Comparative study of lactation curves and milk quality in Holstein versus Swedish Red and White-Holstein Cross Cows

The objective of this study reported in this research paper was to compare the lactation curves of the production of milk, fat, protein, percentages of fat and protein, and somatic cell score in purebred Holstein (H) cows and Swedish Red and White (SRW) - Holstein (SxH) crossbred cows in the south-central region of the province of Cordoba, Argentina. The data set consisted of 32847 herd-test records from 1244 purebred H cows and 310 SRW x H crossbred cows, from three commercial dairy farms with cows of first to fifth or more lactations. The curves were modeled using the fourth-order Legendre orthogonal polynomials. In this study, the data of production of milk, fat production, protein production, percentage of fat, percentage of protein and somatic cell score (SCS) were analyzed. Purebred H cows had significantly higher milk production, more fat production and higher protein production levels than did SxH crossbred cows. However, SxH crossbred cows produced milk that had a higher percentage of fat and a higher percentage protein than did purebred H cows. In none of the lactations did somatic cell score differ significantly between the two breed groups. The results of our study showed that, SxH crossbred cows had significantly higher percentages of fat and protein; however, purebred H cows were significantly superior to SxH crossbred cows for the production of 305-d milk, fat, and protein. Mammary health, expressed in SCS, did not differ significantly between the two breed groups. Thus, suggest that crossbreeding Holstein purebred cows with SRW bulls can improve the composition of milk solids without affecting mammary health and, in this way, compensate substantially for any potential loss in the production and/or quality of the milk of the crossbred cows compared to H purebred cows.Fil: Pipino, Diego. Agroveterinaria Pipino; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; ArgentinaFil: Piccardi, Mónica Belén. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Departamento de Desarrollo Rural. Area de Estadística y Biometría; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lembeye, Felipe. Soprole. Gerencia de Abastecimiento. Departamento Agropecuario; ChileFil: Lopez Villalobos, Nicolas. Massey University; Nueva ZelandaFil: Vazquez, Maria Isabel. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Effect of morphological characteristics and productive traits on the survival of dual-purpose Simmental cows

In recent years, dairy farmers have observed a substantial decrease in cow survival, with a direct negative consequence on the profitability. Shorter lifespan raises questions about animal welfare and farming conditions at which cows are exposed to. Traditionally, the cows’ productive life length is affected by voluntary and involuntary culling, e.g. sale, slaughter, salvage, or death. Culling risks are affected by animal-related features such as calving events, lactation stage, energy balance, reproduction, and aging, but also external factors, namely management and season. The present study aimed to investigate the morphological and productive traits affecting the survival of Italian Simmental dual-purpose cattle. Data available belonged to 2656 Italian Simmental dairy cows from 324 dairy herds (Emilia Romagna region, Italy). Cows involved in the study were linear classified once, as primiparous, between the 2002/2003 to 2019/2020 dairy seasons. Kaplan-Meier survival analyses were performed with the LIFETEST procedure of SAS software v 9.4 using milk yield, muscularity, and body condition score (in classes) as independent variable and survival at the subsequent lactation up to the 6th as dependent variable. As expected, the culling risk increased with parity, i.e. as the age of cows progressed. In general, animals with a low production level and medium body conditions have the highest probability of survival compared to high-producing cows. This trend was more evident in later parities: in fact, cows in parity 5 with low milk production and medium muscularity were more likely (+20.11% of probability) to survive at the subsequent lactation compared to others (13.99 vs 10.49, for medium and high production levels, respectively). Moreover, high-producing cows with medium body conditions were those with the lowest probability to survive at the subsequent lactation. The reasons that could explain these findings may be linked to the metabolic stress experienced by the cows during lactation. Indeed, especially during the peripartum period, lactating cows undergo a state of negative energy balance and a reduction of immune competence. Results from this study indicated that other than productivity level, morphological traits are important for making culling decisions in the Italian Simmental cattle

Heritability and repeatability of milk lactose and its relationships with traditional milk traits, somatic cell score and freezing point in Holstein cows

Lactose percentage (LP) in milk is currently determined in most herd-testing schemes, and globally, it is usually routinely recorded in the framework of the official milk recording procedures. However, few studies have investigated the phenotypic and genetic variability of this component. Data used in the present paper consisted of 59 811 test-day records from 4355 Holstein cows in 266 herds. Heritabilities of LP and lactose yield (LY) were estimated through single-trait repeatability animal models, whereas genetic and phenotypic correlations of LP and LY with milk composition and production traits, somatic cell score and milk freezing point were estimated using bivariate models. Fixed effects included in the analyses were herd-test-date, season of calving, parity, stage of lactation and the interaction between parity and stage of lactation. Random effects were animal additive genetic, within and across lactation permanent environment and the residual. Lactation curves of LP and LY increased from parturition to the peak of lactation and decreased thereafter, mirroring the typical curve of milk yield. Lactose percentage was greater in first- than later-parity cows. Heritabilities of LP and LY were 0.43 ± 0.03 and 0.14 ± 0.02, respectively, and LP and protein percentage were the most repeatable traits. Genetic correlations (ra) of LP with somatic cell score, LY and milk freezing point were −0.22 ± 0.08, 0.28 ± 0.08 and −0.46 ± 0.05, respectively. Genetic relationships of LY with milk yield (ra = 0.97 ± 0.00), fat percentage (ra = −0.71 ± 0.06), protein percentage (ra = −0.57 ± 0.06) and protein yield (ra = 0.64 ± 0.06) were moderate to strong. Results suggest that milk LP could be considered in breeding strategies to accelerate the gain of correlated low heritable traits. Further research is needed to evaluate the feasibility of including LP in the selection index of Italian Holstein population to address country-specific needs and market demands

