Environmental impact of Holstein Friesian and 3-breed crossbred dairy cows using a life cycle assessment approach applied to individual animals.

This study aimed to set up a life cycle assessment (LCA) approach at the level of individual animals to assess the effects of a 3-breed crossbreeding program on the environmental impact of cows. The study involved 564 cows, 279 purebred Holstein Friesian (HO) and 285 crossbred cows (CR), that originated from a 3-breed crossbreeding program based on the rotational use of Viking Red, Montebèliarde, and HO sires and kept in 2 dairy herds of northern Italy (224 and 340 cows/herd, respectively). The reference unit of the LCA model was the lifetime of cows, from the birth to culling or death. Data were collected at different levels: individual animal-based data referred to the whole life (birth, calving, dry, cull or death dates, and milk production); individual test-date collection of body measures and BCS, used to predict BW and to estimate energy requirements; common farm-based data concerning herd management (diets composition, and materials used). Data were used to compute DMI, milk and milk components production, gross income (GI), and income over feed costs (IOFC) pertaining to the lifespan of cows. An individual LCA-derived approach was set up to compute global warming potential (GWP), acidification and eutrophication potential (AP and EP, respectively), and land occupation (LO), which have been associated with different functional units (cow in her whole life or per day of life; kilograms of milk fat plus protein, and GI and IOFC [in euros] produced in the herd life). Data were analyzed using a generalized linear model including the fixed effects of genetic group (CR vs. HO), farm, and their interaction (genetic group × farm). Compared with HO, CR cows completed more lactations (+12%), had earlier first calving (-2 wk), yielded more fat plus protein in milk both in the lifespan (+8%) and per day of life (+4%). Concerning the environmental impact, when compared with HO herd mates, CR cows had nominal greater emissions per cow in the whole life, similar emissions per day of life and ∼3% lower GWP, AP, and EP per kilogram of fat plus protein yielded in lifespan. Income over feed costs per unit of emission tended to be ∼4% greater in CR compared with HO cows. Also, the use of land tended to be lower in CR compared with HO in most indicators considered. In conclusion, LCA could be adapted to represent individual animals. Moreover, managing dairy cows according to a 3-breed rotational crossbreeding scheme may be regarded as a strategy that can contribute to mitigate the emissions and to improve the environmental impact of dairy operations.

Effect of intramammary infection and inflammation on milk protein profile assessed at the quarter level in Holstein cows.

In this study we wanted to investigate the associations between naturally occurring subclinical intramammary infection (IMI) caused by different etiological agents (i.e., Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, and Prototheca spp.), in combination with somatic cell count (SCC), on the detailed milk protein profile measured at the individual mammary gland quarter. An initial bacteriological screening (time 0; T0) conducted on individual composite milk from 450 Holstein cows reared in 3 herds, was performed to identify cows with subclinical IMI. We identified 78 infected animals which were followed up at the quarter level at 2 different sampling times: T1 and T2, 2 and 6 wk after T0, respectively. A total of 529 quarter samples belonging to the previously selected animals were collected at the 2 sampling points and analyzed with a reversed phase HPLC (RP-HPLC) validated method. Specifically, we identified and quantified 4 caseins (CN), namely αS1-CN, αS2-CN, κ-CN, and ß-CN, and 3 whey protein fractions, namely ß-lactoglobulin, α-lactalbumin, and lactoferrin (LF), which were later expressed both quantitatively (g/L) and qualitatively (as a percentage of the total milk nitrogen content, % N). Data were analyzed with a hierarchical linear mixed model with the following fixed effects: days in milk (DIM), parity, herd, SCC, bacteriological status (BACT), and the SCC × BACT interaction. The random effect of individual cow, nested within herd, DIM and parity was used as the error term for the latter effects. Both IMI (i.e., BACT) and SCC significantly reduced the proportion of ß-CN and αS1-CN, ascribed to the increased activity of both milk endogenous and microbial proteases. Less evident alterations were found for whey proteins, except for LF, which being a glycoprotein with direct and undirect antimicrobial activity, increased both with IMI and SCC, suggesting its involvement in the modulation of both the innate and adaptive immune response. Finally, increasing SCC in the positive samples was associated with a more marked reduction of total caseins at T1, and αS1-CN at T2, suggesting a synergic effect of infection and inflammation, more evident at high SCC. In conclusion, our work helps clarify the behavior of protein fractions at quarter level in animals having subclinical IMI. The inflammation status driven by the increase in SCC, rather the infection, was associated with the most significant changes, suggesting that the activity of endogenous proteolytic enzymes related to the onset of inflammation might have a pivotal role in directing the alteration of the milk protein profile.

