Search results for " milk production"

Determination of milk production losses and variations of fat and protein percentages according to different levels of somatic cell count in Valle de…

2018

The somatic cell count (SCC) of milk is widely used to monitor udder health and the milk quality and because of its positive genetic correlation with mastitis this trait was included in breeding schemes of dairy sheep. The aim of this study was to estimate the loss in milk yield (MY) and related composition resulting from different levels of somatic cell count in Valle del Belice dairy sheep. Data were collected between 2006 and 2016 in 15 flocks following an A4 recording scheme. Somatic cell count (SCC), fat and protein percentage (F% and P%) were determined using mid-infrared spectroscopy. To evaluate loss in test day MY, F% and P%, five different classes of SCC were arbitrarily defined: …

Intake and milk production of goats grazing Sulla forage under different stocking rates

2010

This investigation aimed to individuate the dietary factors affecting the milk urea nitrogen (MUN) concentration in goats grazing herbaceous pasture and, particularly, to verify the relationship linking the diet crude protein (CP) content to MUN. A total of 205 individual observations regarding dietary and milk variables of 37 Girgentana goats involved in two experiments were used. Goats, averaging 154±14 days in milk and 38.1±5.4 kg of live weight, grazed on swards and received 500 g/d of barley meal. Sward biomass, herbage selected by goats and individual milk yield were measured and sampled weekly. The herbage intake and diet digestibility were estimated by the n-alkane method. Milk urea…

Genome-wide association study for milk production traits in an economically important local dairy sheep breed

2021

In this study, we conducted a genome-wide association study (GWAS) for five milk production traits in the Valle del Belice sheep. Repeated measurements for milk yield (MY), fat percentage and yield (F% and FY) and protein percentage and yield (P% and PY) on 481 ewes, were available for the analysis. The animals were genotyped using the Illumina Ovine 50k BeadChip. Weighted deregressed breeding values (DEBVw) were used as phenotypes for GWAS analysis. A total of 23 genome-wide significant SNPs were identified: 3 associated with MY, 9 with FY, and 11 with P%. Several SNPs mapped within known candidate genes or previously reported QTL for milk production traits in livestock species. Additional…

Detection of genomic regions underlying milk production traits in Valle del Belice dairy sheep using regional heritability mapping

2021

The aim of this study was to identify genomic regions underlying milk production traits in the Valle del Belice dairy sheep using regional heritability mapping (RHM). Repeated measurements for milk yield (MY), fat percentage and yield (F% and FY) and protein percentage and yield (P% and PY), collected over a period of six years (2006-2012) on 481 Valle del Belice ewes, were used for the analysis. Animals were genotyped with the Illumina 50k SNP chip. Variance components, heritabilities, and repeatability within and across lactations were estimated, fitting parity, litter size, season of lambing, and fortnights in milk, as fixed; and additive genetic, permanent environment within and across …

Aseasonal sheep and goat milk production in the Mediterranean area: Physiological and technical insights

2015

Abstract Aseasonal or out-of-season milk production for small ruminants raised in Mediterranean areas refers generally to milk having to be produced at a time that corresponds to summer which is when conditions are generally unfavourable with respect to both physiological aspects and nutritional factors related to seasonal climatic trends. In fact, sheep and goat milk production in the Mediterranean basin is mostly based on pasture utilization and thus follows the pasture availability pattern. This causes a strong seasonal pattern to the amount of milk processed by cheese processes plants, with the peak being in the spring, a marked reduction in early summer and nil or low availability of m…

Feeding and management techniques to favour summer sheep milk and cheese production in the Mediterranean environment

2015

Sheep milk production in summer can lead to a diversification of milk products and to a more regular product distribution in the market throughout the year. However, in Mediterranean countries small ruminant production cycles are subjected to seasonal variations in forage resources. During summer, a key period for out of season production systems, nutrition plays a fundamental role in regulating the quantity and quality of milk production. In this review, feeding strategies and techniques that could be applied for out of season production in dairy ewes under different Mediterranean conditions are described for intensive, pasture-based and mixed systems. The most common feeding strategies us…

Comparison of Genome Wide Association Studies for milk production traits in Valle del Belice dairy sheep

The great achievements in livestock species selection during the last 50 years largely relied on quantitative genetic theory and infinitesimal genetic model. In the last 20 years, due to the application of advanced techniques in molecular genetics and statistics, several chromosomal regions that influence quantitative traits have been discovered. Combinations of molecular and classical quantitative information in a composite selection index have been proposed to increase the accuracy of selection. Nowadays, many genotyping arrays for thousands of SNPs are available for several livestock species, such as: cattle, sheep, pigs, horses, goat and chickens. The overall aim of this thesis is the c…

Effects of grazing Trifolium subterraneum and Lolium multiflorum in various proportions on forage intake and milk production of dairy ewes

2011

The aim of this research was to evaluate the effects of grazing Trifolium subterraneum (T) and Lolium multiflorum (L), as pure or associated crops, on forage intake and milk yield and composition in Comisana ewes. The four following fenced subplots, each of 2500 m2, were used for grazing: T, 100% of surface; L, 100% of surface; TL, T and L on 66.6 and 33.3 % of surface; LT, T and L on 33.3 and 66.6% of surface, respectively. Each subplot was divided into two parcels in order to have two replicates. Forty ewes were divided into eight homogeneous groups, with regard to milk yield, days in milk and live weight. In spring for 70 days, each group grazed daily for 8 h one of the fenced parcels. M…

Effect of the inclusion of lemon citrus pulp in the diet of Valle del Belice lactating ewes. Milk production and composition.

2015

Lemon citrus pulp residues from the citrus juice industry; it belongs to the citrus by-product that are more extensively used for livestock feeding. Furthermore, citrus pulp is a source of flavonoids such as hesperidin and naringin, which have antioxidant properties. This study aimed to investigate the effect of fresh lemon citrus pulp (LP) as natural antioxidant, on feeding behavior, milk yield and milk quality of Valle del Belice lactating ewes in the hot summer season in Sicily. A total of 15 second lambing ewes were individually allocated in 3¥3 m box and fed with 3 diets in a 3 ¥ 3 Latin square design, with 3 phases composed of 21 days. The diets were: LP0, mixed hay ad libitum plus 60…

Effects of αs1-casein and k- casein genotypes on nutrient intake and milk production in Girgentana goats: a further investigation

2013

The influence of polymorphism at αs1-casein locus (CSN1S1) on goat milk properties is adequately known, whereas the knowl- edge is limited on the effects of κ-casein gene variants (CSN3), C-093 and the association between variants of CSN1S1 and CSN3 Milking technique in jenny: effects on milk production genes. This study aimed to investigate the effect of some CSN1S1-CSN3 composite genotypes (CG) on feed intake and milk production of 95 Girgentana goats from 6 experiments (551 Rossella Di Palo, Diana Neri, Barbara Ariota, Rosanna Serafini, observations). Goats, genotyped using specific PCR protocols at DNA level and IEF technique at milk protein level, were equal at αs2-casein and β-casein …