The effect of first-lactation calving season, milk production, and morphology on the survival of Simmental cows

Longevity in dairy and dual-purpose cattle is a complex trait which depends on many individual and managerial factors. The purpose of the present study was to investigate the survival (SURV) rate of Italian Simmental dual-purpose cows across different parities. Data of this study referred to 2 173 primiparous cows under official milk recording that calved between 2002 and 2020. Only cows linearly classified for type traits, including muscularity (MU) and body condition score (BCS) were kept. Survival analysis was carried out, through the Cox regression model, for different pairwise combinations of classes of milk productivity MU, BCS, and calving season. Herd-year of first calving was also considered in the model. SURV (0 = culled; 1 = survived) at each lactation up to the 6th were the dependent variables, so that, for example, SURV2 equal to 1 was attributed to cows that entered the 2nd lactation. Survival rates were 98, 71, 63, 56, and 53% for 2nd, 3rd, 4th, 5th, and 6th lactation, respectively. Results revealed that SURV2 was not dependent on milk yield, while in subsequent parities, low-producing cows were characterized by higher SURV compared to high-producing ones. Additionally, cows starting the lactation in autumn survived less (47.38%) than those starting in spring (53.49%), suggesting that facing the late gestation phase in summer could increase the culling risk. The present study indicates that SURV in Italian Simmental cows is influenced by various factors in addition to milk productivity. However, it is important to consider that in this study all first-calving cows culled before the linear evaluation - carried out between mid- and late lactation in this breed - were not accounted for. Finding can be transferred to other dual-purpose breeds, where the cows' body conformation and muscle development - i.e. meat-related features - are often considered as important as milk performance by farmers undertaking culling decisions.

Invited review: Bovine colostrum, a promising ingredient for humans and animals-Properties, processing technologies, and uses

Mammalian colostrum, known as "liquid gold," is considered a valuable source of essential nutrients, growth factors, probiotics, prebiotics, antibodies, and other bioactive compounds. Precisely for this reason, bovine colostrum (BC) is an emerging ingredient for the feed, food, and pharmaceutical industries, being nowadays commercially available in a variety of forms in several countries. Moreover, quite a large number of functional foods and supplements for athletes, human medicines, pet nutrition plans, and complementary feed for some livestock categories, such as piglets and calves, contain BC. The amount of BC yielded by a cow after calving represents approximately 0.5% of the yearly output in dairy breeds. For its nutritional properties and low availability, BC is characterized by a greater market value and an increasing demand compared with other by-products of the dairy sector. However, information regarding the market size of BC for the food and pharmaceutical industries, as well as future developments and perspectives, is scarcely available in the scientific literature. This lack can be attributed to industrial secrecy as well as to the relatively small scale of the BC business when compared with other dairy products, which makes the BC market limited, specific, and intended for a restricted audience. From a legal perspective, regulations assign BC to the large family of milk-derived powders; thus, collecting specific production data, as well as import-export trend information, is not straightforward and can result in unprecise estimates. Given that the interest in BC is increasing in different fields, it is important to have an overview of the production steps and of pros and cons of this emerging ingredient. The present narrative review discloses why BC has started to be considered a product rather than a by-product of the dairy industry. Moreover, the present document aims to summarize the existing methodologies used to assess BC quality in terms of immunoglobulin concentration, the different applications of BC in the industry, and the BC processing technologies. Finally, a panoramic view of the current international market is provided for the first time for this dairy product.

Invited review: Iodine level in dairy products-A feed-to-fork overview

The theme of iodine in the dairy sector is of particular interest due to the involvement and the interconnection of several stakeholders along the dairy food chain. Iodine plays a fundamental role in animal nutrition and physiology, and in cattle it is an essential micronutrient during lactation and for fetal development and the calf's growth. Its correct use in food supplementation is crucial to guarantee the animal's recommended daily requirement to avoid excess intake and long-term toxicity. Milk iodine is fundamental for public health, being one of the major sources of iodine in Mediterranean and Western diets. Public authorities and the scientific community have made great efforts to address how and to what extent different drivers may affect milk iodine concentration. The scientific literature concurs that the amount of iodine administered through animal feed and mineral supplements is the most important factor affecting its concentration in milk of most common dairy species. Additionally, farming practices related to milking (e.g., use of iodized teat sanitizers), herd management (e.g., pasture vs. confinement), and other environmental factors (e.g., seasonality) have been identified as sources of variation of milk iodine concentration. Overall, the aim of this review is to provide a multilevel overview on the mechanisms that contribute to the iodine concentration of milk and dairy products.

