Strategies to Improve Transition Dairy Cows Health and Milk Quality

Despite numerous studies since decades, transition period of dairy cows remains a big issue for both researcher and farmers. The endocrine changes that characterize this period expose the animals to metabolic imbalance, immune depression and oxidative stress. This situation results in the emergence of metabolic and infectious disease in addition to reduced and impaired milk production, that finally lead to the 15% of culling occurring in the first weeks of lactation. Therefore, several strategies have been put in place in order to improve health and welfare of transition cows, taking into account environment, nutrition and management aspects. The main purpose of this work is to investigate through 3 studies the effects of some of these strategies. In the first study, the effects of overcrowding during dry period were evaluated on stress related blood markers, behavior and welfare of animals. Overcrowded cows showed higher blood level of dehydroepiandrosterone (DHEA) and cortisol than controls and a restlessness behavior. The second study aimed to investigate the impact of an immunomodulant feed supplement (Omnigen-AF) fed to 190 cows from dry off to 150 DIM, on their health and milk composition and quality. Supplemented cows, compared to controls, had lower incidence of postpartum disease and lower culling rate within 60 DIM. Milk production and quality was not influenced by the treatment except for a reduction of SCC among Holstein cows. The last study evaluated the consequences on quality of milk and Parmigiano Reggiano cheese of an antiketotic treatment (Kexxtone). Despite the great concern on this aspect among cheese producers, the treatment didn’t impaired nor milk nor cheese production, confirming the usefulness and safety of this treatment for the prevention of ketosis. Overall, this thesis confirms the need and the effectiveness of different strategies that aimed to improve transition dairy cows health and their milk production

Effects of 00-rapeseed meal inclusion in Parmigiano Reggiano hay-based ration on dairy cows’ production, reticular pH and fibre digestibility

Hay-based diets are typically used in Parmigiano Reggiano cheese production. Parmigiano Reggiano feeding regulation prohibits 00-rapeseed dietary inclusion. The objectives of this study were to investigate the effects of substituting soybean-meal with different levels of 00-rapeseed-meal in dairy cows’ diets, to evaluate the possibility to include it in Parmigiano Reggiano regulation. The study had a Latin square design with 8 tie stall dairy cows. The isoenergetic and isoproteic dietary treatments differed in protein source (% of DM): S (0.0% 00-rapeseed-meal, 9.3% of soybean-meal), LR (3.8% 00-rapeseed-meal, 6.8% of soybean-meal), MR (8.5% 00-rapeseed-meal, 3.4% of soybean-meal), and HR (13.2% 00-rapeseed-meal, 0.0% of soybean-meal). DMI, milk production and composition, rumination and reticular-pH were recorded daily. Dietary fibre digestibility was evaluated by in vitro fermentation and milk gointrin content was quantified by liquid chromatography–tandem mass spectrometry. Statistical analysis was performed by mixed model. Milk yield, protein and casein content increased for incremental 00-rapeseed-meal dietary levels. MR treatment compared to the others resulted in higher daily reticular-pH (5.92), and fewer minutes with pH below 5.8 (467) and 5.5 (72). Goitrin was detectable in milk when 00-rapeseed-meal was included in the diet. Overall, the inclusion of 00-rapeseed-meal in the Parmigiano Reggiano type ratio did not compromise the performances of cows pointing to it as a reliable substitute for soybean-meal. Our results suggest that 00-rapeseed-meal should be tested in feeding studies to determine its effects on milk organoleptic characteristics and cheese production and quality to see if it can be included in the Italian PDO cheese regulation

Effects of complete replacement of corn flour with sorghum flour in dairycows fed Parmigiano Reggiano dry hay-based ration

The aim of this research was to evaluate of the productive responses of cows fed a dry hay based total mixed ration (TMR) in which sorghum (SOR) or corn (COR) meal (8 kg/h/d) were the main source of starch. The study involved two dairy herds located in the Parmigiano Reggiano PDO area, for a total of 1,400 cows (30% primiparous and 70% pluriparous). Each herd was fed alternatively SOR or COR TMR for 4 periods of 3 weeks: two weeks of adaptation and one week of data collection. Total milk production and composition, cheesemaking properties, fatty acid content and cheese yield were measured. In addition, within each herd, a random subgroup of 50 cows was selected for individual milk production, composition and cheesemaking properties analysis. Fibre digestibility was evaluated on faecal samples collected in 15 cows randomly selected in each subgroup. Data were analysed by a linear mixed model procedure with diet, herd, days in milk, parity and their interactions as fixed effects and cow as random effect. Individual milk production increase in SOR (32.43 vs. 31.34 kg, for SOR and COR, respectively; p<.0001) however, bulk milk and cheese yield did not show differences. Milk urea content was higher in SOR (27.38 vs. 22.79 mg/dL, for SOR and COR, respectively; p<.05).In this study the complete replacement of corn with finely ground sorghum meal in dairy cow diets in the Parmigiano Reggiano region did not result in negative effects on cows\u2019productivity, cheese making properties and production

