pH dynamics and bacterial community composition in the rumen of lactating dairy cows

The influence of pH dynamics on ruminal bacterial community composition was studied in 8 ruminally cannulated Holstein cows fitted with indwelling electrodes that recorded pH at 10-min intervals over a 54-h period. Cows were fed a silage-based total mixed ration supplemented with monensin. Ruminal samples were collected each day just before feeding and at 3 and 6h after feeding. Solid and liquid phases were separated at collection, and extracted DNA was subjected to PCR amplification followed by automated ribosomal intergenic spacer analysis (ARISA). Although cows displayed widely different pH profiles (mean pH=6.11 to 6.51, diurnal pH range=0.45 to 1.39), correspondence analysis of the ARISA profiles revealed that 6 of the 8 cows showed very similar bacterial community compositions. The 2 cows having substantially different community compositions had intermediate mean pH values (6.30 and 6.33) and intermediate diurnal pH ranges (averaging 0.89 and 0.81 pH units). Fortuitously, these 2 cows alone also displayed milk fat depression, along with markedly higher ruminal populations of 1 bacterial operational taxonomic unit (OTU) and reduced populations of another ARISA amplicon. Cloning and sequencing of the elevated OTU revealed phylogenetic similarity to Megasphaera elsdenii, a species reportedly associated with milk fat depression. The higher populations of both M. elsdenii and OTU246 in these 2 cows were confirmed using quantitative real-time PCR (qPCR) with species-specific primers, and the fraction of total bacterial rDNA copies contributed by these 2 taxa were very highly correlated within individual cows. By contrast, the fraction of total bacterial rDNA copies contributed by Streptococcus bovis and genus Ruminococcus, 2 taxa expected to respond to ruminal pH, did not differ among cows (mean= <0.01 and 10.6%, respectively, of rRNA gene copies, determined by qPCR). The data indicate that cows with widely differing pH profiles can have similar ruminal bacterial community compositions, and that milk fat depression can occur at intermediate ruminal pH. The results support recent reports that milk fat depression is associated with shifts in bacterial community composition in rumine and is specifically related to the relative abundance of Megasphaera elsdenii.

Genome-Wide Association Mapping and Genomic Selection for Alfalfa (Medicago sativa) Forage Quality Traits

Genetic progress for forage quality has been poor in alfalfa (Medicago sativa L.), the most-grown forage legume worldwide. This study aimed at exploring opportunities for marker-assisted selection (MAS) and genomic selection of forage quality traits based on breeding values of parent plants. Some 154 genotypes from a broadly-based reference population were genotyped by genotyping-by-sequencing (GBS), and phenotyped for leaf-to-stem ratio, leaf and stem contents of protein, neutral detergent fiber (NDF) and acid detergent lignin (ADL), and leaf and stem NDF digestibility after 24 hours (NDFD), of their dense-planted half-sib progenies in three growing conditions (summer harvest, full irrigation; summer harvest, suspended irrigation; autumn harvest). Trait-marker analyses were performed on progeny values averaged over conditions, owing to modest germplasm × condition interaction. Genomic selection exploited 11,450 polymorphic SNP markers, whereas a subset of 8,494 M. truncatula-aligned markers were used for a genome-wide association study (GWAS). GWAS confirmed the polygenic control of quality traits and, in agreement with phenotypic correlations, indicated substantially different genetic control of a given trait in stems and leaves. It detected several SNPs in different annotated genes that were highly linked to stem protein content. Also, it identified a small genomic region on chromosome 8 with high concentration of annotated genes associated with leaf ADL, including one gene probably involved in the lignin pathway. Three genomic selection models, i.e., Ridge-regression BLUP, Bayes B and Bayesian Lasso, displayed similar prediction accuracy, whereas SVR-lin was less accurate. Accuracy values were moderate (0.3-0.4) for stem NDFD and leaf protein content, modest for leaf ADL and NDFD, and low to very low for the other traits. Along with previous results for the same germplasm set, this study indicates that GBS data can be exploited to improve both quality traits (by genomic selection or MAS) and forage yield.