Limiting total mixed ration availability alters eating and rumination patterns of lactating dairy cows

The objective of this study was to investigate the effect of restricting total mixed ration (TMR) eating time with or without supplemental long hay offered on diurnal total intake, rumination, and rumen pH patterns in mid-lactation dairy cows. Eight multiparous Holstein cows were used in a replicated 4 × 4 Latin square design study with 21-d periods. The basal diet was the same for all 4 treatments with or without additional long grass hay (the same hay used in the TMR). For cows on limited-time TMR, diets were taken away at 1500 h (5 h before evening milking and feeding), and dry matter intake (DMI), ruminating, and rumen pH were monitored and summarized every 10 m for 7 d in each period. With restricted feeding, cows changed DMI patterns by consuming a large meal after feed was reinstated, resulting in lower DMI. Ruminating patterns closely mirrored intake patterns, as could be expected. Rumen pH was not different between groups but resulted in different diurnal patterns due to differences in eating and rumination patterns between the groups. Limiting feed availability can be used to change eating and rumination patterns, resulting in different rumen pH patterns.

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.

Calving time identified by the automatic detection of tail movements and rumination time, and observation of cow behavioural changes

The use of electronic devices to improve animal health, welfare and farm efficiency in precision livestock farming is a developing area of great scientific and commercial interest. In particular, the use of on-site dairy farm instruments to detect calving is a tool in reproduction livestock farming. The primary aim of this study was to validate the ability of the Moocall device (MD) to detect calving cows. In addition, behavioural changes in parturient dairy cows were evaluated using video-based observations. The MD was applied approximately 9 days before cow delivery. Observational sessions were conducted three times a day for each cow from the day before MD application to calving time. The sensitivity (Se) and specificity (Sp) at 3 and 24 h before calving were measured to test the effectiveness of the MD. In addition, behavioural changes were investigated before and after the MD application as well as before and during calving time. The 3 h Se and the 3 h Sp obtained were 95.2 and 71.4%, respectively. No false negatives were observed in the 24 h before delivery (24 h Se=100%) while the 3 h Se was 95.2%. The MD was well tolerated by the dairy cows since no change in behaviours was observed in this study among the cows with or without the MD, except for an increase in eating behaviour in the animals with the MD. As regards, the behavioural pattern during calving time (8 h before calving) in comparison with the previous phases, a significant increase in tail contraction frequency and raised tail position, and a decrease in eating behaviour and rumination time were observed. The first principal component (PC) was primarily explained by these variables, and calving cows best contributed to this PC. According to the results of the present study, the use of the MD can be a useful tool in detecting the moment of calving.

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.

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.

Automatically monitoring of dietary effects on rumination and activity of finishing heifers

Rumination and activity behaviours are important welfare indexes in beef-cattle housing. The main objective of the present study was to assess whether the automatic collars are able to reliably assess the rumination and activity patterns of beef heifers. For this purpose, individual rumination time and activity (RT and AT respectively) were continuously recorded using an automatic neck-collar system (Hr-Tag, SCR Engineers Ltd, Israel) on the three trials performed. For Experiment 1, 60 Italian crossbred heifers were randomly assigned to one of two experimental diets for 9 months: the corn–silage diet (CS), which included 50% forage on a dry-matter (DM) basis (43% corn–silage, 7% wheat straw) and the hay diet (HAY), with 57% forage on DM basis (28.5% grass hay, 28.5% alfalfa hay). Heifers consuming HAY diet showed greater (P &lt; 0.05) RT (min/day) and AT (bits/day) than did those on CS diet. Rumination time per kilogram of dry matter and per kilogram of amylase- and sodium sulfite-treated neutral detergent fibre corrected for ash residue (aNDFom) intake were similar in the two experimental groups, while RT per kilogram of physical effective NDF (peNDF) intake was greater (P &lt; 0.05) in the CS group than in the HAY one. Daily rumination and activity patterns (min/2 h and bits/2 h respectively) were significantly different between CS and HAY groups. In the second experiment, 32 beef heifers were randomly allocated in two homogeneous pens, each containing eight animals, and two non-homogeneous ones, in which animals were added at different periods. The AT of non-homogeneous pens was significantly higher than that of the homogeneous ones, suggesting a distress condition for values higher than 309 bits/day AT. In the third experiment, RT and AT of three animals with respiratory disease were collected using the automatic collar system and compared with AT and RT of the healthy animals. Sick animals presented a significantly lower RT and higher AT than did the healthy ones. The cut-off to distinguish sick from healthy heifers was set to 537 bits/day AT and 381 min/day RT. In conclusion, the present study demonstrated that automatic collars can reliably monitor different rumination and activity behaviours of beef animals in various management conditions and different health statuses.