Fertility and survival of Swedish Red and White × Holstein crossbred cows and purebred Holstein cows

Swedish Red and White × Holstein (S×H) cows were compared with pure Holstein (HOL) cows for fertility and survival traits in 2 commercial dairy farms in central-southern Córdoba province, Argentina, over 6 years (2008–2013). The following traits were evaluated: first service conception rate (FSCR), overall conception rate (CR), number of services per conception (SC), days open (DO), mortality rate, culling rate, survival to subsequent calvings, and length of productive life (LPL). The data set consisted of 506 lactations from 240 S×H crossbred cows and 1,331 lactations from 576 HOL cows. The FSCR and CR were analyzed using logistic regression, DO and LPL were analyzed using a Cox's proportional hazards regression model, and differences of proportions were calculated for mortality rate, culling rate, and survival to subsequent calvings. The S×H cows were superior to HOL cows in overall lactations for all the fertility traits (+10.5% FSCR, +7.7% CR, −0.5 SC, and 35 fewer DO). During the first lactation, S×H cows were superior to HOL cows for all fertility traits (+12.8% FSCR, +8.0% CR, −0.4 SC, and 34 fewer DO). In the second lactation, S×H cows exhibited lower SC (−0.5) and 21 fewer DO than HOL cows. In the third or greater lactations, S×H cows showed higher FSCR (+11.0%) and CR (+12.2%), lower SC (−0.8), and 44 fewer DO than pure HOL cows. In addition, S×H cows had a lower mortality rate (−4.7%) and a lower culling rate (−13.7%) than HOL cows. Due to the higher fertility and lower mortality and culling rates, the S×H cows had higher survival to the second (+9.2%), third (+16.9%), and fourth (+18.7%) calvings than HOL cows. Because of these results, S×H cows had longer LPL (+10.3 mo) than HOL cows. These results indicate that S×H cows had higher fertility and survival than HOL cows on commercial dairy farms in Argentina.Fil: Pipino, D. F.. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Producción Animal; ArgentinaFil: Piccardi, Mónica Belén. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; ArgentinaFil: Lopez Villalobos, Nicolas. Massey University; Nueva ZelandaFil: Hickson, R. E.. Massey University; Nueva ZelandaFil: Vazquez, Maria Isabel. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

Phenotypic analysis of milk composition, milk urea nitrogen and somatic cell score of Italian Jersey cattle breed

The present study aimed to assess the phenotypic variation of milk yield (MY) and quality traits in Italian Jersey (IJ) breed. Sources of variation were investigated through a linear mixed model, including the fixed effects of days in milk (DIM), parity, calving season, milking frequency, recording type, the interaction between DIM and parity, and the random effects of herd-test-day (HTD), cow and the residual. Results highlighted the high contents of milk fat (5.18%), protein (4.08%) and casein (3.16%) of IJ cows. Somatic cell score, averaging 3.35 units, should be lowered through specific managerial actions. Phenotypic variances of MY and milk quality traits were mainly due to cow effect, whereas phenotypic variance of milk urea nitrogen (MUN) content was mainly due to HTD effect, meaning that managerial conditions, especially feeding, are very important to explain the variation of MUN. In conclusion, the present study allowed to characterise milk of IJ cows at population level and to identify environmental factors associated with variation of MY and quality traits, which will be useful to adjust phenotypic records in genetic evaluation of Jersey breed.Highlights Factors affecting milk quality traits of Italian Jersey cows have been investigated. Phenotypic variance of milk composition and SCS was mainly due to cow effect, and that of MUN was mainly driven by herd-test-day effect. Significant environmental factors identified in the present study will be used to adjust phenotypic records in genetic analysis

In vitro gas production of foliage from three browse tree species treated with different dose levels of exogenous fibrolytic enzymes

The aim of this study was to evaluate the effect of different dose levels of exogenous fibrolytic enzymes (EFE) on in vitro ruminal fermentation kinetics and energy utilization of foliages from three browse trees (Pithecellobium dulce, Heliocarpus velutinus and Guazuma ulmifolia). Mixture of EFE product was added to the leaves of the three browse tree species at three dose levels: 0 (control), 3.5 and 7.0 mg/g of DM. Chemical composition of the foliages, including plant secondary metabolites such as total phenolics (TP), saponins (SAP) and aqueous fraction (AF), was determined. In addition, in vitro assaying of ruminal gas production kinetics was determined for the three browse three foliages treated with EFE. P. dulce had the highest crude protein content (p < 0.05), whereas G. ulmifolia had the highest content of neutral detergent fibre and SAP (p < 0.05) and H. velutinus had the lowest content of TP (p < 0.05). The interaction between tree species and dose level of EFE was significant (p < 0.05) for gas production (GP) at 24 h of incubation, parameters b and c of the accumulated GP curve, short-chain fatty acids (SCFA) and metabolizable energy (ME). The lowest (p < 0.01) extent of accumulated GP as well as the b and c values occurred in G. ulmifolia at 0 mg EFE/g DM. P. dulce had the highest (p < 0.05) values for ME and SCFA at the highest dose of EFE. Tree species and dose level had significant (p < 0.05) effects on all parameters describing in vitro ruminal fermentation kinetics and energy utilization. Addition of EFE improved the fermentation kinetics of the browse species considered in this study.UAE