Short communication: Characterization of molasses chemical composition

Beet and cane molasses are produced worldwide as a by-product of sugar extraction and are widely used in animal nutrition. Due to their composition, they are fed to ruminants as an energy source. However, molasses has not been properly characterized in the literature; its description has been limited to the type (sugarcane or beet) or to the amount of dry matter (DM), total or water-soluble sugars, crude protein, and ash. Our objective was to better characterize the composition of cane and beet molasses, examine possible differences, and obtain a proper definition of such feeds. For this purpose, 16 cane and 16 beet molasses samples were sourced worldwide and analyzed for chemical composition. The chemical analysis used in this trial characterized 97.4 and 98.3% of the compounds in the DM of cane and beet molasses, respectively. Cane molasses contained less DM compared with beet molasses (76.8 ± 1.02 vs. 78.3 ± 1.61%) as well as crude protein content (6.7 ± 1.8 vs. 13.5 ± 1.4% of DM), with a minimum value of 2.2% of DM in cane molasses and a maximum of 15.6% of DM in beet molasses. The amount of sucrose differed between beet and cane molasses (60.9 ± 4.4 vs. 48.8 ± 6.4% of DM), but variability was high even within cane molasses (39.2-67.3% of DM) and beet molasses. Glucose and fructose were detected in cane molasses (5.3 ± 2.7 and 8.1 ± 2.8% of DM, respectively), showing high variability. Organic acid composition differed as well. Lactic acid was more concentrated in cane molasses than in beet molasses (6.1 ± 2.8 vs. 4.5 ± 1.8% of DM), varying from 1.6 to 12.8% of DM in cane molasses. Dietary cation-anion difference showed numerical differences among cane and beet molasses (7 ± 53 vs. 66 ± 45 mEq/100 g of DM, on average). It varied from -76 to +155 mEq/100 g of DM in the cane group and from +0 to +162 mEq/100 g of DM in the beet group. Data obtained in this study detailed differences in composition between sources of molasses and suggested that a more complete characterization could improve the use of molasses in ration formulation.

Influence of maturity on alfalfa hay nutritional fractions and indigestible fiber content

This study focused on changes in fibrous and protein fractions, changes in fiber digestibility and amount of indigestible neutral detergent fiber (NDF) as a consequence of increased maturity in alfalfa. A total area of 720 m(2) was divided in 18 blocks randomly assigned to 3 treatments, differing in cutting intervals. Treatment 1 was harvested with a 21-d cutting schedule, at a prebloom stage; treatment 2 with a 28-d schedule, at about first-bloom stage; whereas a full bloom was observed in treatment 3, harvested with a 35-d cutting schedule. Treatments were replicated 4 times through the spring-summer period for 2 subsequent years, 2011 and 2012. Statistical differences were observed for crude protein [treatment 1: 20.8%, treatment 2: 17.3%, and treatment 3: 17.0%; standard error of the mean (SEM)=0.83], soluble protein, and nonprotein nitrogen among treatments on a dry matter basis. Similar results were observed for acid detergent lignin (6.3, 6.9, and 7.3%, respectively; SEM=0.39), lower in treatment 1 compared with others, and in vitro NDF digestibility at 24 or 240 h. Indigestible NDF at 240 h resulted in lower values for treatment 1 compared with treatments 2 and 3 (15.5, 17.2, and 18.3%, respectively; SEM=1.54). Moreover, the indigestible NDF:acid detergent lignin ratio varied numerically but not statistically among treatments, being as much as 9% greater than the 2.4 fixed value applied for rate of digestion calculation and Cornell Net Carbohydrate Protein System (Cornell University, Ithaca, NY)-based model equations. Assuming the diet composition remained unchanged, treatment 3 (35-d cutting interval) would be expected to yield 1.4 kg less milk per day based on energy supply, and 2.8 kg less milk daily based on protein supply than treatment 1.