Animal performance and stress at weaning when dairy cows suckle their calves for short versus long daily durations.

Calves in most dairy farms are separated from their dams either immediately or within a few hours after birth, prompting increasing concern of the society for reasons of animal welfare. The aim of this study was to identify systems to maintain cow-calf contact (CCC) that balance the benefits for calf growth and health against the negative impacts on sellable milk and stress at weaning. We tested reuniting cows and calves for 20 min before (Before-group) or 2.5 h after (After-group) morning milking (in Trial 1) or for a 9 h period between the morning and evening milkings (Half-day-group, in Trial 2). In Control-groups, calves were separated from their dam at birth and fed with artificial nipple with tank milk provided daily at 13% (Trial 1) and 14% (Trial 2) of their BW. In both trials, each practice was applied on a group of 14 dam-calf pairs (7 Holstein [Ho] and 7 Montbéliarde [Mo]). All calves were weaned at a BW of at least 100 kg. In Trial 1, the After-group was prematurely stopped when the calves were eight weeks of age as calf growth became limited (340 g/d) due to low milk intakes (2.97 kg/d). During the first eight weeks of lactation, milk yield at the parlour was 29%, 51% and 42% lower in After-, Before- and Half-day-cows respectively compared to Controls. From week 14 to 16 when all calves were separated from their dam, Before-cows still produced 25% less milk than Control-cows while Half-day-cows reached the milk yield of Control-cows within a week. There were no significant differences in milk somatic cell count and in frequency of health disorders (cows and calves) between suckling and Control-groups. Compared to Control-calves, calf growth until weaning was higher in the suckling calves in Trial 1 (861 vs 699 g/d) and similar in Trial 2 (943 vs 929 g/d). At weaning, Before- and Half-day-calves started to vocalise earlier and continued to vocalise longer than Controls. In conclusion, the best compromise between cow milk yield and calf growth is a long period of CCC (9 h) between the morning and evening milkings. Still abrupt weaning stresses both cows and calves even if CCC has been restricted before separation.

Body traits, carcass characteristics and price of cull cows as affected by farm type, breed, age and calving to culling interval.

Beef production from cull cows is an additional source of income for dairy farms and greatly contributes to red meat production, but the sources of variation of live animal characteristics and the carcass traits of cull cows have rarely been examined. This study investigated the effects of the farm type, breed, age at slaughter (AGE) and calving to culling interval (Calv_Cull) on the body traits and carcass characteristics of dairy and dual-purpose cull cows. Data from 555 cull cows from 182 herds belonging to five farm types, characterised by a combination of housing and feeding systems, were recorded and analysed. Dairy breeds, such as Holstein Friesian and Brown Swiss, and dual-purpose breeds (Simmental, Rendena) were included in the trait assessments. The day before slaughter, the cows were weighed and scored for body condition (BCS) and fleshiness, and then, their heart girth and wither height were measured. At the slaughterhouse, the carcass weight (CW), dressing percentage (DP), carcass conformation and fatness scores, carcass price per kg and carcass total value were obtained. On average, the cows were slaughtered at nearly 71±27 months of age, 285±187 days after the last calving; 615±95 kg BW; and provided a 257±51 kg CW. Nearly 50% of the cows fell within the BCS range of 2.75 to 3.50, and the carcasses were mostly graded in the lowest class of conformation and fatness scores. Cull cows from free-stall farms had a higher DP, carcass conformation score and price than those from traditional tie-stall farms. The breed influenced the AGE, live animal characteristics and carcass traits. Cows from dairy breeds were younger at slaughter, had a lower BCS and fleshiness, and greater body measurements, but a lower DP and carcass price than those from dual-purpose breeds, although differences between the breeds were found within both groups. The age of the cows at slaughter influenced the Calv_Cull and increased the BW, body measurements and CW, but not the fleshiness and fatness appreciation (both in vivo and postmortem) or carcass price. The increasing Calv_Cull improved the BW, BCS, fleshiness, CW and carcass conformation and fatness. In conclusion, the decision to cull dairy cows should also take into account the factors that affect their carcass value in regards to improving the carcass price of cows.