In vitro gas production kinetics and degradability of a diet for growing lambs: effect of fibrolytic enzyme products at different dose levels

The objective of this study was to evaluate the effects of three fibrolytic enzyme products (cellulase (CEL), xylanase (XYL) and a 1:1 mixture of CEL and XYL (MIX)) at three dose levels (0, 1 and 3 lL/0.5 g DM) on the in vitro fermentation of a diet for growing lambs. Bottles were incubated for 96 h at 39 C. A mathematical model was used to estimate the parameters describing the gas production (GP) curve (b, c and L). Dry matter degradability (DMD) and fibre (NDFD and ADFD) degradability were determined at the end of the incubation period. Metabolisable energy (ME) and short chain fatty acids (SCFA) were calculated at 24 h of incubation. The asymptotic GP (parameter b) was affected (p<0.02) by enzyme product and dose level, with a significant linear response (p<0.05). Dose level affected ME and SCFA with a significant linear (p<0.05) and quadratic (p<0.01) response. The interaction between enzyme product and dose level was significant (p<0.05) for cumulative GP up to 72 and 96 h of incubation, pH, ADFD and DMD. The results suggest that application of exogenous cellulases has the potential to alter asymptotic GP and degradability of ADF and DM of a diet for growing lambs, but most of the results depend on the interaction between enzyme product and dose level. Future studies are required to determine the ideal combination between enzyme product and dose level for optimal degradation of ruminant feeds

Effects of exogenous enzymes and application method on nutrient intake, digestibility and growth performance of Pelibuey lambs

Pelibuey sheep is the main breed in the tropical and subtropical regions of Mexico, and high demand of sheep meat has favored the finishing of lambs in feedlots with diets containing high levels of grains. The objective of this study was to evaluate the effects of exogenous enzymes (EE) and application method on nutrient intake and digestibility and performance of growing Pelibuey lambs. Treatments were based on comparison of two different methods of adding an enzyme product (sprayed on the total mixed ration or applied orally to the lambs) versus control treatment (no added enzyme). Twenty-one Pelibuey lambs, weighing 15.7 kg (SD = 1.8 kg) initial body weight, were individually housed in shaded pens and assigned randomly to one of the three enzyme treatments. At the end of study (lasting for 45 days), three lambs from each treatment were randomly selected and adapted to a pants and harness designed for fecal collection to measure nutrient digestibilities. Total body gain and average daily gain were affected (P < 0.05) by supplemental EE. The application method of EE had significant (P < 0.05) effect on FCE and FCR, but no effects were observed on nutrient intake. Supplemental EE did improve (P < 0.05) the digestibilities of dry matter, organic matter, neutral and acid detergent fiber, but no differences were observed in crude protein digestibility. The application method of EE had significant (P < 0.05) effect on the digestibility of acid detergent fiber. Supplemental EE can improve body weight gain and nutrient digestibilities without affecting nutrient intake in Pelibuey lambs, but the results of feed conversion efficiency and acid detergent fiber digestibility depend on the application method used of the EE

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

Fatty acid composition of milk from Holstein-Friesian, Brown Swiss, Simmental and Alpine Grey cows predicted by mid-infrared spectroscopy

The aim of this study was to investigate the sources of variation of milk fatty acids (FA) routinely predicted by mid-infrared spectroscopy in Holstein-Friesian (HF), Brown Swiss (BS), Simmental (SI) and Alpine Grey (AG) cattle breeds. A linear mixed model was used to analyse the data which included 153,801 individual milk samples from 14,301 cows. Fixed effects included in the model were breed, month of sampling, year of sampling, stage of lactation, parity and first order interactions between them, and random effects were herd nested within breed, cow nested within breed and the residual error. Milk of AG cows exhibited the lowest content of saturated FA and the greatest content of unsaturated FA, whereas milk of BS had an opposite pattern. Holstein-Friesian and SI were intermediate between AG and BS breeds for all the FA except for total C18:1, which was the greatest in HF. Saturated FA, C14:0 and C16:0 increased from calving until 120 days in milk, whereas unsaturated FA and C18:1 decreased. First parity cows produced milk with lower concentration of de novo FA than multiparous animals. The greatest content of unsaturated FA and C18:1 was observed in summer, whereas saturated FA, C14:0, C16:0 and C18:0 decreased in summer and increased in winter. The differences in milk FA profile among breeds are useful for genetic selection and for feeding strategies