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.

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.

Using single or multiple liquor-donor cows for in vitro digestibility of amylase- and sodium sulfite-treated neutral detergent fiber with ash correction

In vitro methods requiring ruminal microorganisms to ferment and digest feeds have been used for decades. Though commonly accepted, collecting and pooling rumen fluid from different donor animals to avoid individual characteristics could affect in vitro fermentations. The current study evaluated the effects of individual or pooled liquors on in vitro digestibility of amylase- and sodium sulfite-treated NDF with ash correction (aNDFom). The study was conducted on 24 samples (8 alfalfa hays, 8 grass hays, and 8 corn silages). The 3 donor animals (treatment 1, 2, and 3) were selected based on similar body weights, parity, days in milk, milk production, and milk composition. Samples were digested in vitro via inoculation of different rumen fluid at different time points (12, 24, 72, and 120h). An equal amount of each liquor collected was sampled and equally mixed with the others to obtain treatment 4. For the alfalfa hay group, differences were observed at 12 (29.95, 27.07, 29.02, and 32.55% aNDFom for treatments 1, 2, 3, and 4, respectively) and 24h (37.35, 35.54, 36.44, and 40.56% aNDFom for treatments 1, 2, 3, and 4, respectively). The inoculum source did not affect in vitro digestibility over longer time periods (72 and 120 h). Similar results were observed in the grass hay group, in which the mixed inoculum had greater digestibility values at both 12 (28.86, 26.89, 27.88, and 30.92% aNDFom for treatments 1, 2, 3, and 4, respectively) and 24h (37.35, 35.54, 36.44, and 40.56% aNDFom for treatment 1, 2, 3, and 4, respectively), but not over longer time periods. For the corn silage group, we observed differences for treatment 4 only at 12h (35.78, 33.87, 34.83, and 37.80% aNDFom for treatment 1, 2, 3, and 4, respectively). These results underline the differences among donor animals, especially when evaluating short incubation time points, and that pooling rumen contents is not equal to averaging across individual animals. Reported data require a deeper investigation on whether or not the method of inoculating a pool of rumen contents represents the actual ability of the animal to digest fiber.

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.

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.

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.

Microencapsulated sorbic acid and nature-identical compounds reduced Salmonella Hadar and Salmonella Enteritidis colonization in experimentally infected chickens

The reduction of Salmonella prevalence in broilers is a priority in European Union agricultural policies because treatment with antibiotics is forbidden by Regulation (EC) 2160/2003. Two trials were conducted to evaluate the efficacy of a microencapsulated blend of sorbic acid and nature-identical compounds (i.e., chemically synthesized botanicals; SAB) on the reduction of the cecal prevalence and contents of Salmonella enterica serovars Hadar and Enteritidis in experimentally infected chickens. In the first trial, 125 one-day-old Lohmann specific-pathogen-free chickens were assigned to one of the following treatments: negative control (not challenged and not treated), positive control (challenged and not treated), SAB0.3, SAB1, or SAB5 (challenged and treated with the microencapsulated blend included in the feed at 0.03, 0.1, or 0.5%, respectively). At 30 d of age, birds were infected with 10(6) cfu of Salmonella Hadar, and after 5, 10, or 20 d postinfection, 5, 10, and 10 birds per treatment, respectively, were killed and the cecal contents and liver and spleen samples were analyzed for Salmonella Hadar. In the second trial, 100 one-day-old Ross 708 chickens were assigned to 1 of 5 treatments: control (not treated), SAB0.3, SAB1, SAB2, or SAB5 (treated with the blend included in the feed at 0.03, 0.1, 0.2, or 0.5%, respectively). At 7 d of age, the birds were challenged with 10(5) cfu of Salmonella Enteritidis, and after 7, 14, or 24 d after challenge, 5, 5, and 10 birds per treatment, respectively, were killed and cecal contents were analyzed for Salmonella Enteritidis. Results showed that in the early stage of infection Salmonella prevalence was high in both studies, whereas at the end of the observation periods, the blends at 0.03, 0.1, and 0.5 in the challenge with Salmonella Hadar and at 0.2 and 0.5% in the challenge with Salmonella Enteritidis significantly reduced (by 2 log(10) cfu) the cecal content of Salmonella. This study showed that intestinal delivery of microencapsulated sorbic acid and nature-identical compounds can result in a 100-fold reduction of Salmonella at the intestinal level in broilers at slaughter age.