Identification with peers as a strategy to muddle through the troubles of the adolescent years

This study was designed to explore critical events during adolescence and coping processes as dependent, first, on the relationship with peers, and second, on the type of peer-groups teenagers join. In all, 75 young people, members of four street groups and two religious groups, were given a questionnaire assessing identification with their peers and demographic characteristics, and then interviewed about critical events. The results show that the nature of the group individuals join is of minor importance, whereas the relationship established with peers is crucial: highly identified subjects not only more often join their peers but seem to derive more profit from interactions with people in general, both peers, friends, and parents. The peer-group is important, not to substitute for contacts with the family or other persons, but as a social entity to fill a vacuum during adolescent years.

Estimation of the indigestible fiber in different forage types

The role of indigestible NDF is essential in relation to OM digestibility prediction, total tract digestibility, rumen fill, passage rate, and digestion kinetics. Moreover, the truly indigestible NDF (iNDF) represents a core point in dynamic models used for diet formulations. However, despite its wide possible applications, few trials have been conducted to quantify iNDF and even fewer to investigate whether or not it is consistent among different forage sources. The objective of this study was to predict the iNDF by measuring the residual NDF after 240-h in vitro fermentation to determine the unavailable NDF (uNDF) within and among various forage types. Finally, a mathematical approach was investigated for the estimation of the uNDF fraction. In all, 688 forages were analyzed in this study. This pool included 122 alfalfa hays, 282 corn silages, and 284 grass hays. Values of uNDF varied among different forages and within the same type (22.7% ± 4.48%, 20.1% ± 4.23%, and 11.8% ± 3.5% DM for grass hay, alfalfa hay, and corn silages, respectively). The relationship among uNDF and ADL was not constant and, for grass hay and corn silage, was different ( 0.05) from the 2.4 × lignin value applied by the traditional Chandler equation. The observed uNDF:ADL ratio was 3.22 for grass hay and 3.11 for corn silage. Relationships among chemical and biological parameters and uNDF were investigated via simple and multiple regression equations. The greatest correlation with a single variable was obtained by ADL and ADF when applied to the whole data set ( = 0.63). Greater coefficients of determination resulted from a multiple regression equation for the whole data set ( = 0.80) and within each forage type ( = 0.65, 0.77, and 0.54 for grass hay, alfalfa hay, and corn silage, respectively). In conclusion, a regression approach requires specific equations and different regression coefficients for each forage type. The direct measurement of uNDF represented the best approach to obtain an accurate prediction of the iNDF and to optimize its specific purpose in dynamic nutrition models.

Immune-metabolic-inflammatory markers in Holstein cows exposed to a nutritional and environmental stressing challenge

Dairy cows are exposed to multiple stressors during the productive cycle, such as metabolic challenges, overcrowding, grouping change, environmental stress and dietary errors. Thus, it is essential to study reliable markers able to detect stress conditions in dairy farms. This study evaluates dairy cows' immunologic and metabolic markers after the sudden and combined exposition to a high-grain diet (75% concentrates) and the abrupt change of the housing system (from free stall to tie stall). A group of twenty-four Holstein cows were enrolled in a challenge study of 28 days duration. Several immunological and metabolic blood markers were evaluated over the trial. Blood samples were taken at day 0 (normal value) and day 1, 3, 7, 14, 21, and 28 (challenge). Data were submitted to a mixed model for repeated measures, including time as fixed and cows as random effects. The nutritional and environmental challenge had heavy effects on animal welfare and cows responded with a dramatic rumination drop. Our results suggest that the most responsive markers after abiotic stressors in cows were as follows: Serum Amyloid A and ROM in the acute response; Ceruloplasmin and GGT in the mid acute and Albumin, Paroxonase and FRAP in the chronic phase. Serum Amyloid A, Ceruloplasmin, Paraoxonase, GGT and ROM resulted as positive phase proteins, while, Albumin and FRAP resulted as negative phase proteins. Preliminary obtained results could concur to develop strategies able to mitigate stressor effects; moreover, the proposed design can be used as a model to test stress nutritional modulators.

