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.

Effects of arginine and guanidinoacetic acid with or without phenylalanine on ascites susceptibility in cold-stressed broilers fed canola meal-based diet.

In order to evaluate the effects of ARG sources (arginine [ARG] and Guanidinoacetic acid [GAA]) and phenylalanine (PHE) supplementation on performance, susceptibility to ascites, intestinal morphology, and nutrient digestibility in the cold-stressed broilers fed a canola meal (CM)-based diet, a 2×2 factorial experiment with four treatments was conducted. The dietary treatments included CM-based diet + 2.57 g/kg ARG, CM-based diet + 2.57 g/kg ARG + 1.5 g/kg PHE, CM-based diet + 1.8 g/kg GAA and CM-based diet + 1.8 g/kg GAA + 1.5 g/kg PHE. The corn-CM diet without supplementation was used as a negative control (NC) group in the fifth treatment that excluded the factorial arrangement. The results showed that adding ARG to diets without PHE supplement increased (p < 0.05) feed intake. Also, birds fed diets containing ARG had higher (p < 0.05) body weight gain (BWG) compared to those fed GAA added diets. Supplementation of PHE improved (p < 0.05) the FCR compared to groups fed diets without added PHE. Further, ARG addition increased (p < 0.05) plasma nitric oxide (NO) concentration, carcass, breast and leg yields, duodenal, jejunal, and ileal villus height (VH) to crypt depth (CD, and dry matter digestibility, while decreasing (p < 0.05) ascites mortality and right ventricle (RV) to total ventricle (TV) ratio compared to GAA added groups. Supplementation of PHE also declined susceptibility to ascites by reducing (p < 0.01) RV to TV ratio while increasing (p < 0.05) plasma NO level. The digestibility of ether extract also increased (p < 0.05) in broilers fed GAA supplemented diets versus those fed ARG added diets. The findings suggested that ARG may improve BWG and lower ascites incidence in broilers fed a diet based on CM under cold stress because of its antihypertensive effects. Moreover, the findings of this study demonstrated the importance of including PHE formulation in ARG-deficient diets to attenuate the adverse effects of cold stress on broilers. It was also concluded that GAA could be efficaciously used in cold-stressed broilers fed an ARG-deficient diet.

Different processing effects on nutritive value of barely grains by gas production method.

The purpose of this study was to investigate the effects of warm and cold physical as well as chemical processing methods on the nutritive value of barley grains by gas production technique. The processing methods included milling, steam flaking, extruding and soaking up the grain in water containing 1.00% citric acid, 1.00% propionic acid and 0.01 M sulfuric acid. Two-hundred mg of milling samples were incubated in special 100 mL glasses and the amount of gas produced at different hr was measured. The data were analyzed in a completely randomized design. The results showed that different treatments did not have a significant effect on chemical composition of barley seeds. Other methods of processing compared to the grinding method, significantly reduced the total amount of produced gas. In the 72 hr incubation period, the lowest amount of gas production was in the extruded (245.6 mL per g dry matter) treatment. However, there was no significant difference between the two methods of extruding and flaking. The highest percentage of digestible organic matter was associated with propionic acid (64.90%), while the steam cracking method (58.74%) was the least. Among the processing methods, the highest amounts of methane production, total protozoa population and volatile fatty acid concentration were related to the grinding method and the least amount of extrusion treatment was observed during 24 hr of incubation. Different experimental treatments had a significant effect on ammonia nitrogen condensation and the highest level was observed in milling. According to our results, processing methods such as extrusion and flaking may improve the grain nutritive value.

Effects of intensified or conventional milk feeding on pre-weaning health and feeding behavior of Holstein female calves around weaning.

Health, inflammatory, and stress indices as well as feeding behavior around weaning were measured for Holstein female calves fed intensified milk or conventionally during the pre-weaning period. Calves (n ꞊ 48) were randomly assigned to one of two experimental treatments including a conventional (CF) or an intensified feeding (IF) groups. In CF group, calves (n ꞊ 24) received 0.52 kg of dry matter (DM) per day from pasteurized whole milk (23.00% crude protein (CP) and 27.00% fat) until day 50 of age. In IF group, calves (n = 24) fed 0.97 kg of DM per day on average for the first three weeks, and then, milk allowance decreased gradually to reach 0.52 kg DM per day and continued until day 50. All calves were gradually weaned from day 51 to 56. Blood samples were taken on days 14, 28, and 57 at 06:30 AM for serum amyloid A (SAA), cortisol, alanine aminotransferase (ALT), and iron analyses. Conventionally fed calves had more days with fever during the pre-weaning period. Blood SAA and cortisol levels were higher in CF calves on day 14. However, SAA levels were higher for IF calves on day 57. Intensified milk-fed calves spent more time for standing than CF calves. A trend to be significant was observed for non-nutritive oral behavior in IF calves. In summary, dairy calf health can be improved by intensified milk feeding during the pre-weaning period; however, this method has the potential to reduce calves welfare around weaning transition.

Effects of feeding with broiler litter in pellet-form diet on Qizil fattening lambs' performance, nutrient digestibility, blood metabolites and husbandry economics.

The aim of this study was to evaluate the feeding of Qizil fattening lambs with different levels of broiler litter (BL) on their weight gain, dry matter intake (DMI), nutrient digestibility, selected blood metabolites and husbandry economics. During an eight-weeks experimental period, 28 male lambs (an average of 42.21 ± 5.63 kg and ages of 7-8 months) were allocated randomly to one of four dietary treatments, including; control diet with no litter (NL, n = 7), diet containing 5% BL (LL, n = 7), diet with 10% BL (ML, n = 7) and diet containing 15.00% BL (HL, n = 7) as dry matter (DM) basis. The lambs were kept in individual pens and had free access to feed and water (ad libitum) throughout the study. In this research, DMI and feed conversion ratio were not influenced significantly by the dietary treatments, while average daily gain (ADG) was found to be significant. The lambs which consumed LL diet (5.00% BL) had the greatest ADG. The DM digestibility significantly influenced by dietary treatments, as the HL diet (15.00% BL) had the least DM digestibility. There were also significant differences in the crude protein and acid detergent fiber digestibility among the treatments. Blood urea nitrogen and glucose levels were significantly affected by the treatments. Low litter treatment had the least FCR and the highest economical advantage. In conclusion, feeding male Qizil lambs with BL can reduce production cost without any negative effects on performance.