Effect of non-forage roughage replacement on feeding behaviour and milk production in dairy cows

The objective of this study was to determine whether the partial replacement of roughage from forage with non-forage fiber sources, in a total mixed ration (TMR), could reduce feed sorting by dairy cows without modifying behaviour and milk production. Twelve Holstein cows were fed two TMR maize silage based diets in a cross-over experiment. Compared to the control diet (C-diet), experimental diet (E-diet) was formulated by replacing 8% neutral detergent fibre (NDF) from straw and alfalfa hay with soybean hulls and wheat bran. E-diet had a lower physical effectiveness factor (pef) (0.37 vs 0.34; P<0.001) and physical effective NDF (peNDF) (15.5 vs 14.6%; P<0.01). Feeding and sorting behaviour, ruminal activity, milk yield and composition and blood metabolites were measured. The results indicated that dry matter intake was not affected by diet. Cows fed the experimental TMR spent less time eating (192 vs. 178 min/d; P<0.05) but showed the same number of meals per day. C-diet fed cows sorted against peNDF in a greater extent (98.3 100.9%; P<0.05). Treatments did not affect cows time budget of general behaviors, with particular regard to ruminating activity. Despite different forage sources in TMR, no significant differences in milk yield and quality were detected

Short communication: The relationship between dietary particle size and undegraded neutral detergent fibre in lactating dairy cows: A prospective cohort observational study

Abstract Physically effective NDF (peNDF) and undegraded aNDF at 240 h (uNDF.240) are important parameters for characterizing NDF in fibre evaluation and are associated with dietary physical form and fibre digestibility characteristics. A new concept that combines peNDF and uNDF.240, physically effective uNDF.240 (peuNDF.240 = pef × uNDF.240), was recently established. The peuNDF.240 value allows determination of dry matter intake (DMI), and the productive response of cows even in the absence of variation in DMI or when cows are fed rations with low uNDF.240 and high peNDF or rations with high uNDF.240 and more finely chopped fibre. The aim of this study was to improve our understanding of the relationships between dietary uNDF.240 content to other fibre fractions, average cow DMI, gross feed efficiency, and milk yield at the farm level. Furthermore, the relation between peuNDF.240 and the productive response of cows was also investigated at the farm level. In the Po' Valley, which is a representative area for dairy production in Italy, a cohort of 22 Holstein dairy farms was monitored over two years (2019–2020). Information regarding average cow DMI, milk yield, and ration composition was obtained through interviews with farmers, and feed samples were collected and chemically analysed. Farms were classified according to their dietary uNDF.240 (% of DM) content: low (uL) ≤ 8.29 or high (uH) > 8.29. Farms with low dietary uNDF.240 used less alfalfa forage as a fibre source compared with farms with high dietary uNDF.240 (6.27 vs. 15.5 % of DM) and showed higher average milk yield (35.9 vs. 33.6 kg/cow/day, respectively) and similar DMI (23.9 vs. 24.3 kg/cow/day, respectively). Dietary peuNDF.240 was negatively related to milk yield (milk yield = 47.4 – 1.87 peuNDF.240, R2 = 0.62, adjusted R2 = 0.60, residual standard error (RSE) = 1.87, P = 0.001) and gross feed efficiency (gross feed efficiency = 1.96 – 0.08 peuNDF.240, R2 = 0.65, adjusted R2 = 0.64, RSE = 0.07, P = 0.001). The results of this study have practical significance for farmers, as they suggest that the inclusion of low digestible forages in the ration (i.e., late-harvested alfalfa characterized by high uNDF.240) may require more fine shredding to reduce the overall value of peuNDF.240 and increase cow production

Near infrared calibration transfer for undried whole maize plant between laboratory and on-site spectrometers