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 &lt; 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 &lt; 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.

Calving difficulty influences rumination time and inflammatory profile in Holstein dairy cows

Difficult calving may adversely affect dairy cow health and performance. Maternal:fetal disproportion is a major cause of dystocia. Therefore, the main objective of this study was to assess the effects of dam:calf body weight ratio (D:C) on calving difficulty, rumination time, lying time, and inflammatory profile in 25 Holstein dairy cows. Using automatic monitoring systems, we monitored behavior and production in 9 primiparous and 16 pluriparous cows between dry-off and 30 d in milk. During the same period, we collected blood samples to monitor metabolism and inflammatory profile of these cows. Calvings were video recorded to assess calving difficulty and observe the duration of the expulsive stage. After parturition, the cows were separated into 3 classes according to their D:C: easy (E; D:C >17), medium (M; 14 < D:C <17), and difficult (D; D:C <14). The cows in class D showed relatively longer labor durations (108 min vs. 54 and 51 min for classes D, M, and E, respectively) and higher calving assistance rates (50% vs. 0 and 11% of calvings for classes D, M, and E, respectively) than those in the other 2 classes. Compared with the cows in classes M and E, those in class D exhibited shorter rumination times on the day of calving (176 min/d vs. 288 and 354 min/d for classes D, M, and E, respectively) and during the first week of lactation (312 min/d vs. 339 and 434 min/d for classes D, M, and E, respectively) and maintained lower rumination values until 30 DIM (399 min/d vs. 451 and 499 min/d for classes D, M, and E, respectively). Primiparous class D cows had shorter resting times during the first week after calving compared with those in class M (8 vs. 11 h/d for classes D and M, respectively). Interclass differences were found in terms of the levels of inflammation markers such as acute-phase proteins (ceruloplasmin, albumin, retinol, and paraoxonase). Moreover, cows in class D had lower plasma levels of fructosamine and creatinine after calving. Low D:C reduced postcalving rumination time and increased inflammation grade, suggesting a lower welfare of these animals at the onset of lactation. The D:C might serve as a useful index for the identification of cows at relatively higher risk of metabolic and inflammatory disease, thus helping farmers and veterinarians improve the welfare and health of these cows.

Effects of a completely pelleted diet on growth performance in Holstein heifers

Forage neutral detergent fiber (NDF) content and particle size are important factors that affect rumen function. The aim of the current study was to evaluate the effects on rumen health, NDF digestibility, and animal performance of pelleting a forage-based diet. Eight Holstein heifers (age 336±30d, body weight 346±35kg) were randomly assigned to a repeated crossover design. Animals were housed in tie-stalls and fed for ad libitum intake. The study included 4 periods of 3 wk, the first 2 wk for adaptation to the diet and the last wk for data collection. Diets had the same ingredients but had a different physical form: total mixed ration (TMR) and pellet (diameter=8mm). The physically effective NDF (peNDF) differed between the 2 treatments (39.8 and 11.8% of NDF in the TMR and pellet diets, respectively). During the trial, dry matter intake (DMI), water intake, rumination time, rumen temperature, and pH were evaluated daily. Fecal samples were collected in wk3 of each period to determine total-tract digestibility of the potential digestible (pd)NDF. Average daily gain and feed conversion ratio were calculated at the end of each period. With the pellet diet, DMI, DMI/body weight, and water consumption were higher. We observed no significant difference in average daily gain or feed conversion ratio. Rumination time was lower for the pellet diet than for the TMR diet (241 vs. 507min/d, respectively). Diet had no effect on rumen temperature or rumen pH. The total-tract digestibility of the pdNDF was greater with the TMR diet than with the pellet diet (90.25 vs. 86.82% pdNDF, respectively). The results of the current study suggest that a complete-feed pellet diet was well accepted by the animals, as demonstrated by higher DMI. Rumination time was reduced with the pellet diet, but rumen pH was not different. The pdNDF digestibility was high for both diets, but significantly higher for the TMR diet. Given that animal performance was similar between the 2 diets, although they differed with respect to DMI and fiber digestion, we hypothesize that the 2 diets had different retention times, related to their physical form. A complete-feed pellet diet formulated to provide a sufficient level of NDF from forages could be fed to growing ruminants without apparent negative effects on rumen health and animal productivity, at least for a short period. More research over a longer growing period is needed before recommending this feeding strategy for growing heifers.