Transition cow: interaction with fertility

In recent years a progressive worsening of fertility indices in dairy cow herds has been observed. Several factors (genetic, dietary and management) seem to be more related to poor fertility than milk yield level. The degree and the length of the energy deficit during the transition period are inversely related to reproductive indices (e.g. conception rate is <30% for BCS decreases over one unit). A serious energy deficit reduces (or suppresses) pulsatile secretion of gonadotrophins (ovarian dysfunction and/or smaller follicles): IGF-I and insulin plasma levels (slower follicle growth and higher embryonic mortality); and progesterone production from the corpus luteum (higher rate of embryonic abortions). The diet influences fertility in several ways. Excess of rumen degradable proteins, apart from negative energy balance, negatively affects reproductive activity. Conversely, some nutrients (i.e. some polyunsaturated fatty acids or some amino acids) seem to show positive effects on fertility. Finally, the relationship between health status, often compromised during the transition period, and fertility efficiency is discussed. The release of cytokines seems to be related directly and indirectly (mainly by the change in usual hepatic metabolism to the malfunction of reproductive apparatus. Quick recovery of reproductive activity requires the adoption of strategies around calving to cover the higher environmental and nutritive requirements and to prevent disorders of any kind.

Relative bioavailability of microgranulated sulfadimidine in veal calves

The kinetics of free and microgranulated sulfadimidine were compared in milk-fed calves dosed orally (180 mg/kg) in a crossover study. Microgranulation results in delayed absorption of sulfadimidine and poor bioavailability, with the area under the plasma concentration-time curve (AUC(0-infinity)) reduced from 7400 to 3781 micrograms.h/mL, and maximum plasma concentration (Cmax) reduced from 188.1 +/- 39.0 to 84.41 +/- 22.6 micrograms/mL. It is concluded that sulfadimidine microgranulated with long chain fatty acids is not suitable for use in milk-fed calves; the gastrointestinal transit time is too rapid to allow full release of the drug, markedly limiting its bioavailability. In adult animals, or in the young of other animal species in which digesta transit time is slower than in calves, the bioavailability of microgranulated sulfadimidine may be much greater.

Relationships of polymorphisms for growth hormone and growth hormone receptor genes with milk production traits for Italian Holstein-Friesian bulls

Allelic variation in the structural or regulatory sequences of growth hormone and its receptor genes might directly or indirectly affect milk traits. This possibility prompted us to investigate the eventual relationships of restriction fragment length polymorphisms at the locus of bovine growth hormone (using TagI and MspI restriction enzymes) and its receptor (using TaqI restriction enzyme) to PTA of milk production traits of bulls. Ninety-one Italian Holstein-Friesian bulls were used in this experiment, and data were analyzed with a fixed linear model. The restriction fragment length polymorphisms at the growth hormone locus did not affect the milk traits studied. Six restriction enzyme TaqI bands of 7.1, 6.2, 5.7, 5.4, 4.2, and 3.3 kb with nine patterns were observed after hybridization by a cDNA probe containing the coding sequences for the intracellular C-terminal part of the receptor. The effect of this polymorphism on PTA for milk protein percentage was highly significant and was favorable for the rare (6.6%) 5.7- and 5.4-kb pattern. Our results indicate that further study is needed to explain the DNA polymorphism and to obtain more definite conclusions about effects on milk traits.

Effect of propylene glycol supplementation around parturition on milk yield, reproduction performance and some hormonal and metabolic characteristics in dairy cows