The analysis of the maize plant immediately after harvest is essential in order to check the composition and maturity of the plant to optimise the quality of silage. NIRS calibrations were carried out on chopped maize using three spectrophotometers: a laboratory instrument (FOSS NIRSystems 5000 scanning monochromator, FOSS, Silver Spring, MD) and two versions of newgeneration portable instruments (poliSPECNIR, PL1 and PL2). The aim was to verify the quality of the transfer of the calibration curves between FOSS, PL1 and PL2 and between PL1 and PL2, obtained by three methods of spectra processing: pre-processing, piecewise direct standardisation (PDS) and direct standardisation (DS). Seventy-six samples of chopped whole maize plant were scanned with the three instruments and were analysed by wet chemistry for dry matter (DM), ash, crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), starch and total sugars, to develop calibration equations. Two more datasets of 15 samples each were used for the standardisation of equations and validation. The calibration transfer obtained, according to the values of R2, standard error of prediction and bias, can be considered satisfactory (0.72>R2<0.97) for DM, ash and NDF for both poliSPECNIR, while CP and ADF have shown a good accuracy of prediction (0.78>R2<0.82) with PL2. Using FOSS as a master instrument, the choice of method of standardisation varies depending on the slave instrument even though the best results are obtained using PDS with PL2. The most accurate predictions are reached using PDS even when PL1 is the master

Effect of unsaturated fatty acid supplementation on performance and milk fatty acid profile in dairy cows fed a high fibre diet.

The influence of unsaturated fatty acid (UFA) supplement on productive performance, physiochemical properties and fatty acid (FA) profile of milk, was investigated in lactating dairy cows fed with high fibre diets. According to a cross-over design, twelve cows were assigned to two experimental settings characterized by different FA profiles. Cows received a high fibre diet (~42% NDF on DM basis) supplemented with soybean based mixtures with these FA compositions: 92.0% of saturated FA (SFA), 2.8% of monounsaturated FA (MUFA) and 5.2% of polyunsaturated FA (PUFA) in the control diet (C-diet); 19.1% of SFA, 20.9% of MUFA and 60.0% of PUFA in the experimental diet (E-diet). The E-diet did not affect dry matter intake nor milk yield. Milk composition and coagulation traits resulted similar between treatments, except for the lactose level, which was lower in the E-diet (5.0 vs 4.8%; P<0.05) and the freezing point (-0.546 vs -0.535 °C; P<0.05). As respects the milk FA profile, the E-diet significantly increased the percentage of UFA because of their greater amount in the ration; however the "transfer" of UFA in milk was limited by the high level of FA biohydrogenation (BH) at the ruminal level. UFA showed low values of carry over in milk (67.5 vs 39.7%; P<0.001) due to the saturation process; on the contrary SFA had a threefold increment (124 vs 323%; P<0.001), mostly due to a peak in the production of stearic acid. In this study, the percentage of CLA in milk (0.50 vs 0.62%; P<0.05) was quite low for both diets, if compared with other studies, and this was probably due to a low vaccenic acid supply at duodenal level

Research Note: Effect of chicken genotype and white striping–wooden breast condition on breast meat proximate composition and amino acid profile

The present experiment compared the proximate composition, the amino acid content, and profile of the breast meat of a commercial broiler hybrid (Hybrid-Normal) vs. a broiler hybrid affected by the simultaneous presence of white striping (WS) and wooden breast (WB) myopathies (Hybrid-WSWB) vs. the Italian purebred Polverara chicken (Polverara). To this purpose, a total of n = 30 breast meat cuts from male chickens/group were subjected to meat quality evaluations. Chickens were slaughtered at their commercial age. The meat of the Polverara breed showed the highest protein (P < 0.0001) and the lowest lipids (P < 0.0001) contents, whereas that of the Hybrid-WSWB broiler chickens had the lowest protein and ash (P < 0.0001) contents and the highest (P < 0.0001) amount of fat. Meat of Hybrid-Normal chickens displayed intermediate values. Polverara meat was the richest in most amino acids (g/100 g meat), whereas Hybrid-WSWB one had the lowest content (P < 0.0001). Taurine was not detected in the meat of the Polverara chicken. The meat of Hybrid-Normal chickens was the richest in valine and taurine amino acids (P < 0.0001). Results on the amino acids proportions (% of total amino acids) highlighted that lysine, arginine, leucine, glutamic acid, aspartic acid, alanine, and serine were the most representative essential and nonessential amino acids, respectively, in all 3 meat-types chickens. The study confirmed that WS and WB myopathies negatively affect the meat proximate composition and the amino acid content. The meat of the Polverara breed displayed a remarkable meat quality including a high protein content of very good quality. This may represent a tool to promote its meat among consumers and help the survival of this endangered breed. Furthermore, research efforts should be conducted to understand why taurine was absent in the breast meat of Polverara chicken