The Use of Monensin for Ketosis Prevention in Dairy Cows during the Transition Period: A Systematic Review

Since the approval by the European Medicines Agency in 2013 of a monensin controlled-release capsule (CRC) for the prevention of ketosis in dairy cows, there has been widespread use across Europe. In recent decades, several papers have investigated the effects of monensin used as a CRC or as a feed additive to improve cattle energy metabolism and improve feed efficiency. Since the CRC is the only form of monensin permitted in Europe in dairy cows, the objective of this review was to report and summarize observations from the literature on the effects of this treatment in transition cows. The peer-reviewed literature published from 1997 was scanned, and papers written in English were evaluated for eligibility. Only papers evaluating the use of monensin in dairy cows for the prevention of ketosis during the transition period were reviewed. In total, 42 papers met the required criteria and were included in this review. The major findings focused on cow metabolism and health, rumen fermentation and milk production and quality. Overall, the review of the existing literature confirmed that monensin delivered as a CRC during the transition period has effects of different magnitude compared to other forms, doses or durations of administration. Studies agree on the antiketotic effects of this treatment, showing evidence of an increased propionate production in the rumen, reduced blood β-hydroxybutyrate, and improved liver function in treated cows, mainly resulting in reduced incidence of peripartum disease. On the contrary, the effects of CRC on ammonia production and rumen microflora are less robust than those reported for other forms. Of importance for the European market is the well-documented absence of any negative impact on milk and cheese production and composition using the CRC treatment.

Effects of a single injection of Flunixin meglumine or Carprofen postpartum on haematological parameters, productive performance and fertility of dairy cattle

The objective of the present research was to evaluate the effects of a single injection of Flunixin meglumine (FM) or Carprofen postpartum on haematological indicators, productive performance and fertility of Italian Friesian dairy cattle. In total, 60 cows, including 42 multiparous and 18 primiparous, were assigned to one of the following three treatments: (1) FM (2.2 mg i.m./kg of bodyweight (BW); Meflosyl 50 mg/mL), (2) Carprofen (CA; 1.4 mg s.c./kg of BW; Rymadil 50 mg/mL) or (3) saline (control) at 2.0 mL s.c./45.5 kg of BW. All treatments were administrated by a single injection within 12 h after calving. Individual milk yield was daily recorded during the trial and composition was determined at 7, 14, 21, 28, 35 and 60 days in milk (DIM). BWs were recorded at –21 ± 5 days before calving, and 1, 7, 14, 21, 28, 35 and 60 days after calving before the morning milking. Individual blood samples were collected from each animal for haemato-biochemical evaluation 3 weeks before calving (T0) and then repeated at the following times: within 12 h after calving, immediately before the administration of the anti-inflammatory drug (FM or CA; T1), ~36 h after calving (T2), 4 days after calving (T3) and 11 days after calving (T4). At each sampling time, the rectal temperature and the heart rate were monitored. Body condition score was determined after each sampling time and at 35 and 60 DIM. FM and CA treatments did not influence rectal temperature and heart rate during the first 11 DIM; no differences in overall milk yield, milk composition and dry matter intake were found. BW and body condition score were not affected by treatments throughout the study. Treatments did not affect serum metabolite concentrations of glucose, non-esterified fatty acids, β-hydroxybutyrate, serum urea nitrogen, total protein and albumin. Control cows showed a higher culling rate (P < 0.05) than did the FM- and CA-treated cows (25% vs 15% vs 5% respectively). FM-treated multiparous cows had a significantly (P < 0.05) lower incidence of retained placenta than did control and CA-treated cows (2.3% vs 9.3% vs 14% respectively). Furthermore, a greater percentage of cows pregnant (35% vs 10%) at the first insemination (P < 0.001) in non-steroidal anti-inflammatory drug groups than in control was found. Our findings evidenced that a single injection of FM or CA to non-febrile cows immediately after parturition could positively affect the metabolic adaptation of the cows at the onset of lactation and this aspect can positively influence reproductive performances and the culling rate.