Thirty-nine multiparous Holstein cows were used to measure the effect of propylene glycol treatment around parturition on milk yield, reproductive efficiency and some hormone and metabolite concentrations. Cows were assigned randomly to control (n = 19) or propylene glycol treated (n = 20) groups. Propylene glycol (300 g) was administered directly mixed with the diet from day 10 prior to the expected calving date until parturition (day 0) and orally after dilution in 1 l water on days 3, 6, 9 and 12. Blood samples were collected on days -20, -5, 0, 3, 10, 25 and 50 while milk samples were taken weekly until 13 weeks post partum. Body condition scores, recorded on days -20, 15 and 50, were not affected by propylene glycol administration. Propylene glycol did not significantly affect milk yield or composition but linear somatic cell score measured from the first 13 weeks post partum was reduced by propylene glycol administration (P < 0.01). Moreover, propylene glycol reduced milk urea (-25 mg/l, P < 0.05), especially during the first 9 weeks post partum. Plasma insulin concentrations were similar in both groups during the experiment while insulin-like growth factor I (P < 0.05) and insulin-like growth factor-binding protein 3 (P < 0.001) levels were higher on days 10, 25 and 50 post partum in the propylene glycol group. Propylene glycol administration decreased plasma non-esterified fatty acid concentrations (P < 0.05 to P < 0.01) but increased total cholesterol levels (P < 0.01) after parturition while 3-hydroxybutyrate levels were unaffected by the treatment. Changes in the hormone and metabolic concentrations after propylene glycol administration in the last few days of gestation and the first week of lactation seem to indicate that energy balance in the treated group was probably more positive than in the control group. There was also evidence that propylene glycol administration prevented fatty liver syndrome and hastened the resumption of oestrous cycles (P < 0.001).

Lactitol enhances short-chain fatty acid and gas production by swine cecal microflora to a greater extent when fermenting low rather than high fiber diets

The study was conducted to determine if the response of swine cecal microflora to lactitol (beta-D-galactopyranosyl-(1-->4)-D-sorbitol; 3 mmol/L) varies when fermenting low (LF) or high fiber (HF) predigested diets. The inoculum was collected from four sows fitted with cecal cannulas, pooled, buffered and dispensed in 27 vessels under anaerobic conditions. The LF or HF predigested diets were used as substrate in two separate experiments. In each trial nine vessels were used as controls (C) without feed addition, nine received predigested feed (LF or HF) and the remaining nine vessels received the same amount of feed with the supplementation of lactitol (LF+L or HF+L). Lactitol (L) significantly lowered pH and the acetic to propionic acid ratio in the first 8 h of fermentation in both experiments (P < 0.05). At 4 and 8 h, the addition of lactitol reduced ammonia by 100 and 84% in LF+L and by 56 and 38% in HF+L (P < 0.05). In addition, LF+L and HF+L diets gave higher short-chain fatty acid energy yields by 70 and 40% than LF and HF, respectively (P < 0.05). Two bacterial growth models (logistic and Gompertz) were tested to fit gas production data. The Gompertz equation provided a better fit than the logistic model to gas production data for both LF and HF experiments. Lactitol reduced culture lag time in both experiments by approximately 50%, but it increased gas production rate and maximum gas production by approximately 60% only when the microflora was fermenting the LF predigested diet (P < 0.05). No difference in the duration of the exponential phase due to lactitol was observed in either experiment. Our results indicate that lactitol may be an interesting additive to animal feeding. It controlled harmful fermentation processes and stimulated short-chain fatty acid production to a greater extent in low than in high fiber diets, suggesting an improved fermentation of low fiber feed carbohydrates and eventually an increased availability of short-chain fatty acids for the host.

Clinical Usefulness of Prostate Specific Antigen and Prostate Specific Antigen Density to Distinguish Benign from Malignant Prostate Diseases

The possibility of distinguishing prostate cancer from BPH with the prostate specific antigen (PSA) determination is particularly poor when PSA levels are between 4.1 and 10 ng/ml. In these cases the quotient of serum PSA and prostate volume, defined as prostate specific antigen density (PSAD), seems to enhance the accuracy of PSA alone. In this study we evaluated retrospectively the preoperative PSA levels in 139 patients with BPH and in 26 patients with prostate cancer who underwent surgical treatment at our Department. We calculated the prostate volume with the following formula: length x width x depth x 0.52. The three dimensions were obtained from the surgical specimen in the patients with prostate cancer and using transrectal ultrasound in the cases of BPH. In patients with a serum PSA level of 4.1 to 10 ng/ml, PSA alone was not able to distinguish benign from malignant prostate disease; the PSAD values, on the contrary, provided a statistically significant (p < 0.003) stratification between BPH and prostate cancer (mean PSAD of 0.0088 and 0.191 respectively). Only 6% of patients with BPH had a PSAD greater than 0.15 compared to 76% of patients with prostate cancer. These results suggest the usefulness of PSAD in predicting the presence of prostate cancer in patients with intermediate levels of serum PSA.