Reciprocal Activating Interaction between Natural Killer Cells and Dendritic Cells

We analyzed the interaction between human peripheral blood natural killer (NK) cells and monocyte-derived immature dendritic cells (DC). Fresh NK cells were activated, as indicated by the induced expression of the CD69 antigen, and their cytolytic activity was strongly augmented by contact with lipopolysaccharide (LPS)-treated mature DC, or with immature DC in the presence of the maturation stimuli LPS, Mycobacterium tuberculosis or interferon (IFN)-α. Reciprocally, fresh NK cells cultured with immature DC in the presence of the maturation stimuli strongly enhanced DC maturation and interleukin (IL)-12 production. IL-2–activated NK cells directly induced maturation of DC and enhanced their ability to stimulate allogeneic naive CD4+ T cells. The effects of NK cells were cell contact dependent, although the secretion of IFN-γ and TNF also contributed to DC maturation. Within peripheral blood lymphocytes the reciprocal activating interaction with DC was restricted to NK cells, because the other lymphocyte subsets were neither induced to express CD69, nor induced to mature in contact with DC. These data demonstrated for the first time a bidirectional cross talk between NK cells and DC, in which NK cells activated by IL-2 or by mature DC induce DC maturation

Effects of axial and ceiling fans on environmental conditions, performance and rumination in beef cattle during the early fattening period

The aim of this study was to assess the effect of two air stirring systems (ceiling fans vs. axial fans) on environment, performance, rumination and activity of beef cattle during the first period after the arrival to the fattening unit. One group of 106 charolais bulls was raised from August to October in a roofed, loose housing facility with straw bedding. Animals were randomly assigned to pens equipped with one of two types of fans: ceiling fans and axial fans. The trial lasted 70 days, and was divided into 3 periods. In the first and third periods fans were in operation, whereas in the second they were switched off. Animals were evaluated for average daily weight gain, cleanliness, dry matter intake, rumination time, activity level and health condition. The temperature-humidity index and the comprehensive climate index were continuously calculated and pens were periodically checked for the dry matter of the bedding. The average temperature-humidity index was lower in the third period (65.5) compared to the first (74.4) and second (75.3) periods (P < 0.001), but was not affected by the air stirring system, while on the contrary the comprehensive climate index was higher in AF than in CF during the first period (27.1 vs. 24.9 °C; P < 0.05). Ceiling fans led to higher dry matter of the bedding in the first (30.6 vs. 45.1%; P < 0.01), second (29.4 vs. 34.3%; P < 0.05) and third periods (22.2 vs. 31.3%; P < 0.05) and to cleaner bulls at the end of the trial. Animals raised with ceiling fans showed higher average daily weight gain (1.20 vs. 1.36 kg/day; P = 0.039), higher daily rumination time in the first period (431 vs. 475 m; P < 0.01) and patterns of rumination and activity compatible with a lower level of heat stress. Based on these results, it appears that ceiling fans are promising tools to be used to reduce heat stress and optimize performance of beef cattle

use of rumination and activity data as health status and performance indicators in beef cattle during the early fattening period

