Colostrum and milk quality of sows fed different diets during mid-pregnancy

Influence of prepartum feed levels on colostrum production and farrowing performance in highly prolific sows in a tropical environment

Currently, there is a lack of data on the effects of altering feed levels on sow performance and piglet characteristics during the transition period in tropical environments. The present study determined the effect of sow feed levels during the transition period on colostrum yield, colostrum immunoglobulin (Ig) G, colostrum intake of piglets, farrowing duration, proportion of stillborn piglets per litter (SB) and the incidence of farrowing assistance in highly prolific sows. A total of 114 Landrace × Yorkshire crossbred sows and their offspring (n = 2 072) were included in the experiment. Sows were assigned to different feed supply levels from entry to farrowing at 110 days of gestation until farrowing based on their parity number. Three feed-level groups were the control group who received 3.0 kg/day of lactation feed (n = 40), treatment 1 group who received 3.6 kg/day of gestation feed (n = 39) and treatment 2 group who received 4.0 kg/day of lactation feed (n = 35). Colostrum samples (5 ml) were obtained from the sows within 3 h after the onset of farrowing for IgG assay. Piglets were weighed immediately after birth and then again 17-24 h later to estimate their colostrum intake. Colostrum yield was determined by aggregating the colostrum intake of piglets within the litter. The total number of piglets born, SB and farrowing duration were 18.2 ± 3.8, 7.5% and 259.1 ± 138.1 min, respectively. Among these sows, 28.9% experienced a farrowing duration exceeding 300 min and 50.9% required assistance during farrowing. Interestingly, piglets in the treatment 2 group demonstrated a greater colostrum intake (403.1 ± 14.9 g) compared to the control group (360.6 ± 15.1 g, P = 0.046) and the treatment 1 group (361.0 ± 12.9 g, P = 0.033). On average, colostrum yield of sows in the treatment 2 group tended to be higher than in the control group (+0.5 kg, P = 0.081), but did not differ from the treatment 1 group (+0.3 kg, P = 0.191). No significant differences in farrowing duration, SB, farrowing assistance, or colostrum IgG concentration were found across various feed-level groups (P > 0.05). In conclusion, the study showed that raising lactation feed by 1.0 kg/day prefarrowing increased piglet colostrum intake and tended to boost sow colostrum production, without significantly affecting farrowing duration, stillbirth rates, or need for assistance.

The importance of optimal body condition to maximise reproductive health and perinatal outcomes in pigs

Overnutrition or undernutrition during all or part of the reproductive cycle predisposes sows to metabolic consequences and poor reproductive health which contributes to a decrease in sow longevity and an increase in perinatal mortality. This represents not only an economic problem for the pig industry but also results in poor animal welfare. To maximise profitability and increase sustainability in pig production, it is pivotal to provide researchers and practitioners with synthesised information about the repercussions of maternal obesity or malnutrition on reproductive health and perinatal outcomes, and to pinpoint currently available nutritional managements to keep sows' body condition in an optimal range. Thus, the present review summarises recent work on the consequences of maternal malnutrition and highlights new findings.

Unveiling the attributes of rabbit milk

Increasing the knowledge of rabbit milk can help in breeding practice to solve issues considering the health and growth of rabbit kits. The goal of the study was to perform a broad physicochemical analysis of rabbit milk and examine the effect of the reproductive status of the females on daily milk yield and milk attributes. The study was conducted on a commercial rabbit farm and included three consecutive lactations of Hycole does. It has been observed that the daily milk production increased from the 2nd till the 14th day of lactation when does produced almost 300 g of milk daily. The day of lactation caused a significant variation in the content of total solids, solids-not-fat, total protein, casein, lactose, C18: 2, C18: 3, Somatic Cell Count, and pH. The percentage of fat globules categorised according to their diameter changed with the ongoing lactation as well, and the diameter increased from 5 to 7 µm. The percentage of small milk fat globules decreased with lactation day, causing a possible decrease in the digestions rates of milk. Pregnancy had a negative impact on milk production, kits growth performance, and the content of total protein, solids-not-fat, and lactose in milk. Therefore, we can speculate about the negative impact of overlapping lactations and pregnancies on rabbit kits, as their growth is dependent on milk production and composition.

Evaluation of Fatty Acid Distributions and Triacylglycerol Species in Sow Milk and Commercial Piglet Formulas: A Comparative Study Based on Fat Sources and Lactation Stages

Total fatty acid and sn-2 fatty acid compositions, and triacylglycerol (TAG) species in 130 sow colostrum, 100 sow milk, and 22 piglet formula samples were analyzed in the present study. Significant differences were found in concentrations of medium chain-saturated fatty acids (MC-SFAs) and distributions of palmitic acid (P) and oleic (O)/linoleic (L) acid. The levels of MC-SFAs in sow colostrum and sow milk fats (2.4-3.1%) were significantly lower than those in piglet formulas (7.9-27.2%). Approximately 63% of palmitic acid was located at the sn-2 position in both sow colostrum and milk fats, which was significantly higher than in piglet formula fats (21.1-39.1%). Correspondingly, only 17.8-28.3% of oleic and linoleic acids were at the sn-2 position in sow milk fats, contributing to their typical triacylglycerol structure in sow colostrum and milk, whose palmitic acid connected to the sn-2 position and unsaturated fatty acids located at the sn-1,3 positions. Sow colostrum, milk, and piglet formulas were notably distinguished into three groups based on their fatty acids and TAGs, among which triacylglycerols were the most differentiated index. A total of 51 TAG species (including their isomers) differed significantly between sow colostrum and milk and piglet formulas. OPL and OPO were the most important differentiating TAGs. The large amount of sn-2 esterified palmitic acid plays a key role in improving the absorption of fat and calcium. The results provide suggestions for design of sow milk fat equivalents.

Triacylglycerol fingerprint of sow milks during different lactation stages and from different breeds

Sow milk fats not only provide energy but also essential nutrients for piglets. Thus, feeding strategies must be aligned with fat composition, especially triacylglycerols (TAGs) and their isomers. The triacylglycerol (TAG) profiles of sow milk fats from five typical breeds (Landrace × Large White, Landrace, Large White, Duroc, Pietrain) and two lactation stages (colostrum and milk) were systematically studied. A total of 45 major TAG species were identified using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The most abundant TAG was oleic acid-palmitic acid-linoleic acid (O-P-L) (13.92% and 12.03% in colostrum and milk, respectively), which was not significantly different in colostrum among all breeds. TAG composition of sow milk was affected mainly by the lactation stage rather than sow breed. Furthermore, TAG compositions of sow milk fats were similar to those of human milk fats, but significant differences were observed between commercial piglet formulas and sow milk. Therefore, the results will contribute to the optimization of piglet formulas to improve the growth and wellness of piglets, as well as potentially providing a basis for food usage as a new source of nutrients for human infants in future.