Cheesemaking in highland pastures: Milk technological properties, cream, cheese and ricotta yields, milk nutrients recovery, and products composition.

Summer transhumance of dairy cows to high Alpine pastures is still practiced in many mountainous areas. It is important for many permanent dairy farms because the use of highland pastures increases milk production and high-priced typical local dairy products often boost farm income. As traditional cheese- and ricotta-making procedures in Alpine pastures are central to this dairy system, the objective of this study was to characterize the quality and efficiency of products and their relationships with the quality and availability of grass during the grazing season. The milk from 148 cows from 12 permanent farms reared on a temporary farm located in Alpine pastures was processed every 2wk during the summer (7 cheesemakings from late June to early September). During each processing, 11 dairy products (4 types of milk, 2 by-products, 3 fresh products, and 2 ripened cheeses) were sampled and analyzed. In addition, 8 samples of fresh forage from the pasture used by the cows were collected and analyzed. At the beginning of the pasture season the cows were at 233±90d in milk, 2.4±1.7 parities, and produced 23.6±5.7kg/d of milk. The milk yield decreased with the move from permanent to temporary farms and during the entire summer transhumance, but partly recovered after the cows returned to the permanent farms. Similar trends were observed for the daily yields of fat, protein, casein, lactose, and energy, as we found no large variations in the quality of the milk, with the exception of the first period of Alpine pasture. The somatic cell counts of milk increased during transhumance, but this resulted from a concentration of cells in a lower quantity of milk rather than an increase in the total number of cells ejected daily from the udder. We noted a quadratic trend in availability of forage (fresh and dry matter weight per hectare), with a maximum in late July. The quality of forage also varied during the summer with a worsening of chemical composition. The evening milk (before and after natural creaming), the whole morning milk, and the mixed vat milk had different chemical compositions, traditional coagulation properties, and curd-firming modeling parameters. These variations over the pasture season were similar to the residual variations with respect to chemical composition, and much lower with respect to coagulation and curd-firming traits. Much larger variations were noted in cream, cheese, and ricotta yields, as well as in nutrient recoveries in curd during the pasture season. The protein content of forage was correlated with some of the coagulation and curd-firming traits, the ether extract of forage was positively correlated with milk fat content and cheese yields, and fiber fractions of forage were unfavorably correlated with some of the chemical and technological traits. Traditional cheese- and ricotta-making procedures showed average cream, cheese, and ricotta yields of 6.3, 14.2, and 4.9%, respectively, and an overall recovery of almost 100% of milk fat, 88% of milk protein, and 60% of total milk solids.

Effect of dairy farming system, herd, season, parity, and days in milk on modeling of the coagulation, curd firming, and syneresis of bovine milk.

The objectives of this study were to characterize the variation in curd firmness model parameters obtained from coagulating bovine milk samples, and to investigate the effects of the dairy system, season, individual farm, and factors related to individual cows (days in milk and parity). Individual milk samples (n = 1,264) were collected during the evening milking of 85 farms representing different environments and farming systems in the northeastern Italian Alps. The dairy herds were classified into 4 farming system categories: traditional system with tied animals (29 herds), modern dairy systems with traditional feeding based on hay and compound feed (30 herds), modern dairy system with total mixed ration (TMR) that included silage as a large proportion of the diet (9 herds), and modern dairy system with silage-free TMR (17 herds). Milk samples were analyzed for milk composition and coagulation properties, and parameters were modeled using curd firmness measures (CFt) collected every 15 s from a lacto-dynamographic analysis of 90 min. When compared with traditional milk coagulation properties (MCP), the curd firming measures showed greater variability and yielded a more accurate description of the milk coagulation process: the model converged for 93.1% of the milk samples, allowing estimation of 4 CFt parameters and 2 derived traits [maximum CF (CF(max)) and time from rennet addition to CF(max) (t(max))] for each sample. The milk samples whose CFt equations did not converge showed longer rennet coagulation times obtained from the model (RCT(eq)) and higher somatic cell score, and came from less-productive cows. Among the sources of variation tested for the CFt parameters, dairy herd system yielded the greatest differences for the contrast between the traditional farm and the 3 modern farms, with the latter showing earlier coagulation and greater instant syneresis rate constant (k(SR)). The use of TMR yielded a greater tmax because of a higher instant curd-firming rate constant (k(CF)). Season of sampling was found to be very important, yielding higher values during winter for all traits except k(CF) and k(SR). All CFt traits were affected by individual cow factors. For parity, milk produced by first-lactation cows showed higher k(CF) and k(SR), but delays in achieving CF(max). With respect to stage of lactation, RCT(eq) and potential asymptotic CF increased during the middle of lactation and stabilized thereafter, whereas the 2 instant rate constants presented the opposite pattern, with the lowest (k(CF)) and highest (k(SR)) values occurring in mid lactation. The new challenge offered by prolonging the test interval and individual modeling of milk technological properties allowed us to study the effects of parameters related to the environment and to individual cows. This novel strategy may be useful for investigating the genetic variability of these new coagulation traits.