Oxidative status of Marchigiana beef enriched in n-3 fatty acids and vitamin E, treated with a blend of oregano and rosemary essential oils

The aim of this study was to evaluate the effects of basal dietary supplementation with linseed and linseed plus vitamin E in Marchigiana young bulls on the instrumental color, oxidative stability, and fatty acid composition of beef steaks with and without treatment with a blend of essential oils (oregano and rosemary) after storage times of 0, 3, 6, and 9 days. The fatty acid composition was evaluated in meat after 0 and 9 days of storage. No variation in the fatty acid composition of each type of meat was observed after storage. The use of dietary linseed and vitamin E, compared with linseed alone, significantly improved the oxidative stability, lightness (L∗), and redness (a∗) of the meat. A higher degree of oxidation was observed in meat samples from animals in the group fed linseed (L) followed by the control group (C) and the group fed linseed and vitamin E (LE). Moreover, the essential oils treatment (O) exerts a significant effect on beef oxidative stability of the group LE more than groups C and L during storage. The fatty acid composition of the meat was also affected by the diet: levels of healthful fatty acids (PUFA, n-3 PUFA, and CLA) were higher in meat from the groups that received linseed than the control group. Our results suggest that dietary vitamin E and treatment with essential oils are effective approaches to preserving the stability of beef cattle receiving a diet enriched in unsaturated fatty acids for up to 9 days of storage

Combined Inclusion of Former Foodstuff and Distiller Grains in Dairy Cows Ration: Effect on Milk Production, Rumen Environment, and Fiber Digestibility

Simple Summary One-third of the global food produced for human consumption is wasted every year. This leads to the wasting of economic, environmental, and social resources. The reallocation of some unconventional agro-industrial by-products, such as former foods or distiller grains, into the animal feed chain, can contribute to increasing the sustainability of livestock production, reducing the need for natural resources such as arable soil, water, fertilisers, and fuels, and consequentially reduce the impact of animal requirements. Many agro-food industrial by-products are already used in animal feeding, but the potential of these feed ingredients has not yet been fully investigated, especially in ruminant nutrition. The aim of the present study was to investigate the effect of the substitution, in dairy cow rations, of traditional protein and starch sources with more sustainable "circular" feeds to increase the sustainability of dairy production. For this purpose, eight multiparous mid-lactating cows were blocked and assigned to one of four treatments and were used in a replicated 4 x 4 Latin squares design with 21-days periods (14 days of adaptation and 7 of data collection). Two different circular feedstuffs were tested: a bakery's former foodstuff (FF) and a wheat distiller's grain with solubles (WDGS). These ingredients were used, alone and in combination, in three experimental diets (FF, WDGS; FF + WDGS) and compared to a standard ration (CTR). Dry matter intake and rumination time were not influenced by these diets. Conversely, dietary treatments partially influenced the milk yield, rumen pH, Volatile Fatty Acids (VFA) production, and fibre digestibility. In particular, the combined inclusion of FF and WDGS increased milk production (37.39 vs. 36.92, 35.48, 35.71 kg/day, for FF, WDGS and CTR diets, respectively) and reduced milk urea content (13.14 vs. 16.19, 15.58, 16.95 mg/dL for FF, WDGS, and CTR diets, respectively). No effects of this association were found in the milk composition, acetic and propionic production, and fibre digestibility. These results suggest that the association of former foodstuff and wheat distillers' grains could be safely included in dairy cow rations to increase the sustainability of cow nutrition and improve milk production without impairing animal health, dry matter intake, and fibre digestibility

Stayability in Simmental cattle as affected by muscularity and body condition score between calvings

The present study aimed to investigate the association between stayability (STAY) traits, muscularity, and body condition score (BCS) in the Italian Simmental dual-purpose cows. Data were collected from 2,656 cows linearly scored in their first lactation from 2002 to 2020 and reared in 324 herds. The binary trait STAY, which is the ability of a cow to stay in the herd, was obtained for each cow-lactation available up to parity 5 (from STAY1-2 to STAY4-5). Analysis of STAY was carried out using logistic regression, considering the fixed effect of energy corrected milk, conception rate, somatic cell score, and muscularity or BCS predicted at different time points. The herd of linear classification and residual error were the random effects. Primiparous cows with a medium BCS and muscularity in early lactation presented a more favorable STAY across life compared to thinner ones (P < 0.05). In fact, cows with an intermediate BCS/muscularity were more likely to stay in the herd after the third lactation (STAY3-4), compared to those presenting a lower BCS/muscularity (P < 0.01). However, cows whose muscularity was high were generally less likely to start the third lactation compared to the others. A potential explanation for this could be the willing to market cows with good conformation for meat purpose. Simmental is in fact a dual-purpose breed known for the good carcass yield and meat quality. This study demonstrates how muscularity and BCS available early in life can be associated with the ability of Simmental cows to stay in the herd

