrony and the metabolizable protein system achieve greater efficiency in the use of nitrogen, without negatively affecting animals' performance or the quality of the carcass.

Does intra-ruminal nitrogen recycling waste valuable resources? A review of major players and their manipulation

Nitrogenous emissions from ruminant livestock production are of increasing public concern and, together with methane, contribute to environmental pollution. The main cause of nitrogen-(N)-containing emissions is the inadequate provision of N to ruminants, leading to an excess of ammonia in the rumen, which is subsequently excreted. Depending on the size and molecular structure, various bacterial, protozoal and fungal species are involved in the ruminal breakdown of nitrogenous compounds (NC). Decelerating ruminal NC degradation by controlling the abundance and activity of proteolytic and deaminating microorganisms, but without reducing cellulolytic processes, is a promising strategy to decrease N emissions along with increasing N utilization by ruminants. Different dietary options, including among others the treatment of feedstuffs with heat or the application of diverse feed additives, as well as vaccination against rumen microorganisms or their enzymes have been evaluated. Thereby, reduced productions of microbial metabolites, e.g. ammonia, and increased microbial N flows give evidence for an improved N retention. However, linkage between these findings and alterations in the rumen microbiota composition, particularly NC-degrading microbes, remains sparse and contradictory findings confound the exact evaluation of these manipulating strategies, thus emphasizing the need for comprehensive research. The demand for increased sustainability in ruminant livestock production requests to apply attention to microbial N utilization efficiency and this will require a better understanding of underlying metabolic processes as well as composition and interactions of ruminal NC-degrading microorganisms.

Influences of dietary protein sources and crude protein levels on intracellular free amino acid profile in the longissimus dorsi muscle of finishing gilts

BACKGROUND

The current study was carried out to determine effects of dietary protein source and crude protein (CP) level on carcass characteristics, meat quality, and muscle amino acid (AA) profile in finishing gilts. The experiment was designed as a 2 × 2 factorial arrangement with two sources of dietary proteins (cottonseed meal, CSM vs. soybean meal, SBM) and two levels of CP (12 % vs. 14 %, as-fed basis). Seventy-two crossbred gilts (89.5 ± 0.9 kg) were allotted to one of four dietary treatments in a randomized complete block design for a period of 28 d. All diets were formulated to be isoenergetic and similar concentrations of standardized ileal digestible essential AA covering the nutrient requirements of pigs.

RESULTS

Growth, carcass characteristics and meat quality were not affected by dietary protein source nor crude protein level (P > 0.10) except that average daily feed intake was increased by CSM diets (P = 0.03). Gilts offered reduced protein diets had lower muscle pH45min (P < 0.05). Neither dietary protein source nor crude protein level influenced N deposition. However, reduced protein diets decreased N intake, N excretion, and serum urea nitrogen content, whilst improved N efficiency (P < 0.01). CSM diets increased N intake (P = 0.04), but did not depress N efficiency. The concentrations of phenylalanine, tryptophan, cysteine and tyrosine (P < 0.05) of the longissimus muscle were decreased when gilts offered CSM diets, while muscle intracellular free valine concentration was increased (P = 0.03). The gilts offered reduced protein diets had greater intracellular concentrations of free methionine, lysine, and total AA in muscle (P < 0.05).

CONCLUSION

These results suggest that CSM could replace SBM as a primary protein source in finishing pig diets in terms of performance, N efficiency, carcass characteristics, and meat quality, but decrease the concentrations of muscle specific AA. Furthermore, the reduced protein diet played an important role in increasing muscle intracellular concentrations of specific free amino acids (FAA), and in reducing the relative ratios of specific FAA to lysine in longissimus dorsi muscle of pig, whose biological meaning needs further studies.

Dairy sheep production research at the University of Wisconsin-Madison, USA - a review

Commercial milking of sheep is a new agricultural industry in the United States starting approximately 30 yr ago. The industry is still small, but it is growing. The majority of the sheep milk is used in the production of specialty cheeses. The United States is the major importer of sheep milk cheeses with 50 to 60% of annual world exports coming to the United States during the past 20 yr. Therefore, there is considerable growth potential for the industry in the United States. The only dairy sheep research flock in North America is located at the Spooner Agricultural Research Station of the University of Wisconsin-Madison. The research program started in 1993 and has been multifaceted; dealing with several areas important to commercial dairy sheep farmers. The East Friesian and Lacaune dairy breeds were compared and introduced to the industry through the research program. Both dairy breeds produced significantly more milk than traditional meat-wool breeds found in the U.S., but the two breeds differed in their production traits. East Friesian-cross ewes produced more lambs and slightly more milk than Lacaune-cross ewes whereas Lacaune-cross ewes produced milk with a higher percentage of fat and protein than East Friesian-cross ewes. Lactation physiology studies have shown that ewes with active corpora lutea have increased milk yields, oxytocin release during milking is required to obtain normal fat percentages in the milk, large udder cisterns of dairy ewes can allow for increased milking intervals, and short daylengths during late pregnancy results in increased milk yield. In the nutrition area, legume-grass pastures and forages with a higher percentage of legume will result in increased milk production. Grazing ewes respond to additional supplementation with increased milk yield, but it is important to match the supplement to the quality of the grazing. Ewes on high quality legume-grass pastures that are high in rumen degradable protein respond with increased milk production to supplements high in energy and/or high in rumen undegraded protein.