Evaluation of fecal sampling time points to estimate apparent nutrient digestibility in lactating Holstein dairy cows

Introduction

The aim of this study was the evaluation of nutrient excretion patterns in samples of feces collected every 2 h to define the best sampling protocol for estimation of apparent digestibility.

Methods

Four multiparous mid-lactation Holstein cows, housed in a tie stall barn and milked twice a day (0800; 1900 h), were enrolled. Dry total mixed ration (TMR) without silages was fed once (0800 h) per day. Feces were sampled every 2 h for 72 h. Each sample was divided in 3 portions: hourly sample sample (8, 10, 12, 14, 16, 18, 20, 22, 00, 2, 4, 6), 8-h composite sample (00-06, 08-14 and 16-22), and a 24-h composite sample. Complete chemical analyses were performed and total tract nutrient digestibility was calculated using undegraded neutral detergent fiber at 240 h of in vitro fermentation (uNDF240h) as a marker. Feeding and rumination patterns were also recorded during the trial.

Results and discussion

For some parameters, excretion was not constant throughout the day: neutral detergent fiber (aNDFom), undegraded neutral detergent fiber at 24 h of in vitro fermentation (uNDF24h), uDNF240h, total tract crude protein digestibility (TTCPD), total tract neutral detergent fiber digestibility (TTaNDFomD), total tract potentially degraded neutral detergent fiber at 240 h of in vitro fermentation digestibility (TTpdNDF240hD) with minimal values after new TMR delivery and maximal values 12 h after feed delivery. Feeding and ruminating behavior seemed to have an important role in the excretion pattern, due to the pushing and evacuating effect they have. Considering our results, two fecal samples at 12 and 24 h after the TMR delivery are suggested. For one daily sample, 12 h post time of most stable and constant rumination 0000-0600 h, which is also 8 h post feed delivery is suggested.

Effect of Ewe Diet on Milk and Muscle Fatty Acid Composition of Suckling Lambs of the Protected Geographical Origin Abbacchio Romano

Simple Summary

Consumers are increasingly aware of the nutritional quality of lamb products, especially in developed countries. Healthier lipid profiles might increase lamb meat consumption by concerned consumers. Pasture diets provide a viable option to enrich milk and meat products with fatty acids beneficial for human health. However, in Mediterranean areas, pasture is not available throughout the year, which means that weaned lambs are fed on concentrates. This investigation aimed to implement feeding strategies in suckling lamb to enhance healthier fatty acids in milk of dams and consequently in lamb’s meat by applying extruded linseed in a total mixed ration or using pasture. The proposed feeding plans were suitable to increase the n-3 fatty acids (FA) profile in milk and thus the lamb’s meat sourced from fresh pasture and linseed-enriched diets. Indoor rearing could include feeding lambs with linseed to help maintain a high level of beneficial fatty acids in lamb meat better than an un-supplemented diet or when pasture is not available.