Abstract The aim of this study was to measure the level of activity and rumination in young bulls and to assess whether these data can be used as indicators of health status and average daily weight gain (ADG). Two groups of animals (period 1: n = 108 animals; period 2: n = 106 animals) were fitted with sensors to measure daily activity and rumination, were weighed on arrival and at the end of the trial (70 days) and were checked twice daily to verify their health condition. Any clinical signs and therapies were recorded. The dishomogeneity index of rumination (DR), and the daily dishomogeneity indices of activity (DDA) and rumination (DDR), were calculated. Bulls had an ADG of 1.42 ± 0.38 kg/day and showed an average duration of daily rumination of 404 ± 63 min and an average activity of 474 ± 46 bits, respectively. Animals characterised by low ADG had lower values of minimum daily rumination ( P = 0.01) and DDA ( P 0.001), and a greater rumination range ( P = 0.007) and DR ( P = 0.003). Bovine respiratory disease and lameness were detected 31 and five times, respectively; among affected animals, the average daily activity, rumination and DDA were lower ( P 0.05) at 3–6 days before the onset of visible clinical signs, whereas DDR increased compared to the values when individuals were apparently healthy. The use of individual sensors appears promising for the early diagnosis of disease in beef cattle and for improving herd management

Lecithin: a by-product of biodiesel production and a source of choline for dairy cows

The aim of the present study was to compare the effects of soy lecithins (L), a by-product of the biodiesel production process, and choline chloride microencapsulated with hydrogenated vegetable oils (C) on dry matter intake, milk yield, milk quality traits, milk choline and haematological profile of dairy cows. A total of 12 mid-lactating Holstein Friesian cows were assigned to one of two experimental groups and fed according to cross-over design (2 diets x 2 periods). Diets were isoenergetic, isofibrous and isonitrogenous and had the same content of choline. Dry matter intake was not affected by the diet, but L led to lower milk choline (P<0.05) and to a significantly higher milk yield (P<0.05), although the 3.5% fat-corrected milk (FCM) did not change owing to the higher content of fat in the milk of the C-diet group (P<0.01). The remaining milk components were unaffected by the supplements, except for the milk urea, which was lower in the L-diet group (P<0.01), reflecting a more effective use of degradable proteins by the micro-organisms present in the rumen. With regard to the haematological profile, L led to lower urea (P<0.001) and to higher values of glucose (P<0.01) and non-esterified fatty acids (NEFA)/Cholesterol ratio (P< 0.05), but all of the values fell within the physiological range of lactating dairy cows. Results indicated that soy lecithins can be used as an available and cost-effective source of choline in mid-lactating dairy cows

Blood Parameters Modification at Different Ruminal Acidosis Conditions

This study evaluated the reliability of various blood parameters to assess the ruminal acidosis in cattle. Six whole heifers were fed three experimental rations in a 3 x 3 Latin square design. The diets had different starch levels: high (HS), medium (MS) or low (CT). Ruminal pH values were continuously measured using wireless sensors. To evaluate the severity of ruminal acidosis, the amount of time per day that the pH was below 5.8, 5.5 and 5.0 was recorded. Blood samples were analyzed for complete blood count, venous blood gas and biochemical profile at 8:00 and 12:00 h. The data were analyzed according to a mixed model. Feeding on CT, MS and HS led to significant differences in DMI (7.7 vs. 6.9 vs. 5.1 kg/d; P < 0.01) which modified the amount of time per day that the pH was below 5.0 (0 vs. 12 vs. 92 min; P < 0.10). Feeding MS and HS diets led to inflammation as indicated by the significant increment of white blood cells when compared to the CT ones and to blood concentration due to the osmotic pressure at ruminal level. Furthermore a significant decrease of bicarbonate level, CO2 partial pressure and oxyhemoglobin was observed as consequence of the activation of metabolic processes aimed to prevent metabolic acidosis. No differences were observed on blood sampling time, suggesting that one daily blood sample was enough to evaluate the metabolic variations related to ruminal acidosis