The relevance of echocardiography heart measures for breeding against the risk of subaortic and pulmonic stenosis in Boxer dogs.

The aims of this study were to investigate the role and relative importance of auscultation and echocardiography traits as risk factors for the diagnosis of subaortic (SubAS) and pulmonic (PS) stenosis and to estimate the heritability (h(2)) of cardiac measurements taken through echocardiography for a random sample of Italian Boxer dogs. The data were cardiovascular examination results of 1,283 Italian Boxer dogs (686 females and 597 males) enrolled in the national screening program for heart defects arranged by the Italian Boxer Club. Examinations were performed during a 6-yr period by a group of 7 veterinary cardiologists following a standard protocol. Occurrence and severity of SubAS and PS were diagnosed, taking into account clinical and echocardiography findings such as the grade of cardiac murmur, direct ultrasound imaging of the anatomic obstructive lesions, and values of aortic or pulmonary blood flow velocities. A Bayesian logistic regression analysis was performed to identify clinical and echocardiography variables related to SubAS and PS diagnosis. Estimation of variance components for clinical and echocardiography traits was performed using a mixed linear animal model, Bayesian procedures, and the Gibbs sampler. Prevalence of SubAS (PS) was 8.4% (2.2) and 10.7% (6.4) for female and male dogs, respectively. Cardiac murmur, peak velocities, and annulus areas behaved as risk factors for SubAS and PS. The risk of a positive diagnosis for SubAS was 3 times greater for dogs with aortic annulus area <2.1 cm(2) relative to dogs with areas >2.37 cm(2), 84 times greater for dogs showing aortic peak velocities >2.19 m/s relative to dogs with peak velocities <1.97 m/s, and 41 times greater for dogs with moderate to severe murmur grades relative to dogs with absent murmur. Similar results were obtained for PS. The estimated h(2) for the occurrence of cardiac defects was 23.3% for SubAS and 8.6% for PS. Echocardiography and cardiac murmur grades exhibited moderate h(2) estimates and exploitable additive genetic variation. The estimated h(2) was 36, 24, and 20% for aortic annulus area, aortic peak velocity, and cardiac murmur score, respectively. For the area of the pulmonary annulus and peak pulmonary velocity, the estimated h(2) were smaller, ranging from 9.5 to 12.8%. These measures are candidate indicator traits that might be effectively used in dog breeding to reduce the prevalence and severity of cardiac defects.

Computer image analysis traits of cross-sectioned dry-cured hams: a genetic analysis.