Abstract

Consumers increasingly pay more attention to the lipid profile of meat products and consume less meat to reduce cholesterol and heart disease. In Italy, sheep producers are increasingly feeding sheep fresh forage. We investigated whether the supplementation of dam diet with extruded linseed would be an alternative strategy to pasture for improving the intramuscular and subcutaneous FA compositions of their suckling lambs. The ewe diets were enriched with either extruded linseed (L), un-supplemented farm diet (F), or pasture (P). Milk saturated fatty acids (SFA) decreased in P and L compared with F, while the opposite pattern was observed for polyunsaturated FA (PUFA) and conjugated linoleic acids after seven days. The FA composition of lamb meat was similar to that of their dam’s milk, showing higher PUFA in P and L compared to F, while SFA was higher in F. Regarding the lamb meat obtained from barn-held ewes, L had lower n-6/n-3 content compared to F, while an intermediate content was found in P. These results indicate a better n-3 FA profile in milk and lamb’s meat from pasture and linseed-enriched diets. No changes in lamb performance were observed.

Influence of fiber degradability of corn silage in diets with lower and higher fiber content on lactational performance, nutrient digestibility, and ruminal characteristics in lactating Holstein cows

The effect of neutral detergent fiber (NDF) degradability of corn silage in diets containing lower and higher NDF concentrations on lactational performance, nutrient digestibility, and ruminal characteristics in lactating Holstein cows was measured. Eight ruminally cannulated Holstein cows averaging 91 ± 4 (standard error) days in milk were used in a replicated 4 × 4 Latin square design with 21-d periods (7-d collection periods). Dietary treatments were formulated to contain either conventional (CON; 48.6% 24-h NDF degradability; NDFD) or brown midrib-3 (BM3; 61.1% 24-h NDFD) corn silage and either lower NDF (LNDF) or higher NDF (HNDF) concentration (32.0 and 35.8% of ration dry matter, DM) by adjusting the dietary forage content (52 and 67% forage, DM basis). The dietary treatments were (1) CON-LNDF, (2) CON-HNDF, (3) BM3-LNDF, and (4) BM3-HNDF. Data were analyzed as a factorial arrangement of diets within a replicated Latin square design with the MIXED procedure of SAS (SAS Institute Inc., Cary, NC) with fixed effects of NDFD, NDF, NDFD × NDF, period(square), and square. Cow within square was the random effect. Time and its interactions with NDFD and NDF were included in the model when appropriate. An interaction between NDFD and NDF content resulted in the HNDF diet decreasing dry matter intake (DMI) with CON corn silage but not with BM3 silage. Cows fed the BM3 corn silage had higher DMI than cows fed the CON corn silage, whereas cows fed the HNDF diet consumed less DM than cows fed the LNDF diet. Cows fed the BM3 diets had greater energy-corrected milk yield, higher milk true protein content, and lower milk urea nitrogen concentration than cows fed CON diets. Additionally, cows fed the BM3 diets had greater total-tract digestibility of organic matter and NDF than cows fed the CON diets. Compared with CON diets, the BMR diets accelerated ruminal NDF turnover. When incorporated into higher NDF diets, corn silage with greater in vitro 24-h NDFD and lower undegradable NDF at 240 h of in vitro fermentation (uNDF240) allowed for greater DMI intake than CON. In contrast, for lower NDF diets, NDFD of corn silage did not affect DMI, which suggests that a threshold level of inclusion of higher NDFD corn silage is necessary to observe enhanced lactational performance. Results suggest that there is a maximum gut fill of dietary uNDF240 and that higher NDFD corn silage can be fed at greater dietary concentrations.

Effects of three different diets on the fatty acid profile and sensory properties of fresh Pecorino cheese "Primo Sale"

Objective

This study aimed to evaluate and compare the effects of three different diets on the fatty acids (FA) profile and sensory properties of a characteristic Italian fresh cheese: Pecorino “Primo Sale” (PS).

