Fertility traits of purebred Holsteins and 2- and 3-breed crossbred heifers and cows obtained from Swedish Red, Montbéliarde, and Brown Swiss sires.

The objective of this study was to compare fertility traits of heifers and primiparous cows from Swedish Red × Holstein (SR × HO; n = 634 and 581, respectively), Montbeliarde × Holstein (MO × HO; n = 126 and 114, respectively), Brown Swiss × Holstein (BS × HO; n = 59 and 50, respectively), and MO × (SR × HO) (n = 241 and 139, respectively) crossbreds, versus those of Holstein heifers and cows (HO; n = 3,483 and 2,549, respectively). Animals were born between 2007 and 2011, and belonged to 4 herds located in northern Italy. Heifers were compared for age at first service (AFS), age at first conception (AFC), interval between first service and conception (IFC), nonreturn rate at 56 d after first service (NR56), conception rate at first service (CR), and number of inseminations required for conception (INS). The same traits were evaluated in primiparous cows, except that AFS and AFC were replaced with days at first service (DFS) and days open (DO). The AFS, AFC, IFC, DFS, and DO traits were continuous variables and were thus analyzed under a proportional hazards Cox model that properly accounted for censoring among cows that were culled or failed to conceive. The NR56, CR, and INS traits were analyzed as binary traits using logistic regression. Our results indicated that, among heifers, SR × HO crossbreds had a better chance of having an earlier first service and conceiving earlier than HO, with hazard ratios (HR) of 1.31 for AFS and 1.34 for AFC. Similarly, MO × (SR × HO) crossbreds differed from HO heifers in this regard (HR = 1.18 and 1.24, respectively). For the primiparous cows, all crossbreds showed significant differences for DFS, DO, and IFC relative to purebred HO, with the exception of the BS × HO crossbreds. The MO × HO, SR × HO, and MO × (SR × HO) crossbred cows showed increased chances of having fewer DFS (HR = 1.40, 1.30, and 1.27, respectively), fewer DO (HR = 1.59, 1.43, and 1.58, respectively), and fewer IFC (HR = 1.52, 1.26, and 1.39, respectively) than HO cows. All crossbred genotypes, including BS × HO cows, showed higher probabilities for higher NR56, higher CR, and lower INS than purebred HO cows. Together, these findings indicate that the studied crossbred cows have higher reproductive potential than Holsteins

Relationships between in vivo Measurements of Backfat Thickness and Several Carcass and Ham Traits in Heavy Pigs

This study investigated the relationships between ultrasound measurements of backfat thickness (UBF) taken on live heavy pigs and several carcass composition and ham quality traits. Before slaughter 240 pigs were weighed (average BW: 167 ±10 kg) and assessed for UBF using an A-mode ultrasonic device (placed above the last rib at approximately 5.5 to 8.0 cm from midline, with increasing distance with increasing BW). At slaughterhouse backfat thickness and weight of carcass and of commercial lean and fat cuts were collected. Aft er 24-h chilling, hams were trimmed, weighed, scored and measured for several quality traits. A sample of trimmed fat was taken to assess iodine number and linoleic acid content. All hams were cured, and weight losses during curing were recorded. The measures of UBF were correlated with all carcass and ham traits available. The strongest relationships with UBF were detected for backfat depth at loin (0.54), backfat weight and yield (0.69), overall yield of lean and fat cuts (-0.59 and 0.51, respectively), score or measure of ham fat covering thickness (0.62 and 0.53, respectively), and linoleic acid content of ham subcutaneous fat (- 0.48). Magnitude of correlations does not provide reliable prediction of carcass, but ultrasound assessment on live animals could be useful to support selection programs of heavy pigs aimed to dry-cured ham production. Further studies are needed to investigate genetic relationships between these traits and UBF

Effect of growth rate on live performance, carcass and green thigh traits of finishing Italian heavy pigs

This study aimed at investigating the effects of growth rate (GR) on live performance, carcass and dressed green ham (DRHAM) traits of finishing heavy pigs managed in accordance with the regulations governing the production of Protected Denomination of Origin (PDO) dry-cured hams. Data were obtained from 233 crossbred pigs restrictively fed from 90 to 165 kg BW. Individual BW, daily feed intake, and weights of carcass and main cuts were recorded. Thighs were measured for subcutaneous fat thickness, analysed for fatty acid composition of subcutaneous fat, and dry-cured hams were weighed. Records were classified according to GR quartile, calculated using the residuals of a statistical model that included the effects of pen, sex and diet. Data were analysed using the same model with the addition of the effect of GR quartile. Average GR ranged from 578 in the first quartile to 748 g/d in the fourth. Final BW and weights of carcass, DRHAM and dry-cured ham increased as the GR quartile increased (p < .01). An increase in GR improved feed efficiency linearly (p < .001) and tended to increase the thickness of subcutaneous fat of DRHAM, whereas seasoning losses decreased linearly with increasing average GR. In conclusion, targeting the GR of finishing pigs at a minimum of 750 g/d and consequently increasing final BW to around 175–180 kg may be a way to improve feed efficiency and some quality traits of DRHAM

Detailed macro- and micromineral profile of milk: Effects of herd productivity, parity, and stage of lactation of cows of 6 dairy and dual-purpose breeds