The aims of this study were to estimate genetic parameters of image analysis traits of cross-sectioned dry-cured hams and carcass weight (CW) and to investigate effects of some nongenetic sources of variation on these traits. Computer image analysis (CIA) had been carried out for digital images of the cross-section of 1,319 San Daniele dry-cured hams. The cross-sectional area (SA, cm(2)); the average thickness of subcutaneous fat (FT, cm); and the proportions of lean (LA, %), fat-eye (FEA, %), and subcutaneous fat area (SCF, %) to SA, and of biceps femoris (BFA, %) and semitendinosus muscle area (STA, %) to LA were recorded. Bivariate analyses were carried out for pairs of traits for estimation of genetic parameters using Bayesian methodology and linear models. Linear models included the nongenetic effects of slaughter groups and sex and the additive genetic effects of pigs and their ancestors (1,888 animals). Variation of FEA was nearly 4-fold that of SA and LA. Variation of CIA traits due to sex effect was not large, whereas slaughter group effects were relevant sources of variation for all traits. For all traits, with the exception of FEA, the posterior probability for the true heritability being greater than 0.1, was greater than 0.95. Point estimates of heritabilities for FT and SCF were 0.42 and 0.51, respectively. Heritability estimates for FEA, LA, BFA, and STA were 0.13, 0.44, 0.44, and 0.36, respectively. The genetic correlations between CW and CIA traits were positive and large for SA (0.86), positive and moderate for FT, FEA, and STA (0.47, 0.40, and 0.45, respectively) and negative with LA (-0.28). Although FEA, FT, and SCF were all measures of the extent of fat deposition in the ham, the genetic correlations between FT or SCF and FEA were very low. A very large estimate (0.74) was obtained for the genetic relationship between SA and FEA, suggesting that reduction of ham roundness through selective breeding would be beneficial for decreasing FEA. On the basis of the estimated parameters, genetic selection is expected to be effective in changing size of fatty and lean areas of the cross-section of dry-cured hams. Causes related to the abnormal development of the fat-eye depot remain unknown, but this study provided evidence that influences of polygenic effects on phenotypic variation of FEA are limited.

The genetic relationship between enzymatic activity of cathepsin B and firmness of dry-cured hams.

This study aimed to investigate the genetic relationship between enzymatic activity of raw hams and firmness of dry-cured hams. Instrumental firmness and sensory panel firmness scores were obtained from 2058 and 3275 dry-cured hams, respectively. On a sub-sample of 988 raw hams for dry-curing, enzymatic activity of cathepsin B was determined through a fluorimetric analytical method. A multiple-trait animal model was used to estimate heritability and genetic correlations of these traits. Estimates of heritability were moderate, ranging from 0.11 for sensory panel firmness scores to 0.25 for cathepsin B activity. Genetic correlations between firmness measures on dry-cured hams and enzymatic activity of raw hams were low. The efficiency of a selection program aimed to reduce the incidence of excessive softness in dry-cured hams on the basis of enzymatic activity of cathepsin B of raw hams is expected to be very limited.

Vertebral mineral density measured by dual-energy X-ray absorptiometry (DEXA) in a group of healthy Italian boxer dogs.

We studied the feasibility of using dual-energy X-ray absorptiometry (DEXA) to obtain reference bone density values in relation to age, gender and body weight in growing and young adult Italian boxer dogs. The study was performed on eight animals (three males and five females) at 7, 12 and 18 months of age. Animals were carefully examined and blood samples were collected from each dog to detect any sign of metabolic and/or endocrine disease. Each subject underwent radiographs to evaluate growth of the spine and hip. One female was not considered in the statistical model because of the development of grade 4 spondylosis deformans during the study period. All animals were serially scanned using DEXA; the region of interest was the whole spine T12-L2, while the subregions of interest were the four vertebrae (T12-T13-L1-L2) within the scanned spine. Statistical analysis was performed separately for each region of interest. Age had the strongest relationship with bone density (P < 0.001). Gender effect on spinal mineral density was not significant while vertebral site effect was highly significant. Average bone mineral density (BMD) +/- SD for the whole spine trait was 0.862 +/- 0.108 g/cm2 while average BMD +/- SD for subregions of interest ranged from 0.836 +/- 0.141 g/cm2 for T12 to 0.928 +/- 0.119 g/cm2 for L2. Estimated reference BMD values at 7, 12 and 18 months of age for each vertebral site in males and females are provided.

Computer image analysis for measuring lean and fatty areas in cross-sectioned dry-cured hams.