Methods

Fifty-four sheep were divided into three feeding groups: total mixed ration (TMR) enriched with extruded linseed (TL), control diet with TMR without any integration (TC), and pasture (P). During cheese production, six cheeses per experimental group were produced each week, stored for 10 days at 4°C, and then analyzed for chemical composition, FA profile, and sensory properties.

Results

Saturated fatty acids (SFA) were significantly higher in PS from group TC (82.11%) than in cheese from other two groups (P 75.48% and TL 66.83%). TL and P groups presented higher values of polyunsaturated fatty acids, 4.35 and 3.65%, respectively, than that of TC group (2.31%). The lowest SFA/unsaturated fatty acid ratio was found in TL and P groups, while the highest was found in the TC group. Vaccenic acid and conjugated linoleic acid (CLA) were higher in group P (p<0.05) than in groups L and TC. Sensory properties of cheese from group P received the highest scores for odor intensity and friability, while control group had a greater chewing consistency. Overall, all cheeses received good scores for acceptability.

Conclusion

In conclusion, this study showed how the integration of extruded linseed improved the FA profile of fresh pecorino cheese PS preserving its sensory properties. Levels of CLA in the PS group achieved using this approach was not higher than that in a grazing diet. Cheeses from groups P and L contained a higher value of FA, with nutritional implications for humans, when compared with un-supplemented diet. Linseed may be a good feeding strategy when pasture is not available.

Does the dry cow treatment with monensin controlled release capsule affect Parmigiano Reggiano cheese production?

We investigated the effects of monensin controlled-release capsule (CRC; Kexxtone, Eli Lilly and Company Ltd., Indianapolis, IN) preventative ketosis treatment on the traditional cheesemaking process as well as the final characteristics of Parmigiano Reggiano (PR) cheese. The use of this prevention product to reduce the incidence of ketosis in transition dairy cows was approved by the European Medicines Agency in 2013. No previous studies are available concerning the effects of this treatment on prolonged-ripening cheese production such as PR. In PR cheese production, feed, feed additives, and cow treatments are strictly regulated to avoid any possible interference with traditional manufacturing processes. For these reasons, on 1 farm where all milk was used for PR cheese production, monensin CRC was administered to 33 cows, 21 d before calving in the monensin-treated group (TRT), whereas untreated cows with similar breed and parity characteristics constituted the control group (CTR). For 20 wk, milk obtained from each group and whey starter were separately managed and transported in the cheese factory, where 2 cheese wheels per group were produced daily, making 552 PR cheese wheels in total. Morning bulk tank milk composition, cheesemaking properties, and whey starter fermentation activities were analyzed twice a week. Every aspect of the cheesemaking process was recorded and the resulting cheese was evaluated after 36 h and 6, 12, and 18 mo from production for yield, texture defects, composition, and fatty acids profile. Milk from the 2 groups differed for somatic cell content (TRT = 3.04 vs. CTR = 4.06, somatic cell score), total bacterial count (TRT = 4.08 vs. CTR = 6.08 × 1,000 cfu/mL), titratable acidity (TRT = 3.66 vs. CTR = 3.72 Soxhlet-Henkel degrees/50 mL), and casein content percentage (TRT = 2.4 vs. CTR = 2.5%). Whey starter parameters were comparable between the 2 groups. Final cheese composition and organoleptic profile were not influenced by the treatment, except for C18:1 content being enhanced (TRT = 22.8 vs. CTR = 20.8% of fatty acids). Percentage of defected ripened cheese was significantly lower in the treated group, both at x-ray evaluation performed at 6 mo (TRT = 6.2 vs. CTR = 12.3%) and at the consortium inspection, performed at 12 mo of ripening (TRT = 1.5 vs. CTR = 6.5%). On the other hand, average cheese yield at 18 mo of ripening was partially reduced (TRT = 7.5 vs. CTR = 7.7%). Overall, the use of monensin CRC had no negative effect on the cheesemaking process, prolonged ripening cheese characteristics, milk composition, or whey starter quality.