The aim of this study was to quantify the major sources of variation in the levels of 15 minerals in individual milk samples collected from cows raised in multibreed dairy herds. The herds (n = 27) were classified into 2 categories, according to milk productivity. Milk productivity was based on the net energy of lactating cows' average daily milk yield. Milk samples were collected from 240 cows of 6 different breeds: 3 specialized dairy (Holstein-Friesian, Brown Swiss, and Jersey) and 3 dual-purpose (Simmental, Rendena, and Alpine Grey). The samples were analyzed for macro-elements (Na, Mg, P, S, K, and Ca), essential micro-elements (Mn, Fe, Cu, Zn, and Se), and environmental micro-elements (B, Si, Sr, and Sn), using inductively coupled plasma-optical emission spectrometry. Data were analyzed using a linear mixed model that included fixed effects of days in milk (DIM), parity, breed, and herd productivity, and a random effect of herd-date within productivity level. Results showed that the effect of herd-date varied across minerals. It was especially large for environmental minerals (ranging from 47 to 91% of total variance) and ranged from 11 to 61% for macrominerals and essential microminerals. Milk samples collected from farms with a high level of herd productivity had a richer mineral profile than samples from low-productivity herds. Parity only influenced macrominerals, with the exception of S and Ca, while DIM influenced almost all minerals, with a few exceptions among the environmental elements. Differences in mineral profile were small between specialized and dual-purpose breeds, but they were large within the group of the specialized cows. These breed differences were reduced after adjusting for milk quality and yield, particularly in the case of milk Mg, S, Ca, Mn, and Zn levels. Milk samples from the Jersey and Brown Swiss cows had higher mineral levels (Sn excluded) than milk from the Holstein-Friesian cows; the other breeds of Alpine origin produced milk of intermediate quality. Our findings suggest that breed has a stronger effect on macrominerals and some of the essential microminerals than herd productivity, parity, and DIM. The modification of the mineral profile in milk seems possible for many minerals, but it likely depends on genetics (e.g., breed, selection) and on environmental and management factors in variable proportions according to the mineral considered

Exploring Different Model Structures for the Genetic Evaluation of Dairy Bull Fertility

The aim of study was to investigate different models for the evaluation of dairy bulls for male fertility. A dataset containing single insemination records performed on Brown Swiss cows and heifers reared in Eastern Italian Alps was used. The outcome variable (successful/ unsuccessful) was analyzed as binary trait. In the first step raw conception rate was computed for each service sire, as the mean of the outcome of all his insemination events. In the second step Bayesian threshold sire models were implemented via Gibbs sampling. Different models increasing in complexity were fitted, in order to obtain variance components and sire solution estimates. Results showed that genetic variance for direct effect(s) on conception rate is low (repeatability=0.014; heritability=0.009-0.073) and raw conception rate is poorly related to solutions from prediction models. If the service sire is a diagonal effect, rank correlations with raw conception rate are about 0.81-0.84, while those decrease to 0.74-0.78 if service sires are related by a relationship matrix, and is null (-0.01-0.06) if is the sire of the service sire to account for the direct genetic effect. Service sire fertility (sire of service sire effect) has been proven to be a different trait to embryo survival (service sire effect) giving rank correlation of 0.11-0.24. In conclusion phenotypic and genetic differences in male fertility among the service sires exist, and should be monitored thought a reliable evaluation system

The use of 2-dimensional gas chromatography to investigate the effect of rumen-protected conjugated linoleic acid, breed, and lactation stage on the fatty acid profile of sheep milk

In this study, 2-dimensional gas chromatography (GC x GC) was used to obtain a detailed fatty acid (FA) profile of sheep milk and to evaluate the effects of a rumen-protected conjugated linoleic acid (rpCLA) supply, breed, days in milk (DIM), sampling period, and number of lambs suckling on the FA profile. Twenty-four ewes, from 3 autochthonous breeds of the Veneto Alps (Brogna, Foza, and Lamon), were housed in 6 pens (2 pens/breed), according to DIM (38 +/- 23 d) and body weight (61 +/- 13 kg). The ewes and their offspring of 3 pens (1 pen/breed) were fed ad libitum a total mixed ration (control), and the other animals received the same diet supplemented with 12 g/d per ewe, plus 4 g/d for each lamb older than 30 d, of an rpCLA mixture. The study lasted 63 d. Two composite milk samples for each ewe were prepared during the first and second months of the trial. The pooled milk samples were analyzed in duplicate for FA profile by 2-dimensional gas chromatography, which allowed us to obtain a detailed FA profile of sheep milk, with 170 different FA detected, including many that were present in small concentrations. The milk relative proportions of individual FA, groups of FA, or FA indices were analyzed by PROC MIXED of SAS (SAS Institute Inc., Cary, NC), considering diet, breed, DIM, and sampling period as sources of variation. The random effect of animal was used to test diet, breed, and DIM, whereas the effects of period were tested on the residual. Breed had a small influence on milk FA profile, mainly on branched-and odd-chain FA. Within breed, animal repeatability for the relative proportions of milk FA was notable for almost all monounsaturated FA and for saturated FA with 14 to 19 carbon atoms, except C16:0, and less so for polyunsaturated FA. The inclusion of rpCLA (CLA cis-9, trans-11 and CLA trans-10, cis-12) increased the presence of the same CLA isomers in the milk as well as that of CLA trans-9, trans-11, and decreased the proportions of de novo-synthesized short-chain FA. From a cluster analysis based on the matrix of correlation coefficients among all FA relative proportions, 3 main FA groups were observed: the first included mainly odd-or branched-chain saturated FA, C18:0, C16:0 and CLA trans-10, cis-12; the second included monounsaturated FA or polyunsaturated FA with 16 to 20 carbons, CLA cis-9, trans-11, and CLA trans-9, trans-11; and the third included short-to medium-chain saturated FA, polyunsaturated FA with 2 to 5 double bonds, and 3 CLA isomers not affected by rpCLA addition (CLA trans-11, cis-13, CLA cis-9, cis-11, and CLA cis-10, cis-12)