The aims of this study were 1) to apply computer image analysis to obtain measures of lean and fatty areas on the cross section of dry-cured hams, 2) to investigate variation of these measures, and 3) to evaluate reproducibility and repeatability of these techniques. Traits of concern were the cross-sectional area (SA), lean, or muscles, area (LA), and the fatty area (FA) centered on the cross section and surrounded by biceps femoris, semimembranosus, semitendinosus, and quadriceps femoris, as well as the FA-to-SA ratio (FESR). Hams were obtained from crossbred pigs (n = 279) slaughtered at 9 mo of age (mean BW of 169 +/- 17 kg). Digital images of the cross section of dry-cured hams were captured using standardized procedures. Three replicated measures of areas were collected by three operators using three image analysis techniques (automatic, automatic-assisted, and manual). Variance components were estimated using a linear model that included slaughter group, gender, and gender x slaughter group as fixed effects and operators, pig, and operator x pig as random effects. Statistical analyses considered all measures (n = 7,533) or measures collected after reinstruction of all operators for spatial calibration of the analysis system (n = 4,428). Average SA, LA, FA, and FESR were 350 cm2, 220 cm2, 8.7 cm2, and 2.5%, respectively. Variability of FA (CV = 42%) and of FESR (CV = 39%) was four times greater than that of SA and LA. Slaughter group, pig, operator, and operator x pig effects were the most (P < 0.01) important sources of variation of measures. Correlations between measures obtained with different techniques were greater (P < 0.01) than 0.90, with the exception of LA measures. Coefficients of reproducibility for SA and LA ranged from 87 to 94%, whereas those for FA and FESR ranged from 88 to 98%. Coefficients of repeatability ranged from 92 to 99%. Automatic-assisted and manual methods provided more reproducible and repeatable measures than the automatic technique. Spatial calibration of the software system was a key issue affecting reproducibility and repeatability. Reinstructing the analysts for spatial calibration enhanced both reproducibility and repeatability of all methods of analysis. Computer image analysis is a technique suitable for measuring lean and fatty areas in cross-sectioned hams, providing reproducible and repeatable measures, and it might be used in large sample-based studies to investigate causes of defective fatty areas.

Prevalence of spondylosis deformans and estimates of genetic parameters for the degree of osteophytes development in Italian Boxer dogs.

The aim of this study was to assess the prevalence of spondylosis deformans and to investigate genetic aspects of the degree of osteophytes development (DOD) in the Italian Boxer dog population. A total of 849 Boxer dogs was radiographed on the thoracic, lumbar, and sacral regions of the spine and scored for DOD. Grading of DOD was performed for all 20 intervertebral sites comprised within the first thoracic site (site T1-T2) and the site between the seventh lumbar and the first sacral vertebra (site L7-S1). Scores for DOD ranged from 0 (no osteophytes development) to 3 (presence of a bony spur formed by osteophytes on adjoining vertebrae). The first five thoracic sites exhibited no variation for DOD and were not considered in the analysis. The prevalence of spondylosis deformans was 84%, and frequency of dogs showing at least one intervertebral site that scored 3 for DOD was 50%. Scores for DOD at different sites were analyzed as different traits. Nongenetic effects influencing DOD scores were sex, age at screening, and the kennel. Posterior densities of heritability (h2) were estimated using a univariate Bayesian analysis. Eight sites exhibited a posterior probability greater than 0.8 for h2 > 10% and were considered in a multivariate restricted maximum likelihood analysis. Estimated h2 from multivariate analysis ranged from 25 to 48% (SE from 5 to 7%). Three sites exhibited h2 estimates greater than 40%. Genetic correlations for DOD scored at different sites ranged from 0.07 to 0.96. All thoracic sites had estimated correlations larger than 0.85 with other thoracic sites. Genetic correlation between the first and the second lumbar site was 0.91. Correlations between thoracic sites and the first two lumbar sites ranged from 0.5 to 0.9. Sites L6-L7 and L7-S1 also exhibited weak relationships with all remaining sites. Breeding values of dogs for DOD at the eight sites were predicted using estimated covariance matrices. A selection index for DOD was computed from predicted breeding values and a set of relative weighting factors produced by a panel of veterinarians. The index was the most important effect influencing phenotypic differences between dogs for average DOD score, number of affected sites, and number of sites with a DOD score > 1 (P < 0.001). The degree of osteophytes development is a trait showing exploitable additive genetic variance, and breeding programs for decreasing prevalence and severity of spondylosis deformans might focus on this trait.