Effect of dietary inclusion of different lipid supplements on performance and carcass quality traits of growing beef heifers

The aim of this study was to evaluate the impact of dietary extruded flaxseed and/or rumen-protected lipids on growth performance and carcass quality of growing beef heifers. Sixty-three crossbreed heifers (Charolais X Limousine) were distributed into seven experimental groups, balanced in terms of age and live weight. Diets fed to the groups were isoproteic and differed in both, the dietary lipid source (extruded linseed and/or rumen-protected conjugated linoleic acid) and the supplementation length (90 or 180 days before slaughtering), having the same total amount of lipids and vitamin E, during their finishing period. The results obtained in the present study confirm that in low-protein diets, the inclusion of rumen-protected CLA, alone or in combination with flaxseed, did not bring any evident effect on feed intake, performance and carcass quality traits of growing beef heifers

Fecal Microbiota, Bile Acids, Sterols, and Fatty Acids in Dogs with Chronic Enteropathy Fed a Home-Cooked Diet Supplemented with Coconut Oil

: Medium-chain fatty acids (MCFAs) are considered to be interesting energy sources for dogs affected by chronic enteropathies (CE). This study analyzed the clinical scores, fecal microbiota, and metabolomes of 18 CE dogs fed a home-cooked diet (HCD) supplemented with virgin coconut oil (VCO), a source of MCFA, at 10% of metabolizable energy (HCD + VCO). The dogs were clinically evaluated with the Canine Chronic Enteropathy Activity Index (CCECAI) before and at the end of study. Fecal samples were collected at baseline, after 7 days of HCD, and after 30 days of HCD + VCO, for fecal score (FS) assessment, microbial analysis, and determination of bile acids (BA), sterols, and fatty acids (FA). The dogs responded positively to diet change, as shown by the CCECAI improvement (p = 0.001); HCD reduced fecal fat excretion and HCD + VCO improved FS (p < 0.001), even though an increase in fecal moisture occurred due to HCD (p = 0.001). HCD modified fecal FA (C6:0: +79%, C14:0: +74%, C20:0: +43%, C22:0: +58%, C24:0: +47%, C18:3n-3: +106%, C20:4n-6: +56%, and monounsaturated FA (MUFA): -23%, p < 0.05) and sterol profile (coprostanol: -27%, sitostanol: -86%, p < 0.01). VCO increased (p < 0.05) fecal total saturated FA (SFA: +28%, C14:0: +142%, C16:0 +21%, C22:0 +33%) and selected MCFAs (+162%; C10:0 +183%, C12:0 +600%), while reducing (p < 0.05) total MUFA (-29%), polyunsaturated FA (-26%), campesterol (-56%) and phyto-/zoosterols ratio (0.93:1 vs. 0.36:1). The median dysbiosis index was <0 and, together with fecal BA, was not significantly affected by HCD nor by VCO. The HCD diet increased total fecal bacteria (p = 0.005) and the abundance of Fusobacterium spp. (p = 0.028). This study confirmed that clinical signs, and to a lesser extent fecal microbiota and metabolome, are positively influenced by HCD in CE dogs. Moreover, it has been shown that fecal proportions of MCFA increased when MCFAs were supplemented in those dogs. The present results emphasize the need for future studies to better understand the intestinal absorptive mechanism of MCFA in dogs

Combined Inclusion of Former Foodstuff and Distiller Grains in Dairy Cows Ration: Effect on Milk Production, Rumen Environment, and Fiber Digestibility

The aim of the present study was to investigate the effect of the substitution, in dairy cow rations, of traditional protein and starch sources with more sustainable “circular” feeds to increase the sustainability of dairy production. For this purpose, eight multiparous mid-lactating cows were blocked and assigned to one of four treatments and were used in a replicated 4 × 4 Latin squares design with 21-days periods (14 days of adaptation and 7 of data collection). Two different circular feedstuffs were tested: a bakery’s former foodstuff (FF) and a wheat distiller’s grain with solubles (WDGS). These ingredients were used, alone and in combination, in three experimental diets (FF, WDGS; FF + WDGS) and compared to a standard ration (CTR). Dry matter intake and rumination time were not influenced by these diets. Conversely, dietary treatments partially influenced the milk yield, rumen pH, Volatile Fatty Acids (VFA) production, and fibre digestibility. In particular, the combined inclusion of FF and WDGS increased milk production (37.39 vs. 36.92, 35.48, 35.71 kg/day, for FF, WDGS and CTR diets, respectively) and reduced milk urea content (13.14 vs. 16.19, 15.58, 16.95 mg/dL for FF, WDGS, and CTR diets, respectively). No effects of this association were found in the milk composition, acetic and propionic production, and fibre digestibility. These results suggest that the association of former foodstuff and wheat distillers’ grains could be safely included in dairy cow rations to increase the sustainability of cow nutrition and improve milk production without impairing animal health, dry matter intake, and fibre digestibility